FDA Briefing Document

May 4, 2004

Oncologic Drugs Advisory Committee

Safety Concerns Associated with Aranesp (darbepoetin alfa) Amgen, Inc.
and Procrit (epoetin alfa) Ortho Biotech, L.P., for the Treatment of
Anemia

Associated with Cancer Chemotherapy

Prepared by

Harvey Luksenburg, M.D. Medical Reviewer,

Division of Therapeutic Biological Oncology Products, ODE 6/OND/CDER

Andrea Weir, Ph.D.

Division of Therapeutic Biological Oncology Products, ODE 6/OND/CDER

Ruth Wager, Ph.D., CMC Reviewer

Division of Therapeutic Proteins, OBP/OPS/CDER

Table of Contents

TABLE OF CONTENTS

[I. EXECUTIVE SUMMARY **Error! Bookmark not
defined.**](#__RefHeading___Toc68932047)

[II. Erythropoietin Biology and Mechanism of Action
6](#erythropoietin-biology-and-mechanism-of-action)

[III. Preclinical Evidence for a Role of Erythropoietins in Tumor
Progression
7](#preclinical-evidence-for-a-role-of-erythropoietins-in-tumor-progression)

[In Vitro Findings 7](#in-vitro-findings)

[In Vivo Findings 9](#in-vivo-findings)

[Conclusions 9](#conclusions)

[IV. Clinical Studies of Epogen/Procrit for the Treatment of the Anemia
due to Chronic Renal Failure
10](#clinical-studies-of-epogenprocrit-for-the-treatment-of-the-anemia-due-to-chronic-renal-failure)

[Treatment of Anemia Due to Chronic Renal Failure in Patients Undergoing
Dialysis
10](#treatment-of-anemia-due-to-chronic-renal-failure-in-patients-undergoing-dialysis)

[Treatment of Anemia Due to Chronic Renal Failure in Patients not
undergoing Dialysis
11](#treatment-of-anemia-due-to-chronic-renal-failure-in-patients-not-undergoing-dialysis)

[Safety Analyses 12](#safety-analyses)

[V. The Normal Hematocrit Study of Epogen/Procrit in Patients with
Chronic Renal Failure and Underlying Cardiovascular Disease
12](#the-normal-hematocrit-study-of-epogenprocrit-in-patients-with-chronic-renal-failure-and-underlying-cardiovascular-disease)

[Safety Results 13](#safety-results)

[VI. Clinical Studies of Aranesp® (darbepoetin alfa) for the Treatment
of the Anemia due to Chronic Renal Failure
14](#clinical-studies-of-aranesp-darbepoetin-alfa-for-the-treatment-of-the-anemia-due-to-chronic-renal-failure)

[Studies In Erythropoietin-Naïve Patients
15](#studies-in-erythropoietin-naïve-patients)

[Studies In Patients Previously Stable on Erythropoietin
15](#studies-in-patients-previously-stable-on-erythropoietin)

[Safety Analyses: Relation between adverse events, hemoglobin, and
hemoglobin rate of rise
16](#safety-analyses-relation-between-adverse-events-hemoglobin-and-hemoglobin-rate-of-rise)

[VII. Clinical Studies of Epogen/Procrit for the Treatment of the Anemia
Associated with Chemotherapy of Cancer.
25](#clinical-studies-of-epogenprocrit-for-the-treatment-of-the-anemia-associated-with-chemotherapy-of-cancer.)

[Efficacy Results 25](#efficacy-results-2)

[VIII. Post-Marketing Study to Assess for Tumor Stimulatory effects of
Epogen/Procrit: Study N93-004
26](#post-marketing-study-to-assess-for-tumor-stimulatory-effects-of-epogenprocrit-study-n93-004)

[Efficacy Results 27](#efficacy-results-3)

[Safety Results 27](#safety-results-1)

[IX. Clinical Studies of Weekly Dosage Schedules of Epogen/Procrit for
Treatment of Anemia Associated with Cancer Chemotherapy
30](#clinical-studies-of-weekly-dosage-schedules-of-epogenprocrit-for-treatment-of-anemia-associated-with-cancer-chemotherapy)

[X. Clinical Studies of Aranesp in the Treatment of the Anemia of Cancer
Chemotherapy
30](#clinical-studies-of-aranesp-in-the-treatment-of-the-anemia-of-cancer-chemotherapy)

[Efficacy Results 31](#efficacy-results-4)

[Safety analyses 32](#safety-analyses-1)

[XI. Study EPO-INT-76: The Breast Cancer Erythropoietin Trial (BEST)
38](#study-epo-int-76-the-breast-cancer-erythropoietin-trial-best)

[Efficacy and Safety Results 39](#efficacy-and-safety-results)

[Intent-to-treat 42](#__RefHeading___Toc68932074)

[XII. The Henke Study 43](#the-henke-study)

[Efficacy Results 46](#efficacy-results-5)

[Safety Findings 48](#safety-findings)

[Conclusions 48](#conclusions-1)

[XIII. Procrit Trials Halted by Johnson & Johnson For Excessive
Thrombotic and Cardiovascular Adverse Events:
49](#procrit-trials-halted-by-johnson-johnson-for-excessive-thrombotic-and-cardiovascular-adverse-events)

[1. Protocol EPO-CAN-15: "A randomized, double-blind placebo controlled
study to evaluate the impact of maintaining haemoglobin levels using
EPREX (Epoetin alfa) in limited disease small cell lung cancer (LD SCLC)
patients receiving combined chemotherapy and radiation therapy." (The
LEGACY Trial)
49](#protocol-epo-can-15-a-randomized-double-blind-placebo-controlled-study-to-evaluate-the-impact-of-maintaining-haemoglobin-levels-using-eprex-epoetin-alfa-in-limited-disease-small-cell-lung-cancer-ld-sclc-patients-receiving-combined-chemotherapy-and-radiation-therapy.-the-legacy-trial)

[2. Study PR00-03-006: "A double-blind, randomized, placebo controlled
study of the efficacy and safety of epoetin alfa administered weekly in
patients with gastric or rectal cancers undergoing preoperative
chemoradiation followed by surgery."
53](#study-pr00-03-006-a-double-blind-randomized-placebo-controlled-study-of-the-efficacy-and-safety-of-epoetin-alfa-administered-weekly-in-patients-with-gastric-or-rectal-cancers-undergoing-preoperative-chemoradiation-followed-by-surgery.)

[3. Study GOG-191 (PR01-04-005): "A phase III trial to evaluate the
efficacy of maintaining Hgb levels above 120 g/l with erythropoietin
versus above 100 g/l without erythropoietin in anemic patients receiving
concurrent radiation and cisplatin for cervical cancer."
54](#study-gog-191-pr01-04-005-a-phase-iii-trial-to-evaluate-the-efficacy-of-maintaining-hgb-levels-above-120-gl-with-erythropoietin-versus-above-100-gl-without-erythropoietin-in-anemic-patients-receiving-concurrent-radiation-and-cisplatin-for-cervical-cancer.)

[XIV. Additional Randomized, Controlled Trials Terminated Prematurely
(not at request of Johnson & Johnson)
57](#additional-randomized-controlled-trials-terminated-prematurely-not-at-request-of-johnson-johnson)

[1. Protocol CAN-20: "A randomized trial of epoetin alfa in patients
with advanced non-small cell carcinoma of the lung."
57](#protocol-can-20-a-randomized-trial-of-epoetin-alfa-in-patients-with-advanced-non-small-cell-carcinoma-of-the-lung.)

[2. Rosenzweig Study: "Increased thrombotic events in a clinical trial
of erythropoietin in metastatic breast cancer."
60](#rosenzweig-study-increased-thrombotic-events-in-a-clinical-trial-of-erythropoietin-in-metastatic-breast-cancer.)

[3. RTOG 99-03: "A randomized phase III trial to assess the effect of
erythropoietin on local-regional control in anemic patients treated with
radiotherapy for carcinoma of the head and neck."
61](#rtog-99-03-a-randomized-phase-iii-trial-to-assess-the-effect-of-erythropoietin-on-local-regional-control-in-anemic-patients-treated-with-radiotherapy-for-carcinoma-of-the-head-and-neck.)

[XV. Summary/Conclusions 62](#summaryconclusions)

#  EXECUTIVE SUMMARY

There are two erythropoietin products currently approved in the U.S. The
first approved agent was epoetin alfa, which is manufactured,
distributed and marketed by Amgen, Inc. under the proprietary name
EPOGEN. The same epoetin alfa product, manufactured by Amgen, Inc., is
also marketed and distributed by Ortho Biotech, L.P., a subsidiary of
Johnson & Johnson, under the proprietary name PROCRIT. EPOGEN/PROCRIT
was licensed in June 1989, with the following indication: "treatment of
anemia associated with chronic renal failure, including patients on
dialysis (end stage renal disease) and patients not on dialysis." Under
a contractual agreement, Ortho Biotech LP has rights to development and
marketing of Procrit for any indication other than for the treatment of
anemia associated with chronic renal failure. Epogen and Procrit have
identical labeling information for all approved indications based on
development programs conducted by Amgen or Ortho Biotech. Labeling was
expanded in April 1993 to include a supplemental indication for the
treatment of anemia associated with cancer chemotherapy.

The second product was darbepoetin alfa, which is manufactured and
distributed by Amgen, Inc., under the proprietary name Aranesp. Aranesp
was licensed in September 2001 with the following indication: "for the
treatment of anemia associated with chronic renal failure, including
patients on dialysis and patients not on dialysis". Labeling was
expanded in July 2002 to include a supplemental indication for the
treatment of anemia associated with cancer chemotherapy.

In this briefing document, FDA provides an overview of the pharmacologic
effects of erythropoietin, a summary of the data on erythropoietin
receptor distribution in normal and malignant tissues, an overview of
relevant non-clinical (animal and laboratory) data suggesting a role for
erythropoietin in tumor stimulation, and a summary the design and
results of studies that supported the approvals of Epogen/Procrit and
Aranesp for the indications of treatment of the anemia of renal failure
and of anemia associated with cancer chemotherapy, as well as other
selected relevant studies provided to the FDA, will be presented. The
extent of the information on associations between Epogen/Procrit or
Aranesp and the risks of thrombotic events, tumor progression and
survival are noted in these summaries. The results of the BEST (INT-76)
and Henke studies will also be summarized.

Evidence of an increased risk of thrombotic events associated with use
of exogenous erythropoietin was noted in the trials that supported the
original approval of Epogen/Procrit. Excessive or poorly-controlled
pharmacodynamic effects of erythropoietins have the potential to
precipitate cardiovascular adverse events (AEs), some severe or
catastrophic. These events are thought to have, as their basis,
alterations in rheologic and/or hemodynamic factors related to
increasing erythropoiesis, and include accelerated hypertension,
congestive heart failure, pulmonary edema, ischemic events (stroke,
transient ischemic attack \[TIA\], acute myocardial infarction \[MI\],
thrombosis of vascular access \[TVA\], peripheral ischemia/gangrene),
and seizures. However, evidence for an increased risk of fatal
cardiovascular events and impaired survival associated with the
administration of exogenous erythropoietin products according to a
specific treatment strategy (i.e., targeting of higher hemoglobin levels
than required for avoidance of transfusion) came several years after the
original approval of Epogen/Procrit. As a result of the "Normal
Hematocrit Study", the labeling of Epogen/Procrit was modified to
include warnings regarding this increased risk and association with this
treatment strategy. The labeling for Aranesp carries similar warning
statements.

Impaired survival and evidence of possible tumor stimulation associated
with erythropoietin products has been observed in the BEST Study
(EPO-INT-76) and the study by Henke, et al, published in the
[Lancet]{.underline} in October 2003. These two studies are large,
multicenter, randomized, placebo-controlled studies whose purposes were
to assess the impact of supplemental erythropoietin use on survival and
tumor outcomes. It is notable that these trials are larger than any
conducted

The data from these two studies may not be applicable to the U.S.
licensed products. Both the BEST and the Henke studies used
erythropoietin products that are not available in the U.S. and both
studies used treatment strategies (high target hemoglobin) that are not
recommended in labeling for either Epogen/Procrit or Aranesp. However,
the biochemical differences between various erythropoietin products are
not associated with marked differences in the pharmacodynamic properties
of the different products when used at recommended doses, thus effects
observed with these non-US-licensed products may be also be associated
with the U.S. licensed product. Furthermore, the presence of
erythropoietin receptors on tumor and tumor vasculature and the
stimulatory effect of erythropoietins on certain tumor lines suggest a
plausible reason for concern. In addition, while the treatment
strategies used in the BEST and Henke trials are not consistent with
current labeling for the U.S. licensed products, the studies used to
support labeling for treatment of anemia associated with cancer for
Epogen/Procrit or Aranesp are smaller and were not of adequate design to
rule out the potential for tumor stimulation or a survival decrement of
a specific magnitude.

Data from non-clinical and clinical studies provide a sound basis for
FDA's request for additional clinical studies to assess the safety and
optimal manner for administration of erythropoietin to patients with
cancer. Erythropoietin products are used an alternative form of
supportive care. In clinical studies in anemic cancer patients,
treatment with an erythropoietin product can reduce the proportion of
patients who receive red blood cell transfusions by approximately
35-50%, beginning about one month after initiation of treatment. It
should be noted that claims of improvement in quality of life are not
been supported by data submitted to the FDA and there is insufficient
evidence to support such a claim from literature reports due to the lack
of adequate and well-controlled trials. In discussion with both firms,
FDA has requested and both firms have agreed to conduct adequately
designed trials that will assess whether, when administered in
accordance with current labeling, there is evidence of tumor stimulation
or impairment in survival (due to tumor stimulation, thrombotic events,
or any cause) with Epogen/Procrit or Aranesp. Amgen, Inc. and Ortho
Biotech LP will present their proposed approach for addressing these
concerns. The approach consists primarily of randomized,
placebo-controlled trials, potentially supplemented by additional
preclinical studies. The FDA requests that the advisory committee
comment on the adequacy of the proposed approach, in particular with
regard to following:

-   Study population, e.g., those with primary tumors where
    erythropoietin receptors (EPOr) are commonly present on tumor, EPOr
    commonly present and are shown to be functional, and EPOr not
    commonly present or when present are ordinarily not functional (to
    assess for effect mediated through angiogenesis rather than direct
    tumor stimulatory effect)

-   Magnitude of decrement in time-to-progression and/or survival that
    studies should be powered to detect.

-   Replication of results/number of different primary tumors that
    should be evaluated.

# Erythropoietin Biology and Mechanism of Action

Erythropoietin is a glycoprotein whose main function is to stimulate the
proliferation and differentiation of erythroid precursors in the bone
marrow.[^1]^,^[^2] Erythropoietin is a 165 amino acid monomeric
polypeptide[^3] containing two intramolecular disulfide bonds. The
primary sequence encodes one consensus O-linked glycosylation site, and
three N-linked consensus glycosylation sites. The primary sequence of
Darbepoetin alfa, an erythropoietin analog, contains two additional
N-linked glycosylation sites resulting from amino acid substitutions in
the peptide backbone. These additional oligosaccharide side chains
increase the molecular weight of the protein from approximately 30 kDa
to 37 kDa. Darbepoetin has a three-fold longer terminal half-life than
erythropoietin alfa[^4], and a five-fold lower affinity for
erythropoietin receptors. In addition to proliferation and
differentiation of erythroid precursors, erythropoietin has also been
shown to be an erythrocyte survival factor, by modulating pro- and
anti-apoptotic mechanisms, and a pro-angiogenic factor[^5]. Studies show
erythropoietin stimulates the proliferation and migration of endothelial
cells *in vitro*, and stimulates the expression of other angiogenic
growth factors, namely Vascular Endothelial Growth Factor (VEGF) and
Placental Growth Factor (PlGF)[^6].

Erythropoietin is produced mainly in the kidneys, though several other
tissues produce lesser amounts of the growth factor^1,\ 2^.
Erythropoietin transcription and the protein's release into the
bloodstream are both induced by hypoxic conditions^1,\ 2^. The
erythropoietin gene contains a hypoxia-responsive element.
Hypoxia-inducible factor-1 (HIF-1), a transcription factor, is activated
when cells are exposed to hypoxia. HIF-1 then binds the
hypoxia-responsive element and up-regulates erythropoietin gene
expression[^7].

There are two types of erythropoietin receptors, high affinity
receptors, expressed predominantly on hematopoietic cells, with kDs of
approximately 95 pM, and low affinity receptors expressed on
non-hematopoietic cells, with binding affinities of approximately 16 nM.
The binding affinity of an erythropoietin ligand for the erythropoietin
receptor is not only influenced by the type of receptor alone, but also
by tissue-dependent receptor numbers and accessory proteins[^8]. Normal
non-hematopoietic cells expressing the erythropoietin receptor include
those of the female reproductive tract (placental trophoblasts, cervical
squamous epithelium, uterine glandular epithelium and endometrium,
ovarian follicles)[^9]^,^[^10]^,^[^11]^,^[^12], breast (mammary
epithelium)[^13], prostate (epithelium)[^14], vasculature
(endothelium)[^15], nervous system (neurons, astrocytes,
oligodendrocytes, microglia)[^16]^,^[^17]^,^[^18], pancreas (islet
cells)[^19], and kidney (cortex, medulla, papilla)[^20]. While the role
of erythropoietin in nonhematopoietic tissues is not completely
understood, the erythropoietin receptors expressed on these tissues are
functional.

Upon ligand binding, the erythropoietin receptor dimerizes and triggers
a variety of responses via several signaling pathways[^21]. These
pathways include proteins with a variety of functions, including
transcription activators, protein kinases and phosphatases, nucleotide
exchange factors, phospholipid modifying enzymes, and adaptor proteins.
Activation of these pathways results in DNA synthesis, cell
differentiation, and cell proliferation. The erythropoietin receptor
activates signaling molecules common to several other growth factor
receptors^21^. These signaling molecules include Jak2-STAT5[^22],
Ras-MAP kinase[^23], and PI3-kinase[^24]. Erythropoietin receptor
signaling results in the down-regulation of several pro-apoptotic
proteins (Fas-ligand[^25], TRAIL^25^, and BAD[^26]), and the
up-regulation and activation of anti-apoptotic proteins (Bcl-X~L~ and
Bcl-2)^6,\ 21^. No functional differences between high and low affinity
receptors, in terms of downstream activities, have been elucidated.
Ligand binding to either class of receptor results in cell proliferation
and/or cell survival under hypoxic conditions.[^27]

In addition, the erythropoietin receptor associates with other
receptors, namely the GM-CSF/IL-3/IL-5 ß common chain[^28] and
c-Kit[^29]^,^ [^30], the receptor for Stem Cell Factor. It is possible
that erythropoietin influences a variety of cell types through this
mechanism.

# Preclinical Evidence for a Role of Erythropoietins in Tumor Progression 

## In Vitro Findings

A substantial body of preclinical studies demonstrates that
erythropoietin receptors are present on a variety of malignant cell
lines^6,\ 10,\ 20,^ [^31]^,^[^32]^,^[^33] as well as on primary tumor
cells. Primary tumor cells have been shown to respond to erythropoietin
administration by proliferating and forming vasculature^20,^
[^34]^,^[^35]^,^[^36]. This information, coupled with the knowledge that
erythropoietin elicits anti-apoptotic effects in stem cells, and and
together with the results of recent clinical studies mandates the
investigation of the potential role of erythropoietin in tumor
progression.

Erythropoietin receptors are expressed on some primary tumor cells, but
not on all. For example, neuroblastomas^6^, Ewing's sarcomas^6^,
hepatoblastomas^6^, Wilm's tumors^6^, brain tumors^6^, cervical
carcinomas^10^, mammary adenocarcinomas^33^, renal carcinomas^20^, acute
monoblastic leukemia^31^, gastric carcinomas^34^, and endometrial^35^,
cervical^10^, and ovarian^35^ adenocarcinomas all have been demonstrated
to express erythropoietin receptors. However, not all tumors of the same
type from the same tissue of origin express erythropoietin receptors at
similar levels. The presence and levels of erythropoietin receptors may
vary from patient to patient. Arcasoy, *et al.*^33^ examined 26 mammary
tumor biopsies. Although ninety percent of these tissue samples
expressed detectable levels of erythropoietin receptors, the remainder
did not.

Interestingly and importantly, erythropoietin receptor expression on
primary tumors often directly correlates with disease staging^10,^
[^37], which may reflect the level of hypoxic stress in more advanced
and aggressive tumor masses. Thus, under these conditions, increased
erythropoietin binding and signaling activity may facilitate tumor
survival by initiating the increased expression of anti-apoptotic genes
and the down-regulation of pro-apoptotic genes, in addition to
facilitating angiogenic activities^6,\ 13,^ [^38].

The expression of erythropoietin receptors on tumor vascular endothelial
cells further suggests that erythropoietin may assist in tumor
progression by promoting endothelial cell proliferation and vessel
formation within the tumor^34,\ 35^. In addition, erythropoietin may
regulate tumor vasculature development indirectly; upon erythropoietin
administration, the levels of other endothelial growth factors, namely
VEGF and PlGF are upregulated^6^. Stimulation of erythropoietin
receptors in vascular endothelial cells leads to cell proliferation and
increased chemotaxis, providing evidence of a role for
erythropoietin/erythropoietin receptors in angiogenesis
[^39]^,^[^40]^,^[^41].

In addition to the expression of erythropoietin receptors on malignant
cells, some tumors also secrete erythropoietin^6,13,20,\ 33,35,38^. This
may allow a tumor to regulate its own growth by an autocrine pathway. It
has been postulated that the local intratumor levels of erythropoietin
produced through this autocrine loop may exceed the level of
erythropoietin the tumor would encounter from therapeutic doses of
erythropoietin. Batra, *et al.*^6^, postulate that, unlike hematopoietic
tissues that respond to relatively low levels of erythropoietin, tumors
might require high concentrations of erythropoietin to achieve a
response. This high concentration of erythropoietin might be achieved
only by local intratumoral erythropoietin production. The effect of
therapeutic erythropoietin administration on tumor progression must be
considered within this context as well.

Among data addressing the capacity of erythropoietin to stimulate tumor
growth, the most convincing are studies demonstrating that tumor
progression and tumor angiogenesis can be inhibited by the addition of
agents that block erythropoietin binding or signaling: e.g.
anti-erythropoietin antibodies, Jak2 inhibitors, and soluble
erythropoietin receptors^32,\ 33^. Yasuda *et al.* (2002)^35^ reported
that erythropoietin and

erythropoietin receptor are expressed in malignant tumors of the female

reproductive organs, where tumor cells and capillary endothelium showed
erythropoietin receptor immunoreactivity, and that the injection of a
monoclonal antibody against erythropoietin or the soluble form of
erythropoietin receptor into tumors reduced capillaries and caused tumor
destruction in a dose-dependent manner. Histopathologic changes
including, fragmented cellular DNA, and the absence of phosphorylated
Jak2 and STAT5 cells in tumors, relative to controls suggested that the
tumor and capillary cell decrease resulted from apoptotic cell death.
These studies support the conclusion that erythropoietin signaling
contributes to tumor survival and to the promotion of tumor growth and
angiogenesis.

It should be noted that the mere presence of erythropoietin receptors on
tumor cells does not necessarily confer on such cells the capacity to
respond to erythropoietin. These receptors must be functional. Not only
must they be able to bind erythropoietin, but they must be able to
activate the downstream intracellular signaling pathways through which
erythropoietin elicits its biological activities. Some *in vitro*
studies on tumor cell lines have demonstrated the lack of proliferation
upon exogenous erythropoietin administration, despite the presence of
erythropoietin receptors on the surface of cells. Westphal *et al.*^31^
evaluated over twenty tumor cell lines, including AML, breast,
pancreatic, prostate, and kidney cell lines. This study demonstrated
that the proliferation rates of these erythropoietin receptor-positive
cell lines were not influenced by the addition of exogenous
erythropoietin. Moreover, addition of erythropoietin did not increase
the tyrosine kinase activity in these cells. The presence of
erythropoietin receptors on these cells was not essential for the growth
of these cells in culture. A lack of proliferative response on
erythropoietin receptor-positive cells was also observed by Takeshita,
*et al.*[^42] when primary AML and melanoma cells were treated with
exogenous erythropoietin. These studies, as opposed to the ones
indicating a trophic effect of erythropoietin, beg the question as to
whether the tumors that respond express the high affinity receptor
versus the low, whether the levels differ, or whether the amount of
endogenous erythropoietin produced by cells that fail to respond to
exogenous erythropoietinin renders such cells resistant to further
stimulation by erythropoietin.

##  In Vivo Findings

While the majority of the published data supporting that erythropoietin
can promote tumor growth, survival and angiogenesis was obtained in *in
vitro* systems, *in vivo* data are also available. First, the direct
exposure of uterine and ovarian tumor slices transplanted into nude mice
to erythropoietin antagonists resulted in reduction in size.
Immunohistochemical staining revealed a decrease in erythropoietin
-responsive malignant and capillary endothelial cells through apoptotic
cell death[^43]. Second, treatment of xenograft models of stomach
choriocarcinoma and melanoma with erythropoietin antagonists inhibited
angiogenesis and survival of tumor cells. In contrast, treatment of the
xenograft models with an erythropoetin-mimetic peptide promoted
angiogenesis and tumor survival^32^. Third, experiments conducted using
a rat syngeneic mammary adenocarcinoma cell line implanted into the
subcutaneous tissue of rats in a chamber revealed that erythropoietin
antagonists delayed tumor growth^33^.

## Conclusions

From the regulatory perspective there are sufficient preclinical data to
support the hypothesis that erythropoietin can promote tumor growth,
survival, and angiogenesis. Although there are, undoubtedly, additional
preclinical studies that could be conducted to further elucidate the
mechanisms underlying erythropoietin's apparent effect on tumors, these
studies would not be able to directly assess the clinical relevance of
this effect. It is recommended that the ability of erythropoietin to
promote tumor growth, survival, and angiogenesis be assessed in an
appropriately designed clinical trials in patients that have been
adequately informed of the potential risk.

# Clinical Studies of Epogen/Procrit for the Treatment of the Anemia due to Chronic Renal Failure

The results of thirteen clinical studies that included a total of 1,010
patients were used support the approval of Epogen/Procrit for treatment
of anemia associated with ESRD. Four other studies were performed in
patients with renal failure whose disease was not severe enough to
require dialysis. Six studies were conducted in normal male volunteers
(157 subjects, 108 of whom received Epogen and 49 of whom received
placebo).

## Treatment of Anemia Due to Chronic Renal Failure in Patients Undergoing Dialysis

The primary efficacy data were derived from two large multicenter
trials. The first study was a multicenter, open-label study in which 412
subjects with end stage renal failure on dialysis received Epogen three
times a week. Patients initially received one of three dose levels: one
group received 300 U/kg only; one group was dosed at 300 U/kg and
subsequent dose reduced to 150 U/kg; and the majority received 150 U/kg
only. When a patient achieved a hematocrit of 35%, or completed 12 weeks
of therapy at the initial dose, they entered the dose adjustment and
long-term maintenance phase of the study.[^44] 309 patients were
evaluable for efficacy, and 95.5% had an increase in hematocrit of 6
points or reached the target hematocrit of 35% within 12 weeks of the
initiation of therapy. Approximately 70% satisfied these criteria within
the first four weeks of therapy. Following six more weeks of therapy,
97% of the evaluable patients met these criteria. The percentage of
patients who responded to therapy was not significantly different
between the three dosage groups: for 300 U/kg, 300 U/kg and 150 U/kg,
and 150 U/kg the values were 100%, 94.5% and 95.2%, respectively.[^45]

When the enrolled patients achieved a hematocrit of 35%, they were
entered into the dose adjustment and long-term maintenance phase, where
the dose was individually adjusted to maintain the hematocrit within the
target range of 32-38%. Sixty-four percent of the patients required
doses of Epogen between 12.5 and 100 U/kg to maintain their hematocrit
within the desired target range.

Transfusion requirements decreased within weeks after the initiation of
therapy. The pre-study transfusion requirements of 0.52 units per
patient per month were reduced to 0.1 units per patient per month after
the first four weeks on Epoetin therapy, and to 0.04 units per patient
per month or less through 14 months on study.

The second major efficacy study was the U.S. Pivotal Double-blind,
Placebo-controlled (DBPC) Multicenter Study in ESRD Patients, which was
conducted at three study sites. This study enrolled 100 anemic ESRD
patients who were on maintenance hemodialysis. Patients were randomized
to receive either placebo or 150 U/kg Epogen t.i.w. for 12 weeks. During
the second 12-week study period, all patients received drug on an
open-label basis. Once a patient's hematocrit reached 35%, they were
entered into the dose adjustment and long-term maintenance phase of this
study.

Of the 62 patients evaluable for efficacy, 95% achieved a hematocrit of
35% or six points over baseline. Ninety-seven percent of the patients
(97%) randomized to therapy achieved this efficacy criterion in the
blinded phase of the study, and 93% of the patient achieved this
criterion after crossover from placebo to Epogen treatment.

Two, double-blind, placebo controlled studies were conducted in Canada
in ESRD patients. In a single-center trial, ESRD patients (6 patients
per group) were treated IV for nine weeks with either placebo or 50
U/kg, 100 U/kg or 200 U/kg Epogen t.i.w. The rate of rise of hematocrit
was dose dependent. In the larger multicenter DBPC trial, patients
received placebo (n=40) or Epogen at an initial dose of 100 U/kg (n=78)
for 26 weeks. The mean change from baseline for hemoglobin was 0.006
g/dl for placebo-treated patients, and 3.8 g/dl for Epogen -treated
patients.

## Treatment of Anemia Due to Chronic Renal Failure in Patients not undergoing Dialysis

Four clinical studies were conducted in CRF patients whose disease was
not severe enough to require dialysis (non-dialysis CRF patients): two
U.S. multicenter double-blind placebo controlled studies, a continuation
long-term maintenance study, and a European open-label study. In the
first U.S. DBPC study, non-dialysis CRF transplants received placebo
(n=31) or Epogen at 50 U/kg (n=28), 100 U/kg (n=28), or 150 U/kg (n=30)
intravenously t.i.w. ; patients were treated for 8 weeks, or until their
anemia was corrected (hematocrits of 40% for males and 35% for females).
Treatment with Epogen increased the hematocrit in a dose-dependent
manner; changes of --0.01, 0.13, 0.20 and 0.26 hematocrit points per day
were seen for the placebo, Epogen 50 U/kg, 100 U/kg, and 150 U/kg dosage
groups, respectively. Upon completion of eight weeks of therapy or
correction of anemia, whichever came first, patients in this study were
enrolled in a 6-month maintenance study protocol. In the maintenance
study, Epogen was administered either intravenously or subcutaneously
t.i.w., and the dose was adjusted to maintain a constant elevated
hematocrit. Ninety-four percent of all patients in the study corrected
their hematocrit, and doses of Epogen 75-150 U/kg per week were shown to
maintain hematocrits of 36-38% for up to six months.

In the second U.S. DBPC trial, non-dialysis CRF patients were
administered either placebo (n=48) or 100 U/kg Epogen (n=45) t.i.w.
subcutaneously for up to 12 weeks or until the hematocrit reached
38-40%, whichever occurred first. Fifty-eight percent of the
Epogen-treated patients, versus 4% of the placebo-treated patients,
corrected their anemia (hematocrit \> 40% for males and \> 35% for
females) during the study period.

## Safety Analyses

Analyses of safety included the data from all studies conducted in
patients with chronic renal failure, including those undergoing dialysis
and those not undergoing dialysis. Hypertension was the most frequently
reported adverse event in both the placebo and Epogen-treated patients.
In patients on dialysis, the incidence of reported hypertensive events
for all Epogen-treated patients was approximately twice that for
placebo-treated patients (0.69 versus 0.33 events per patient-year,
respectively). In non-dialysis CRF patients, the rate of hypertension
was higher, occurring at a rate of 1.70 and 3.28 events per patient-year
in Epogen- and placebo-treated patients, respectively.[^46] When
patients in the U.S. Phase III multicenter ESRD trial were analyzed for
incidence of hypertension as a function of the rate of rise in
hematocrit, there was a trend towards more reports of hypertension in
the first 90 days of therapy in patients who had increases in hematocrit
that were greater than 0.3 points per day.

In placebo-controlled studies enrolling over 300 patients with chronic
renal failure, the following adverse events occurred at a higher
incidence Epogen-treatment patients as compared to placebo controls:
hypertension (24% vs. 18%), headache (16% vs. 12%), arthralgias (11% vs.
6%), diarrhea (8% vs. 6%), vomiting (8 % vs. 5%), and clotted vascular
access (6.8% vs. 2.3%). In US and non-US studies, the annual rates
(events per patient-year) of clotted vascular access in patients
receiving Epogen was 0.25 and 0.27 events/patient-year,
respectively.[^47]

# The Normal Hematocrit Study of Epogen/Procrit in Patients with Chronic Renal Failure and Underlying Cardiovascular Disease

Amgen, Inc. conducted a study in 1,233 patients with chronic renal
failure on dialysis[^48] and clinical evidence of congestive heart
failure or ischemic heart disease. Patients were randomized to an Epogen
dose titrated to achieve a target hematocrit of 42% (±3) (the "normal
hematocrit group" or an epoetin dose titrated to achieve and maintain a
target hematocrit of 30% (±3) (the "low hematocrit group"). The study
was designed to test the hypothesis that correction of anemia in chronic
renal failure patients on dialysis with clinical evidence of congestive
heart failure or ischemic heart disease would have improved survival and
better exercise tolerance if treated with Epogen to obtain a higher
hematocrit than had been commonly targeted in clinical practice. The
primary endpoint was the length of time to death or a first nonfatal
myocardial infarction.

This study was halted at the third interim analysis on the
recommendation of the Data Safety Monitoring Board. At 29 months, there
were 183 deaths and 19 first nonfatal myocardial infarctions in the
group with a normal hematocrit and 150 deaths and 14 nonfatal myocardial
infarctions in the low hematocrit group. (Figure 2) Even though these
differences did not reach the prespecified statistical stopping
boundary, the study was halted "because differences in mortality between
the groups were recognized as sufficient to make it very unlikely that a
continuation of the study would reveal a benefit for the
normal-hematocrit group and the results were nearing the statistical
boundary of a higher mortality in the normal-hematocrit group."[^49]

## Safety Results

The incidences of non-fatal MI were 3.1% and 2.3% in the normal and low
hematocrit groups, respectively. The incidences of CVA (39% versus 29%)
and all other thrombotic events (22% versus 18%) were also higher in the
normal hematocrit group. There was a trend to decreasing mortality with
increasing hematocrit values within both groups. (Figure 1)

This study demonstrated that the aggressive use of erythropoietin to
correct the hematocrit to normal values is associated with higher risks
in subjects with chronic renal failure and pre-existing cardiovascular
disease. As a result, a Warning was added to the Epogen and Procrit
Package Inserts.

These findings also led FDA to examine the risks associated with the
rate of rise of hemoglobin in the studies that were submitted to support
the licensure of Aranesp for treatment of anemia in chronic renal
failure (see below).

![](media/image1.png){width="3.8854166666666665in"
height="3.2916666666666665in"}

Figure 1: Mean (±SE) Mortality Rate as a Function of the Average
Hematocrit Value in the Normal-Hematocrit and Low-Hematocrit Groups.

![](media/image2.png){width="5.5in" height="3.8333333333333335in"}

Figure 2: Kaplan--Meier Estimates of the Probability of Death or a First
Nonfatal Myocardial Infarction in the Normal-Hematocrit and
Low-Hematocrit Groups.

# Clinical Studies of Aranesp® (darbepoetin alfa) for the Treatment of the Anemia due to Chronic Renal Failure

The licensure of Aranesp in subjects with chronic renal failure was
based on two active controlled open-label studies in EPO naïve patients,
and two randomized double-blind non-inferiority studies in patients who
had previously been on a stable dose of epoetin alfa. The two studies in
EPO naïve patients were Study 211: An Open-Label Randomized Study of
ARANESP and Recombinant Human Erythropoietin (r-HuEPO) (EPOGEN) for
Treatment of Anemia in Patients With End-Stage Renal Disease Receiving
Dialysis (North American Phase 2 Study in EPO-Naïve Subjects), and Study
202: A Randomized Study of ARANESP and Recombinant Human Erythropoietin
(r-HuEPO) for Treatment of Anemia in Predialysis Chronic Renal Failure
Subjects (European Phase 2 Study in Pre-Dialysis, EPO-Naïve Subjects).
The two studies in patients who had previously been on a stable dose of
EPO were: Study 117: A Randomized Double-blind, Non-Inferiority Study of
IV ARANESP Compared to IV Recombinant Human Erythropoietin (EPO) for
Treatment of Anemia in Patients with End-Stage Renal Disease (ESRD)
Receiving Hemodialysis, and Study 200: A Randomized, Comparative Study
of ARANESP Recombinant Human Erythropoietin for Prevention of Anemia in
Subjects With Chronic Renal Failure Receiving Dialysis.

## Studies In Erythropoietin-Naïve Patients

In Study 211, 120 subjects with chronic renal failure, on dialysis, were
randomized 3:1 to receive 0.45 μg/kg of Aranesp QW or 50 U/kg of EPO
administered T.I.W. IV or s.c. for 20 weeks.

In Study 202, 160 subjects with chronic renal failure, but not receiving
dialysis, were randomized in a 3:1 ratio to receive Aranesp 0.45 μg/kg
QW or EPO 50 U/kg BIW s.c. for ≤ 24 weeks, with both agents to be
administered subcutaneously.

For both studies, dose adjustments were to be made, if necessary to
achieve a hemoglobin increase of ≥ 1.0 g/dl above baseline, to within a
target range of 11-13 g/dl.

The primary efficacy endpoint in both studies was the proportion of
subjects achieving a hemoglobin target, defined as a hemoglobin ≥ 1.0
g/dl from baseline and a hemoglobin concentration of ≥ 11.0 g/dl during
the study. The time points for assessment of the endpoint were 20 and 24
weeks in Study 211 and 202, respectively.

### Efficacy results

In Study 211 the hemoglobin target was achieved by 72% (95% CI: 62%,
81%) of the 90 patients treated with Aranesp and 84% (95% CI: 66%, 95%)
of the 31 patients treated with Epoetin alfa. The mean increase in
hemoglobin over the initial 4 weeks of Aranesp was 1.10 g/dl (95% CI:
0.82 g/dl, 1.37 g/dl).

In Study 202 the primary efficacy endpoint was achieved by 93% (95% CI:
87%, 97%) of the 129 patients treated with Aranesp and 92% (CI: 78%,
98%) of the 37 patients treated with Epoetin alfa. The mean increase in
hemoglobin from baseline through the initial 4 weeks of Aranesp
treatment was 1.38 g/dl (95% CI: 1.21 g/dl, 1.55 g/dl).

## Studies In Patients Previously Stable on Erythropoietin

The objectives of both of these studies were to show that Aranesp was
not inferior to EPO for the treatment of anemia in patients with ESRD
receiving dialysis, and to compare the safety of the two agents.

Study 117, the North American pivotal phase 3 study, was a randomized,
double-blind, active control study of Aranesp versus EPO for the
maintenance of hemoglobin in subjects with ESRD receiving hemodialysis.
Study 200, the European/Australian study, was similar in design, except
that it was open-label, and subjects could be receiving hemodialysis or
peritoneal dialysis.

The primary efficacy endpoint was the change in hemoglobin from baseline
through the evaluation period (Week 21-28).

Subjects were to be on a stable regimen of Epoetin, with a baseline Hgb
between 9.5-12.5 g/dl at the time of enrollment. In Study 200, subjects
could be receiving Epoetin alfa or Epoetin beta at baseline, whereas
Study 117 enrolled subjects on Epoetin alfa only. After a 2-week
screening and baseline periods, subjects were to be randomized 2:1 to
Aranesp or Epoetin alfa or beta. Subjects assigned to Epoetin were to
continue on their previous dose of Epoetin. Subjects assigned to Aranesp
were to switch to Aranesp, at a total weekly starting dose that was
based on the total weekly Epoetin dose at the time of randomization
using the proportionality 1 μg Aranesp to 200 units Epoetin. Hemoglobin
was to be maintained within a target range of --1.0 to +1.5 g/dl of the
baseline hemoglobin and between 9-13 g/dl for up to 28 weeks, with dose
adjustments as needed per protocol-specified algorithms.

### Efficacy Results

The results of Study 117 showed that the distributions of changes in
hemoglobin from baseline through the evaluation period were similar for
the two treatment groups. The prospectively defined primary efficacy
endpoint, the mean change in hemoglobin, adjusted for center and
baseline hemoglobin concentration, was similar in the Aranesp and
Epoetin arms: 0.24 ± 0.10 g/dl versus 0.11 ± 0.07 g/dl (mean ± SEM)
respectively. The difference between groups was 0.13 g/dl (95% CI:
-0.08, 0.33). The lower boundary of the 2-sided 95% CI was above the
protocol-specified non-inferiority margin of --1.0 g/dl, providing
support that Aranesp was not inferior to Epoetin in maintaining Hgb in
this study.

For Study 200, the results showed that the change (mean ± SD) in Hgb
from baseline to the evaluation period was similar in the Aranesp and
Epoetin arms (0.05 ± 0.80 versus 0.00 ± 0.87 g/dL, respectively). After
adjustment for covariates (center, frequency of Epoetin dosing at
baseline, modality of dialysis, route of administration, and baseline
Hgb concentration), the difference in the mean change in Hgb between the
2 groups was 0.03 g/dL (95% CI: -0.16, 0.21). The lower limit of the
2-sided 95% CI was above the protocol-specified non-inferiority margin
of -0.5 g/dL, providing support that Aranesp was not inferior to Epoetin
in maintaining the mean Hgb concentration in this study.

## Safety Analyses: Relation between adverse events, hemoglobin, and hemoglobin rate of rise

The development program of Aranesp for the anemia of chronic renal
failure (CRF) indication evaluated the use of Aranesp in the settings of
pre-dialysis, peritoneal dialysis, and hemodialysis. In addition, it
assessed two types of Aranesp use: 1) the treatment of anemia in
subjects who had not been treated previously with erythropoietins (i.e.,
anemia "correction" studies); and 2) as maintenance therapy for patients
whose anemia had been treated with a stable regimen of Epoetin alfa
(EPO) prior to study enrollment (i.e., "conversion" studies). Details of
FDA's safety analyses can be found in the Medical Officer's clinical
review of Aranesp for anemia of CRF.[^50]

Overall, the safety database included 1598 Aranesp-treated subjects and
600 EPO-treated subjects, with median lengths of exposure of 24 and 28
weeks, respectively. The substantive investigations were either
active-controlled studies using EPO as a comparator, or uncontrolled
studies. The vast majority of the clinical experience was unblinded.

Given the lack of placebo-controlled studies and the pattern of AEs
observed, characterization of the safety of Aranesp during review of the
marketing application was not straightforward. Adverse events occur
frequently in the CRF patient population, and treatment emergent AEs had
to be assessed against this background. Moreover, cardiovascular disease
is prevalent in the CRF patient population, and cardiovascular events
occur fairly commonly, yet they also constitute a primary manifestation
of excessive erythropoiesis, as noted above.

FDA undertook a number of approaches in its assessment of the Aranesp
safety database, beyond simple comparisons of AE rates in Aranesp- and
Epoetin alfa-treated subjects and subgroups. One of these approaches
involved analyses of AEs with putative mechanisms Involving hemodynamic
and/or rheologic factors, an approach that involved four analyses:

A)  Analysis of AEs by Hgb Concentration. FDA assessed AEs by Hgb
    concentration as determined on the week of the reported event. This
    purpose of this analysis was to provide information on potential
    associations between AEs and specific Hgb levels.

B)  Analysis of AEs by Hgb Rate of Rise. FDA assessed AEs by Hgb rate of
    rise (ROR) during the weeks preceding reported AEs. The objective of
    this analysis was to assess potential associations between AEs and
    specific rates of Hgb increase.

C)  Analysis of AEs by Hgb Rate of Decline. This complementary analysis
    assessed rates of AEs by Hgb rate of decline during the weeks
    preceding the events.

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D)  Examination of Potential Interaction Between Hgb Concentration, Hgb
    Rate of Rise and AEs: FDA combined all AEs with putative mechanisms
    involving hemodynamic and/or rheologic factors, and examined the
    potential interactions between the rate of these AEs, Hgb
    concentration, and Hgb ROR.

## 

General Methods:

Weekly Hgb values were classified by both 1-g/dL range and quintile.
Ranges were defined as: [\<]{.underline}10 g/dL, \>10 to
[\<]{.underline}11 g/dL, \>11 to [\<]{.underline}12 g/dL, \>12 to
[\<]{.underline}13 g/dL, \>13 to [\<]{.underline}14 g/dL, and \>14 g/dL.
Quintiles were ascertained as: \<10.1 g/dL, 10.1 to \<10.8 g/dL, ≥10.8
to \<11.4 g/dL, ≥11.4 to \<12.2 g/dL, and ≥12.2 g/dL.

For each subject-week, the slope of the preceding Hgb-time relation was
determined, when possible, using the following approach:

1.  The slope of the Hgb-time relation leading up to each date was
    calculated using Hgb values obtained over a 2-week period (i.e., 3
    Hgb values).

2.  Missing Hgb values were not interpolated.

3.  Hgb values were construed as having been obtained on the week
    indicated, i.e., the actual date was not used in calculations.
    Slopes were expressed as weekly change in Hgb concentration.

4.  If \<2 Hgb values were reported over a 2-week (3-value) period, such
    that a slope could not be calculated, an attempt was made to
    calculate slope over a 4-week period.

5.  Positive and negative slopes were analyzed separately, with slopes
    of 0 classified with the positive slopes.

6.  Slope (m) was classified by group, as follows:

m \> 0.2 and [\<]{.underline} 0.25 g/dL/week (1 g/dL per \<5 to 4 weeks)

m \> 0.25 and [\<]{.underline} 0.333 g/dL/week (1 g/dL per \<4 to 3
weeks)

m \> 0.333 and [\<]{.underline} 0.5 g/dL/week (1 g/dL per \<3 to 2
weeks)

m \> 0.5 and [\<]{.underline} 1 g/dL/week (1 g/dL per \< 2 to 1 week)

m \> 1 g/dL/week (1 g/dL per \<1 week)

Each AE reported was linked, by reported week of occurrence, to its
associated weekly Hgb value range, quintile, and slope. Multiple AEs
were linked by pathophysiologic mechanism, e.g., fluid overload included
edema, dyspnea, orthopnea and pleural effusion. Congestive heart failure
(CHF), abnormal ejection fraction and pulmonary edema were grouped
together. Cerebrovascular disorders included cerebral ischemia,
intracranial hemorrhage (ICH), and cerebral/subarachnoid hemorrhage.
Angina was grouped with coronary artery disease, myocardial ischemia,
and chest pain (non-specific chest pain was not included in this
category). A category representing thrombosis/ischemia (but omitting
TVA) was constructed including the terms arterial occlusion, embolism,
arteriosclerosis, carotid stenosis, claudication, peripheral vascular
disease, ischemic necrosis, gangrene, superior vena caval syndrome,
phlebitis, thrombophlebitis, arterial/venous thrombosis, intestinal
ischemia, pulmonary embolism, and TIA.

### 

### Absolute Hgb Values (Table 1):

Serum Hgb was analyzed both by quintiles, and by 1-gram/dL categories.
For each quintile and category, the denominator used was the number of
weekly Hgb values observed that fit that particular category, divided by
1000 (i.e., the number of events per 1000 weekly Hgb observations). The
Ns are given at the bottom of Table .

For Aranesp -treated subjects, there were trends suggesting possible
associations between reported Hgb values \>13 and seizures, hypertension
(HTN), and arrhythmias, though the latter appeared to be associated with
Hgb values \>11 g/dL, as well. Importantly, Hgb values of \>13 g/dL did
not appear to be associated with increased risks of these events. Of
note, for ARANESP-treated subjects, Hgb values \<10 g/dL appeared to be
associated with excess risks of fluid overload, CHF, pulmonary edema,
acute MI and TVA, whereas these risks were not apparent at Hgb values
≥10 g/dL.

### Hgb Rate of Rise (Table 2): ![](media/image3.wmf){width="5.4631944444444445in" height="7.925in"}

Adverse events are shown for Hgb rates of increase and decrease in Table
2. Rates were determined by whole fractions of a gram of Hgb (i.e., 1.0,
0.5, 0.33, 0.25, 0.20, and 0.10 g/dL/week). The denominators used for
each quintile and category were the number of weekly Hgb slopes that fit
that particular category, divided by 1000 (i.e., the number of events
per 1000 weekly Hgb observations, table bottom).

For Aranesp-treated subjects, there appeared to be excess risk of HTN,
pulmonary edema, cardiac arrest and TVA associated with Hgb ROR \>0.5
and particularly 1.0 g/dL/week. There also appeared to be an association
between rapid Hgb rise and fluid overload, acute MI and seizures,
although the association between Hgb rate of rise and these events was
less clear.

FDA also assessed the rates of these AEs in the Aranesp treatment group,
with subgroups by history of cardiovascular disease (CVD). Across Hgb
and Hgb ROR categories, event rates generally followed similar patterns
for subjects with and without a history of CVD, though rates were higher
in CVD(+) subjects. There were 2 apparent exceptions:

1)  CHF was strongly associated with the extremes of Hgb categories
    (both \<10 and \>14 g/dL) in the CVD(+) group, whereas there was
    only a weak association between CHF and Hgb \<10 g/dL in the CVD(-)
    subgroup. A Hgb ROR exceeding 0.5 was strongly associated with CHF,
    both in CVD(+) and CVD(-) subgroups.

2)  There was no clear association between angina and Hgb ROR in either
    subgroup; however, a Hgb \<10g/dL was strongly associated with
    angina in the CVD(+) group.

### 

### Hgb Rate of Decline:

With respect to falling Hgb in Aranesp-treated subjects (rate of Hgb
decrease preceding AEs), there were apparent associations between a \>1
g/dL weekly decline in Hgb and worsened anemia, CHF, pulmonary edema,
acute MI, cardiac arrest, angina, arterial occlusion, and death, though
the numbers of subject-weeks and events in this category were limited.

### 

Interaction Between Hgb Concentration, Hgb Rate of Rise, and AEs:

For the Aranesp treatment group, FDA combined [all]{.underline} of the
AEs with putative mechanisms involving hemodynamic and/or rheologic
factors, and examined the interaction between the rate of these AEs, Hgb
concentration and Hgb ROR. These events included: accelerated HTN, fluid
overload, edema, dyspnea, orthopnea, pleural effusion, pulmonary edema,
CHF, abnormal ejection fraction, angina, coronary artery disease,
myocardial ischemia, chest pain (cardiac), arrhythmia, syncope, cardiac
arrest, impaired consciousness, encephalopathy, seizure, cerebrovascular
disorder, TIA, cerebral ischemia, ICH, subarachnoid hemorrhage, arterial
occlusion, arteriosclerosis, carotid stenosis, claudication, gangrene,
ischemic necrosis, peripheral ischemia, arterial embolism, phlebitis,
superior vena caval syndrome, thrombophlebitis, arterial/venous
thrombosis, and intestinal ischemia. Each AE was linked, by week of
reported occurrence, to its corresponding Hgb category, as well as to
its appropriate Hgb ROR category.

The results of this analysis are shown in Table 3. The top panel shows
the numbers of subject-weeks that fulfill the criteria for Hgb and Hgb
ROR categories. These data serve as the denominators (Ns) for these
analyses. The middle panel shows the numbers of events for each Hgb/Hgb
ROR category, and the bottom panel shows event rates per 1000
subject-weeks. Each row, representing a particular Hgb ROR category, is
summed in the right-most column ("All Hgb"). Note that event rates
(bottom panel) tend to be similar for all ROR categories  0.50
g/dL/week, whereas event rates for ROR  0.50 g/dL/week tend to be
higher. The individual Hgb categories are summed in the bottom row ("All
Slopes"). The lowest event rates are in the \>11 to 12 g/dL Hgb
category. A slight increase in event rate is evident above this range,
with a sharper increase in event rate below this
range.![](media/image4.wmf){width="5.997222222222222in"
height="7.825694444444444in"}

![](media/image5.wmf){width="5.999305555555556in"
height="4.540277777777778in"}

Figure 3 (top) displays these event rates graphically. A general trend
towards higher event rates for the lowest Hgb categories
([\<]{.underline}10; \>10 to [\<]{.underline}11) is apparent at the left
side of the graph. Event rates are higher in the row corresponding to a
Hgb ROR \>0.5 g/dL/week. The middle panel shows the event rates for the
subset of subjects with a reported history of cardiovascular disease.
Rates are generally higher for this subgroup. Of note, higher event
rates appear to be associated with the lowest Hgb class (\<10 g/dL), and
the highest ROR class (\>0.5 g/dL/week). For the subset of subjects
without a reported history of cardiovascular disease (lower panel), the
events rates tend to be lower, but the trends are similar. Importantly,
therefore, even subjects without overt cardiovascular disease appear to
incur excess risk with Hgb ROR in excess of 0.5 g/dL/week.
![](media/image6.wmf){width="3.2993055555555557in"
height="2.4472222222222224in"}![](media/image7.wmf){width="3.2993055555555557in"
height="2.4472222222222224in"}![](media/image8.wmf){width="3.3in"
height="2.4472222222222224in"}

In summary, FDA's exploratory analyses suggested that higher Hgb
concentration, per se, is not associated with increased rates of events
that involve hemodynamic or rheologic mechanisms. Importantly, however,
the hemoglobin rate of rise appears to be particularly relevant with
respect to these events. Specifically, a hemoglobin rate of rise in
excess of 0.5 g/dL/week appears to be associated with increased event
rates, irrespective of the presence or absence of overt cardiovascular
disease. This finding provided the basis for the Warning on
cardiovascular events in the Aranesp package insert.

# Clinical Studies of Epogen/Procrit for the Treatment of the Anemia Associated with Chemotherapy of Cancer. 

In April 1993, Epogen/Procrit was approved for the indication of
treatment of anemia in patients with non-myeloid malignancies where
anemia is due to the effect of concomitantly administered chemotherapy.
The data supporting this supplemental indication was based on pooled
data from six randomized, placebo-controlled, double-blind, trials, in a
total of 131 anemic cancer patients. 72 of these patients were treated
with concomitant chemotherapy regimens that did not contain cisplatin,
and 59 patients were treated with regimens that contained cisplatin.
Patients were randomized to Procrit 150 units/kg or placebo
subcutaneously t.i.w. for 12 weeks.[^51]

## Efficacy Results

**Proportion of Patients Transfused During Chemotherapy (Efficacy
Population)^a^**

  -------------- -------------- -------------- -------------- --------------
  Chemotherapy   On Study^b^                   During Months  
  Regimen                                      2 and 3^c^     

                 EPO            Placebo        EPO            Placebo

  Regimens       44% (15/34)    44% (16/36)    21% (6/29)     33% (11/33)
  without                                                     
  cisplatin                                                   

  Regimens       50%(14/28)     63%(19/30)     23% (5/22)     56% (14/25)
  containing                                                  
  cisplatin                                                   

  Combined       47% (29/62)    53% (35/66)    22% (11/51)^d^ 43% (25/58)
  -------------- -------------- -------------- -------------- --------------

^a^ Limited to patients remaining on study at least 15 days.

^b^ Includes all transfusions from day 1 through the end of the study.

^c^ Limited to patients remaining on study beyond week 6 and includes
only transfusions during weeks 5-12.

^d^Unadjusted 2-sided p \< 0.05.

Data were not systematically collected on tumor response, tumor
progression, or survival. The reviewer noted that "Based in part on the
percentage of Epoetin alfa and placebo-treated patients who discontinued
therapy due to death, disease progression or adverse experiences (22%
and 13% respectively, p= 0.25) the clinical outcome in Epoetin alfa and
placebo-treated patients appeared to be similar.

#  

FDA noted that Procrit could potentially serve as a growth factor for
malignant tumors, however the pivotal studies that had been used to
support supplemented approval were not designed to examine tumor
response rate, time to progression or overall survival. Because of this
concern, Amgen agreed to the following post-marketing commitment to
conduct a study to assess:

> "The effect of Epoetin alfa on initial response rate and response rate
> at the completion of chemotherapy, site of first relapse and overall
> survival will be investigated in a randomized, double-blind,
> placebo-controlled phase IV study in patients with limited stage small
> cell lung cancer."[^52]

# Post-Marketing Study to Assess for Tumor Stimulatory effects of Epogen/Procrit: Study N93-004

Protocol, Study N93-004, "The Effect of r-HuEPO in Patients with Small
Cell Cancer (SCLC): A Randomized, Double blind, Placebo-controlled
Trial" to FDA on January 7, 1993. In July 2001, Amgen and Ortho Biotech
LP notified FDA of its intention to prematurely terminate the study
after accrual of 225 subjects, (instead of the planned accrual of 400),
due to slow accrual rates. FDA stated that the results of than study
should be submitted and, based on review of the data, a determination
would be made as to whether additional studies would be required.

Study N93-004 was a randomized, double-blind placebo-controlled trial
conducted at 35 sites in the United States. The primary objective was to
determine the effect of Procrit on tumor response in SCLC in patients
receiving treatment with etoposide and cisplatin. The primary endpoint
was determination of the objective response rate (defined as partial
response plus complete response) after 3 cycles of chemotherapy. The
secondary endpoints were: effects of Procrit on survival, hemoglobin,
and transfusion rates. Eligible subjects were those with newly diagnosed
limited or extensive stage small cell carcinoma of the lung. Subjects
were randomized to receive chemotherapy with etoposide and cisplatin
every 3 weeks for 3 cycles with either Procrit 150 IU/kg t.i.w. or
placebo. Subjects continued to receive study medication until
approximately 3 weeks after the final cycle of chemotherapy. No target
hemoglobin was specified, but the study medication was to be held if the
hemoglobin rose above 16 g/dl and restarted at a 50% dose reduction when
the hemoglobin fell to less than 14 g/dl.

The study was designed with a sample size of 400 (200 patients/arm). The
sample size was selected in order to be able to exclude, with 90% power,
an absolute decrement in overall response rate of 15% in the
Procrit-treated arm as compared to placebo, based on the 95% confidence
interval around the observed difference in response rate. The assumed
response rate in the placebo arm was 60%.

In the intent-to-treat population of 224 subjects, there were 115 in the
placebo and 109 in the Procrit arm. There were no differences between
the two groups in baseline demographics or other baseline entry
variables (including baseline hemoglobin), with the exception of a
slightly higher proportion of subjects in the Procrit arm had extensive
stage SCLC than in the placebo arm (66% versus 59%). In both arms, 72%
received at least 3 cycles of chemotherapy. The median number of cycles
was 4 for both arms. The median doses of both etoposide and cisplatin
were not significantly different between the groups.

## Efficacy Results

For the primary endpoint, the tumor response (CR + PR) after 3 cycles of
chemotherapy, the results were as follows (intent-to-treat population):

+--------------------------------+------------------+------------------+
|                                | Placebo          | Procrit          |
|                                |                  |                  |
|                                | (n=115)          | (n=109)          |
+--------------------------------+------------------+------------------+
| No. having CR/PR               | 77               | 79               |
+--------------------------------+------------------+------------------+
| Tumor response rate            | 67%              | 72%              |
+--------------------------------+------------------+------------------+
| 95% CI around observed         | 58-67%           | 64-81%           |
| response rate                  |                  |                  |
+--------------------------------+------------------+------------------+
| 95% confidence interval around | -6% to 18%       |                  |
| observed difference in ORR     |                  |                  |
+--------------------------------+------------------+------------------+

The observed difference in tumor response rates between the Procrit and
placebo arms was 6% (95% CI: -6%% 18%). The lower bound of the 95%
confidence interval around the difference in response rates was --6%,
indicating that in this trial, the response rate observed in the Procrit
arm would not be more than 6% lower than that of the placebo arm. The
methods used to collect data on tumor response and patient follow-up did
not permit the determination of time to progression.

## Safety Results

### Thrombotic Vascular Events:

> Twenty-two percent of the subjects in the Procrit arm and 23% of the
> subjects in the placebo arm expired at least one thrombotic vascular
> event. The incidences of specific subtype of thrombotic vascular event
> were generally similar between the two treatment arms with the
> exceptions of chest pain, which was reported by 14% of placebo treated
> subjects as compared to 7% of Procrit-treated subjects, and vascular
> (extracardiac) disorders, which was reported in 4% of placebo patients
> and 10% of Procrit-treated patients.

##### Incidence of Thrombotic Vascular Events

##### In Study N93-004 

+-----------------------------------+-----------------+----------------+
| **Preferred Term**                | **Placebo**     | **Procrit**    |
|                                   |                 |                |
|                                   | **N=115**       | **N=109**      |
+-----------------------------------+-----------------+----------------+
| Chest pain                        | 16 (14%)        | 8 (7%)         |
+-----------------------------------+-----------------+----------------+
| Chest pain substernal             | 0 (0)           | 1 (1%)         |
+-----------------------------------+-----------------+----------------+
|                                   |                 |                |
+-----------------------------------+-----------------+----------------+
| **Vascular (extracardiac)**       | 5 (4%)          | 11 (10%)       |
+-----------------------------------+-----------------+----------------+
| Cerebrovascular disorder          | 2 (2%)          | 3 (3%)         |
+-----------------------------------+-----------------+----------------+
| Phlebitis                         | 1 (1%)          | 3 (3%)         |
+-----------------------------------+-----------------+----------------+
| Thrombophlebitis, deep            | 1 (1%)          | 2 (2%)         |
+-----------------------------------+-----------------+----------------+
| Thrombophlebitis                  | 1(1%)           | 1 (1%)         |
+-----------------------------------+-----------------+----------------+
| Peripheral ischemia               | 0 (0)           | 1 (1%)         |
+-----------------------------------+-----------------+----------------+
| Phlebitis, superficial            | 0 (0)           | 1 (1%)         |
+-----------------------------------+-----------------+----------------+
|                                   |                 |                |
+-----------------------------------+-----------------+----------------+
| **Platelet, bleeding, and         | 7 (6%)          | 5 (5%)         |
| clotting**                        |                 |                |
+-----------------------------------+-----------------+----------------+
| Thrombosis                        | 3 (3%)          | 2 (2%)         |
+-----------------------------------+-----------------+----------------+
| Pulmonary embolism                | 2 (2%)          | 2 (2%)         |
+-----------------------------------+-----------------+----------------+
| Thrombosis venous arm             | 2 (2%)          | 1 (1%)         |
+-----------------------------------+-----------------+----------------+
| Thromboembolism                   | 0 (0)           | 1 (1%)         |
+-----------------------------------+-----------------+----------------+
|                                   |                 |                |
+-----------------------------------+-----------------+----------------+
| **Myo-, endo-, pericardial- and   | 1 (1%)          | 2 (2%)         |
| valve**                           |                 |                |
+-----------------------------------+-----------------+----------------+
| Myocardial infarction             | 0 (**2)**       | 2 (2%)         |
+-----------------------------------+-----------------+----------------+
| Angina                            | 1 (1%)          | 0 (0)          |
+-----------------------------------+-----------------+----------------+
|                                   |                 |                |
+-----------------------------------+-----------------+----------------+
| **Heart rate and rhythm**         | 0 (0)           | 1 (1%)         |
+-----------------------------------+-----------------+----------------+
| Cardiac arrest                    | 0 (0)           | 1(1%)          |
+-----------------------------------+-----------------+----------------+

### Survival[^53]

A total of 201 of the 224 subjects enrolled in this study died at some
time during the study treatment period or 3 year follow-up. The overall
mortality rate in the Procrit arm (100 of 109 subjects, 92%) was similar
to that in the placebo arm (101 of 115 subjects, 88%). The median
duration of survival (based on Kaplan Meier estimates) was 10.5 months
among Procrit-treated subjects compared with 20.4 months among
placebo-treated subjects.

**Summary of Survival Over Time in N93-004 (Intent-to-treat
Population)**

![](media/image9.png){width="5.716666666666667in" height="3.69375in"}

The FDA biostatistical reviewer confirmed the sponsor's survival
analysis, presented in the table below (Sponsor's Table 17)[^54]:

Sponsor's ITT Survival Analysis in Months^\*^

(Table 17)

  ---------- ---------- ---------- ---------- ---------- ---------- ----------
             PLACEBO                          PROCRIT               

             Estimate   95% CI                Estimate   95% CI     

  Quartile              Lower      Upper                 Lower      Upper

  75%        5.9        3.5        7.7        6.6        4.3        7.6

  Median     10.4       8.3        12.9       10.5       9.2        12.9

  25%        23.3       15.3       27.3       17.1       14.0       20.1
  ---------- ---------- ---------- ---------- ---------- ---------- ----------

^\*^ Note: To convert days to months, the sponsor used a divisor of 28
days rather than the more usual 30.437 days, which takes into account
leap year.

A total of 201 out of 224 subjects enrolled in this study died at some
time during the study treatment period or during the 3-year follow-up. A
somewhat higher proportion of subjects assigned to the Procrit arm had
extensive stage disease at diagnosis (66%) compared to the placebo arm
(59%). Since stage of disease (limited vs. extensive) was a
stratification factor, the FDA statistical reviewer examined the
descriptive stratified Kaplan-Meier analysis provided by the sponsor.
Kaplan-Meier survival plots were comparable in the Procrit and placebo
arms through Months 17 to 18 after study start. As for the overall ITT
population, the variability after study completion along with the small
number of subjects in the two extent of disease subgroups does not
permit any conclusive statement to be made.

### Tumor Outcomes

Response duration was not calculated. No data were provided for date of
tumor response.

Time to disease progression (TTP) could not be accurately calculated. In
Protocol N93-004 subjects were allowed to withdraw early for progressive
disease. In these cases, the date of discontinuation was captured and
not the actual date of progression. For the 25 subjects who were
discontinued from the study for disease progression, the progression
date was on or before the date of discontinuation."

# Clinical Studies of Weekly Dosage Schedules of Epogen/Procrit for Treatment of Anemia Associated with Cancer Chemotherapy

The recommended starting dose of Epogen/Procrit in cancer patients
receiving chemotherapy in the package insert is 150 Units/kg t.i.w.
However, many community oncologists administer Epogen/Procrit at a dose
of 40,000 Units once a week. FDA is currently reviewing the results of a
study[^55], in which 344 patients with cancer receiving chemotherapy
were randomized to receive either placebo or Epogen/Procrit 40,000
U/week. The patient population consists of anemic patients with a
variety of malignancies, who were receiving standard therapy. Given the
heterogeneity of the population and cancer treatments, no comparative
assessments are possible regarding tumor outcomes (response rates,
time-to-progression) or survival. Analyses of adverse events, including
incidence of thrombotic vascular events is in progress.

# Clinical Studies of Aranesp in the Treatment of the Anemia of Cancer Chemotherapy

Aranesp (darbepoetin alfa) received supplemental approval "for the
treatment of anemia in patients with non-myeloid malignancies where
anemia is due to the effect of concomitantly administered chemotherapy"
in July 2002.[^56]

The data supporting this supplemental indication was based on the
results of Protocol 980297: A Double-blind, Placebo-Controlled,
Randomized, Study of NESP for the Treatment of Anemia in Lung Cancer
Receiving Multicycle Platinum Containing Chemotherapy. This was a
multicenter, multinational study in which 320 patients were enrolled and
randomized 1:1 to receive either Aranesp 2.25 μg/kg QW (treatment arm)
or placebo. Eligibility criteria included lung cancer (either small cell
carcinoma or non-small cell carcinoma) a cancer treatment plan of at
least 12 additional weeks of platinum-containing chemotherapy, and
anemia (hemoglobin ≤ 11 g/dl). The primary endpoint was the estimated
Kaplan-Meier proportion of subjects who received RBC transfusions
between week 5 and the end of the treatment phase (EOTP). Week 5 was
specified since hematologic responses to Aranesp are not observed until
3-6 weeks after the initiation of therapy.

## Efficacy Results

The primary efficacy analysis was conducted in patients who had
completed the first 4 weeks of study. In this analysis, patients who
withdrew or discontinued from the study after week 4 for death or
disease progression were censored, while those who withdrew for any
other reason were imputed to be transfused (treatment failures for
primary endpoint).[^57] The Kaplan-Meier proportion of patients
transfused was 51% for the patients in the placebo arm versus 21% in the
Aranesp arm. The same analysis was also performed in the intent-to-treat
dataset, which included patient information across all 12 weeks on. The
comparable figures were 60% for the Kaplan-Meier proportion of
transfused patients in the placebo arm versus 26% in the Aranesp arm.

Proportion of Patients Transfused in Weeks 5 through End-of-Treatment

In Protocol 980297

+---------------------------+----------------------+-------------------+
|                           | Placebo arm          | Aranesp arm       |
|                           |                      |                   |
|                           | N=149                | N=148             |
+---------------------------+----------------------+-------------------+
| Number of patients        | 74                   | 39                |
| transfused                |                      |                   |
+---------------------------+----------------------+-------------------+
| Kaplan-Meier estimated    | 51%                  | 21%               |
| proportion                |                      |                   |
+---------------------------+----------------------+-------------------+
| 95% CI                    | 43, 60               | 15, 28            |
+---------------------------+----------------------+-------------------+

Secondary analysis

Proportion of Patients Transfused Between Entry and End-of-Treatment

In Protocol 980297

+-----------------------+-----------------------+-----------------------+
|                       | Placebo arm           | Aranesp arm           |
|                       |                       |                       |
|                       | N=158                 | N=156                 |
+-----------------------+-----------------------+-----------------------+
| Number of patients    | 89                    | 53                    |
| transfused            |                       |                       |
+-----------------------+-----------------------+-----------------------+
| Kaplan-Meier          | 60%                   | 26%                   |
| proportion            |                       |                       |
+-----------------------+-----------------------+-----------------------+
| 95% CI                | 52, 68                | 20, 33                |
+-----------------------+-----------------------+-----------------------+

## Safety analyses

There were 314 protocol 980297 patients who received study drug; 156
were randomized to Aranesp and 158 to placebo. A single patient
randomized to the Aranesp arm failed to receive the study drug. In the
efficacy analyses, he remained in the Aranesp arm to which he had been
randomized but for Safety studies he was switched to the placebo arm.
Thus safety data are provided for 155 Aranesp-treated patients and 159
placebo-treated patients.

### Time to Progression

In the long-term follow-up to the pivotal, phase 3 study (NESP 980297),
the median observation period was 12 months for disease progression and
11 months for survival. Long-term follow-up analyses were based on the
subjects included in the safety analysis set of Aranesp disease
progression. All 314 subjects in the safety analysis set are included in
the analysis of disease progression, death, and disease progression or
death.

Ninety-four subjects (61% of the safety analysis set) in the Aranesp
group and

110 subjects (69%) in the placebo group had disease progression either
during NESP

980297 or during the long-term follow-up period evaluated. The hazards
ratio for disease progression comparing the Aranesp group to the placebo
group was 0.70 (95% CI: 0.53, 0.92) based on the Cox-proportional
hazards model that includes only treatment group as an independent
variable and was 0.71 (95% CI: 0.54, 0.94) after adjusting for tumor
type and region. Figure 1 shows the Kaplan-Meier curve for time to
disease progression by treatment group for subjects in the safety
analysis set. The median time to disease progression in the NESP group
was 29 weeks compared with 22 weeks in the placebo group."[^58]

![](media/image10.png){width="5.739583333333333in" height="3.65625in"}

### Survival

"Sixty-six subjects (43%) in the NESP group and 78 subjects (49%) in the
placebo group

died within 30 days of the last dose of study drug or during the
long-term follow-up period evaluated. The hazards ratio was calculated
as 0.80 (95% CI: 0.58, 1.11) based on the Cox-proportional hazards model
that includes only treatment group as an independent variable and after
adjusting for the effects of tumor type and region. Figure 2 shows the
Kaplan-Meier curve for time to death by treatment group for subjects in
the safety analysis set. The median time to death in the NESP group was
43 weeks compared with 35 weeks in the placebo group."[^59]

![](media/image11.png){width="5.8125in" height="3.6770833333333335in"}

### Progression-free Survival

"One hundred five subjects (68%) in the NESP group and 120 subjects
(75%) in the placebo group had disease progression or died within 30
days of the last dose of study drug or during the long-term follow-up
period evaluated. The hazards ratio was calculated as 0.73 (95% CI:
0.56, 0.95) based on the Cox-proportional hazards model that includes
only treatment group as an independent variable and was 0.74

(95% CI: 0.57, 0.97) when adjusted for tumor type and region. This
indicates that, on average, subjects in the placebo group had a 35%
higher odds of either disease progression or death (i.e., 1 / 0.74) as
compared with subjects in the NESP group."

"The Kaplan-Meier plot of time to either disease progression or death
for all subjects in the safety analysis set by treatment group is shown
in Figure 3. The Kaplan-Meier plot is very similar to that for time to
disease progression, with an apparent prolonged time to either disease
progression or death observed in the NESP group compared with the

placebo group. The median time to disease progression or death was 26
weeks for the

NESP group and 20 weeks for the placebo group."[^60]

![](media/image12.png){width="5.447916666666667in"
height="3.7083333333333335in"}

[Exploratory Analyses of Relationships between Rate of Rise of
Hemoglobin and Cardiovascular/Thrombotic Events in the Aranesp
Integrated Summary of Safety (ISS)]{.underline}

The ISS consisted of 873 patients from 6 major studies who received
Aranesp, 115 patients who received Epogen/Procrit in the active-control
arms, and 221 patients who received placebo. All patients also received
concomitant chemotherapy. The mean observation period for the majority
of subjects was 12 weeks on treatment plus 4 succeeding weeks off
treatment.

######### INCIDENCE OF AEs ASSOCIATED WITH EPOETIN ALFA

+-----------------+---------+-------+-----------+--------+-----------+
|                 | ISS     |       |           | Pr     |           |
|                 |         |       |           | otocol |           |
|                 |         |       |           | 980297 |           |
+-----------------+---------+-------+-----------+--------+-----------+
|                 | Aranesp | Pl    | Procrit   | A      | Placebo   |
|                 |         | acebo |           | ranesp |           |
+-----------------+---------+-------+-----------+--------+-----------+
|                 | n=862   | n=217 | n=113     | n=155  | 159       |
+-----------------+---------+-------+-----------+--------+-----------+
| #######         | 3.7%    | 3.2%  | 2%        | 9 (6%) | 6 (4%)    |
| # Hypertension+ |         |       |           |        |           |
+-----------------+---------+-------+-----------+--------+-----------+
| Convulsions\*\* | 0.6%    | 0.5%  | 1%        | 0      | 1 (1%)    |
+-----------------+---------+-------+-----------+--------+-----------+
| Thrombotic      | 6.2%    | 4.1%  | 1%        | 7 (5%) | 5(3%)     |
| events\$        |         |       |           |        |           |
+-----------------+---------+-------+-----------+--------+-----------+

> **+** Hypertension included preferred terms Hypertension and
> Hypertension aggravated
>
> \*\*Convulsions included the Preferred terms Convulsions, Convulsions
> Grand Mal and Convulsions Local
>
> \$ Thrombosis includes Preferred terms Thromboembolism,
> Thrombophlebitis Deep, Thrombosis, Thrombosis Venous, Thrombosis
> Venous Deep, and Pulmonary Embolism

When the incidence for all of the Preferred Terms are combined there was
no major difference in the incidence of thrombotic events between study
arms. This was attributable to the large variety of types of venous
adverse events. Notably, pulmonary emboli and related thromboembolism
were restricted entirely to the Aranesp subjects. There was also a trend
toward higher incidences of thrombophlebitis thrombophlebitis deep, and
thrombosis in Aranesp-treated patients. The incidences of adverse event
by specific preferred terms across the treatment groups in the ISS are
displayed in the following table.

**Incidence of Thrombotic Events By Preferred Term**

#   {#section-5 .nor}

  ---------------------------- ------------- ------------- ---------------
  **Preferred term**           **rHuEPO**    **Aranesp**   **Placebo**

                               **N= 115**    **N=873**     **N=221**

  Embolism, pulmonary          0             11            0

  Thromboembolism              0             1             0

  Thrombophlebitis             0             4             0

  Thrombophlebitis , deep      0             2             1

  Thrombosis, venous           1             8             2

  Thrombosis, venous deep      3             27            6

  Thrombosis                   0             5             0

  Total \# AEs                 4 (4.7%)      58 (7.4%)     9 (4.1%)

  Total pts with AEs           85            781           221
  ---------------------------- ------------- ------------- ---------------

The FDA requested that Amgen provide an analysis exploring the
correlations between rate of rise of hemoglobin (ROR) and the following:
death, hypertension, cerebrovascular events (seizures, TIAs, "strokes"),
cardiovascular events (myocardial infarction, CAD, arrhythmia, angina,
CHF, cardiac failure, cardiac arrest), thrombotic events, ischemic and
peripheral vascular disease and pulmonary edema. For comparison, the
results of a similar analysis using Aranesp-treated patients enrolled in
Amgen-sponsored studies for treatment of chronic renal failure were also
provided. .

**Adverse event/week per 1000 events**[^61] **as a function of Rate of
Rise of Hgb**

+---------------+------+---------+-------+-------+---------+--------+
| Adverse Event | Pati |         |       | Pat   |         |        |
| Term          | ents |         |       | ients |         |        |
|               | with |         |       | with  |         |        |
|               | CRF  |         |       | C     |         |        |
|               |      |         |       | ancer |         |        |
|               | N=   |         |       |       |         |        |
|               | 1598 |         |       | N=873 |         |        |
+---------------+------+---------+-------+-------+---------+--------+
|               | Rate |         |       | Rate  |         |        |
|               | of   |         |       | of    |         |        |
|               | rise |         |       | rise  |         |        |
|               | in   |         |       | in    |         |        |
|               | hgb/ |         |       | hgb   |         |        |
|               | week |         |       | /week |         |        |
+---------------+------+---------+-------+-------+---------+--------+
|               | \<   | 0.5 to  | 1.0   | \<    | 0.5 to  | 0.67   |
|               | 0.1  | 1.0     | or \> | 0.1   | 0.67    | or \>  |
+---------------+------+---------+-------+-------+---------+--------+
| Hypertension  | 7.5  | 19.9    | 13.1  | 2.1   | 1.8     | 5.2    |
+---------------+------+---------+-------+-------+---------+--------+
| Seizures      | 0.4  | 1.0     | 1.9   | 1.1   | 0       | 1.3    |
+---------------+------+---------+-------+-------+---------+--------+
| Vascular\*    | 1.7  | 3.8     | 7.5   | 1.1   | 7.1     | 3.9    |
+---------------+------+---------+-------+-------+---------+--------+
| Fluid         | 15.4 | 18.9    | 35.4  | 25.6  | 26.5    | 29.5   |
| overload      |      |         |       |       |         |        |
+---------------+------+---------+-------+-------+---------+--------+
| Cardiac       | 0.0  | 1.0     | 1.9   | 0     | 0       | 0      |
| arrest        |      |         |       |       |         |        |
+---------------+------+---------+-------+-------+---------+--------+
| Myocardial    | 0.4  | 0.3     | 1.9   | 0     | 0       | 0      |
| infarction,   |      |         |       |       |         |        |
| acute         |      |         |       |       |         |        |
+---------------+------+---------+-------+-------+---------+--------+
| Pulmonary     | 1.5  | 3.1     | 7.5   | 0     | 0       | 0      |
| edema         |      |         |       |       |         |        |
+---------------+------+---------+-------+-------+---------+--------+

\*thrombosis, ischemia, infarction

The analysis provided suggests that the incidences of hypertension and
vascular events are increased in patients with higher ROR compared to
those who had less rapid ROR. [^62]

The ISS database was also used to examine for a possible relationship
between the hemoglobin value at the time of an event and the incidence
of specific adverse events, possibly or probably associated with
Aranesp. The FDA reviewer concluded that: "The major events of interest
were death, hypertension, cardiac events, cerebrovascular events, and
thrombotic events. There did not appear to be a relationship between
increasing hemoglobin concentration and increased risk of adverse event
across any the adverse event groups evaluated. Death (n=18) was the only
event group in which the highest event rates for Aranesp and Procrit
were in the category representing the highest hemoglobin increase (\>
0.667 g/dl/week hemoglobin slope). Of these 18 subjects, 12 received
Aranesp, 4 received placebo, and 2 received Procrit. The death rate was
13.6 per 1000 subject weeks and 7.8 per 1000 subject weeks for the
Procrit and Aranesp groups, respectively. Of the 18 subjects how died in
this slope category, 13 died of disease progression, 3 died of sepsis,
and 2 died of clinically suspected but not objectively confirmed
pulmonary embolisms."[^63]

##### Incidence of Selected Adverse Events Occurring

**Within 14 days of Rapid Rise of Hgb**[^64]

+------------------------------------+----------+--------+------------+
|                                    | Placebo  | P      | Aranesp    |
|                                    |          | rocrit |            |
|                                    | n=221    |        | N=873      |
|                                    |          | N=115  |            |
+------------------------------------+----------+--------+------------+
| Number of patients with            | 5 (2.2%) | 0      | 12 (1.3%)  |
| hypertension (%)                   |          |        |            |
+------------------------------------+----------+--------+------------+
| Number of patients with            | 0        | 0      | 2 (0.2%)   |
| Convulsions (%)                    |          |        |            |
+------------------------------------+----------+--------+------------+
| Number of Patients with Thrombosis | 5 (2.2%) | 2      | 14 (1.6%)  |
| (%)                                |          | (1.7%) |            |
+------------------------------------+----------+--------+------------+

Because the combined term "thrombosis" included a small number of
specific thrombotic events that were clearly increased in the
Aranesp-treated group (notably pulmonary emboli), an assessment was made
of the clinical course of these subjects. The displayed in the following
table summarizes the dose, schedule, and clinical treatment course of
patients who suffered pulmonary emboli.

**Assessment of ROR and Maximum Hemoglobin Levels in Relationship to the
Development and Time of Onset of Pulmonary Emboli in Aranesp-Treated
Patients**

+----------+---------+-------+-------+-------+-------+--------+------+
| Pul      | Dose    | Dose  | Week  | Rapid | Week  | Max.   | Max. |
| m.emboli | s       | ug/kg | of AE | ROR   | rapid | incr.  | hgb  |
|          | chedule |       |       |       |       | Hgb    |      |
| Subject  |         |       |       |       | ROR   |        | u    |
|          | Aranesp |       |       |       |       | ug/dL  | g/dL |
+----------+---------+-------+-------+-------+-------+--------+------+
| 10101144 | QW      | 4.5   | 4     | Yes   | 4     | 3.1    | 13.7 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 10116003 | QW      | 1.0   | 3     | No    | \-    | 2.8    | 13.9 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 12003012 | Q3W     | 12.0  | 3     | No    | \-    | 6.5    | 15.5 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 12502021 | Q3W     | 9.0   | 1     | Yes   | 11    | 4.4    | 14.2 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 12506009 | Q3W     | 9.0   | 1     | Yes   | 1     | 0.7    | 11.3 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 12609001 | Q3W     | 4.5   | 11    | Yes   | 17    | 4.5    | 12.6 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 12610013 | Q3W     | 9.0   | 3     | Yes   | 23    | 1.6    | 12.9 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 13035204 | OW      | 2.25  | 16    | Yes   | 10 on | 6.3    | 14.3 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 13044102 | OW      | 2.25  | \*    | Yes   | 5 & 6 | 3.7    | 13.0 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 11109009 | OW      | 2.25  | 9     | Na    | \*    | 0.7    | 10.0 |
+----------+---------+-------+-------+-------+-------+--------+------+
| 16049012 | OW      | 2.25  | 5     | Yes   | 5     | 2.9    | 12.0 |
+----------+---------+-------+-------+-------+-------+--------+------+

The protocol permitted maximum hemoglobin thresholds of 14.0 g/dl for
women and 15.0 g/dl for men. An analysis was performed in which the
number and percentage of adverse events occurred in each study
population in patients who exceeded the maximum hemoglobin threshold, if
the event happened within 14 days of the time the threshold was
exceeded.

**Adverse event By Treatment Assignment in Patients Exceeding**

**Maximum Hgb Threshold**[^65]

+------------------------+----------------+------------+--------------+
|                        | ##             | *          | **Aranesp**  |
|                        | ## **Placebo** | *Procrit** |              |
|                        |                |            | **N=873**    |
|                        | **N=221**      | **N=115**  |              |
+------------------------+----------------+------------+--------------+
| Number patients        | 4/221 (2%)     | 15/115     | 114/873      |
| exceeding maximum      |                | (14%)      | (13%)        |
| threshold (%)          |                |            |              |
+------------------------+----------------+------------+--------------+
| Number patients with   | 0              | 0          | 4            |
| hypertension within 14 |                |            |              |
| days                   |                |            |              |
+------------------------+----------------+------------+--------------+
| Number Pts with        | 0              | 0          | 0            |
| convulsions within 14  |                |            |              |
| days                   |                |            |              |
+------------------------+----------------+------------+--------------+
| Number Pts with        | 1              | 0          | 3            |
| Thrombosis within 14   |                |            |              |
| days                   |                |            |              |
+------------------------+----------------+------------+--------------+

**Incidence of Specific Adverse events in Patients Exceeding Maximum
hemoglobin Threshold Regardless of Study Arm and Regardless of Time of
Occurrence**[^66]

+---------------------------+--------------------+---------------------+
| **Adverse Event Term**    | **Maximum          | **Maximum threshold |
|                           | threshold**        | reached**           |
|                           |                    |                     |
|                           | **not reached**    | **(n=134)**         |
|                           |                    |                     |
|                           | **(n=1074)**       |                     |
+---------------------------+--------------------+---------------------+
| Hypertension              | 33 (3%)            | 8 (6%)              |
+---------------------------+--------------------+---------------------+
| Arrhythmia                | 85 (8%)            | 7 (5%)              |
+---------------------------+--------------------+---------------------+
| Coronary artery disease   | 18 (2%)            | 3 (2%)              |
+---------------------------+--------------------+---------------------+
| CHF                       | 22 (2%)            | 2 (1%)              |
+---------------------------+--------------------+---------------------+
| CVA                       | 9 (1%)             | 1 (1%)              |
+---------------------------+--------------------+---------------------+
| Cardiac arrest            | 2 (\<1%)           | 0                   |
+---------------------------+--------------------+---------------------+
| Fluid overload            | 388 (36%)          | 42 (31%)            |
+---------------------------+--------------------+---------------------+
| Myocardial infarction     | 5 (\<1%)           | 0                   |
+---------------------------+--------------------+---------------------+
| Seizures                  | 5 (\<1%)           | 1 (1%)              |
+---------------------------+--------------------+---------------------+
| Vascular thrombosis &     | 67 (6%)            | 5 (4%)              |
| ischemia/infarction       |                    |                     |
+---------------------------+--------------------+---------------------+

-   The FDA reviewer concluded: "No major disparities are noted. It is
    noted that hypertension was higher in the Aranesp population."[^67]

In these exploratory analyses, there was no clear association between
risk of cardiovascular or thrombotic adverse events and either maximum
hemoglobin levels achieved or the rapidity of the rate of rise in
hemoglobin.

# Study EPO-INT-76: The Breast Cancer Erythropoietin Trial (BEST) 

The Breast Cancer Erythropoietin Trial (BEST), designed by Johnson &
Johnson, was conducted to extend and possibly confirm the results of an
earlier trial (Study EPO-INT-10) EPO-INT-10[^68] was a randomized,
placebo-controlled trial that had enrolled 375 subjects. The patients
had either solid or non-myeloid hematologic malignancies and hemoglobin
levels of either ≤ 10.5 g/dl or between 10.5 and 12.0 g/dl after a
hemoglobin decrease of at least 1.5 g/dl per cycle since starting
chemotherapy. Patients received study drug for 12 to 24 weeks. No
specific target hemoglobin was given, however, the dose of EPREX was to
be held if the hemoglobin was greater than 15 g/dl, and restarted at 12
g/dl. The trial was not powered for survival, but there was a trend in
overall survival favoring the EPREX arm (log rank test p=0.13; Cox
regression analysis hazards ratio of 1.309 (p=0.052)). At 12 months, the
Kaplan-Meier estimate of survival was 60% for the EPREX arm and 49% for
the placebo arm. The median survival times were 17 months with EPREX and
11 months with placebo. An additional basis for initiation of EPO-INT-76
was the supposition that use of an erythropoietin to increase hemoglobin
levels might improve survival given the literature suggesting a link
between low hemoglobin levels (as a marker for tumor hypoxia), poorer
response to treatment (both radiation and chemotherapy), and worsening
survival.[^69]

Study EPO-INT-76 was designed to test the hypothesis that maintaining
hemoglobin in the range of 12 to 14 g/dl via the administration of EPREX
would improve survival and quality of life in patients with metastatic
breast cancer receiving chemotherapy. The study was conducted at 139
sites in 20 countries (Western and Eastern Europe, Canada, Australia,
South Africa). Eligible patients were women with breast cancer who were
receiving first-line chemotherapy for metastatic disease. Randomization
was stratified by the following three variables: disease restricted to
the skeleton; extraskeletal measurable disease, extraskeletal
nonmeasurable disease.

Subjects were randomly assigned to receive either 40,000 IU EPREX or
placebo subcutaneously QW. Study drug was administered once a week to
maintain hemoglobin in the range of 12 to 14 g/dl for 12 months. The
choice of chemotherapy or hormonal therapy was left to the discretion of
the investigator. Study drug was to be initiated only when the
hemoglobin was 13 g/dl or lower. The study drug was withheld if the
hemoglobin rose above 14 g/dl.[^70]

The primary endpoint was survival at 12 months after randomization.
Secondary endpoints included assessment of hematologic effects, tumor
response rates to chemotherapy, time to progression, transfusion
requirements, and quality of life determinations.

The planned enrollment was 870 (435/treatment group). A total of 939
subjects (470 on placebo and 469 on EPREX) were enrolled and analyzed in
the intent-to-treat (all randomized) population. The sample size was
based on the assumption of 70% survival in the placebo arm and 80% in
the EPREX arm at the end of the 12-month double-blind treatment phase.
This assumption took into consideration an estimate that 25% of the
study population comprised subjects who had bone only metastases. The
primary statistical objective was to detect a minimum absolute 10%
improvement (i.e., 80% survival). A 100% follow-up was anticipated with
respect to 12-month survival status. Based on these assumptions and a
2-sided significant level of 0.05, a planned total of 870 subjects
(435/arm) yielded greater than 90% power for testing the null hypothesis
of an equal 12-month survival rate between the two treatment arms.

## Efficacy and Safety Results

939 patients were enrolled. The study was initiated in June 2000, and
the last subject was enrolled in June 2001. In January 2002, an
Independent Data Monitoring Committee was established at the request of
the Ethics Committees of Germany and the United Kingdom. In April 2002,
the IDMC reviewed the available data from 938 subjects. The Committee
expressed concern over an unexpected excess mortality observed in the
EPREX -treated arm. At the time of this interim analysis, there were 179
deaths, 101 in the EPREX- treated arm and 78 in the placebo arm. On
April 24, 2002, the IDMC asked Johnson & Johnson to discontinue
administration of the study drug to all participating subjects. The J&J
also commissioned an outside consulting firm to conduct a medical chart
review, in which the primary documents were reviewed in a blinded manner
in an attempt to "collect additional information concerning factors of
prognostic significance for breast cancer and potentially fatal medical
conditions". This latter review was conducted in August 2002. The
results in the tables below contain data from the "Clinical Trial
Database" which was derived from the Case Report Forms (CRFs) submitted
by the investigators at each site; and the "Medical Chart Review
Database" that was based on a chart review by an outside consulting
firm.

The results of the unplanned interim analysis of this study are as
follows:

-   The Kaplan-Meier estimates for 12-month survival in the
    intent-to-treat population was shorter in the EPREX arm (70%)
    compared with the placebo arm (76%). This difference was
    statistically significant (p=0.0117, relative risk=1.359).

```{=html}
<!-- -->
```
-   At 4 months after randomization, there was different evidence of
    increased early in mortality in patients randomized to EPREX; among
    57 subjects who died within the first 4 months, 41 (72%) were in the
    EPREX arm and 16 (28%) were in the placebo arm.

-   Twice as many patients in EPREX arm experienced disease progression
    as in the placebo arm: 28 (6%) versus 13 (3%).

-   There was also an increased incidence to thrombotic vascular and
    cardiovascular adverse events: 2.3% in the EPREX arm versus 0.4% in
    the placebo arm.

-   The overall response rate (complete and partial responses) was 46%
    in the placebo arm and 45% in the EPREX arm.

-   Patients in the EPREX arm received study drug for an average of 30.4
    weeks versus 36.9 weeks for the placebo arms.

-   In the EPREX arm, 59% of hemoglobin determinations were within the
    target range (12-14 g/dl). In the placebo arm, this value was
    45%.[^71] Of note, the median baseline hemoglobin was 12.8 g/dl in
    both arms.

**Causes of Death Among Subjects Who Died Within the First 4 Months
After Randomization (Study EPO-INT-76: Intent-to-treat Population)**

**Data Source: Clinical Trial Database**[^72]

+-------------------------------+------------------+-------------------+
|                               | **Placebo**      | **EPREX (N=469)** |
|                               |                  |                   |
|                               | **(N=470)**      |                   |
+-------------------------------+------------------+-------------------+
| No. (%) died within 4 months  | 16 (3)           | 41 (9)            |
+-------------------------------+------------------+-------------------+
| No. (%) alive at 4 months     | 454 (97)         | 428 (91)          |
+-------------------------------+------------------+-------------------+
| Cause of death within 4       |                  |                   |
| months, no. (%)               |                  |                   |
+-------------------------------+------------------+-------------------+
| Chemotherapy toxicity         | 1 (0)            | 3 (1)             |
+-------------------------------+------------------+-------------------+
| Disease progression           | 13 (3)           | 28 (6)            |
+-------------------------------+------------------+-------------------+
| Missing                       | 0                | 1 (0)[^73]        |
+-------------------------------+------------------+-------------------+
| Thrombotic vascular event     | 1 (0)            | 5 (1)             |
+-------------------------------+------------------+-------------------+
| Other[^74]                    | 1 (0)            | 4 (1)             |
+-------------------------------+------------------+-------------------+

**Cardiovascular/Thrombotic/Vascular Deaths**

**(Study EPO-INT-76: All Randomized Subjects)**

**Data Source: Medical Chart Review Database**

+------------------------------------------------+---------+-----------+
|                                                | Placebo | EPREX     |
|                                                |         |           |
|                                                | (n=468) | (n=469)   |
+------------------------------------------------+---------+-----------+
|                                                | N (%)   | N (%)     |
+------------------------------------------------+---------+-----------+
| Cardiovascular/TVE death in the first 4 months | 2       | 11 (2.3%) |
|                                                | (0.4%)  |           |
| after study randomization                      |         |           |
+------------------------------------------------+---------+-----------+
| Cardiovascular/TVE death more than 4 months    | 7       | 3 (0.6%)  |
|                                                | (1.5%)  |           |
| after study randomized                         |         |           |
+------------------------------------------------+---------+-----------+
| Total                                          | 9       | 14 (3.0%) |
|                                                | (1.9%)  |           |
+------------------------------------------------+---------+-----------+

**Causes of Death in Subjects Dying During the 4 Months After Study
Randomization**

**(Study EPO-INT-76: All Randomized Subjects)**

**Data Source: Medical Chart Review Database**

+------------------------------+-------------------+-------------------+
|                              | Placebo           | EPREX             |
|                              |                   |                   |
|                              | N=468             | N=469             |
+------------------------------+-------------------+-------------------+
|                              | N (%)             | N                 |
+------------------------------+-------------------+-------------------+
| Disease Progression          | 10 (2%)           | 21 (4%)           |
+------------------------------+-------------------+-------------------+
| Adverse event^a^             | 1 (\<1%)          | 10 (2%)           |
+------------------------------+-------------------+-------------------+
| Other^b^                     | 5 (1%)            | 10 (2%)           |
+------------------------------+-------------------+-------------------+
| Total                        | 16 (3%)           | 41 (9%)           |
+------------------------------+-------------------+-------------------+

^a^ [placebo]{.underline}: 1 sepsis; [epoetin alfa]{.underline}: 7
sudden death/cardiac/TVE, 1 hepatotoxicity/heart failure, 1 unknown, 1
multiorgan failure.

^b^ [placebo]{.underline}: 1 fatty embolism, 2 cardiac/TVE, 1 unknown, 1
pneumonia; [epoetin alfa]{.underline}: 4 sudden death/cardiac/TVE; 1
pancytopenia, 3 unknown, 1 pneumonia, 1 hepatorenal syndrome.

[Survival]{.underline}

**Primary Efficacy Variable: 12-Month Survival Rate** [^75]

+-----------------+-----------------+-----------------+-----------------+
|                 | Placebo         | EPREX           | Hazard ratio    |
|                 |                 |                 | (95% CI) p      |
|                 |                 |                 | value^a^        |
+-----------------+-----------------+-----------------+-----------------+
| []{#__RefHeadin | N=470           | N=469           | 1.37            |
| g___Toc68932074 |                 |                 | (1.37,1.74)     |
| .anchor}        |                 |                 |                 |
| Intent-to-treat |                 |                 | 0.0117          |
+-----------------+-----------------+-----------------+-----------------+
| Died^b^         | 115 (24%)       | 148 (30%)       |                 |
+-----------------+-----------------+-----------------+-----------------+
| Survived^b^     | 355 (76%)       | 321 (70%)       |                 |
+-----------------+-----------------+-----------------+-----------------+
|                 |                 |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Efficacy**^c^** | N=456           | N=448           |                 |
+-----------------+-----------------+-----------------+-----------------+
| Died^b^         | 109(23%)        | 137 (29%)       | 1.35            |
|                 |                 |                 | (1.05,1.74)     |
|                 |                 |                 |                 |
|                 |                 |                 | 0.0189          |
+-----------------+-----------------+-----------------+-----------------+
| Survived^b^     | 347 (77%)       | 311 (71%)       |                 |
+-----------------+-----------------+-----------------+-----------------+

^a^ Based on Cox's model stratified by metastatic category

^b^ Percentage of subjects who survived or died within 12 (+ 2 week
window) of randomization are based on Kaplan-Meier estimates.

^c^ Efficacy population comprised only of subjects who received study
drug.

![](media/image13.wmf)

Figure 4: Kaplan-Meier Curves of Survival (August 2003[^76])

The results of this study have not been published. However, Dr.
Leyland-Jones, the principal investigator of the study, did publish an
article describing the results in [Lancet Oncology]{.underline}. He
criticized the design and conduct of the study: "the study was not
designed to prospectively collect data on many potential prognostic
survival factors that might have affected the study outcome." "The study
design suffered from a lack of standard assessment and documentation of
important prognostic factors for survival including: definition of
disease site; initial prognosis and specific assessment of tumor
response at predefined intervals; and type duration and dose of
chemotherapy". He stated "it is not currently possible to account for
the observed difference in survival by referral to differences in
prognostic indicators between treatment groups or to rule out the
possibility of an adverse treatment effect".

However, he concluded, "the study findings do not support the use of
erythropoietin as an adjunct to first-line chemotherapy for patients
with metastatic breast cancer who have normal hemoglobin
concentrations".

# The Henke Study 

Previous studies indicated that the results of radiotherapy for
malignant disease are less effective when anemia is present[^77]. Henke
et al conducted a study to test the hypothesis that correction of anemia
in subjects receiving radiation therapy for the treatment of head and
neck carcinoma could possibly improve tumor control.

In a study published in [The Lancet]{.underline} in October 2003, Henke
et al[^78] reported a double-blind, placebo controlled trial in subjects
with squamous cell carcinoma of the head and neck who were undergoing
treatment with radiation therapy, and were randomized to receive either
epoetin beta or placebo. Eligibility criteria included anemia (Hgb \<
12.0 g/dl for women and \< 13.0 g/dl for men), advanced stage disease
(T3, T4 or nodal involvement), and were scheduled to receive either
definitive treatment with radiotherapy or postoperative radiotherapy.

Patients were stratified according to tumor resection status: stratum 1:
postoperative radiation of complete (R0) resection; stratum 2:
postoperative radiation of incompletely resected disease, stratum 3:
primary definitive radiotherapy. Either placebo or epoetin beta (300
IU/kg) was administered subcutaneously three times a week. The study
drug was started 10 to 14 days before radiotherapy and was continued
throughout the radiation treatments. Study drug was discontinued when
the target hemoglobin exceeded 14.0 g/dl for women or 15.0 g/dl for men.

Patients were seen for first follow-up 6 weeks after the end of
radiotherapy, and thereafter every 3 months for assessment of
locoregional control and survival.

The primary endpoint was locoregional progression-free survival, defined
as the time to locoregional tumor progression or death, whichever
occurred first.[^79] The primary analysis was to be performed in the
intent-to-treat population. The study power was set at 80% to detect a
32% risk -reduction in locoregional progression-free survival at 220
events. The authors also included a "radiotherapy-correct population"
that consisted of patients who received radiation according to protocol
and presented on at least one follow-up visit; and a "per-protocol
population" that included all the radiotherapy-correct population except
those who received less than 80% of the scheduled studied medicine
administrations. (see Figure 5, below).

Three hundred and fifty one patients in 23 sites were enrolled.

Table 1. Baseline characterstics

![](media/image14.png){width="6.885416666666667in"
height="6.583333333333333in"}

AJCC=American Joint Cancer Committee. Values n (%) unless marked
otherwise.

![](media/image15.png){width="3.28125in" height="3.5in"}

Figure 5.

## Efficacy Results

The major findings in this study (Table 2 and Figure 6, below):

-   The stage-adjusted and stratum-adjusted relative risk for
    locoregional progression-free survival was 1.62 for epoetin beta
    (95% CI 1.22-2.14, P=0.0008) (table 2).

-   The corresponding Kaplan-Meier estimate showed a median locoregional
    progression-free survival of 745 days for placebo versus 406 days
    for epoetin beta (p=0.04, figure 2).

-   For locoregional progression the relative risk was 1.69 (95% CI
    1.16-2.47, P=0.007).

-   In the actuarial analysis, patients in the placebo arm had an
    estimated median survival of 928 days compared with an estimated
    median survival of 605 days in the epoetin beta arm (p=0.09).

-   The mean hemoglobin concentrations after 4 weeks of treatment were
    12.3 g/dl for the placebo arm and 14.8 g/dl for epoetin beta arm.

"In the intent-to-treat population, locoregional tumor progression
occurred in 49 placebo- and 65 epoetin beta-treated patients, with 122
and 115 censored observations, respectively. The adjusted relative risk
for locoregional progression was 1.69 (95% CI 1.16-2.47, p=0.007). The
univariate Kaplan-Meier estimate showed a difference in time to
progression favouring placebo (median not reached versus 280 days,
p-0.09). In the same population, 89 placebo and 109 epoetin beta
patients died (82 and 71 censored). The adjusted relative risk of death
was 1.39 for epoetin beta patients (95% CII 1.05-1.84, p=0.02). In the
actuarial analysis, patients treatment with placebo survived a median of
928 days compared with 605 days in the epoetin beta group
(p=0.09)."[^80]

Exploratory Analyses by Randomization Stratum:

"According to stratum, locoregional tumor progression or death occurred
in 41 placebo and 47 epoetin beta patients in radiotherapy stratum 1,
and the Kaplan-Meier estimate for locoregional progression-free survival
was 1152 and 1049 days, respectively, (p=0.9). By contrast, 16 placebo
and 30 epoetin beta patients in stratum 2 experienced locoregional
progression or died, and median locoregional progression-free survival
was 1791 and 377 days, respectively (p=0.001, Figure 2, below).
Similarly, in stratum 3, 35 Phase 1 and 39 epoetin beta patients had
locoregional tumor progression or died and the Kaplan-Meier analysis
showed a favourable outcome for placebo (207 versus 141 days, p=0.006,
Figure 2)." "Multivariate analysis, including treatment stratum, tumor
stage, baseline smoking, and relapse status, tumor site, hemoglobin
concentration, transferrin saturation, and days between start of drug
administration and radiotherapy supported the finding that epoetin beta
treatment is associated with unfavourable outcome (relative risk 1.26
\[95% CI 0.93-1.7\], p=0.13). "

Table 2. Effect of
epoetin-![](media/image16.png){width="0.10416666666666667in"
height="0.16666666666666666in"} treatment on study endpoints

![](media/image17.png){width="6.052083333333333in"
height="3.7395833333333335in"}

![](media/image18.png){width="5.996527777777778in"
height="4.409027777777778in"}

Figure 6: Probability of Locoregional Progression Free Survival

## Safety Findings

Vascular disorders (hypertension, hemorrhage, venous
thrombosis/pulmonary embolism, CVA) developed in 5% of the placebo group
and in 11% of the epoetin beta arm.

The numbers of patients who died from "cardiac disorders" also differed:
five placebo-treated patients as compared to ten epoetin beta-treated
patients.

## Conclusions

In his discussion Henke called the poorer progression-free survival in
the epoetin treated patients an "unexpected finding". In Letters to the
Editor in *The Lancet* ^50-52^ this study has been criticized for
imbalance in the groups: there was a higher proportion of current
smokers and relapsed disease in the epoetin beta group. Information
concerning performance status and TNM staging was not provided.
Chemotherapy was not part of the treatment for incompletely resected or
stage IV patients. In addition the survival data in this study was lower
than comparable studies in head and neck cancer.[^81] The inclusion of
subjects with postoperative completely resected tumors was criticized,
since "assuming that erythropoietin was given to correct tumour hypoxia,
complete resection would mean that there was no hypoxic tumour left to
treat".[^82]

Henke responded to these criticisms[^83] by stating that chemotherapy
was not part of standardized treatment when the study was initiated. As
for the poor outcome of the patients in this study, "we deliberately
selected patients with low hemoglobin concentrations for whom the
outcome was dismal. The comparator studies cited . . . enrolled
non-anaemic patients with better prognoses." He disagreed with the
contention that patients irradiated after complete resection should not
have been studied: "Prognosis correlates particularly closely with
hemoglobin concentration in adjuvant radiotherapy".

He admitted to not assessing the performance status of all patients
"however it was evenly distributed between placebo and erythropoietin
patients in the largest recruiting center".

# Procrit Trials Halted by Johnson & Johnson For Excessive Thrombotic and Cardiovascular Adverse Events: 

On November 27, 2003, the [New York Times]{.underline} reported that
Johnson & Johnson had halted four clinical trials "because of unexpected
levels of blood clotting"[^84].

Ortho Biotech LP, through Amgen, has submitted the following details
concerning the studies that have been closed.[^85]

## Protocol EPO-CAN-15: "A randomized, double-blind placebo controlled study to evaluate the impact of maintaining haemoglobin levels using EPREX (Epoetin alfa) in limited disease small cell lung cancer (LD SCLC) patients receiving combined chemotherapy and radiation therapy." (The LEGACY Trial)

Objective: The objective of this study is to evaluate the impact of
maintaining Hgb in the range of 14 to 16 g/dl on disease
progression-free survival using EPREX (Epoetin alfa)/Procrit or placebo
in limited disease small cell lung cancer subjects receiving combined
modality chemoradiation therapy.

This double-blind, randomized, placebo-controlled multicenter trial that
was designed to enroll 620 limited disease SCLC subjects scheduled to
receive a platinum-based plus etoposide chemotherapy regimen plus
concurrent thoracic radiotherapy. Patients could receive between four
and six cycles of chemotherapy. Subjects were randomized in a 1:1 ratio
to either EPREX/Procrit 40,000 IU or matching placebo. Study drug was
administered once weekly by subcutaneous injection to maintain Hgb
levels between 14 and 16 g/dl for the duration of the given chemotherapy
plus concurrent radiation treatment and prophylactic cranial irradiation
(if given). Both groups received RBC transfusions if clinically
necessary. Subjects who met the entry criteria were randomized and study
drug was administered when the Hgb was ≤ 14 g/dl. Subjects completed all
follow-up assessments until disease progression (i.e. disease relapse)
was confirmed, or death occurred. Subsequent to confirmed disease
progression, subjects were followed for overall survival status.

The primary efficacy endpoint was duration of disease progression-free
survival. One interim analysis, was planned six months after
randomization of the 310^th^ subject.

Secondary efficacy endpoints were:

-   Tumor response to first line chemotherapy plus concurrent radiation
    treatment.

-   Median and overall survival.

-   Local disease progression.

-   Hgb over time (baseline to study completion).

-   Proportion of subjects receiving RBC transfusions.

-   Quality of life change scores between EPREX/Procrit and placebo
    groups.

[Meeting of the Data Safety Monitoring Board, October 1,
2003:]{.underline}

Johnson & Johnson requested that the IDMC review the safety data from
this study on Sept.12, 2003. J&J was notified Sept 19, 2003 by the IDMC
of an increased frequency of TVE's in the EPREX/Procrit arm as compared
to the placebo arm (12/53 versus 2/53, per IDMC). J&J suspended
enrollment on Sept. 29,2003. There were 106 patients on the trial as of
Sept. 29, 2003.

[Letter to Investigators, October 1, 2003.]{.underline} (from Cathy Lau,
Senior Director---Medical Affairs, Ortho Biotech and Richard K. Plante,
Project Manager---Medical Affairs, Ortho Biotech):

"The overall incidence of TVE's \[thrombovascular events\] in the
treatment group in these trials is higher than would be expected based
on prior controlled clinical trials.'

"Ortho Biotech is thus temporarily suspending enrollment in certain
company-sponsored investigational trials in patients with cancer treated
to hemoglobin levels \> 130 g/L, including the LEGACY trial, pending a
full analysis of this and other available data."

From: "Preliminary Analyses of Thrombotic Vascular Events in Oncology
Studies", submitted by Ortho through Amgen, Jan. 19, 2004.[^86]

"The study population was to include 620 subjects. A total of 106
subjects (53 placebo, 53 epoetin alfa t) were enrolled at the time the
study was suspended. Of these 106 patients, 3 (6%) placebo and 18 (34%)
epoetin alfa -treated subjects had a thrombotic vascular event reported.
After adjusting the bias for early termination of the study the odds
ratio (epoetin alfa versus control) was 7.74."

Safety Analyses

Incidence of Thrombotic Vascular Events to Date:

Odds Ratio and 95% Confidence Interval (Study EPO-CAN-15)

  ----------- ----------- --------------- ----------- ----------- -------------
  Placebo                 EPREX/Procrit               Odds ratio  

  N           TVE         N               TVE         Estimate    95% CI

  53          3 (6%)      53              18 (34%)    7.74        \[1.65,
                                                                  44.41\]
  ----------- ----------- --------------- ----------- ----------- -------------

##### Preliminary Listing of Subjects With Thrombotic/Vascular Events

**(Study EPO-CAN-15)**

+----------------+-----+------------------+----------+------+--------+
| Treatment      | Age | Preferred Term   | Rela     | Day  | Total  |
|                |     |                  | tionship | of   | Days   |
| Subject ID     |     |                  | to Study | O    | of     |
|                |     |                  | Drug     | nset | T      |
|                |     |                  |          |      | herapy |
+----------------+-----+------------------+----------+------+--------+
| Placebo        |     |                  |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1148           | 64  | TIA/mini stroke  | Doubtful | 28   | 26     |
+----------------+-----+------------------+----------+------+--------+
| 1217           | 54  | CVA (visceral    | Not      | 29   | 0      |
|                |     | arterial         | related  |      |        |
|                |     | ischemia)        |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1245           | 66  | Cardiac          | Not      | 29   | 28     |
|                |     | isc              | related  |      |        |
|                |     | hemia/infarction |          |      |        |
+----------------+-----+------------------+----------+------+--------+

**Preliminary Listing of Subjects With Thrombotic/Vascular Events**

**(Study EPO-CAN-15 -continued)**

+----------------+-----+------------------+----------+------+--------+
| Treatment      | Age | Preferred Term   | Rela     | Day  | Total  |
|                |     |                  | tionship | of   | Days   |
| Subject ID     |     |                  | to Study | O    | of     |
|                |     |                  | Drug     | nset | T      |
|                |     |                  |          |      | herapy |
+----------------+-----+------------------+----------+------+--------+
| EPREX/Procrit  |     |                  |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1052           | 42  | Hemorrhagic      | Doubtful | 8    | 7      |
|                |     | cerebral         |          |      |        |
|                |     | infarction and   |          |      |        |
|                |     | thrombosis       |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1112           | 63  | DVT              | Not      | 39   | 38     |
|                |     |                  | related  |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1129           | 56  | Acute arterial   | Not      | 15   | 13     |
|                |     | embolism         | related  |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1132           | 63  | Dyspnea, cardiac | Not      | 3    | 3      |
|                |     | arrest           | related  |      |        |
|                |     |                  | 3        |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1133           | 67  | DVT              | Possible | 16   | 7      |
+----------------+-----+------------------+----------+------+--------+
| 1140           | 70  | Cardiac          | Not      | 19   | 19     |
|                |     | ischemia, death  | related  |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1142           | 62  | Inferior         | Doubtful | 41   | 19     |
|                |     | myocardial       |          |      |        |
|                |     | infarction       |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 15             | 65  | Acute coronary   | Not      | 1    | 0      |
|                |     | syndrome         | related  |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1155           | 65  | Cardiac          | Doubtful | 49   | 48     |
|                |     | isc              |          |      |        |
|                |     | hemia/infarction |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1170           | 60  | Cereberovascular | Doubtful | 6    | 6      |
|                |     | ischemia         |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1174           | 47  | Peripheral       | Possible | 53   | 51     |
|                |     | arterial         |          |      |        |
|                |     | ischemia         |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1183           | 70  | Thrombosis       | Not      | 25   | 0      |
|                |     |                  | related  |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1194           | 67  | Myocardial       | Not      | 60   | 18     |
|                |     | infarction       | related  |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1195           | 58  | Cereberovascular | Possible | 27   | 26     |
|                |     | ischemia         |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1200           | 74  | Dyspnea,         | Possible | 197  | 197    |
|                |     | pulmonary        |          |      |        |
|                |     | embolism         |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1206           | 41  | Thr              | Possible | 83   | 5      |
|                |     | ombosis/embolism |          |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1265           | 63  | Pulmonary edema, | Not      | 3    | 1      |
|                |     | death            | related  |      |        |
+----------------+-----+------------------+----------+------+--------+
| 1284           | 65  | Left femoral     | Not      | 9    | 0      |
|                |     | embolism         | related  |      |        |
+----------------+-----+------------------+----------+------+--------+

"Results of preliminary analysis showed that 14 of 18 epoetin alfa
treated subjects with thrombotic vascular events had a hemoglobin
concentration greater than 13 g/dl within the 28 days prior to the
thrombotic vascular event; 2 of these subjects did not receive study
drug prior to the thrombotic vascular event."

Hemoglobin (g/dl) Concentrations Within the 28 Days Prior to the Event
in Subjects With Thrombotic Vascular Events (Study EPO-CAN-15)

  --------------------------- --------------------- ----------------------
                              Placebo               EPREX/Procrit

  Total                       3                     18

  Hgb ≥ 13 g/dl               2                     14

  Hgb \< 13 g/dl              1                     3

  Unknown                     0                     1
  --------------------------- --------------------- ----------------------

## Study PR00-03-006: "A double-blind, randomized, placebo controlled study of the efficacy and safety of epoetin alfa administered weekly in patients with gastric or rectal cancers undergoing preoperative chemoradiation followed by surgery."

[Design:]{.underline} randomized (stratified by: type of primary disease
(gastric or rectal cancer), by presence (Hgb ≤ 13 g/dl) or absence (Hgb
\> 13 g/dl) of anemia, and by study center), double-blind, US
multicenter trial.

[Patient population:]{.underline} 184 patients with histologically
confirmed gastric or rectal cancer for whom the treatment plan is
preoperative chemoradiation followed by surgery. Baseline Hgb was
required to be ≥ 10 g/dl and \< 15 g/dl.

[Treatment:]{.underline} PROCRIT 40,000 IU subcutaneous qw versus
placebo for a total of 16 weeks or up to 4 weeks after surgery,
whichever comes first. Study drug was to be held if ≥ 15 g/dl; resumed
if Hgb ≤ 14.0 g/dl at a 50% dose reduction.

[Primary endpoint:]{.underline} Proportion receiving RBC transfusions 4
weeks after start of study drug up to end of study.

[Secondary endpoints]{.underline}: Hgb response, transfusion, QoL, local
tumor response, pathological response post-surgery to assess the
curative response to the combined modality treatment.

Follow-up: Safety follow-up for 90 days post-study.

From "Preliminary Analyses of Thrombotic Vascular Events in Oncology
Studies", submitted by Ortho through Amgen, Jan. 19, 2004.[^87]

"A total of 60 subjects out of a projected 184, had been enrolled when
the trial was suspended. Thirty-one were in the placebo arm, and 29 in
the epoetin alfa arm. Of these 60 subjects, 2 (6%) placebo-treated, and
7 (24%) epoetin alfa treated subjects had a thrombotic vascular event.
After adjusting for bias due to early suspension of the study, the odds
ratio (epoetin alfa versus control) was 3.79."

Incidence of Thrombotic Vascular Events to Date:

Odds Ratio and 95% Confidence Interval (Study PR00-03-006)

  ----------- ----------- ----------- ----------- ----------- ----------------
  Placebo                 Procrit                 Odds ratio  

  N           TVE         N           TVE         Estimate    95% CI

  31          2 (6%)      29          7 (24%)     3.79        \[0.66,32.22\]
  ----------- ----------- ----------- ----------- ----------- ----------------

**Preliminary Listing of Subjects With Thrombotic/Vascular Events**

**(Study PR00-03-006)**

+-----------+-----------+-----------+-----------+-----------+-----------+
| Treatment | Age       | Inv       | Rel       | Day of    | Total     |
| &         |           | estigator | ationship | Onset     | Days of   |
|           |           | Term      | to Study  |           | Therapy   |
| Subject   |           |           | Drug      |           |           |
| ID        |           |           |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| Placebo   |           |           |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2008      | 50        | Chest     | Not       | N/A       | N/A       |
|           |           | pain      | related   |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
|           |           | Chest     | Not       | N/A       | N/A       |
|           |           | pain      | related   |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2150      | 71        | DVT       | Doubtful  | 139       | 104       |
+-----------+-----------+-----------+-----------+-----------+-----------+
| Procrit   |           |           |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2016      | 58        | DVT       | Possible  | 87        | 70        |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2019      | 57        | DVT       | Not       | 195       | 105       |
|           |           |           | related   |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2066      | 68        | Chest     | Not       | N/A       | N/A       |
|           |           | pain      | related   |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2141      | 71        | DVT       | Possible  | 67        | 67        |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2142      | 76        | DVT       | Possible  | 56        | 22        |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2154      | 71        | DVT       | Possible  | 87        | 22        |
+-----------+-----------+-----------+-----------+-----------+-----------+
| 2210      | 40        | T         | Possible  | 14        | 19        |
|           |           | hrombosis |           |           |           |
+-----------+-----------+-----------+-----------+-----------+-----------+

"Results of preliminary analysis showed that 5 of 7 epoetin alfa treated
subjects with thrombotic vascular events had a hemoglobin concentration
greater than 13 g/dl within the 28 days prior to the thrombotic vascular
event."

Hemoglobin (g/dl) Concentrations Within the 28 Days Prior to the Event
in Subjects With Thrombotic Vascular Events (Study PR00-03-006)

  -------------------------- ------------------- ------------------------
                             Placebo             Procrit

  Total                      2                   7

  Hgb ≥ 13 g/dl              0                   5

  Hgb \< 13 g/dl             1                   1

  Unknown                    1                   1
  -------------------------- ------------------- ------------------------

## Study GOG-191 (PR01-04-005): "A phase III trial to evaluate the efficacy of maintaining Hgb levels above 120 g/l with erythropoietin versus above 100 g/l without erythropoietin in anemic patients receiving concurrent radiation and cisplatin for cervical cancer."

Design: 1:1 randomized, US/Canada cooperative group (GOG, NCIC) trial.

Patient population: 460 subjects with primary, previously untreated,
histologically confirmed invasive squamous cell carcinoma,
adenocarcinoma, or adenosquamous carcinoma of the uterine cervix Stage
IIB, IIIB, or IVA were to be enrolled. Patients were required to have
baseline Hgb \< 14 g/dl.

Treatment: Procrit 40,000 IU subcutaneous weekly versus transfusion prn.
Procrit dose was to be titrated to maintain Hgb ≥ 13 gm/dl. Treatment
was continued for the duration of radiation treatment Primary endpoint:
Progression-free survival.

Secondary endpoints: Overall survival, local control.

Follow-up: Followed for progression and survival.

Enrollment statistical: 111/460.

***Trial suspended effective Sept. 12, 2002.***

[Letter, from Philip Disaia, M.D. Chairman GOG., dated Sept. 22,
2003.]{.underline}

"As you are aware, it was noted on 9/15/03 that there appeared to be an
increased number of cardiovascular events (compared to historical
experience) on this study. I was notified of this finding and
recommended to you that accrual be suspended pending investigation and
you concurred . . .."

"A review of GOG protocol 165 (Radiation plus Chemotherapy in a similar
patient population) revealed an incidence of grade 3 or 4 cardiovascular
events of 5%. The incidence of grade 3 or 4 cardiovascular events in GOG
Protocol 191 (79 evaluable patients) is 13.9% with Regimen P being 7.9%
and regimen Q being 19.5%. Review of each case confirmed the events."

"The DMC discussed the findings in great detail and the salient points
of that discussion are that while the events do not reach statistical
significance (between the two arms), the trend does raise concern. The
recommendations of the DMC are as follows:

1.  The DMC does not recommend than study be closed.

2.  The DMC recommends the consent form be changed to clarify the
    potential of increased cardiovascular events.

3.  The DMC recommends that all investigators be informed by mail of the
    potential increased risk and that they be encouraged to consider
    anti-thrombosis prophylaxis if, in their judgment, such prophylaxis
    is not contraindicated.

4.  The cardiovascular events on this study be closely monitored and the
    protocol should be reevaluated by the DMC at the January 2004 GOG
    meeting."

[Memo from GOG Administrative Office, Sept. 26, 2003:]{.underline}

To: All Principal Investigators.

"In response to the concerns of Ortho Biotech, this study will continue
to be suspended to patient accrual, effective Sept. 12, 2003.

Effective immediately, patients currently on therapy can continue
treatment but **[erythropoietin must be discontinued]{.underline}**.".

From "Preliminary Analyses of Thrombotic Vascular Events in Oncology
Studies", submitted by Ortho through Amgen, Jan. 19, 2004.[^88]

"A total of 113 subjects (55 control, 58 epoetin alfa) were enrolled
when the study was terminated. Of these 113 subjects, 3 (5%) control and
9 (16%) epoetin alfa treated subjects had a thrombotic vascular event
reported. After adjusting for a bias due to early termination of the
study, the odds ratio (epoetin alfa versus control) was 2.65."

**Incidence of Thrombotic Vascular Events to Date:**

**Odds Ratio and 95% Confidence Interval (Study PR01-04-005)**

  ----------- ----------- ----------- ----------- ---------- --------------
  Placebo                 Procrit                 Odds ratio 

  N           TVE         N           TVE         Estimate   95% CI

  55          3 (5%)      58          9 (16%)     2.65       \[0.47,
                                                             16.90\]
  ----------- ----------- ----------- ----------- ---------- --------------

"Results of preliminary analyses showed that 5 of the 9 epoetin alfa
treated subjects with thrombotic vascular events had a hemoglobin
concentration greater than 13 g/dl within the 28 days prior to the
thrombotic vascular event."

Hemoglobin (g/dl) Concentrations Within the 28 Days Prior to the Event
in Subjects With Thrombotic Vascular Events (Study PR01-04-005)

  ------------------------------ ------------------ ----------------------
                                 Placebo            Procrit

  Total                          3                  9

  Hgb ≥ 13 g/dl                  1                  5

  Hgb \< 13 g/dl                 2                  2

  Unknown                        0                  2
  ------------------------------ ------------------ ----------------------

**Preliminary Listing of Subjects With Thrombotic/Vascular Events**

**(Study PR01-04-005)**

  --------------- ----- ----------------------- -------------- ------------
  Subject ID      Age   Investigator Term       Relationship   Total Days
                                                to Study Drug  of Therapy

  Standard of                                                  
  Care (SOC)                                                   

  046-191-002     51    DVT                     Not related    SOC

  56-191-005      70    DVT                     Not related    SOC

  56-191-007      60    DVT                     Not related    SOC

  Epoetin alfa                                                 

  002-191-002     38    Pulmonary embolism      Possible       42

  020-191-008     49    Pulmonary embolism      Possible       21

  034-191-002     46    Cerebral infarct        Not related    42

  047-191-001     52    Thromboembolus          Unrelated      35

  056-191-004     44    Pulmonary embolism      Possible       42

  076-191-006     75    Cardiac arrest          Not related    42

  083-191-006     52    DVT                     Not related    28

  85-191-004      37    Pulmonary embolism      Related        49

  85-191-018      37    Intracranial hemorrhage Possible       14
  --------------- ----- ----------------------- -------------- ------------

# Additional Randomized, Controlled Trials Terminated Prematurely (not at request of Johnson & Johnson)

## Protocol CAN-20: "A randomized trial of epoetin alfa in patients with advanced non-small cell carcinoma of the lung."

Design: 1:1 randomized, double-blind, placebo-controlled multicenter
Canadian trial.

Patient population: 300 planned locally advanced, metastatic, or
recurrent, non-small cell lung cancer subjects who are to receive
radiation treatment plus or minus non-platinum chemotherapy. Patients
were required to have entry Hgb ≤ 12 g/dl.

Primary endpoint: Change in quality of life (FACT-An Aneaemia scale)
from baseline to week 12.

Secondary endpoints: quality of life measures at baseline, weeks 4, 8,
12 and 16 weeks; Hgb and Hct levels at baseline; weeks 4, 8, 12, and 16
weeks, transfusion requirements).

Treatment: 40,000 IU qw versus placebo for 12 weeks.

Follow-up: 4 week post-study quality of life plus up to two months post
study drug follow-up (descriptive only).

**Termination of the Trial:**

Trial terminated, at the recommendation of the DMC.

[Letter, dated Nov. 27, 2003, from Dr. Jim Wright, PI "Suspension of
EPO-CAN-20"]{.underline}[^89][:]{.underline}

"Recently, information from other trials that epoetin alfa is associated
with a higher than expected risk of thrombotic events, prompted the
external DSMB for the OCOG \[Ontario Clinical Oncology Group\]
EPO-CAN-20 trial to review the accumulated data collected by the OCOG
Coordinating and Methods Centre. This was an unplanned analysis. The
DSMB examined thrombotic events and, because of the results of the EPO-
INT-76 trial, mortality was also investigated."

"The Steering Committed for the EPO-CAN-20 trial met Nov. 24, 2003 to
review the analysis prepared by the DSMB."

"Preliminary results of their analysis revealed that:

1.  The rates of thrombosis were low in both treatment groups and there
    was no increase in thrombosis associated with epoetin alfa.

2.  A large proportion of patients on the trial had completed the 12
    week QoL assessment (the primary outcome measure), due to high rates
    of mortality.

3.  Patients on the active arm of the trial appear to have higher rates
    of mortality when compared to the placebo arm of the trial."

\[Letter then goes on to quote the results of the Henke trial in head
and neck cancer.\]

"Based on this information, the EPO-CAN-20 Steering Committee has
decided to suspend recruitment for this study. Hence no further patients
should be randomized at this time and all patients should stop taking
study medication. We will, however, continue to collect all scheduled
follow-up and QoL \[quality of life\] data as outlined in the protocol."

"It is important to note that the EPO-CAN-20 trial is a QoL study and
was not set up to capture very detailed information on cancer treatment
or potentially confounding variables that may have influenced survival.
In an attempt to better understand this situation, we plan to examine
patient records in more detail focusing on each patient's cancer and
treatment for the cancer. Therefore, a more complete analysis of
survival is required before there can be any discussion on whether to
continue the study."

## Protocol EPO-GBR-7[^90]:"Open-label randomized, comparative group evaluation of the effect of epoetin alfa on local disease-free survival and quality of life in head and neck cancer patients receiving radical radiotherapy."

Design: Phase 3, open-label, multicenter study in subjects with head and
neck cancer for with radical radiotherapy with curative intent was
imminent. Subjects were required to have no previous chemotherapy or
surgical intervention for the malignant pertaining to the study. Hgb at
entry required to be ≤ 15 g/dl

Planned sample size was 800 patients.

Subjects were to randomized 1:1 to receive either standard radiotherapy
alone (Observation Group) or standard radiotherapy plus epoetin alfa
(Epoetin Alfa Group).

Subjects assigned to the active treatment group were to receive
treatment immediately after randomization if their radiotherapy was
scheduled to start in 2-4 weeks; or 4 weeks after randomization if their
radiotherapy was to start in more than 4 weeks. : Treatment was to be
titrated to achieve and be maintained a hemoglobin between 12.5 g/dl and
15 g/dl during the treatment phase.

Endpoints: "To evaluate the effect of treatment with epoetin alfa on
length of local disease-free survival, local tumor control, and quality
of life in subjects receiving radical radiotherapy with curative
intention of head and neck cancer".

**Termination of the study:**

"Due to slow accrual, study enrollment was terminated in 2002 after 301
subjects had been recruited across 21 sites. Per protocol, the study
treatment phase has been completed and the 5 year follow-up phase
continues at this time."

*Efficacy Endpoints*:

Local Tumor Response 12 Weeks After Radiotherapy

"At the time of the interim analysis, Week 12 local tumor response data
were available for 110 (74%) of the subjects in the observation group
and 115 (76%) in the epoetin alfa group. Based on those who had such
data available, 95% of the subjects had complete response and 4% had
partial response to radiotherapy on the primary tumor sites in both
treatment groups. Similar results were also seen in response on lymph
nodes."

Local Tumor Evidence:

Local tumor evidence was assessed at weeks 1,4, and 8, and Years 1,2,3
and 5 after completion of radiotherapy. Since this trial is still
ongoing, not all subjects had reach all the assessment time points; and
in particular no subject had had the Year 5 assessment at the time of
the interim analysis. Based on the data available at this time, epoetin
alfa treatment appeared to have no effect on the outcomes of these
assessments".

Local Tumor Recurrence at Study Completion/Discontinuation:

"Forty-two (28%) of the subjects in the observation group and 38 (25%)
in the epoetin alfa group were reported to have local tumor recurrence
within the irradiated volume at their completion or discontinuation.
Relapse outside the irradiated volume was reported in 21 (14%) of the
subjects in the observation group and 20 (13%) in the epoetin alfa
group. Again, epoetin alfa treatment did not seem to have an effect on
the outcome of this assessment."

Overall Survival:

"At the time of the interim analysis, the Kaplan-Meier estimate of the
overall survival time showed a non-significant trend (p=0.535, logrank
test) toward a longer survival in the observation group than in the
epoetin alfa group. The Kaplan-Meier estimate of the one year survival
rate was 85% (95% confidence interval 79% to 91%) for the observation
group and 81% (95% confidence interval 74%to 87%) for the epoetin alfa
group."

Safety (Thrombotic Vascular Events):

"At the time of the interim analysis, 1 (1%) of the subjects in the
observation group and 5 (3%) in the epoetin alfa group were reported to
have experienced at least one thrombotic vascular event. Reported
clinically relevant events (cardiac arrest, angina, and pulmonary
embolism) were all in the epoetin alfa group."

## Rosenzweig Study[^91]: "Increased thrombotic events in a clinical trial of erythropoietin in metastatic breast cancer." 

ASCO Abstract (2002):

Rosenzweig, M., et al., University of Pittsburgh School of Medicine:
Increased thrombotic events in a clinical trial of erythropoietin in
metastatic breast cancer.

"100 women with metastatic breast cancer with Hgb \< 12.0. Patients were
randomized to receive usual care (G1) or usual care plus EPO (G2). EPO
was given at 40,000 IU sq qw. At 4 weeks, dose was increased to 60,000
IU sq qw without a \> 1.0 g/dl Hgb increase and discontinued at 8 weeks
if Hgb improvement was \< 1.0 g/dl.

"*Results:* This study was terminated early (n=27, G1=13, G2=20), when
4/14 (28.5%) subjects in G2 developed thrombotic events (1 DVT, 1 DVT +
pulmonary embolism, 1 DVT + pulmonary embolism l month after EPO
discontinuation, 1 brachial vein thrombosis). In all 4 patients the Hgb
was normal at the time of the event.. No patient in G1 developed a
thrombotic event. The historic incidence (Jan. 99 to June 01) of
thrombotic events in the UPCI MBC population was 5.5%. The incidence of
thrombotic events in G2 was significant greater than the historic
incidence (p\< 0.05)."

## RTOG 99-03[^92]: "A randomized phase III trial to assess the effect of erythropoietin on local-regional control in anemic patients treated with radiotherapy for carcinoma of the head and neck."

Design: 1:1 randomized, open-label, US, cooperative group (RTOG) trial.

Patient population: 372 patients with head and neck cancer. Baseline Hgb
criterion: males ≥ 9 g/dl, to 13.5 g/dl. females ≥ 9 to 12.5.

Treatment: epoetin alfa 40,000 IU subcutaneous qwk for 8-9 weeks or
until completion of XRT versus no epoetin alfa. Epoetin alfa doses were
held if Hgb ≥ 16 in males or ≥ 14 in females; dosing resumed when Hgb ≤
13.5 in males and ≥ 12.5 in females, at a dose reduction of 30,000 IU.

The primary endpoint was improvement in local-regional control rate,
while secondary endpoints included survival and site of first failure.

Enrollment status at termination: 147/372

Trial suspended.

Memo to RTOG Investigators, from Joseph Aisner, M.D. RTOG Monitoring
Committee Chair, November 19, 2003.

"On Oct. 28, 2003, the RTOG DMC met to discuss the recently published
Lancet article \[Henke\] and the disposition of RTOG 99-03. .. This
study had a design and patient population similar to RTOG 99-03. The
RTOG DMC reviewed the above information alone with results of a rapidly
compiled (unplanned) interim analysis of RTOG 99-03. The interim
analysis of results from RTOG 99-03 showed no statistically significant
differences, but non-significant trends towards lower local-regional
control and lower survival in the epoetin alfa arm. The RTOG DMC
concluded that RTOG 99-03 should be permanently closed to accrual."

[RTOG Analysis for DMC Telephonic Conference, Oct. 24,
2003.]{.underline}

Preliminary analysis of time to local-regional failure and survival for
RTOG 9903. This data is not yet mature, as the median follow-up for
patients still alive is only 8.7 months and only 22/117 patients have
died.

148 patients have been entered in to RTOG 9903, one is ineligible and 30
have no follow-up, leaving 117 for analysis.

# Summary/Conclusions

Recombinant Erythropoietin Products and Thrombotic/Cardiovascular
Events:

The Normal Hematocrit Trial in patients with chronic renal failure
demonstrated an increased risk of cardiovascular adverse events and
death occurs using a dosing strategy in which a higher target hematocrit
than in the currently approved labeling is sought. Subsequent analyses
of the studies that supported the use of Aranesp (darbepoetin alfa) in
chronic renal failure identified a rate of rise in hemoglobin of greater
than 0.5 g/dl/week correlating with an increased risk of hypertension,
pulmonary edema, cardiac arrest and CVA. A similar risk associated with
an increased rate of rise was not clearly seen in the studies that
supported the oncology indication for Aranesp, although a suggestion
both of increased risk of serious thrombotic events, and of more rapid
ROR in patients suffering pulmonary emboli suggest that a relationship
may also exist in this setting.

There have been three randomized, placebo-controlled trials where a
population of patients with the same histological type of malignancy was
administered epoetin alfa or epoetin beta with the aim of achieving a
target hemoglobin of greater than 12 g/dl. In the N93-004 trial,
performed in subjects with SCLC receiving chemotherapy, there was a
higher incidence of vascular (extracardiac) adverse events in the group
receiving Procrit. In the EPO-INT-76 trial, in a population of women
with metastatic breast cancer, at four months, there was a higher
incidence of cardiovascular/thrombotic vascular events in the group who
received EPREX (1.4% in the placebo arm versus 2.3% in the EPREX arm).
In the Henke trial, where the population consisted of subjects with head
and neck carcinoma who were to receive radiotherapy, the incidence of
"vascular disorders" (hypertension, hemorrhage, venous
thrombosis/pulmonary embolism, CVA) was 5% in the placebo arm and 11% in
the epoetin beta arm. The numbers of patients who died from "cardiac
disorders" also differed: 5 placebo and 10 epoetin beta subjects.

Finally, the three oncology studies stopped by Johnson & Johnson in
September 2003, were all designed with the intention to achieve target
hemoglobin levels at normal or greater than normal levels: EPO-CAN-15
(EPREX/Procrit), where a target Hgb of 14-16 g/dl was used, PR01-04-005
(Procrit), where a target hemoglobin of \> 13 g/dl was used, and
PR00-03-006 (Procrit), where a hemoglobin of up to 15 g/dl was allowed.
All three of these studies were halted because of an excessive incidence
of thrombotic vascular events in the arms receiving an erythropoietin
product. There is as yet no analysis available on the effect of rate of
rise of hemoglobin on the incidence of thrombotic vascular events.

It is clear from this data that both the rate of rise in hemoglobin and
a target hemoglobin of greater than 12.0 g/dl may contribute to an
increased risk of cardiovascular/thrombotic events in patients with
chronic renal failure on dialysis. The data from major efficacy study
that supported the supplemental approval for Aranesp for treatment of
the anemia of cancer chemotherapy demonstrated a rapid rate of rise in
hemoglobin (more than 0.5 g/dl/week) was associated with an increased
incidence of hypertension, vascular thrombosis, ischemia and infarction.

The Agency considers studies conducted using target hemoglobin levels of
greater than 12 g/dl to potentially unsafe; studies employing such
strategies should be conducted under IND. In addition, such studies
should be specifically designed to detect an impact on survival as well
as the impact on thrombotic event rates. With regard to clinical
practice, clinicians should adhere to the dose adjustments governing the
rate of rise of hemoglobin that have been incorporated into the Aranesp
and Procrit/Epogen package inserts.[^93]

### Recombinant Erythropoietin and the Risk of Tumor Promotion

There is now a body of literature consisting of studies in cell lines
and in animal models that supports the possibility that erythropoietin
may have a role to play in the growth of certain tumors. There are also
other studies that suggest that erythropoietin has no such role. The
question of whether EPO does or does not function as a growth factor for
tumors (and/or vasculature) now has more immediacy, because of the
results of the clinical studies outlined in this document.

Four multicenter, randomized, placebo controlled clinical trials have
been conducted thus far, the N93-004 (Procrit), NESP 980297 (Aranesp),
EPO-INT-76 (EPREX), and the Henke (epoetin beta) study, which were
designed to measure tumor outcomes or survival in homogenous populations
of tumors. In two of the four studies, which also happen to be the two
largest studies, there was evidence of a tumor promotion effect in the
arm that received recombinant erythropoietin. In EPO-INT-76, there was
also a detrimental effect on 12-month survival. While aspects both of
these studies have been criticized, the size of the two trials that
showed evidence of tumor promotion (929 subjects in the EPO-INT-76
trial, 351 in the Henke trial), the size and design (randomized,
placebo-controlled) of both trials and the consistency in results
provide data that in the opinion of the FDA, warrant further
investigation.

The basis for the adverse effects of erythropoietin on malignancy/tumor
stimulation is uncertain, however, it seems reasonable that an effect
could be mediated through binding to erythropoietin receptors on both
tumor and vascular cells. The three studies were performed in three
different primary tumor types: small cell carcinoma of the lung,
metastatic breast cancer, and carcinoma of the head and neck. A tumor
promotion effect was seen in the breast cancer and head and neck
studies, but not in the small cell lung cancer study. This may indicate
heterogeneity of malignancies, such as differences in erythropoietin
receptor distributions between types of malignant tumors.

Future studies that investigate the effect of erythropoeitic growth
factors on tumor promotion should incorporate the following features
into their design:

-   Homogenous primary tumor .

-   Homogenous chemotherapy and/or radiation regimens.

-   Randomized, placebo-controlled.

-   Data collection that will allow the systematic acquisition of
    information of tumor response, time to progression, and survival.

-   Target hemoglobin values of no greater than 12.0 g/dl, with
    prespecified rules for dose adjustment.

-   Prespecified definitions for cardiovascular and thrombovascular
    events.

-   A Data Safety Monitoring Board with a charter that states criteria
    for halting the study in the event of a prespecified number of
    cardiovascular or thrombotic adverse events occurs.

-   Collection of data regarding the erythropoietin receptor status of
    primary tumor sites.

-   Studies on tumor populations with high, low, and intermediate
    quantities of erythropoietin receptors.

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[^44]: Ibid, p. 9.

[^45]: Ibid, p. 9.

[^46]: Ibid, p. 16.

[^47]: Ibid, p. 19.

[^48]: Besarab A, et al., *New England Journal of Medicine*, 339: 584,
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[^49]: Ibid.

[^50]: <http://www.fda.gov/cder/biologics/products/darbamg091701.htm>

[^51]: Document: Summary for Basis of Approval, Epoetin alfa (Amgen),
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[^52]: Ibid, p. 5.

[^53]: Final Study Report, Protocol N93-004, Johnson & Johnson, October
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[^54]: Luksenburg H., Gnecco C. FDA Clinical Review of sBLA STN
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[^55]: Final Study Report PR98-27-008, Johnson & Johnson, ?Date.

[^56]: STN BL 103951/5001 Approval Letter, July 19, 2002.

[^57]: Litwin, S. Clinical Review of BLA STN 103951/5001, Amgen, Inc.,
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[^58]: Ibid, p. 59-60.

[^59]: Ibid, p. 60.

[^60]: Ibid, p. 60-61.

[^61]: Ibid, p. 53.

[^62]: Ibid, p. 53.

[^63]: Ibid, p. 85.

[^64]: Ibid, p. 54.

[^65]: Ibid, p. 55.

[^66]: Ibid, p. 55.

[^67]: Ibid, p. 55.

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[^70]: Clinical Expert Report on INT-76, submitted by Johnson & Johnson
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[^71]: Ibid, p. 12.

[^72]: Ibid, p. 104.

[^73]: Cause of death was unknown. Subject died suddenly on Study Day
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[^74]: Other causes include: fatty embolism, ischemic colon perforation,
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[^75]: Ibid, p.75.

[^76]: Leyland-Jones, B and the BEST Investigators and Study Group.
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[^78]: Henke et al. *Lancet* 362:1255, 2003.

[^79]: Ibid

[^80]: Ibid.

[^81]: Kaanders J, van der Kogel A, Lancet 363:78, 204, Haddad R, Posner
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[^82]: Haddad R, Posner M. Lancet 363:79, 2004.

[^83]: Henke M. et al. Lancet 363:81, 2004.

[^84]: "Drug Company Halts Trials of Procrit", *New York Times*, Nov.
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[^85]: Johnson & Johnson Pharmaceutical Research & Development, L.L.C..
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[^86]: Ibid, p. 26, 30-1.

[^87]: Ibid, p. 24-25, 28.

[^88]: Ibid, p. 25-26, 29-30.

[^89]: Ibid, p. 54-56.

[^90]: Ibid, p. 57-69.

[^91]: Rosenzweig M, et al. ASCO 2002 Meeting, abstract 1522.

[^92]: Information Package submitted to the FDA by Ortho Biotech through
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[^93]: Aranesp® (Amgen, Inc.) package insert, DOSAGE AND ADMINISTRATION,
    Dose Adjustment: "the dose should be adjusted for each patient to
    achieve and maintain a target hemoglobin not to exceed 12 g/dl..

    Increases in dose should not be made more frequently than once a
    month. If the hemoglobin is increasing and approaching 12 g/dl, the
    dose should be reduced by approximately 25%. If the hemoglobin
    continues to increase, doses should be temporarily withheld until
    the hemoglobin begins to decrease, at which point therapy should be
    reinitiated at a dose approximately 25% below the previous dose. If
    the hemoglobin increases by more than 1.0 g/dl in a 2 week period,
    the dose should be decreased by approximately 25%."