Summary of Safety and Effectiveness Data

# GENERAL INFORMATION

  ------------------------------------- ---------------------------------
  Device Generic Name:                  Prostate Specific Antigen (PSA)
                                        Chemiluminescent Enzyme
                                        Immunoassay

  Device Trade Name:                    IMMULITE^®^ PSA\
                                        IMMULITE^®^ 2000 PSA\
                                        IMMULITE^®^ Third Generation PSA\
                                        IMMULITE^®^2000 Third Generation
                                        PSA

  Applicant\'s Name and Address:        Diagnostic Products Corporation
                                        (DPC)\
                                        5700 West 96th Street\
                                        Los Angeles, California 90045

  Premarket Approval Application (PMA)  P930027/S4
  Number:                               

  Date of Panel Recommendation:         Not applicable (see section X)

  Date of Notice of Approval to the     June 19, 2001
  Applicant:                            
  ------------------------------------- ---------------------------------

# II. INDICATIONS FOR USE

The IMMULITE^^ PSA is indicated for in vitro diagnostic use with the
Immulite Analyzer-for the quantitative measurement of prostate -
specific antigen (PSA) in human serum, as an aid in the detection of
prostate cancer when used in conjunction with digital rectal examination
(DRE) in men aged 50 years or older.

IMMULITE^^ Third Generation PSA is indicated for in vitro diagnostic
use with the Immulite Analyzer-for the quantitative measurement of
prostate-specific antigen (PSA) in human serum, as an aid in the
detection of prostate cancer when used in conjunction with digital
rectal examination (DRE) in men aged 50 years or older.

IMMULITE^^ 2000 PSA is indicated for in vitro diagnostic use with the
Immulite 2000 Analyzer- for the quantitative measurement of prostate -
specific antigen (PSA) in human serum, as an aid in the detection of
prostate cancer when used in conjunction with digital examination (DRE)
in men aged 50 years or older.

IMMULITE^^ 2000 Third Generation PSA is indicated for in vitro
diagnostic use with the Immulite 2000 Analyzer-for the quantitative
measurement of prostate specific-antigen (PSA) in human serum as an aid
in the detection of prostate cancer when used in conjunction with
digital rectal examination (DRE) in men aged 50 years or older.

The IMMULITE^^ PSA, IMMULITE^^ Third Generation PSA, IMMULITE^^ 2000
PSA, and IMMULITE^^ 2000 Third Generation PSA were previously cleared
or approved for marketing as an adjunctive test to aid in the management
of prostate cancer patients (P930027/S1, K972095, K972021, and
K974842/S1).

# III. CONTRAINDICATIONS

There are no contraindications for the Immulite PSA, Immulite Third
generation PSA, Immulite 2000 and Immulite 2000 Third Generation PSA.

IV. **WARNINGS AND PRECAUTIONS**

Refer to the device labeling for a list of the warnings and precautions.

# V. DESCRIPTION OF DEVICES

**IMMULITE PSA** is a solid-phase, two-site chemiluminescent enzyme
immunoassay for use with the Immulite Analyzer. The solid phase, a
polystyrene bead enclosed within an IMMULITE Test Unit, is coated with a
polyclonal antibody specific for PSA. The patient sample and reagent
(containing alkaline phosphatase-conjugated monoclonal antibody) are
incubated for approximately 30 minutes at 37oC in the Test Unit with
intermittent agitation. During this time, PSA in the sample becomes
bound to the surface of the bead. Unbound conjugate is removed by a
centrifugal wash. The substrate is then added and the Test Unit is
incubated for a further 10 minutes.

The chemiluminescent substrate, a phosphate ester of adamantyl
dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase
to yield an unstable intermediate. The continuous production of this
intermediate results in the sustained emission of light. The bound
complex, and thus also the photon output as measured by the luminometer,
is proportional to the concentration of PSA in the sample. The
concentration of PSA in the patient sample is obtained using a stored
master curve within the IMMULITE analyzer. The IMMULITE PSA assay has a
reportable range of 0.04 to 150 nanograms of PSA per milliliter.

**IMMULITE Third Generation PSA** is a solid phase, two-site sequential
chemiluminescent enzyme immunoassay for use with the Immulite Analyzer.
The solid phase, a polystyrene bead enclosed within an IMMULITE Test
Unit, is coated with a monoclonal antibody specific for PSA. The patient
sample and a buffer/serum matrix are simultaneously introduced to the
Test Unit and incubated for approximately 30 minutes at 37oC with
intermittent agitation. During this time, PSA in the sample becomes
bound to the surface of the bead. Unbound serum is then removed by a
centrifugal wash. An alkaline phosphatase-conjugated polyclonal antibody
is introduced, and the Test Unit is incubated for another 30-minute
cycle. The unbound enzyme conjugate is removed by a centrifugal wash.
Substrate is then added and the Test Unit is incubated for a further 10
minutes.

The chemiluminescent substrate, a phosphate ester of adamantyl
dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase
to yield an unstable intermediate. The continuous production of this
intermediate results in the sustained emission of light. The bound
complex, and thus also the photon output as measured by the luminometer,
is proportional to the concentration of PSA in the sample. The
concentration of PSA in the patient sample is obtained using a stored
master calibration curve within the IMMULITE analyzer. The IMMULITE
Third Generation PSA assay has a reportable range of 0.01 to

20 nanograms of PSA per milliliter.

**IMMULITE 2000 PSA** is a solid-phase, two-site chemiluminescent enzyme
immunoassay for use with the Immulite 2000 Analyzer. The solid phase, a
polystyrene bead, is coated with a polyclonal antibody specific for PSA.
While the patient serum sample and alkaline phosphatase-conjugated
monoclonal antibody are incubated for approximately 30 minutes at 37^o^C
in the Reaction Tube with agitation, PSA in the sample is bound to form
an antibody sandwich complex. Unbound conjugate is then removed by a
centrifugal wash, after which substrate is added and the Reaction Tube
is incubated at 37^o^C with agitation for a further 5 minutes.

The chemiluminescent substrate, a phosphate ester of adamantyl
dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase
to yield an unstable intermediate. The continuous production of this
intermediate results in the sustained emission of light. The bound
complex, and thus also the photon output as measured by the luminometer,
is proportional to the concentration of PSA in the sample. The IMMULITE
2000 PSA assay has a reportable range of 0.04 to 150 nanograms of PSA
per milliliter.

**IMMULITE 2000 Third Generation PSA** is a solid-phase, two-site
sequential chemiluminescent enzyme immunoassay for use with the Immulite
2000 Analyzer. The solid phase is a polystyrene bead coated with a
monoclonal antibody specific for PSA. The patient sample and a
buffer/serum matrix are introduced into the Reaction Tube containing the
bead and incubated for approximately 30 minutes at 37^o^C with
agitation. During this time, PSA in the sample binds to the monocolonal
anti-PSA antibody-coated bead. Unbound serum is then removed by
centrifugal wash.

An alkaline phosphatase -labeled polyclonal goat anti-PSA antibody is
introduced, and the Reaction Tube is incubated for another 30-minute
cycle. The unbound enzyme conjugate is then removed by a centrifugal
wash. Substrate is then added, and the Reaction Tube is incubated for a
further 5 minutes.

The chemiluminescent substrate, a phosphate ester of adamantyl
dioxetane, undergoes hydrolysis in the presence of alkaline phosphatase
to yield an unstable intermediate. The continuous production of this
intermediate results in the sustained emission of light. The bound
complex, and thus also the photon output as measured by the luminometer,
is proportional to the concentration of PSA in the sample. The IMMULITE
2000 Third Generation PSA assay has a reportable range of 0.01 to 20
nanograms of PSA per milliliter.

# VI. ALTERNATIVE PRACTICES OR PROCEDURES

Alternative practices and procedures to aid in the detection of prostate
cancer include a physical examination by digital rectal examination and
imaging by ultrasound. Other devices for which there is an approved PMA
for measuring serum total PSA are available to aid in the detection of
prostate cancer in conjunction with DRE in men age 50 years or older.
Confirmation of prostate cancer requires biopsy with histological
examination of prostatic tissue.

# VII. MARKETING HISTORY

IMMULITE PSA has been marketed in 52 countries; IMMULITE Third
Generation PSA has been marketed in 38 countries; IMMULITE 2000 PSA has
been marketed in 31 countries; IMMULITE 2000 Third Generation PSA has
been marketed in 21 countries. These assays were previously approved or
cleared for marketing as an aid in the management of prostate cancer
patients under P930027/S1, K972095, K972021, and K974842/S1.

None of these PSA assays have been withdrawn from marketing for any
reason relating to the safety and effectiveness of the device.

# VIII. POTENTIAL ADVERSE EFFECTS OF THE DEVICE ON HEALTH

Assessment of patient status must not be based entirely on PSA results.
Elevation in PSA values occurs in patients with benign prostatic
disorders. A falsely elevated result could lead to an unnecessary
biopsy. Low concentrations are not always associated with absence of
disease. A false low PSA result could deprive the patient of a biopsy
and treatment. There are no significant adverse effects on health of
patients when this device is used as indicated.

# IX. SUMMARY OF STUDIES

## **Non-clinical studies**

Non-clinical studies were submitted in P930027/S1, K972095, K972021, and
K974842/S1 to support the indications for use -- to aid in the
management of prostate cancer patients. New non-clinical studies were
not performed since the assays have been previously cleared for use in
the management of patients with prostate cancer. The following table
summarizes non-clinical performance of the assays.

Table 1

All four devices/assays have the same indication for use. The major
differences between the devices are in the antibody used to coat the
bead, the antibody used in the conjugate, and the analyzer to be used.

## **Clinical studies**

Studies at three separate sites assessed the safety and effectiveness of
IMMULITE PSA, IMMULITE Third Generation PSA, IMMULITE 2000 PSA and
IMMULITE 2000 Third Generation PSA for the indications for use. Two
retrospective studies were conducted in the United States, one in the
northwest and one in the south. The third study was a prospective study
conducted in Chile. Retrospective samples meeting the
inclusion/exclusion criteria were sequentially selected for entry from
the specimen banks maintained at each clinical site.

Inclusion criteria:

1.  males aged 50 years or older

2.  no evidence of acute prostatitis or urinary tract infection at time
    of specimen collection

3.  no personal history of prostate cancer prior to specimen collection

4.  A DRE result no more than 6 months prior to specimen collection and
    no more than 1 month, and more than 1 week, after specimen
    collection

5.  If PSA results are greater than 4.0 ng/ml and/or DRE results are
    suggestive of cancer, documentation of biopsy results should be
    provided

6.  If biopsy results are positive for cancer, then clinical and/or
    pathological staging should be provided

7.  Serum specimens should be stored at -70C for no more than 5 years

Exclusion criteria:

1.  treatment of benign prostatic hyperplasia within the previous 4
    weeks

2.  prior transurethral resection of the prostate

3.  treatment with medications that might alter the serum PSA
    concentration

4.  needle biopsy within the previous 6 weeks

5.  men with a life expectancy of less than 10-15 years

6.  if possible, do not include men with hereditary or familial history
    of prostate cancer

Studies using the IMMULITE PSA were conducted at three clinical sites. A
total of 3810 serum specimens were collected. For all subjects 91%
Caucasians, 6% African Americans, 2% Asians, \<1% others or with no
ethnic information. For the four race categories shown below, there were
different percentages at each site:

> Table 2

+-----------------------+-------------------------+-------------------+
| **Race category**     | **Site**                | **% of subjects** |
+-----------------------+-------------------------+-------------------+
| **Caucasian**         | Southern US             | 62.8%             |
|                       |                         |                   |
|                       | Northwest US            | 91.2%             |
|                       |                         |                   |
|                       | Chile                   | 10%               |
+-----------------------+-------------------------+-------------------+
| **Black**             | Southern US             | 23.4%             |
|                       |                         |                   |
|                       | Northwest US            | 1.7%              |
|                       |                         |                   |
|                       | Chile                   | unstated          |
+-----------------------+-------------------------+-------------------+
| **Hispanic**          | Southern US             | 9.4%              |
|                       |                         |                   |
|                       | Northwest US            | 1.5%              |
|                       |                         |                   |
|                       | Chile                   | 90%               |
+-----------------------+-------------------------+-------------------+
| **Asian, Native       | Southern US             | 4.4%              |
| American, and unknown |                         |                   |
| race**                | Northwest US            | 5.6%              |
|                       |                         |                   |
|                       | Chile                   | 0%                |
+-----------------------+-------------------------+-------------------+

The mean age of subjects was 62.0 years.

To summarize the site analysis of patient characteristics, the following
were found:

-   cancer rate by site is not different (p = 0.12, cancer yield overall
    = 0.322)

-   rate of elevated PSA (p = 0.005, Chi square test) and mean PSA (p \<
    0.001 by analysis of variance) by site are different

-   rate of abnormal DRE by site is different (p \< 0.001, Chi square
    test)

-   race category by site is different (p \< 0.0001, Chi square test)

-   mean age by site is different (p \< 0.0001 by analysis of variance)

To examine the percentage of subjects who had a biopsy at each site for
differences from the overall percentage, the following table summarizes
the results.

> Table 3 Frequency of biopsy follow-up by clinical site

  -------------------- -------------- ------------------ ----------- ---------------
  **Site**             **Biopsied**   **non-biopsied**   **total**   **Frequency**

  **Southwest US**     37             964                1001        3.7%

  **Northwest US**     52             425                477         10.9%

  **Chile**            197            2135               2332        8.4%

  **Total**            286            3524               3810        7.5%
  -------------------- -------------- ------------------ ----------- ---------------

The probability of equal frequencies of biopsy at each site was \<
0.0001

(Chi square = 31.8 for 2 degrees of freedom).

Because there was a differential rate of biopsy, elevated PSA, and
abnormal DRE at each site there could be differences in the performance
of these diagnostic tests at each site. To investigate differences,
several parameters were examined. The first test performance analyzed
was the performance of PSA in relation to biopsy result. The odds ratio
of cancer given an elevated PSA was calculated for each site and
compared to the mean odds ratio. The mean odds ratio of cancer given an
elevated PSA across the three sites was 2.67 (95% confidence interval
1.04 to 6.81). The odds ratio of cancer for all three sites was 1.85.
The probability of homogeneous odds ratios was 0.78. There was no
significant difference in odds ratios at each site compared to the mean
odds ratio.

The next test performance analyzed was the performance of DRE in
relation to biopsy result. The odds ratio of cancer given an abnormal
DRE was calculated for each site and compared to the mean odds ratio.
The mean odds ratio of cancer given an abnormal DRE across the three
sites was 2.095 (95% confidence interval 1.085 to 4.048). The odds ratio
of cancer given an abnormal DRE for all three sites was 2.348. The
probability of homogeneous odds ratios was 0.71.

The third test performance analyzed was the performance of PSA and DRE
(when both are positive) in relation to biopsy result. The odds ratio of
cancer given an abnormal PSA and DRE result (i.e., when both are
positive) was calculated for each site and compared to the mean odds
ratio. The mean odds ratio of cancer given an abnormal result across the
three sites was 3.172 (95% confidence interval 1.477 to 6.812). The odds
ratio of cancer given an abnormal result for all three sites was 3.187.
The probability of homogeneous odds ratios was 0.75.

The last test performance analyzed was the performance of PSA in
relation to DRE result. The odds ratio of an elevated PSA given an
abnormal DRE result was calculated for each site for all subjects
(biopsied and non-biopsied) and compared to the mean odds ratio. The
mean odds ratio of an elevated PSA given an abnormal DRE result across
the three sites was 5.714 (95% confidence interval 3.998 to 8.167). The
odds ratios for the sites ranged from 2.443 to 9.593. The odds ratio of
an elevated PSA given an abnormal DRE result for all three sites was
5.549. The probability of homogeneous odds ratios was 0.012. There was a
significant difference in odds ratios at each site compared to the mean
odds ratio. This result suggests that an elevated PSA in relation to an
abnormal DRE result was not equivalent at each site. The results suggest
that the odds ratios were not homogeneous due to large variation in the
odds ratios. This result is consistent with non-homogeneous rates of
abnormal DRE and rates of elevated PSA among all subjects at each sites,
as noted above.

In summary, three of four analyses of test performance at the sites
indicate that PSA and DRE performed equivalently despite differences in
several patients characteristics. The rate of elevated PSA and mean PSA,
rate of abnormal DRE, mean age, and distribution of racial categories
were different between sites. However, the cancer rate was not different
by site. Though patient characteristics were different between sites,
the test performance was on average not different between sites. This
rationale would support the pooling of data, at least for the Immulite
PSA assay. If it is assumed that the distribution of PSA results using
the other assays is the same as the distribution of PSA results for the
Immulite PSA then it could be assumed that data for the other PSA assay
can be pooled. However, the differential rate of biopsy and mean age
differences between sites could also be associated with diagnostic test
performance in ways other than across clinical study site. The
poolability analysis does not exclude the possibility of non-random
association of diagnostic test performance with such factors as:

-   undergoing a biopsy procedure based on age or a diagnostic test
    value near the cut-off;

-   family history of prostate cancer;

-   racial or ethnic background.

The poolability analysis indicated that PSA and DRE performed
equivalently despite differences in several patient characteristics and
biopsy follow-up. The analysis did not exclude the possibility of
non-random association between diagnostic test result (PSA and/or DRE),
age, and biopsy follow-up.

### 

### Study Results

The studies for IMMULITE PSA were conducted at three sites. Samples from
3810 men, aged 50 or older, were collected. Of the 3810 total subjects,
3438 patients also had DRE results. The percentage of subjects with
abnormal DRE results was 4.6%. Of the 3438 screened subjects with DRE
results, 252 subjects had a biopsy (7.3% of total screened) and 81
cancers were found (2.4% of all screened, 32.1% of biopsied subjects).

The following table (Table 4) gives the numbers of all screened subjects
and subjects who underwent biopsy with both PSA results (classified as
positive when \>4 ng/mL or negative when ≤4 ng/mL) and DRE results
(classified as positive when suspicious for cancer and negative when
non-suspicious).

Table 4

+----------+----------------------------+-----------------------------+
|          | **PSA+**                   | **PSA-**                    |
+----------+----------------------------+-----------------------------+
| **DRE+** | n=64                       | n=93                        |
|          |                            |                             |
|          | (PSA median=7.1)           | (PSA median=1.3)            |
|          |                            |                             |
|          | 34 (53%) subjects          | 16 (17%) subjects underwent |
|          | underwent biopsy           | biopsy                      |
|          |                            |                             |
|          | (PSA median=7.6)           | (PSA median=2.3)            |
+----------+----------------------------+-----------------------------+
| **DRE-** | n=353                      | n=2,928                     |
|          |                            |                             |
|          | (PSA median=5.9)           | (PSA median=1.0)            |
|          |                            |                             |
|          | 191 (54%) subjects         | 11 (0.4%) subjects          |
|          | underwent biopsy           | underwent biopsy            |
|          |                            |                             |
|          | (PSA median=6.0)           | (PSA median=3.4)            |
+----------+----------------------------+-----------------------------+

> The biopsy results are presented in the following tables (Tables 5,
> 6):

  ------- ---------- -------- -------- ---------- ---------- --------- --------
          **Table                                 **Table              
          5**                                     6**                  

          Biopsy                                  Biopsy               
          positive                                Negative             

          PSA +      PSA --   N                   PSA +      PSA --    N

  DRE+    19         5        24       DRE +      15         11        26

  DRE --  55         2        57       DRE --     136        9         145

          74         7        81                  151        20        171
  ------- ---------- -------- -------- ---------- ---------- --------- --------

Unbiased estimates of TP (sensitivity) and FP (1- specificity) can be
obtained if the biopsy was performed on all subjects for whom DRE and
PSA tests have been applied. But in these studies, subjects with both
DRE and PSA negative test results were not verified by biopsy and,
therefore, the TP and FP fractions of DRE and PSA cannot be calculated
directly from these data. These data provide information about the ratio
of TP relative to TP of DRE, ratio of FP to FP of DRE (see reference 3),
and the rates of positive biopsy results (see reference 4).

It can be seen from Table 5 that the TP rates of DRE alone, PSA alone,
the combination of PSA and DRE (when both are positive), and combination
of DRE and/or PSA are as follows: TP(DRE) = 24/n1; TP(PSA) = 74/n1;
TP(PSA and DRE) = 19/n1; TP(PSA and/or DRE) = 79/n1, where n1 is unknown
number.

Then the ratio of TP rates relative to DRE alone is unbiased:

TP(PSA)/TP(DRE)= 74/24= 3.1 with 95% CI: 2.2 - 4.4;\
TP(PSA and DRE)/TP(DRE) = 19/24 = 0.79 with 95% CI: 0.74-0.84); and\
TP(PSA and/or DRE)/TP(DRE)=79/24 = 3.3 with 95% CI: 2.4 - 4.6.

Similarly, the ratio of FP rates relative to the FP rate of DRE alone is
calculated from Table 6: FP(DRE) = 26/n2; FP(PSA) = 151/n1; FP(PSA and
DRE) = 15/n2; FP(PSA and/or DRE) = 162/n2 where n2 is unknown number.
Then the ratio of FP rates relative to DRE alone is:

FP(PSA)/FP(DRE)=151/26=5.8 and

FP(PSA and DRE)/FP(DRE) = 15/26= 0.58 and\
FP(PSA and/or DRE)/TP(DRE)=7162/26=6.2.

The study demonstrated that PSA determinations detected 68% (55/81) of
cancers that DRE did not; PSA elevations greater than 4 ng/mL may
warrant additional testing even if the DRE is negative. However, the
converse is also true: a subject with suspicious DRE and a normal PSA
may also require additional testing since DRE detected 6% (5/81) of
cancers that PSA determinations did not. PSA alone detected 3.1 times
more cancers than DRE alone while obtaining 5.8 times more false
positive results. The combination PSA and/or DRE detected 3.3 times more
cancers than DRE alone while obtaining 6.2 times more false positive
results.

The following table (Table 7) gives the estimates of % positive biopsies
in various diagnostic categories:

Table 7

  ---------------- ------------ ------------ ------------- ----------------
                   **No. Of     **No. of     **No. of      **% Positive
                   Subjects**   Biopsies     Prostate      Biopsies\
                                (%)**        Cancers**     (95% CI)**

  **All subjects** 3438         252          81            32.1%\
                                                           (26.4% - 38.2%)

  **PSA \> 4.0**   417          225          74            32.9%\
                                                           (26.8%-62.6%)

  **DRE +**        157          50           24            48.0%\
                                                           (33.6% - 62.6%)

  **PSA \> 4.0     64           34           19            55.9%\
  DRE+**                                                   (37.9% - 72.8%

  **PSA\<= 4.0     93           16           5             31.3%\
  DRE+**                                                   (13.2% - 57.1%

  **PSA \> 4.0 DRE 353          191          55            28.8%\
  -**                                                      (22.5% - 35.5%)

  **PSA \<= 4.0    2928         11           2             18.2%\
  DRE -**                                                  (2.3% - 51.8%)
  ---------------- ------------ ------------ ------------- ----------------

One common difficulty of clinical studies of diagnostic tests is the
potential for overestimated or underestimated test performance due to
selection of a non-random subset of subjects with biopsy results from
among all subjects. An absence for some reason of biopsy results for
subjects who should have biopsy according to the study protocol but did
not have biopsy can be considered as a problem of missing data. If the
mechanism for the missing values is independent of the result of PSA
test - then the estimation of the PSA performance will be unbiased but
less efficient. All estimates (ratio of TP to TP (DRE), ratio of FP to
FP (DRE),and the %positive biopsies for different diagnostic categories)
are unbiased only if the missing results of biopsy occurred completely
at random and in the same proportion for all groups (PSA+, DRE+), (PSA+,
DRE-), and (PSA-, DRE+).

Statistical analysis showed that missing results of biopsy occurred at
random only in two groups of subjects: (PSA+, DRE+ and PSA+, DRE-).
Comparison of median PSA results suggests that the median PSA value for
biopsied subjects with PSA \> 4.0 ng/ml and abnormal DRE (7.6 ng/ml) is
similar to the median PSA value for all screened subjects with these
diagnostic test results (7.1 ng/ml). Comparison of median PSA results
for biopsied subjects with PSA \> 4.0 ng/ml and normal DRE (6.0 ng/ml)
is similar to median PSA value for screened subjects with PSA \> 4.0
ng/ml and normal DRE (5.9 ng/ml). Also, the proportion of biopsied
subjects in these two cells are almost the same (53-54%).

Logistic regression analysis showed that the absolute value of the PSA
assay was a significant predictor for data missingness in the cell
(PSA-, DRE+). It indicated that biopsied subjects were not randomly
selected from all screened subjects with abnormal DRE and PSA\<4.0
ng/ml. Comparison of median PSA values for biopsied subjects with PSA \<
4 ng/ml and abnormal DRE (2.3 ng/ml) is different from median values for
screened subjects with these test results (1.3 ng/ml). Also the
proportion of biopsied subjects in this group (17%) is much smaller than
in PSA+, DRE+ and PSA+, DRE- groups. Subjects with negative results on
both PSA and DRE were biopsied at a very low frequency (0.4%) and not at
random. The median values for biopsied subjects with PSA \< 4.0 ng/ml
and normal DRE (3.4 ng/ml) is different from screened subjects with
these test results (1.0 ng/ml). As a result of the lack of random
selection to biopsy, initial estimators of ratio of TP rates relative to
TP(DRE), ratio of FP rates relative to FP(DRE), and %positive biopsies
were inaccurate estimates.

The missing data and subsequent overestimation of DRE performance
stimulated statistical modeling (multiple imputation technique) in the
subject counts for biopsy positive and biopsy negative subjects with
abnormal DRE and PSA \< 4.0 ng/ml (see reference 1). If initial subject
counts are sufficiently large to allow building of a model, then the
technique of multiple imputation for missing data can be applied. For
the Immulite PSA study, the variables Age, PSA and the interaction term
Age\*PSA are significant predictors for the biopsy results for the
subjects with PSA- DRE+ results. The multiple imputation technique
estimated

8 subjects with positive biopsy results and 42 subjects with negative
biopsy results (percentage of subjects with biopsy = 53.7% (50/93)). No
modeling was performed for subjects with normal DRE and PSA \< 4.0 ng/ml
due to insufficient number of biopsied subjects (11) to allow estimation
by modeling. After application of multiple imputation technique, the
tables of the biopsy results

adjusted for missingness are the following (Tables 8 and 9):

> Subject count after statistical modeling

  ---------- ----------- ---------- --------- ---------- ---------- ----------
             **Table 8**                                 **Table    
                                                         9**        

             Biopsy                                      Biopsy     
             positive                                    Negative   

             PSA+        PSA-                            PSA+       PSA-

  DRE+       19          **8**                DRE+       15         **42**

  DRE-       55          n/a                  DRE-       136        n/a
  ---------- ----------- ---------- --------- ---------- ---------- ----------

The following table (Table 10) summarizes the subject counts by biopsy
result prior to and after statistical modeling and the percent positive
biopsies (positive predictive values):

Table 10

  ---------- ------------ ------------ ------------ ------------ ------------- ------------
             **No.        **No.        **No. Benign **No. Benign **%positive   **% positive
             Cancers      Cancers with without      with         biopsies      biopsies
             without      modeling**   modeling**   modeling**   without       with
             modeling**                                          modeling**    modeling**

  **PSA \>   74           74           151          151          32.9%\        32.9%\
  4.0**                                                          (26.8 -62.6)  (26.8 -
                                                                               39.0)

  **DRE +**  24           27           26           57           48.0%\        32.1%\
                                                                 (33.6 - 62.6) (22.2 -
                                                                               42.1)

  **PSA \>   19           19           15           15           55.9%\        55.9%\
  4.0 DRE+**                                                     (37.9 - 72.8) (39.2 -
                                                                               72.6)

  **PSA\<=   5            8            11           42           31.3%\        16.0%\
  4.0 DRE+**                                                     (13.2 - 57.1) (5.8 - 26.2)

  **PSA \>   55           55           136          136          28.8%\        26.7%\
  4.0 DRE                                                        (22.5 - 35.5) (22.4 -
  -**                                                                          35.2)
  ---------- ------------ ------------ ------------ ------------ ------------- ------------

The yield of cancer after modeling was 28.8% (95% confidence interval
23.5% to 34.0%). This yield is equivalent with the cancer yield prior to
modeling (32.2%, 95% confidence interval 26.8% to 37.6%). The positive
predictive value of DRE alone was 32.1% after modeling (negative
predictive value 72.6% ± 3.1%). The positive predictive value of PSA
alone was 32.9% after modeling (negative predictive value 86.7% ± 4.4%).
At a cutoff of 4.0 ng/ml the Immulite PSA assay detects 91% of all
cancer cases regardless of the result of the rectal examination. At a
cutoff of 4.0 ng/ml, 26% of all benign cases regardless of the result of
the rectal examination are less than 4.0 ng/ml in the Immulite PSA
assay. The mean PSA in cancer subjects was 13.0 ng/ml ± 20.4. The mean
PSA in subjects with benign disease was 6.6 ng/ml ± 4.6. The probability
of no difference in the mean PSA value of cancer subjects compared with
the mean PSA value of benign subjects was 0.001 (Mann Whitney test).

The positive predictive value of PSA and DRE (when both are positive)
was 55.9% after modeling (negative predictive value 74.9% ± 2.7%). The
positive predictive value of PSA and DRE is significantly higher than
the modeled and unmodeled cancer yield (p \< 0.01). This result supports
a conclusion that PSA and DRE in combination were able to detect cancer.
The positive predictive value of PSA and DRE in combination is also
significantly higher than the positive predictive value of DRE alone (p
= 0.01). This supports a conclusion that PSA and DRE in combination
detect more cancers than DRE alone.

The positive predictive value of PSA and/or DRE (when both PSA \> 4.0
and abnormal DRE or PSA \> 4.0 ng/ml alone or abnormal DRE alone) was
29.8% ± 2.8% after modeling (negative predictive value 100% ± 0%). This
result supports a conclusion that PSA and DRE in conjunction were able
to detect cancer.

The following table (Table 11) summarizes ratios of true positive and
false positive rates prior to and after multiple imputation:

Table 11

  ---------- --------------- --------------- --------------- --------------
             **TP / TP(DRE)\ **FP / FP(DRE)\ **TP / TP(DRE)  **FP / FP(DRE)
             without         without         with modeling\  with modeling\
             modeling**      modeling**      (95% CI)**      (95% CI)**

  **PSA**    3.1             5.8             2.7\            2.6\
                                             (1.9-3.9)       (2.0-3.5)

  **PSA      3.3             6.2             3.0\            3.4\
  and/or                                     (2.0-3.5)       (2.7-4.2)
  DRE**                                                      

  **PSA and  0.79            0.58            0.70\           0.26\
  DRE**                                      (0.66-0.75)     (0.25-0.28)
  ---------- --------------- --------------- --------------- --------------

The data in the table indicate that the use of PSA increased true
positive and false positive rates almost in the same proportion (TP/FP
rate = 0.88 to 1.04) compared to DRE alone. The use of PSA and DRE (when
both are positive) decreased the true positive rate and decreased the
false positive rate relative to the rate for DRE but in a different
proportion. The ratio of the true positive rate to the false positive
rate for the combination of PSA and DRE (when both are positive) was
2.7. The use of PSA and DRE when both are positive yields more true
positive subjects than false positive subjects relative to the TP/FP
ratio of DRE alone. The use of the PSA testing increased the negative
predictive values while the positive predictive values compared to the
DRE alone were similar after modeling to positive predictive values
prior to modeling.

In the same studies, 2928 participants in the clinical study were
identified as asymptomatic subjects. The following table contains the
distribution of PSA values by age decade for asymptomatic subjects who
had both a negative PSA and DRE test result and were unbiopsied as well
as for those subjects who were negative for cancer on biopsy. There is
no certainty that all of these subjects were indeed free of prostate
disease. Therefore, these data should be interpreted with caution since
it is questionable whether these subjects represent a truly normal
population. Presently, there are no data proving that the use of
age-specific reference ranges are safe or effective.

> Table 12 - Immulite PSA distribution by age decade

  ---------------------------- -------------- --------------- ------------
  **Distribution of PSA        **N**          **PSA Median**  **PSA\
  Levels**                                                    95^th^
                                                              %ile**

  **All subjects**             2928           1.00            3.30

  **50--59 age group**         1338           0.93            3.00

  **60--69 age group**         1144           1.20            3.40

  **≥70 age group**            446            1.40            3.60
  ---------------------------- -------------- --------------- ------------

Consider these limits as *guidelines* only. Each laboratory should
establish its own reference ranges.

The studies for **IMMULITE Third Generation PSA** were conducted at two
U.S. clinical sites. Samples were collected from 1477 men, aged 50 or
older. Of these, 78% were Caucasian; 16% were African American; 4% were
Asian; \<1% were other or provided no ethnic information. Of these 1477
men, 1468 also underwent DRE. Of these 1468 subjects, 88 were biopsied
for elevated (\> 4.0 ng/mL) PSA and/or suspicious DRE. Thirty-five
cancers were found.

The following table gives the number of all screened subjects with both
PSA results (classified as positive when \>4 ng/mL or negative when ≤4
ng/mL) and DRE results (classified as positive when suspicious for
cancer and negative when non-suspicious).

Table 13

  ----------- ---------------------------- ------------------------------
              **PSA+**                     **PSA-**

  **DRE+**    n=35\                        n=71\
              (PSA median=6.7)\            (PSA median=1.3)\
              \                            \
              16 (47%) subjects underwent  15 (21%) subjects underwent
              biopsy\                      biopsy\
              (PSA median=6.3)             (PSA median=2.3)

  **DRE-**    n=126\                       n=1,236\
              (PSA median=5.8)\            (PSA median=1.0)\
              \                            \
              48 (38%) subjects underwent  9 (0.7%) subjects underwent
              biopsy\                      biopsy\
              (PSA median=6.2)             (PSA median=3.4)
  ----------- ---------------------------- ------------------------------

The biopsy results are presented in the following tables:

> Table 14 Table 15

  ---------- ------------ ---------- -------- ---- ---------- ------------ ---------- -------
             **Biopsy                                         **Biopsy                
             Positive**                                       Negative**              

             **PSA+**     **PSA-**   **n**                    **PSA+**     **PSA-**   **n**

  **DRE+**   10           5          15            **DRE+**   6            10         16

  **DRE-**   18           2          20            **DRE-**   30           7          37

             28           7          35                       36           17         53
  ---------- ------------ ---------- -------- ---- ---------- ------------ ---------- -------

The following table presents the % positive biopsies using the Immulite
3^rd^ generation PSA assay:

> Table 16

  -------------- --------------- ------------ ------------ ----------------
                 **No. of        **No. of     **No. of     **% Positive
                 Subjects\       Biopsies\    Cancers\     Biopsies\
                 N (% of         N (% )**     N**          (95% CI)**
                 total)**                                  

  **All          1468            88           35           **39.8%\
  Subjects**                                               **29.6% - 50.0%

  **PSA\>4.0**   161\            64\          28           **43.8%\
                 (11.0%)         (39.8%)                   **(31.4 - 56.7)

  **DRE+**       106\            31\          15           **48.4%\
                 (7.2%)          (29.2%)                   **(31.0 - 66.9)

  **PSA\>4.0     35\             16\          10           **62.5%\
  DRE+**         (2.4%)          (45.7%)                   **(35.4 - 82.2)

  PSA≤4.0 DRE+   71\             15\          5            **33.3%\
                 (4.8%)          (21.1%)                   **(14.2 - 61.6)

  PSA\>4.0 DRE-  126\            48\          18           **37.5%\
                 (8.6%)          (38.1%)                   **(24.0 - 52.6)

  PSA≤4.0 DRE-   1,236\          9\           2            **22.2%\
                 (84.2%)         (0.7%)                    **(2.8 - 60.0)
  -------------- --------------- ------------ ------------ ----------------

The results indicated that PSA determinations detected 51% (18/35) of
cancers that DRE did not; and DRE detected 14% (5/35) of cancers that
PSA determinations did not. PSA alone detected 1.9 (28/15=1.9 with
95%CI: 1.2-3.0) times more cancers than DRE alone and the combination of
PSA and/or DRE detected 2.2 (33/15=2.2 with 95% CI: 1.5-3.2) times more
cancers than DRE alone. The use of PSA alone increased false positive
rate 2.3 (36/16) times relative to DRE and the use of the combination of
PSA and/or DRE increased the false positive rate 2.9 (46/16) times
relative to DRE. The use of PSA and DRE when both are positive detected
0.67 times (10/15=0.67 with 95% CI: 0.55-0.78) fewer cancers than DRE
alone and 0.38 times (6/16= 0.38 with 95% CI: 0.27-0.48) fewer false
positives than DRE alone. The combination of PSA and DRE detected 1.8
times as many true positives as false positives relative to TP/FP ratio
of DRE.

Logistic regression analysis indicated that the absolute value of the
PSA test was a significant predictor for the absence of biopsy results
for subjects with DRE+ and PSA-. The PSA median of biopsied subjects was
2.3 while PSA median of all screened subjects was 1.3. Also, the
proportion of missing biopsy results in this group is larger than in the
groups DRE+, PSA+ and DRE-, PSA+. The correlation of the absolute value
of the PSA test with the performance of a biopsy lead to overestimation
of the DRE performance. After application of multiple imputation
technique, the tables of the biopsy results adjusted for missingness are
following:

  ------- ---------- -------- -------- ---------- ---------- --------- --------
          **Table                                 **Table              
          17**                                    18**                 

          Biopsy                                  Biopsy               
          positive                                Negative             

          PSA +      PSA --                       PSA +      PSA --    

  DRE+    10         6                 DRE +      6          27        

  DRE --  22         n/a               DRE --     36         n/a       

                                                                       
  ------- ---------- -------- -------- ---------- ---------- --------- --------

> n/a -- not available

The following table (Table 19) summarizes the subject counts by biopsy
result prior to and after statistical modeling and the percent positive
biopsies (positive predictive values):

Table 19

+---------+--------+--------+--------+--------+-----------+---------+
|         | **No.  | **No.  | **No.  | **No.  | **        | **%p    |
|         | C      | C      | Benign | Benign | %positive | ositive |
|         | ancers | ancers | w      | with   | biopsies  | b       |
|         | w      | with   | ithout | mode   | without   | iopsies |
|         | ithout | mode   | mode   | ling** | m         | with    |
|         | mode   | ling** | ling** |        | odeling** | mod     |
|         | ling** |        |        |        |           | eling** |
+---------+--------+--------+--------+--------+-----------+---------+
| **PSA   | 28     | 32     | 36     | 42     | 43.8%\    | 43.2%   |
| \>      |        |        |        |        | (31.4 --  |         |
| 4.0**   |        |        |        |        | 56.7)     | (31.8   |
|         |        |        |        |        |           | --      |
|         |        |        |        |        |           | 55.3)   |
+---------+--------+--------+--------+--------+-----------+---------+
| **DRE   | 15     | 16     | 16     | 33     | 48.4%\    | 32.6%\  |
| +**     |        |        |        |        | (31.0 --  | (20.0   |
|         |        |        |        |        | 66.9)     | --      |
|         |        |        |        |        |           | 37.5)   |
+---------+--------+--------+--------+--------+-----------+---------+
| **PSA   | 10     | 10     | 6      | 6      | 62.5%\    | 62.5%\  |
| \> 4.0  |        |        |        |        | (35.4 -   | (35.4 - |
| DRE+**  |        |        |        |        | 82.2)     | 82.2)   |
+---------+--------+--------+--------+--------+-----------+---------+
| *       | 5      | 6      | 10     | 27     | 33.3%\    | 18.2%\  |
| *PSA\<= |        |        |        |        | (14.2 --  | (7.0 -- |
| 4.0     |        |        |        |        | 61.6)     | 35.5)   |
| DRE+**  |        |        |        |        |           |         |
+---------+--------+--------+--------+--------+-----------+---------+
| **PSA   | 18     | 22     | 30     | 36     | 37.5%\    | 37.9%\  |
| \> 4.0  |        |        |        |        | (24.0 --  | (25.5   |
| DRE -** |        |        |        |        | 52.6)     | --      |
|         |        |        |        |        |           | 51.6)   |
+---------+--------+--------+--------+--------+-----------+---------+

The yield of cancer after modeling was 33.0% (95% confidence interval
24.4% to 41.6%). This yield is equivalent with the cancer yield prior to
modeling (39.8%, 95% confidence interval 31.6% to 50.0%).

The positive predictive value of PSA and DRE is significantly higher
than the adjusted cancer yield (p = 0.007). The positive predictive
value of PSA and DRE is also significantly higher than the positive
predictive value of DRE alone (p = 0.002).

The following table summarizes ratios of true positive and false
positive rates prior to and after multiple imputation:

> Table 20

+---------+--------------+--------------+--------------+-------------+
|         | **TP /       | **FP /       | **TP /       | **FP /      |
|         | TP(DRE)**    | FP(DRE)**    | TP(DRE) with | FP(DRE)     |
|         |              |              | modeling**   | with        |
|         | **without    | **without    |              | modeling**  |
|         | modeling**   | modeling**   | **(95% CI)** |             |
|         |              |              |              | **(95%      |
|         |              |              |              | CI)**       |
+---------+--------------+--------------+--------------+-------------+
| **PSA** | 1.9          | 2.3          | 2.0          | 1.3         |
|         |              |              |              |             |
|         |              |              | (1.3-3.2)    | (0.8-1.9)   |
+---------+--------------+--------------+--------------+-------------+
| **PSA   | 2.2          | 2.9          | 2.4          | 2.1         |
| and/or  |              |              |              |             |
| DRE**   |              |              | (1.6-3.4)    | (1.6-2.7)   |
+---------+--------------+--------------+--------------+-------------+
| **PSA   | 0.67\        | 0.38\        | 0.63\        | 0.18\       |
| and     | (0.55-0.78)) | (0.27-0.48)  | (0.51-0.74)  | (0.08-0.29) |
| DRE**   |              |              |              |             |
+---------+--------------+--------------+--------------+-------------+

The data in the table indicate that the use of PSA alone increased true
positive and false positive rates almost in the same proportion compared
to DRE alone. The use of PSA and/or DRE also increased the true positive
and false positive rates in the same proportion compared to DRE alone.
The use of PSA and DRE when both are positive decreased the true
positive rate and false positive rate compared to DRE. However, the
reduction of TP and FP rates was not in equal proportions (i.e., TP/FP ≈
1.0) but was 3.4 (95% CI: 2.2-4.7) relative to DRE alone. The use of the
PSA testing increased the negative predictive values while the positive
predictive values compared to the DRE alone were similar after modeling
to positive predictive values prior to modeling.

In the same studies, 1236 participants were identified as asymptomatic
subjects in the clinical study. The following table contains the
distribution of PSA values by age decade for asymptomatic subjects who
had both a negative PSA and DRE and were unbiopsied as well as for those
subjects who were negative for cancer on biopsy. There is no certainty
that all of these subjects were indeed free of prostate disease.
Therefore, these data should be interpreted with caution since it is
questionable whether these subjects represent a truly normal population.
There are presently no data proving that the use of age-specific
reference ranges are safe or effective.

> Table 21 - Immulite 3^rd^ Generation PSA distribution by age decade

  --------------------------- ------------ -------------- -----------------
  **Distribution of PSA       **n**        **PSA Median** **PSA\
  Levels**                                                95^th^ %ile**

  **All subjects**            1236         0.98           3.28

  **50--59 age group**        612          0.81           2.73

  **60--69 age group**        458          1.11           3.45

  **≥70 age group**           166          1.35           3.65
  --------------------------- ------------ -------------- -----------------

Consider these limits as *guidelines* only. Each laboratory should
establish its own reference ranges.

The study for **IMMULITE 2000 PSA** and **IMMULITE 2000 Third Generation
PSA** was conducted at one clinical site. Samples were collected from
477 men, aged 50 or older. Of these 477 subjects, 20 (4%) were Asian; 8
(2%) were African American; 440 (92%) were Caucasian; 7 (\<1%) were
other and 2 (\<1%) provided no ethnic information. All patients also
underwent DRE. Of these, 52 were biopsied for elevated (\> 4.0 ng/mL)
PSA and/or suspicious DRE. Eighteen cancers were found.

### IMMULITE 2000 PSA

The following table gives the number of all screened subjects with both
PSA results (classified as positive when \>4 ng/mL or negative when ≤4
ng/mL) and DRE results (classified as positive when suspicious for
cancer and negative when non-suspicious).

Table 22

  ----------- ---------------------------- ------------------------------
              **PSA+**                     **PSA-**

  **DRE+**    n=23\                        n=31\
              \                            \
              12 (52%) subjects underwent  5 (16%) subjects underwent
              biopsy                       biopsy

  **DRE-**    n=47\                        n=376\
              \                            \
              26 (55%) subjects underwent  9 (2.4%) subjects underwent
              biopsy                       biopsy
  ----------- ---------------------------- ------------------------------

The biopsy results are presented in the following tables:

  ------- ---------- -------- -------- ---------- ---------- --------- --------
          **Table                                 **Table              
          23**                                    24**                 

          Biopsy                                  Biopsy               
          positive                                Negative             

          PSA +      PSA --   N                   PSA +      PSA --    N

  DRE+    6          2        8        DRE +      6          3         9

  DRE --  9          1        10       DRE --     17         8         25

          15         3        18                  23         11        34
  ------- ---------- -------- -------- ---------- ---------- --------- --------

PSA determinations detected 50% (9/18) of cancers that DRE did not; and
DRE detected 11% (2/18) of cancers that PSA determinations did not. PSA
alone detected 1.9 (15/8) times more cancers than DRE alone. The
combination of PSA and/or DRE detected 2.1 (17/8) times more cancers
than DRE alone. The combination of PSA and DRE when both are positive
detected 0.75 (6/8) times as many cancers as DRE alone. The use of PSA
alone increased the false positive rate 2.6 (23/9) times relative to the
rate for DRE. Use of the combination of PSA and/or DRE increased the
false positive rate 2.9 (26/9) times relative to the rate for DRE. The
combination of PSA and DRE when both are positive increased the false
positive rate 0.7 times (6/9) relative to the rate of DRE alone.

In the same study, 376 participants were identified as asymptomatic
subjects. The following table contains the distribution of PSA values by
age decade for asymptomatic subjects who had both a negative PSA and DRE
and were unbiopsied as well as for those subjects who were negative for
cancer biopsy. There is no certainty that all of these subjects were
indeed free of prostate disease. Therefore, these data should be
interpreted with caution since it is questionable whether these subjects
represent a truly normal population. There are presently no data proving
that the use of age-specific reference ranges are safe or effective.

> Table 25 - Immulite 2000 PSA distribution by age decade

  --------------------------- ------------- ------------- ----------------
  **Distribution of PSA       ***n***       **PSA         **PSA\
  Levels**                                  Median**      95^th^ %ile**

  **All subjects**            376           0.78          2.98

  **50--59 age group**        159           0.60          2.30

  **60--69 age group**        143           0.91          2.84

  **≥70 age group**           74            1.17          3.17
  --------------------------- ------------- ------------- ----------------

Consider these limits as *guidelines* only. Each laboratory should
establish its own reference ranges.

### IMMULITE 2000 Third Generation PSA 

Table 26

  ----------- ---------------------------- ------------------------------
              **PSA+**                     **PSA-**

  **DRE+**    n=25\                        n=29\
              \                            \
              13 (52%) subjects underwent  4 (14%) subjects underwent
              biopsy                       biopsy

  **DRE-**    n=60\                        n=363\
              \                            \
              32 (55%) subjects underwent  3 (0.8%) subjects underwent
              biopsy                       biopsy
  ----------- ---------------------------- ------------------------------

The biopsy results are presented in the following tables:

  ------- ---------- -------- -------- ---------- ---------- --------- --------
          **Table                                 **Table              
          27**                                    28**                 

          Biopsy                                  Biopsy               
          positive                                Negative             

          PSA +      PSA --   N                   PSA +      PSA --    N

  DRE+    7          1        8        DRE +      6          3         9

  DRE --  9          1        10       DRE --     23         2         25

          16         2        18                  29         5         34
  ------- ---------- -------- -------- ---------- ---------- --------- --------

PSA determinations detected 50% (9/18) of cancers that DRE did not; and
DRE detected 6% (1/18) of cancers that PSA determinations did not. PSA
alone detected 2.0 (16/8) times more cancers than DRE alone. The
combination of PSA and/or DRE detected 2.1 (17/8) times more cancers
than the DRE alone. The use of PSA alone increased the false positive
rate 3.2 (29/9) times relative to the FP rate of DRE. Use of the
combination of PSA and/or DRE increased the false positive rate 3.6
(32/9) times relative to the rate of DRE. The combination of PSA and DRE
when both are positive detected 0.9 (7/8) times as many cancers as DRE
alone but decreased the false positive rate 0.7 times the false positive
rate of DRE alone.

In the same study, 363 participants were identified as asymptomatic
subjects. The following table contains the distribution of PSA values by
age decade for asymptomatic subjects who had both a negative PSA and DRE
and were unbiopsied as well as for those subjects who were negative for
cancer on biopsy. There is no certainty that all of these subjects were
indeed free of prostate disease. Therefore, these data should be
interpreted with caution since it is questionable whether these subjects
represent a truly normal population. There are presently no data proving
that the use of age-specific reference ranges are safe or effective.

> Table 29 - Immulite 2000 3^rd^ generation PSA distribution by age
> decade

  ------------------------ ------------ --------------- ------------------
  **Distribution of PSA    **N**        **PSA Median**  **PSA\
  Levels**                                              95^th^ %ile**

  **All subjects**         363          1.02            3.20

  **50--59 age group**     157          0.88            2.83

  **60--69 age group**     137          1.12            3.15

  **≥70 age group**        69           1.48            3.58
  ------------------------ ------------ --------------- ------------------

Consider these limits as *guidelines* only. Each laboratory should
establish its own reference ranges.

The following table presents the model adjusted % positive biopsies for
the IMMULITE PSA, IMMULITE Third Generation PSA, IMMULITE 2000 PSA, and
IMMULITE Third Generation PSA:

Table- 30 Model adjusted % positive biopsies for each PSA assay

  --------------- ------------- -------------- ------------- --------------
                  **IMMULITE    **IMMULITE     **IMMULITE    **IMMULITE
                  PSA**         Third          2000 PSA**    2000 Third
                                Generation**                 Generation**

  PSA\>4.0        32.9%\        43.2%\         39.5%\        35.6%\
                  (26.8 - 39.1) (31.8 -- 55.3) (24.0 --      (21.7 -- 49.5)
                                               54.0)         

  DRE+            32.1%\        32.6%\         47.1%\        47.1%\
                  (22.2 --42.1) (20.0 -- 37.5) (25.3 --      (23.4 -- 70.8)
                                               72.2)         

  PSA\>4.0 DRE+   55.9%\        62.5%\         50.0%\        53.8%\
                  (39.2 --      (35.4 -- 82.2) (23.6 --      (26.8 -- 80.8)
                  72.6)                        76.4)         

  PSA≤4.0 DRE+    16.0%\        18.2%\         40.0%\        25.0%\
                  (5.8 -- 26.2) (7.0 -- 35.5)  (0 -- 82.9)   (0 -- 67.5)

  PSA\>4.0 DRE-   26.7%\        37.9%\         34.6%\        28.1%\
                  (22.4 --      (24.0 -- 51.6) (16.4 --      (12.6 -- 43.6)
                  35.2)                        52.8)         
  --------------- ------------- -------------- ------------- --------------

## 

## Method Comparison Studies 

All four PSA assays were compared using Deming regression analysis.
Samples used were within the working range of the assays. The table
below presents the results of the Deming regressions, with columns as
Y-variable, and rows as X-variable.

Table 31 - Deming Regression analysis

+----------+----------+-----------+-----------+----------+-----------+
|          |          | *         | *         | **       | *         |
|          |          | *Immulite | *Immulite | Immulite | *Immulite |
|          |          | PSA**     | 2000      | 3^rd^    | 2000      |
|          |          |           | PSA**     | Ge       | 3^rd^     |
|          |          |           |           | neration | g         |
|          |          |           |           | PSA**    | eneration |
|          |          |           |           |          | PSA**     |
+----------+----------+-----------+-----------+----------+-----------+
| > **     | **N**    |           | 477       | 474      | 473       |
| Immulite |          |           |           |          |           |
| > PSA**  | *        |           | 0.94      | 0.99     | 1.08      |
|          | *Slope** |           |           |          |           |
|          |          |           | (0.93 to  | (0.98 to | (1.07 to  |
|          | **(95%   |           | 0.95      | 1.00)    | 1.10)     |
|          | CI)**    |           |           |          |           |
|          |          |           | -0.11     | 0.05     | 0.06      |
|          | **Int    |           |           |          |           |
|          | ercept** |           | (-0.15 to | (0.02 to | (0.02 to  |
|          |          |           | -0.07)    | 0.09     | 0.22      |
|          | **(95%   |           |           |          |           |
|          | CI)**    |           | 0.992     | 0.993    | 0.991     |
|          |          |           |           |          |           |
|          | **Corr.  |           |           |          |           |
|          | Coeff.** |           |           |          |           |
+----------+----------+-----------+-----------+----------+-----------+
| > **     | **N**    | 477       |           | 474      | 473       |
| Immulite |          |           |           |          |           |
| > 2000   | *        | 1.06      |           | 1.06     | 1.16      |
| > PSA**  | *Slope** |           |           |          |           |
|          |          | (1.05 to  |           | (1.05 to | (1.14 to  |
|          | **(95%   | 1.08)     |           | 1.08)    | 1.17)     |
|          | CI)**    |           |           |          |           |
|          |          | 0.12      |           | 0.15     | 0.18      |
|          | **Int    |           |           |          |           |
|          | ercept** | (0.08 to  |           | (0.11 to | (0.14 to  |
|          |          | 0.16)     |           | 0.20)    | 0.23)     |
|          | **(95%   |           |           |          |           |
|          | CI)**    | 0.992     |           | 0.988    | 0.990     |
|          |          |           |           |          |           |
|          | **Corr.  |           |           |          |           |
|          | Coeff.** |           |           |          |           |
+----------+----------+-----------+-----------+----------+-----------+
| > **     | **n**    | 474       | 474       |          | 472       |
| Immulite |          |           |           |          |           |
| > 3^rd^  | *        | 1.01      | 0.94      |          | 1.10      |
| > Ge     | *slope** |           |           |          |           |
| neration |          | (1.00 to  | (0.93 to  |          | (1.09 to  |
| > PSA**  | **(95%   | 1.03)     | 0.96)     |          | 1.11)     |
|          | CI)**    |           |           |          |           |
|          |          | -0.06     | -0.15     |          | -0.00     |
|          | **Int    |           |           |          |           |
|          | ercept** | (-0.09 to | (-0.19 to |          | (-0.05 to |
|          |          | -0.02)    | -0.10)    |          | 0.05)     |
|          | **(95%   |           |           |          |           |
|          | CI)**    | 0.993     | 0.988     |          | 0.990     |
|          |          |           |           |          |           |
|          | **Corr.  |           |           |          |           |
|          | Coeff.** |           |           |          |           |
+----------+----------+-----------+-----------+----------+-----------+
| > **     | **n**    | 473       | 473       | 472      |           |
| Immulite |          |           |           |          |           |
| > 2000   | *        | 0.92      | 0.86      | 0.91     |           |
| > 3^rd^  | *slope** |           |           |          |           |
| > ge     |          | (0.91 to  | (0.85 to  | (0.90 to |           |
| neration | **(95%   | 0.94)     | 0.87)     | 0.92)    |           |
| > PSA**  | CI)**    |           |           |          |           |
|          |          | -0.06     | -0.16     | 0.00     |           |
|          | **Int    |           |           |          |           |
|          | ercept** | (-0.10 to | (-0.20 to | (-0.04   |           |
|          |          | -0.02     | -0.12)    | to 0.04) |           |
|          | **(95%   |           |           |          |           |
|          | CI)**    | 0.991     | 0.990     | 0.990    |           |
|          |          |           |           |          |           |
|          | **Corr.  |           |           |          |           |
|          | Coeff.** |           |           |          |           |
+----------+----------+-----------+-----------+----------+-----------+

The data suggest that the Immulite PSA and Immulite 2000 PSA assays
differ statistically by 5-6% in PSA value. These two assays have similar
reportable ranges and immunoassay design. The percentage coefficient of
variation for inter-assay imprecision for these assays is 5-10% (see
table in non-clinical studies section). It is likely that the
statistical difference in these studies is not clinically relevant since
the inter-assay imprecision is of similar size.

The data suggest that the Immulite 3^rd^ Generation PSA and Immulite
2000 3^rd^ Generation PSA assays differ by 10% in PSA value. These two
assays also have similar reportable ranges and immunoassay design. The
percentage coefficient of variation for inter-assay imprecision for
these assays is 3.5 to 20% (see table in non-clinical studies section).
It is likely that the statistical difference in these studies is not
clinically relevant since the inter-assay imprecision is of similar
size.

## Summary of clinical studies

Retrospectively obtained serum samples from 3810 men aged 50 or older
without acute prostatitis, urinary tract infection, or personal history
of prostate cancer were obtained from 3 clinical sites (2 in the US and
1 foreign site). Results of digital rectal examination were available
for 3438 subjects. Ninety-one percent of subjects were Caucasian, 2%
Asian, 6% African Americans, \<1% other ethnic category or no ethnic
information. Mean age of subjects was 62 years. The percentage of
subjects with elevated Immulite PSA results was 12.2%. The percentage of
subjects with abnormal DRE results was 4.6%. Of the 3438 screened
subjects, 252 subjects had a biopsy (7.3% of total screened) and 81
cancers were found (2.4% of all screened, 32.1% of biopsied subjects).

The mean PSA value of cancer subjects using the Immulite PSA assay was
significantly higher than the mean PSA value of benign subjects (p =
0.001). Initial positive predictive value estimates for DRE and PSA were
imprecise due to non-random verification of clinical status on biopsy.
In addition, statistical modeling to correct for missing data was
performed to obtain better estimation of DRE diagnostic performance.
After modeling and calculation of ratio of TP, FP rates and %positive
biopsies (positive predictive values) for data using the Immulite PSA
assay, the use of PSA increased true and false positive rates almost in
the same proportion compared to the DRE alone. It means that the use of
the PSA testing increased the negative predictive values while the
positive predictive values stayed almost the same compared to the DRE
alone. The positive predictive value of PSA using the Immulite PSA assay
and DRE in combination is also significantly higher than the positive
predictive value of DRE alone (p = 0.01). This supports a conclusion
that Immulite PSA assay and DRE in combination detect more cancers than
DRE alone. Immulite PSA assay determinations detected 68% of cancers
that DRE did not; DRE detected 6% of cancers that PSA determinations did
not. Positive predictive values for the Immulite PSA assay were similar
to positive predictive values for the Immulite 3^rd^ Generation PSA,
Immulite 2000 PSA, and Immulite 2000 3^rd^ Generation PSA assays. The
95^th^ percentile values for each PSA assay are less than 4 ng/ml. The
PSA values of each assay do not differ from each other in a clinically
meaningful way.

# X. CONCLUSIONS DRAWN FROM THE STUDIES

## Safety

As a routine diagnostic test, the PSA assay involves removal of blood
for testing purposes. The test, therefore, presents no more safety
hazard than other tests where blood is removed from subjects.

## Effectiveness

> The current studies showed that the use of PSA increased true positive
> and false positive rates in cancer detection in the same proportion
> compared to the DRE alone. It means that the use of the PSA testing
> increased the negative predictive value while the positive predictive
> value stayed the same compared to the DRE alone.

The positive predictive value of PSA in combination with DRE (when
positive on both) is also significantly higher than the positive
predictive value of DRE alone. In earlier studies of prostate cancer,
DRE has been shown effective in cancer detection and has served as a
more traditional cancer detection method.

## Benefit/Risk Analysis

An elevated level of serum PSA may not necessarily indicate the presence
of prostate cancer (88% false positive subjects in the current studies).
Subjects with falsely elevated PSA may have unnecessary biopsies. A low
level of serum PSA does not necessarily indicate the absence of prostate
cancer (9% false negative subjects in the current studies). Subjects
with falsely negative PSA results may not have a necessary biopsy. The
physician should utilize PSA test results in conjunction with DRE, the
patient\'s overall clinical assessment, and other diagnostic tests such
as TRUS. Therefore, assessment of patient status should not be based
exclusively on a serum PSA result. The risk of falsely identifying
cancer to the risk of missing actual cancer (false positive to false
negative ratio) for PSA is approximately 5:1 (10.2:1 in the current
studies).

Confirmation of prostate cancer can only be determined by prostatic
biopsy. However, it is estimated that the percentage of subjects falsely
identified as free of cancer using prostate tissue from six cores is
approximately 25% on first sampling and declines to approximately 5% on
repeat biopsy one year later. Therefore, the presence of elevated PSA
may fail to detect prostate cancer on first biopsy sampling. Physicians
and patients should keep in mind the risks of failure to detect cancer
when a negative biopsy result (absence of cancer) is received.

It is reasonable to conclude that the benefits of use of the device for
the target population outweigh the risk of illness or injury when used
as indicated in accordance with the directions for use.

# XI. PANEL RECOMMENDATION 

In accordance with the provisions of section 515 (c)(2) of the act as
amended by the Safe Medical Devices Act of 1990, this PMA was not
referred to the Immunology Devices Panel, an FDA advisory committee, for
review and recommendation because the information in the PMA supplement
substantially duplicates information previously reviewed by this panel.

# XII. CDRH DECISION

FDA issued an approval order on June 19, 2001

# XIII. APPROVAL SPECIFICATIONS

Directions for use: See the labeling.

Hazards to Health from Use of the Device: See Indications,
Contraindications, Warnings, precautions and Adverse Events in the
labeling.

Postapproval Requirements and Restrictions: See approval order

# XIV. References

1.  Rubin, D. 1987. Multiple imputation for nonresponse in surveys. John
    Wiley and Sons, Inc.

2.  Begg C.B. and Greenes R.A. Assessment of diagnostic tests when
    disease verification is subjects to selection bias. *Biometrics*
    1983, 39, 207-215.

3.  Schatzkin A., Connor R.J., Taylor P.R., and Bunnag B. Comparing new
    and old screening tests when a reference procedure cannot be
    performed on all screeners. *American Journal of Epidemiology* 1987,
    vol.125, No.4, p.672-678.

4.  Xiao-Hua Zhou. Effect of verification bias on positive and negative
    predictive values. *Statistics* *in Medicine* 1994, vol.13,
    1737-1745.

5.  Chock C., Irwing L., Berry G., and Glasziou P. Comparing dichotomous
    screening tests when individuals negative on both tests are not
    verified. *Journal of Clinical Epidemiology* 1997, vol.50, No. 11,
    p.1211-1217.

6.  Xiao-Hua Zhou. Correcting for verification bias in studies of a
    diagnostic test's accuracy. *Statistical Methods in Medical
    Research* 1998, **7**:337-353.