National PBM Drug Monograph

Hyaluronidase (November 2008)

(Bovine, [Amphadase]{.underline}^TM^ [Hydase]{.underline}^TM^)

(Ovine, [Vitrase]{.underline}^TM^)

(Human Recombinant, [Hylenex]{.underline}^TM^)

VHA Pharmacy Benefits Management Service and the Medical Advisory Panel

*The purpose of VACO PBM-SHG drug monographs is to provide a
comprehensive drug review for making formulary decisions.  These
documents will be updated when new data warrant additional formulary
discussion. Documents will be placed in the Archive section when the
information is deemed to be no longer current.*

# Executive Summary: 

-   **Indications:** Bovine, ovine, and human recombinant hyaluronidase
    preparations are all indicated as adjuvants to increase the
    absorption and dispersion of other injected drugs; for
    hypodermo-clysis; and as adjuvants in subcutaneous urography for
    improving resorption of radioopaque agents. Ovine hyaluronidase has
    received off-label study for treatment of vitreous hemorrhage and
    chronic pain attributed to post-laminectomy fibrosis.

-   **Efficacy:** Hyaluronidase preparations have been used in
    combination with local anesthetic agents for ophthalmic surgery
    where they have been demonstrated to speed onset of analgesia by
    increasing tissue permeability and promoting the dispersion of the
    anesthetic, allow for smaller volumes of anesthetic to be used, and
    improve globe and lid akinesia. Hyaluronidase has also been used to
    maintain adequate hydration in patients who are unable to take
    adequate fluids orally, who are mildly to moderately dehydrated and
    in whom it is difficult or impractical to insert an intravenous
    line. Hyaluronidase-augmented subcutaneous infusions of lactated
    Ringer's solution enabled flow rates 250 to 400% faster than
    infusions without hyaluronidase and reduced edema associated with
    subcutaneous infusion of fluids. The combined subcutaneous
    administration of hyaluronidase and saline can significantly reduce
    tissue injury following extravasation of a number of drugs,
    electrolytes, nutritional and diagnostic substances including
    amphotericin, vancomycin, lipid emulsion, potassium solutions, total
    parenteral nutrition solution, and vinca alkaloids. Administration
    of morphine with recombinant hyaluronidase has been shown to
    accelerate T~max~ and alter AUC of subcutaneously administered
    morphine to the extent that they were comparable to values
    associated with intravenous morphine administration. Intradermal
    hyaluronidase injections have been used to treat granulomatous
    foreign-body reactions or unwanted placement associated with the
    injection of cross-linked, biosynthetic hyaluronic acid products
    used in cosmetic dermal augmentation. The intravitreal injection of
    ovine hyaluronidase 55IU resulted in a clinically significant
    improvement in clearance of vitreous hemorrhage sufficient for the
    ophthalmologist to see the underlying pathology and complete
    treatment, significantly increased the percentage of patients
    attaining ≥ 3 lines in best corrected visual acuity, and
    significantly reduced vitreous hemorrhage density. Repeated caudal
    epidermal injection of hyaluronidase reduced pain and increased
    quality of life measures in patients with post-laminectomy fibrosis.

-   **Safety:** The most frequent adverse events reported with
    subcutaneously administered hyaluronidase have been local injection
    site reactions. Hyaluronidase is antigenic and repeated injections
    of relatively large amounts of hyaluronidase preparations may result
    in the formation of neutralizing antibodies. Allergic reactions,
    such as urticaria and angioedema, have been reported in \<0.1% of
    patients receiving hyaluronidase. While the human recombinant
    hyaluronidase product is proposed to alleviate the allergy,
    immunology, and infectious risks associated with nonhuman proteins
    derived from animal sources, anaphylactic reactions to
    non-recombinant preparations of hyaluronidase have been rare and no
    cases of animal pathogens (including transmissible spongiform
    encephalopathies) have been linked to animal-derived hyaluronidase
    preparations. The intravitreous injection of ovine hyaluronidase was
    generally well-tolerated; transient, self-limited, sterile iritis
    was the most common ocular adverse event. Non-infectious hypopyon
    were only seen in ovine hyaluronidase-treated eyes but occurred
    infrequently and responded well to topical anti-inflammatory
    therapy.

-   **Dose:** For hypodermoclysis, initiation of subcutaneous infusion
    may be followed by injection of 150 units of hyaluronidase into the
    infusion line. Alternatively, 150 units of hyaluronidase may be
    injected under the skin prior to clysis. Absorption and dispersion
    of injected drugs may be enhanced by adding 50-300 units (usually
    150 units) of hyaluronidase to the injection solution. In cases of
    extravasation injury, a ten-fold dilution of hyaluronidase in normal
    saline is made to a concentration of 15 units/ml, followed by
    injection of 1ml diluted solution through the catheter (if still in
    place), or subcutaneously around the site. An alternative method
    involves dividing the dose into 0.2 ml subcutaneous injections which
    are given in four sites equally spaced around the edges of the
    extravasation site. Hyaluronidase 150 to 200 units has been
    suggested as the amount required for removal of one cubic centimeter
    of hyaluronic acid when unwanted reactions or poor cosmetic results
    have occurred.

-   **Cost:** Bovine hyaluronidase products are available for
    approximately \$13 for a 150 USP unit vial while 200 USP units of
    ovine hyaluronidase is \$16.35/vial. Human recombinant hyaluronidase
    is \$45.89 for a 150 USP unit vial.

-   **Place in Therapy:** The promotion of absorption and dispersion of
    injected drugs, biologic fluids, or medical devices by hyaluronidase
    appears to be a clinically useful property, especially regarding
    ophthalmic and dermatologic procedures and extravasation events.
    Hyaluronidase can accelerate subcutaneous infusion of fluids and
    thus augment this alternative route for hydration when oral or
    intravenous replacement is not possible or impractical.

**[Introduction]{.underline}**

The purposes of this monograph are to (1) evaluate the available
evidence of safety, efficacy, cost, and other pharmaceutical issues that
would be relevant to evaluating biologic source-specific preparations of
hyaluronidase for possible addition to the VA National Formulary; (2)
define its role in therapy; and (3) identify parameters for its rational
use in the VA.

# Pharmacology^1-4^

Hyaluronidase is a spreading or diffusing substance that modifies the
permeability of connective tissue through the depolymerization of
hyaluronic acid, mucopolysaccharides, and the chondroitin sulfates A and
C. Hyaluronic acid is a polysaccharide found in the intracellular ground
substance of connective tissue and of certain specialized tissues, such
as the umbilical cord and vitreous humor. Hyaluronidase hydrolyzes
hyaluronic acid by splitting the glucosaminidic bond between C1 of the
N-acetylglucosamine moiety and C4 of a glucuronic acid. This temporarily
decreases the viscosity of the cellular cement and promotes diffusion of
injected fluids or localized transudates or exudates, thus facilitating
their absorption.

When no spreading factor is present, a material injected subcutaneously
spreads very slowly, but hyaluronidase causes rapid spreading, provided
local interstitial pressure is adequate to furnish the necessary
mechanical impulse. Such an impulse is normally initiated by injected
solutions. The rate of diffusion is proportionate to the amount of
enzyme, and the extent is proportionate to the volume of solution.

The reconstitution of the dermal barrier removed by the intradermal
injection of hyaluronidase (20, 2, 0.2, 0.02, and 0.02 units/ml) to
adult humans indicated that at 24 hours the restoration of the barrier
is incomplete and inversely related to the dosage of the enzyme; at 48
hours, the barrier is completely restored in all treated areas.^2^

The FDA considers all hyaluronidase products as distinct entities due to
variations among their sources and chemical compositions; as
'biogenerics' approved as follow-on protein products under section
505(b)(2) of the Food, Drug, and Cosmetic Act they are considered to be
similar but not interchangeable^5,6^. Hydase™ and Amphadase™ are
preparations of purified bovine testicular hyaluronidase^1,3^; while
Vitrase™ is an ovine (ram) testicular product (table 1).^4^ These
animal-source hyaluronidase products have a molecular weight of
approximately 55,000 Daltons.^7,8^ Hylenex™ (also called rHuPH20) is a
preparation of the enzyme recombinant human hyaluronidase produced by
genetically engineered Chinese Hamster Ovary cells containing a DNA
plasmid encoding for a soluble fragment of human hyaluronidase. The
purified recombinant hyaluronidase has an approximate molecular weight
of 61,000 Daltons.^2^

**Table 1: Biologic sources, dosage forms, and costs of commercially
available preparations of**

**hyaluronidase^1-4^**

+-----------+-----------+-----------+-----------------------+---------+
| **Source  | **Trade   | **Date of | **Available Dosage    | **Cost  |
| of        | name**    | FDA**     | form ^b^**            | ^c^**   |
| hyalur    |           |           |                       |         |
| onidase** |           | *         |                       |         |
|           |           | *Approval |                       |         |
|           |           | ^a^**     |                       |         |
+-----------+-----------+-----------+-----------------------+---------+
| Bovine    | A         | Oct 26,   | 150 USP units per ml, | \$12.   |
|           | mphadase™ | 2004      | 2ml vial **^e^**      | 78/vial |
|           | **^d^**   |           |                       |         |
+-----------+-----------+-----------+-----------------------+---------+
| Bovine    | Hydase™   | Oct 25,   | 150 USP units per ml, | \$12.   |
|           |           | 2005      | 2ml vial **^e^**      | 36/vial |
+-----------+-----------+-----------+-----------------------+---------+
| Ovine     | Vitrase™  | May 5,    | 200 USP units per ml, | \$16.   |
|           |           | 2004      | 2ml vial **^e^**      | 35/vial |
|           |           |           |                       |         |
|           |           | May 5,    | 6200 USP units per    | \$557.  |
|           |           | 2004      | kit ^**f**^           | 71/vial |
+-----------+-----------+-----------+-----------------------+---------+
| Human     | Hylenex™  | Dec 2,    | 150 USP units per ml, | \$45.   |
|           |           | 2005      | 2ml vial **^e^**      | 89/vial |
| re        |           |           |                       |         |
| combinant |           |           |                       |         |
+-----------+-----------+-----------+-----------------------+---------+

^a^ Source: Orange Book at <http://www.fda.gov/cder/ob/default.htm>

^b^ Unless otherwise specified, products are available as a clear,
colorless, ready for use solution

^c^ Prices from August 2008, all FSS

^d^ Amphadase™ contains thimerosal as a preservative; all other
hyaluronidase products listed are preservative-free

^e^ 1ml hyaluronidase in a 2ml vial; store unopened vial in refrigerator
at 2-8ºC (35-46ºF)

^f^ 6200 USP units of lyophilized ovine hyaluronidase in a single-use
5ml vial; one 1ml sterile polycarbonate syringe; one 5µm

sterile filter needle. Store at 20-25ºC (68-77ºF) after reconstitution;
use within 6 hours. The lyophilized product is manufactured

to provide a source for a high-concentration, low-volume dose as would
be required in off-label use for vitreous hemorrhage.

A product containing recombinant human hyaluronidase (Cumulase™**)** has
been marketed as an alternative to the bovine enzyme used for *in vitro*
fertilization (IVF).^9^ Hyaluronidase is used *ex vivo* to strip
hyaluronic acid from oocytes prior to the process of intracytoplasmic
sperm injection.^10^ FDA considers hyaluronidase IVF products to be
medical devices^11^ and VA does not provide IVF (see VHA Handbook
1330.1, "VHA Services for Women Veterans" July 16, 2004) -- thus, this
product will not be further reviewed.

Hyaluronidase activity is expressed in units; a unit is defined as that
amount of enzyme which liberates one micromole of N-acetylglucosamine
(from hyaluronic acid) per minute at 37˚ and pH 4.0. One International
Unit (IU) = one USP unit = one NF unit.^7^

**[Pharmacokinetics]{.underline}^1-4^**

Knowledge of the mechanisms involved in the disappearance of injected
hyaluronidase is limited. The blood of a number of mammalian species
brings about the inactivation of hyaluronidase.

Hyaluronidase is known to have a relatively short half-life of 60 to 112
hours in ocular tissues.^12^

# FDA Approved Indications^1-4^

Bovine and ovine hyaluronidases (Amphadase™, Hydase™, Vitrase™) and
recombinant human hyaluronidase (Hylenex™) are all indicated as
adjuvants to increase the absorption and dispersion of other injected
drugs; for hypodermoclysis; and as adjuvants in subcutaneous urography
for improving resorption of radioopaque agents.

Hyaluronidase preparations have been commonly used in combination with
local anesthetic agents for ophthalmic surgery, speeding the onset of
analgesia by increasing tissue permeability and promoting the dispersion
of the anesthetic.^13^

Hyaluronidase has been used to maintain adequate hydration in patients
who are unable to take adequate fluids orally, who are mildly to
moderately dehydrated and in whom it is difficult or impractical to
insert an intravenous line.^14^

Hyaluronidase may reduce the extent of tissue damage following
extravasations of a number of drugs, electrolytes, nutritional and
diagnostic substances intended for intravenous administration.^15^

The subcutaneous route of administration of urographic contrast media is
indicated when intravenous administration cannot be successfully
accomplished, particularly in infants and small children.

**[Off-label use]{.underline}**

Ovine hyaluronidase (Vitrase™) has been studied for the treatment of
vitreous hemorrhage.^12^ Hyaluronidase causes liquefaction of the
vitreous and is believed to promote the clearance of vision-distorting
blood to restore vision and/or provide an ophthalmologist with an
unobstructed view of the retina, allowing the diagnosis and treatment of
the underlying cause of the hemorrhage.

Intradermal hyaluronidase injections can be used to treat granulomatous
foreign-body reactions or unwanted placement associated with the
injection of cross-linked, biosynthetic hyaluronic acid products used
for cosmetic filling (Restylene™, Juvederm™).^16^

Repeated caudal epidermal injections of hyaluronidase have been shown to
reduce pain and increase quality of life measures in patients with
post-laminectomy fibrosis.^17^

# Current VA National Formulary Alternatives

Hyaluronidase is on the VA National Formulary; however, biological
source of the enzyme listed is not specified.

# Dosage and Administration

***Hypodermoclysis***: Several methods may be employed to administer
hyaluronidase to facilitate subcutaneous infusion of fluids. One method
involves first starting the fluid infusion and then injecting 150 units
of hyaluronidase into the infusion line. An alternative method is to
inject hyaluronidase 150 U under the skin prior to clysis. This amount
of hyaluronidase will facilitate absorption of 1,000ml or more of
solution. The dose, the rate of injection, and the type of solution
should be adjusted carefully to the individual patient. The rate and
volume of administration should not exceed those employed for
intravenous infusion.^2^

***Absorption and dispersion of other injected drugs*** may be enhanced
by adding 50-300 units, usually 150 units of hyaluronidase, to the
injection solution.^2,\ 18^

***Absorption and dispersion of injected medical devices*** Repeated
injections of 5 or 10 units of hyaluronidase every 2 weeks were
recommended to reverse poor cosmetic outcomes with hyaluronic acid and
minimize the possibility of allergic reactions to hyaluronidase;
however, others investigators have suggested that larger doses of 150 to
200 units are required for removal of each one cubic centimeter of
hyaluronic acid.^19^

## *Subcutaneous Urography* The subcutaneous route of administration of urographic contrast media is indicated when intravenous administration cannot be successfully accomplished; as stated, this typically occurs in pediatric cases. With the patient prone, 75 U of hyaluronidase is injected subcutaneously over each scapula, followed by injection of the contrast medium at the same sites.^2^

***Extravasation*** Hyaluronidase and normal saline are typically used
together to reduce tissue damage.^15^ Administration techniques differ,
but most sources recommend making a ten-fold dilution of hyaluronidase
to provide a concentration of 15 units/ml, then injecting 1 ml of the
solution through the catheter, if still in place, or subcutaneously
around the site.^15^ Banta recommended dividing the dose into 0.2 ml
subcutaneous injections given with a tuberculin syringe and a 25 gauge
needle in four sites equally spaced around the edges of the
extravasation site.^20^ Flemmer and Chan described a similar technique
and provided a detailed protocol for the overall management of
extravasations.^21^

# 

# Efficacy

**Hypodermoclysis**

The subcutaneous administration of fluids has primarily occurred in
geriatric and palliative medicine settings where oral hydration is often
difficult in the presence of cognitive impairment, vomiting and nausea,
infection, abdominal obstruction related to cancer, or cerebrovascular
accident. Hospitalization costs and the risk of nosocomial infection
discourage the admission of patients for hydration only, while at-home
administration of intravenous infusions can pose increased risk and
requires close supervision by skilled medical staff. These issues and
the safety and ease of subcutaneous fluid administration make
hypodermoclysis a potentially useful alternative to intravenous
hydration.^22^

In a randomized controlled trial of local injections of hyaluronidase
versus placebo in 21 patients with advanced cancer receiving
subcutaneous hydration the administration of 150 IU immediately before
starting a one hour infusion of 500ml (2/3 dextrose 5% and 1/3 NS) did
not alter patient comfort (reduce pain, swelling, rash or leakage).^23^
The authors concluded that hyaluronidase is not necessary for routine
bolus subcutaneous hydration, but may be useful for a minority of
patients who are not able to tolerate subcutaneous infusion due to
swelling or pain.

In a retrospective observation, Pirrello et al. (2007) reported their
clinical experience with a series of patients administered recombinant
hyaluronidase (rHuPH20).^14^ Thirty-two patients were treated with
rHuPH20 in a hospice setting over a six-month period. Of these, 26
received rHuPH20 150 units once every 24 hours to enhance
hypodermoclysis with standard hydration fluids (including normal saline,
5% dextrose in normal saline, and 5% dextrose) for symptom control of
delirium, myoclonus, and mild-to-moderate dehydration. Initial flow
rates of 200 to 500ml/h for the first 1 to 2 hours were achieved when
immediate hydration was desired, followed by typical maintenance rates
of 50 to 100ml/h. Duration of rHuPH20-assisted hypodermoclysis lasted up
to 7 days. Electrolyte replacement in hydration fluid was achieved
without incident in 5 patients receiving potassium (20 meq/L) and in one
patient receiving potassium (20 meq/L) and magnesium (1g/L). In addition
to use for hydration, six patients received rHuPH20 to enhance
subcutaneous infusion of nine different medications (hydromorphine,
lidocaine, dexamethasone, haloperidol, midazolam, ondansetron,
famotidine, sufentanil, and glycopyrrolate). There were no significant
adverse events; induration at the infusion site occurred in one patient
receiving hydration and higher than expected serum lidocaine
concentration was observed in another patient.

The Increased Flow Utilizing Subcutaneously-Enabled Lactated Ringer\'s
clinical trial, or INFUSE-LR study (Thomas et al., 2007), was designed
to determine the subcutaneous infusion flow rate of lactated Ringer\'s
(LR) solution with and without rHuPH20, determine the subcutaneous
infusion flow rate dose response to rHuPH20 over one order of magnitude
of dose, and assess safety and tolerability (appendix).^24^ This
prospective, double-blind, randomized, placebo-controlled,
dose-comparison study enrolled 54 volunteer subjects who received
subcutaneous infusions simultaneously in both upper arms through
24-gauge catheters. Key findings from this study: in every subject
tested, rHuPH20 injection preceding the gravity-driven LR infusions
enabled flow rates approximately 250% to 400% faster than the infusions
without rHuPH20. The overall mean flow rate for subcutaneous infusion
with rHuPH20 was 464 ml/h versus 118 ml/hr with placebo (p\<0.0001).
Despite the faster rate of LR infusion into the rHuPH20-assisted arms,
the rHuPH20 arms demonstrated significantly less edema in all rHuPH20
dose groups and all timepoints during infusions. Across the three
rHuPH20 dose cohorts, 94% of subjects had moderate or severe arm edema
with placebo compared to 17% with rHuPH20 (p \< 0.0001). Adverse events
occurring following treatment were mild to moderate in severity,
localized to the infusion sites, and evenly distributed between placebo
and rHuPH20 treatment arms. There were no severe or serious adverse
events. In the double-blinded global preference ranking, both study
subjects and the investigator preferred, in 92% of cases across the
three dose cohorts, the rHuPH20-assisted arms for subcutaneous infusions
rather than placebo arms (p \< 0.0001).

**Absorption and Dispersion of Other Drugs**

Numerous adverse events associated with continuous subcutaneous infusion
(CSI) of drugs have been attributed to the addition of hyaluronidase;
thus, the routine addition of hyaluronidase to these admixtures has
fallen on disfavor, although a recent survey of CSI practices in United
States hospices revealed that this practice still continues.^25^

An unpublished double-blind, randomized, crossover, placebo-controlled,
clinical trial entitled Increased Flow Utilizing Subcutaneously-Enabled
Morphine (INFUSE-Morphine) was designed to determine the time to maximal
blood levels (T~max~) of morphine after subcutaneous administration with
and without rHuPH20, to determine T~max~ after intravenous
administration of morphine, and to assess safety and
tolerability.^26,27^Among the 12 evaluable hospice and palliative care
patients included in the trial, co-administration of rHuPH20 with 5mg of
morphine resulted in a significant acceleration in the average T~max~ of
morphine when compared to placebo; T~max~ was reduced from 13.8 minutes
(when injected subcutaneously with the saline placebo) to 9.2 minutes
when injected with rHuPH20, a 33% reduction (p\<0.05). Subcutaneous
administration of morphine with rHuPH20 provided total drug exposure
(4-hour area under the concentration-time curve, AUC) of morphine and
its active metabolite that was comparable to IV morphine administration.
The results suggested that subcutaneous morphine plus rHuPH20 has a
pharmacokinetic profile less like that of subcutaneously administered
morphine and closer to that of intravenous morphine.

**Injected Anesthetics in Ophthalmologic Surgery**

Hyaluronidase speeds the onset and deepens the penetration of injected
anesthetics used in surgical procedures in ophthalmology. The enzyme can
increase the spread of anesthesia, but it may also decrease the duration
of action of anesthetic agents via increased absorption and elimination.
Also, as expected, increased absorption caused by hyaluronidase may also
lead to the potential for a greater incidence of toxic reactions
resulting from elevated blood levels of anesthetic. ^28,\ 29,\ 30^

Hyaluronidase allows for smaller volumes of anesthetic to be used, which
may possibly reduce intraocular pressure and distortion of the surgical
site.^31,\ 32^

Hyaluronidase has been proposed to improve the safety of the
ophthalmological anesthetic and surgical procedure by promoting improved
globe and lid akinesia;^28,\ 33,\ 3,\ 35^ however, this has not been a
universal finding^31^ , and an Agency for Healthcare Research and
Quality report (2000) indicated that, while hyaluronidase appeared to
produce better akinesia than placebo (consistently taking 2 to 3 minutes
less), the difference was not always statistically significant.^36^

The literature does not present an absolute consensus re: the dose of
hyaluronidase that should be added to the anesthetic or anesthetics used
in ophthalmic surgery; published studies cover concentrations from an
ineffective concentration of 0.75 units/ml to an effective one of 300
units/ml.^30,\ 34^ While retrobulbar blocks appear to be consistently
improved by using hyaluronidase in concentrations of 7.5 to 60 units/ml,
the quality of peribulbar blocks was equal with or without hyaluronidase
in concentrations from 3.75 to 150 units/ml.^31,\ 34^

**Extravasation**

Hyaluronidase allows the dispersion, diffusion, and resorption of the
extravasated fluids and substances present in the interstitial spaces,
thereby decreasing potential tissue damage from these substances.^15^
Hyaluronidase has been used to treat extravasation of the agents listed
in table 2.

Hyaluronidase and normal saline are typically used together to reduce
tissue damage.^15^ Timely administration of hyaluronidase is a key
factor following an extravasation injury. For best results,
hyaluronidase should be injected subcutaneously or intradermally within
1 hour of the IV extravasation injury although injuries for up to 24
hours of age may benefit from this therapy.^15,\ 20,\ 21^

**Table 2**

+-----------------------------------------------------------------------+
| Extravasated agents treated with hyaluronidase                        |
+-----------------------------------------------------------------------+
| Aminophylline Gentamicin                                              |
|                                                                       |
| Amphotericin Lipid emulsion                                           |
|                                                                       |
| Calcium salts Mannitol                                                |
|                                                                       |
| Cloxicillin Phenytoin                                                 |
|                                                                       |
| Contrast media Potassium solutions                                    |
|                                                                       |
| Dextrose solution, 10% Radio-labeled contrast media                   |
|                                                                       |
| Diazepam Sodium bicarbonate solution                                  |
|                                                                       |
| Erythromycin Total parenteral nutrition solution                      |
|                                                                       |
| Tromethamine Vinblastine                                              |
|                                                                       |
| Vancomycin Vincristine                                                |
+-----------------------------------------------------------------------+

References 15, 37, 38, 39

**Dispersion of Hyaluronic Acid**

Non-animal stabilized hyaluronic acid gel (NASHA gel; Restylene™ or
Juvederm™) is approved by the FDA for the temporary filling of moderate
to severe wrinkles around the nose or mouth. Hyaluronidase can be used
to correct unintended dermal augmentation with NASHA gel (due to
overcorrection or injection error) and to promote dissipation of NASHA
gel in the event of allergic reaction or skin
discoloration.^16,\ 19,\ 40,\ 41,\ 42^

Vartanian et al. (2005) reported the results from a prospective,
randomized study: part one compared the effect of hyaluronidase to that
of saline on post-NASHA dermal augmentation; part two consisted of a
dose-response evaluation.^40^ Palpation scores of treated volunteers
were assigned by a blinded examiner. The injection of hyaluronidase
after NASHA gel forearm skin augmentation markedly decreased palpation
scores compared to saline by end of the first week (20% of baseline vs.
90%, respectively; p \< 0.001). By the end of 14 days, the
hyaluronidase-treated palpation skin scores declined to 0; those treated
with saline had a median score of 2. By 90 days, there continued to be
no palpable NASHA gel in the hyaluronidase-treated group, while 100% of
the saline-injected volunteers had a palpable trace. Dose-related
response to injected hyaluronidase was observed but differences were not
statistically significant. The authors recommended a 5 or 10 unit
initial injection of hyaluronidase with repeat injections every 2 weeks
to provide optimal dispersion of NASHA gel and to minimize the
possibility of allergic reaction to hyaluronidase.

Inflammatory reactions to NASHA may be managed with hyaluronidase; this
modality appears to present a desirable alternative to corticosteroids
(oral or locally injected) or surgical excision of the NASHA
filler.^16,\ 19,\ 41^ The practice experience of Soparkar et al. (2007)
indicated that hyaluronidase reversal of the palpable effects of NASHA
requires a larger injection of hyaluronidase (150 to 200 units for
removal of one cubic centimeter of NASHA) but occurs in a much smaller
time frame (hours vs. days) than those reported by Vartanian et al.
(2005).^19^

**Vitreous Hemorrhage**

A vitreous hemorrhage occurs when retinal blood vessels rupture and
bleed into the vitreous gel. These hemorrhages result from leakage from
abnormal, weak blood vessels and are associated with diabetic
retinopathy, branch or central retinal vein occlusion, posterior
vitreous detachment with or without a retinal tear and ocular trauma.
Vitreous hemorrhage can reduce the amount of light that can pass through
the normally clear vitreous to the retina. The effects of this can vary
from a few dark spots in the visual field to completely obscured vision.
Depending on the severity of the vitreous hemorrhage, it may take
several months or significantly longer for the body to reabsorb the
blood and for the patient to regain vision. Early visualization of the
retina to identify and treat the underlying causative disorder is
critical to maximizing the return of visual function.^12,\ 43,\ 44^
Treatment options for patients with a vitreous hemorrhage are limited.
Some retinal specialists initially recommend a period of watchful
waiting for 1 to 3 months in the hope that the hemorrhage will clear on
its own; however, the risks related to this conservative care may
include continued bleeding and, if caused by diabetic retinopathy,
disease progression during the time it takes for the blood to clear on
its own (if at all). An alternative to watchful waiting is vitrectomy
but the risks associated with that procedure (cataract formation,
retinal detachment, recurrent hemorrhage, and others) may limit its use
as an initial treatment option for vitreous hemorrhage
patients.^12,\ 43,\ 44^

Ovine hyaluronidase was investigated in two multinational, randomized,
double-blinded, placebo-controlled, phase III trials in patients with
severe vitreous hemorrhage (appendix).^12^ Among the 1125 patients
randomized, 76% were diabetic, 90.4% were unable to read any letters on
the eye chart with their affected eye, and mean duration of vitreous
hemorrhage was 120.4 days. Pooled efficacy results showed that 55IU of
ovine hyaluronidase resulted in significant improvement in clearance of
vitreous hemorrhage sufficient to see underlying pathology and complete
treatment, cumulative percentage of patients attaining ≥ 3 lines in best
corrected visual acuity (BCVA), and reduction in vitreous hemorrhage
density. The greatest relative treatment effect was seen by
post-treatment month 1; however, improvements continued through
post-treatment month 3. The safety results from these two trials were
published separately and are discussed under Adverse Events/Safety
Data.^44^

A subset analysis of patients with diabetes from the ovine hyaluronidase
phase III trials indicated that total hemorrhage point score (THPS, a
measurement of the density of vitreous hemorrhage) allowed prediction of
treatment success following a single intravitreous injection of ovine
hyaluronidase.^45^ Specifically, THPS at one month was a predictor of
treatment success with ovine hyaluronidase as measured by BCVA of three
or more lines on an eye chart at three months when compared to a single
injection of saline solution (p \< .0001 or p\< .0003 for 55 IU or 75 IU
ovine hyaluronidase, respectively). THPS at one month was also a
predictor of treatment success with ovine hyaluronidase as measured by
completion of panretinal laser photocoagulation by three months without
vitrectomy when compared to a single injection of saline solution (p \<
.0001 or p\< .0003, for 55 IU or 75 IU ovine hyaluronidase,
respectively).

A New Drug Application (NDA) for ovine hyaluronidase (Vitrase®) was
filed with the FDA for the treatment of vitreous hemorrhage in December,
2002. The FDA\'s Dermatologic and Ophthalmic Drugs Advisory Committee
reviewed the NDA in March, 2003 and voted 8 to 4 that there was
insufficient statistical evidence to support the use of ovine
hyaluronidase for the treatment of vitreous hemorrhage; however, the
Committee did recognize that, in certain patient subgroups, the benefits
of treatment outweighed the potential risks. In April, 2003, the FDA
issued an approvable letter for ovine hyaluronidase for the treatment of
vitreous hemorrhage; the FDA requested additional analysis of the
existing data and an additional confirmatory clinical study based upon
that analysis.^45^ As of August, 2008, no further studies had been
conducted regarding the use of ovine hyaluronidase for this
indication.^46^

**Post-laminectomy Syndrome**

Repeated caudal epidural injections (every 2 months) of hyaluronidase
3000 IU in combination with 35ml 0.05% bupivicaine were given to 12
patients with chronic radicular pain and MRI evidence of
post-laminectomy scar tissue during a 2 year observational study.^17^
Most of the patients in the study had an improved quality of life and
significant pain reduction (assessed by questionnaires and visual
analogue scales, respectively). The authors speculated that the pain
relieving effect of the treatment may have been a result of the
enzymatic effect of hyaluronidase on epidural scar tissue.

# 

# Adverse Events (Safety Data)^1-4^

Edema has been reported in association with hypodermoclysis^16^ and
hyaluronidase has been reported to enhance the adverse events associated
with co-administered drug products.

The most frequent adverse events reported with subcutaneously
administered hyaluronidase have been local injection site reactions.
Studies have demonstrated that hyaluronidase is antigenic; repeated
injections of relatively large amounts of hyaluronidase preparations may
result in the formation of neutralizing antibodies.

In large published studies, the frequency of events including
anaphylactic-like (allergic) reactions has been less than 0.1
percent.^18^ Subcutaneously administered bovine hyaluronidase has caused
allergic reactions and rarely anaphylaxis.^47^ Anaphylactic-like
reactions following retrobulbar block or IV injections of hyaluronidase
have occurred, but rarely.^1-4^

Human hyaluronidase has a unique DNA structure with an amino acid
sequence that is 35% different from bovine and ovine hyaluronidase
sequences.^48^ The human recombinant hyaluronidase product (rHuPH20) is
proposed to alleviate the allergy and immunology risks associated with
nonhuman proteins.

Yocum et al. (2007) injected 100 healthy volunteers (mean age 37 years;
range 18-70) with a single intradermal (ID) dose of 0.1ml (15 units) of
rHuPH20 in a double-blind, placebo-controlled, single-dose study
designed to evaluate sensitivity to the recombinant product.^48^
Volunteers were injected with rHuPH20 in one forearm and saline control
in the other forearm and evaluated for allergic responses and injection
site side effects. The data showed injection site discomfort of 28% in
the saline arm and 3% in the rHuPH20 arm. No allergic reactions were
observed among the subjects (as defined by the occurrence of a wheal
with pseudopods within 5 minutes of injection that persisted for at
least 20 minutes and was accompanied by localized itching). The 0%
allergic reaction rate for rHuPH20 compared favorably to those reported
for bovine (5%) and ovine (0%) hyaluronidase products when administered
to human volunteers at one fifth of the rHuPH20 unit dose.

A preliminary skin test for hypersensitivity to rHuPH20 can be
performed.^2^ The skin test is made by an ID injection of approximately
0.02ml (3 units) of a 150 unit/ml solution. A positive reaction consists
of a wheal with pseudopods appearing within 5 minutes and persisting for
20 to 30 minutes and is accompanied by localized itching. Transient
vasodilation at the site of the test; i.e. erythema, is not considered a
positive reaction.

Kuppermann et al. (2006) reported safety results from the aforementioned
combined phase III trials of intravitreous injection of ovine
hyaluronidase for the management of vitreous hemorrhage (appendix).^44^
Transient, self-limited, sterile iritis was the most common ocular
adverse event and occurred in all treatment groups, including those
administered saline. Acute iritis was reported in the study eye of 126
of 1344 patients (incidence of 33.3%, 62.1%, 58.9%, and 62.1% among
subjects in the saline, or 7.5IU, 55IU, 75IU hyaluronidase groups,
respectively) and occurred in a dose-dependent fashion in cases judged
to be moderate or severe. Non-infectious hypopyon were seen in ovine
hyaluronidase-treated eyes only and occurred in a dose-dependent manner
(incidence of 0.5%, 1.6%, and 5.4% in the 7.5IU, 55IU, and 75IU ovine
hyaluronidase groups, respectively), but were managed successfully with
topical anti-inflammatory therapy. Other ocular adverse events such as
retinal detachment and cataracts were as frequent in saline-administered
eyes as ovine-hyaluronidase treated eyes and were believed to be related
to the underlying pathologic processes.

The use of human recombinant hyaluronidase is proposed to negate the
possible risks associated with animal-derived animal hyaluronidases.^48^
Although no cases of pathogens including transmissible spongiform
encephalopathies have been linked to animal-derived hyaluronidase
preparations, such hyaluronidase extracts carry the theoretical risk of
transmission.

Results from an experimental study, in humans, on the influence of
hyaluronidase in bone repair support the conclusion that this enzyme
alone, in the usual clinical dosage, does not deter bone healing.

**[Contraindications]{.underline}^1-4^**

Hypersensitivity to hyaluronidase or any other ingredient in the
formulation is a contraindication to the use of the product.

**[Warnings and Precautions]{.underline}^1-4^**

Hyaluronidase should be discontinued if sensitization occurs.
Hyaluronidase should not be used to enhance the absorption and
dispersion of dopamine and/or alpha agonist drugs, to reduce the
swelling of bites or stings, or for intravenous injections (due to rapid
inactivation of the enzyme). Hyaluronidase should not be injected into
or around an infected or acutely inflamed area because of the danger of
spreading a localized infection; it should not be applied directly to
the cornea (also see Drug Interactions).

**Pregnancy/Nursing Mothers (PI)**

Hyaluronidase is pregnancy category C. No adequate and well controlled
animal studies have been conducted with hyaluronidase to determine
reproductive effects or effects in pregnant women. Hyaluronidase should
be used during pregnancy only if clearly needed.

**[Look-alike / Sound-alike (LA / SA) Error Risk
Potential]{.underline}**

The VA PBM and Center for Medication Safety is conducting a pilot
program which queries a multi-attribute drug product search engine for
similar sounding and appearing drug names based on orthographic and
phonologic similarities, as well as similarities in dosage form,
strength and route of administration. Based on similarity scores as well
as clinical judgment, the following drug names [may]{.underline} be
potential sources of drug name confusion:

  ----------------------------------- -----------------------------------
  **Drug Name**                       **LA/SA Drug Name**

  **Hyaluronidase (generic) 150, 200, Hyaluronic acid, Hyaluronate,
  or 6200IU vials**                   Hyaluronidase recombinant human,
                                      Urokinase 250,000IU, Abbokinase
                                      250,000IU, alglucerase 80U/ml,
                                      Hyalgan, Hylenex 150IU, Hypaque,
                                      haloperidol decanoate 100mg,
                                      haloperidol lactate 5mg, Ceredase
                                      80U/ml, Hydase 150IU

  **Hyaluronidase recombinant human   Hyaluronic acid, Hyaluronidase,
  (generic) 150IU vials**             Hyaluronate, Hydase 150IU,
                                      Urokinase 250,000IU, Abbokinase
                                      250,000IU, alglucerase 80U/ml,
                                      Amphadase 150IU, Hyalgan, Hypaque,
                                      Vitrase 200IU, haloperidol
                                      decanoate 100mg, haloperidol
                                      lactate 5mg, Ceredase 80U/ml

  **Amphadase (brand) 150IU vial**    Amphotec 50 or 100mg/vial,
                                      amphetamine aspartate or sulfate
                                      2.5mg, Amidate 2mg/ml, Amphotericin
                                      B 50 or 100mg/vial, Hydase 150IU,
                                      Abbokinase 250,000 IU, Inflamase
                                      Forte, Inflamase Mild, Ceredase
                                      80U/ml

  **Hylenex (brand) 150IU vial**      Herplex, Hydase 150IU, Hyalgan,
                                      Hyaluronate, Buprenex 0.3mg,
                                      Hexalen 50mg, Hiprex 1gm, Repronex
                                      75 or 150IU hormone activity,
                                      Mycelex, Zoladex 10.8MG

  **Hydase (brand) 150IU vial**       Hydrea 500mg, Amphadase 150IU,
                                      Ceredase 80U/ml, Hyalgan,
                                      Hyaluronate, Hypaque, Glynase
                                      1.5mg, Hylenex 150IU, Vitrase 200IU

  **Vitrase (brand) 200IU and 6200IU  Vitrasert 4.5mg, Vidaza 100mg,
  vials**                             Videx 10mg, Videx EC 125mg,
                                      Invirase 200mg, Visipaque 270 or
                                      320
  ----------------------------------- -----------------------------------

# Drug-Drug Interactions^1-4^

# Furosemide, benzodiazepines and phenytoin have been found to be incompatible with hyaluronidase. 

When considering the administration of any other drug with
hyaluronidase, it is recommended that appropriate references first be
consulted to determine the usual precautions for the use of the other
drug; e.g., when epinephrine is injected along with hyaluronidase, the
precautions for the use of epinephrine in cardiovascular disease,
thyroid disease, diabetes, digital nerve block, ischemia of the fingers
and toes, etc., should be observed.

Patients receiving large doses of salicylates, cortisone, ACTH,
estrogens, or antihistamines may require larger amounts of hyaluronidase
for equivalent dispersing effect, since these drugs apparently render
tissues partly resistant to the action of hyaluronidase.

*In vitro* ovine hyaluronidase activity remained unchanged for 24 hours
when prepared at a sample concentration of 68 USP units in combination
with 100 microliters of triamcinolone acetonide 40mg/ml.^49^

# Acquisition Costs

See table 1 for a summary of FSS pricing for all forms of hyaluronidase
effective as of August, 2008.

**[VA Utilization]{.underline}**

# Utilization of hyaluronidase products within VA appears relatively low. VA prime vendor purchases from July 2007 through June 2008 totaled 898 vials at a total cost of \$82,827. There were neither purchases of the human recombinant product (Hylenex™) nor purchases of bovine-derived Amphadase™ during the assessment period; national VA percentage utilization of ovine source hyaluronidase (Vitrase™) was equivalent to that of bovine-derived Hydase™.

# Conclusions

# Hyaluronidase preparations are all indicated as adjuvants to increase the absorption and dispersion of other injected drugs; for hypodermoclysis; and as adjuvants in subcutaneous urography for improving resorption of radioopaque agents. Ovine hyaluronidase has received off-label study for treatment of vitreous hemorrhage and to reverse unwanted effects from cosmetic use of hyaluronic acid. Human recombinant hyaluronidase is purported to be associated with reduced immunologic and infectious risk compared to animal-derived hyaluronidases; however, the allergic reaction rate of the human recombinant product appears to be the same as that of ovine-sourced product and there have been no reported cases where pathogens were transmitted via animal-sourced hyaluronidase products.

# Recommendations: Hyaluronidase should be maintained on the VA National Formulary. There are no known differences in efficacy or infectious risk between animal-sourced and human recombinant hyaluronidase products. The immunological risk of human recombinant hyaluronidase appears to be less than that associated with bovine-sourced products but the same as that resulting from ovine-sourced hyaluronidase. Thus, the increased cost associated with the use of human hyaluronidase (Hylenex™) does not appear to be justified. Hyaluronidase biogenerics should be considered similar, but not interchangeable.

#  

# Ovine-sourced hyaluronidase (Vitrase™) may be preferred due to its low antigenicity, lack of preservative, widespread use and comparable cost compared to bovine-derived products. 

# References:

1.  Amphadase™ (hyaluronidase) package insert. Rancho Cucamonga, CA:
    Amphastar Pharmaceuticals, Inc.; November, 2005.

2.  Hylenex™ (hyaluronidase) package insert. San Diego, CA; Baxter
    Healthcare Corporation; March, 2006.

3.  Hydase™ (hyaluronidase) package insert. San Diego, CA; PrimaPharm;
    October, 2005.

4.  Vitrase™ (hyaluronidase) package insert, Irvine, CA. ISTA
    Pharmaceuticals, Inc.; 2007.

5.  Doering PL and Boothby LA. New Drug Update 2005 -- Part 2. Drug
    Topics 2006 (Feb 20); 43-52.

6.  http://patentbaristas.com/archives/2007/03/26/fda-chief-biogenerics-will-be-similar-not-interchangable/

7.  Hyaluronidase from ovine testes, SERVA Electrophoresis, available at
    <http://www.serva.de/servaweb/www_root/documents/25118.pdf>

8.  Hyaluronidase, available at
    <http://www.calzyme.com/commerce/catalog>

9.  [http://www.cumulase.com](http://www.cumulase.com/)

10. Taylor TH, Elliott T, Colturato LF et al. Comparison of bovine- and
    recombinant-derived hyaluronidase with regard to fertilization rates
    and embryo morphology in a sibling oocyte model: a prospective,
    blinded, randomized study. Fertil Steril 2006; 85:1544-6.

11. <http://www.halozyme.com/products_cumulase.php>

12. Kuppermann BD, Thomas EL, de Smet MD et al. Pooled Efficacy Results
    from Two Multinational Randomized Controlled Clinical Trials of a
    Single Intravitreous Injection of Highly Purified Ovine
    Hyaluronidase (Vitrase®) for the Management of Vitreous Hemorrhage.
    Amer J of Ophth 2005 ; 140 (4):573-84.

13. Waknine Y. FDA Drug and Device Approvals: May 13, 2004, available at
    <http://www.medscape.com/viewarticle/477655>

14. Pirrello RD, Chen CT, Thomas SH. Initial Experiences with
    Subcutaneous Recombinant Hyaluronidase. J Palliat Med 2007; 10 (4):
    861-4.

15. Treatment of Intravenous Extravasations from Ped Pharm 4(1), 1998,
    available at <http://www.medscape.com/viewarticle/416651_5>

16. Brody HJ. Use of Hyaluronidase in the Treatment of Granulomatous
    Hyaluronic Acid Reactions or Unwanted Hyaluronic Acid Misplacement.
    Dermatol Surg 2005; 31:893-7.

17. McCleane GJ. Caudal epidural hyaluronidase can significantly reduce
    the pain associated with failed back surgery syndrome. Pain Clinic
    2001; 13(2): 119-123.

18. Doering PL and Boothby LA. New Drug Update 2005 -- Part 1. Drug
    Topics 2006 (Feb 6); 21-34.

19. Soparkar CNS, Patrinely JR, Skibell BC et al. Hyaluronidase and
    Restylane. Arch Facial Plast Surg 2007;9(4):299-300.

20. Banta C, Noerr B. Hyaluronidase. Neonatal Network 1992;
    11(6):103-19.

21. Flemmer L, Chan JSL. A pediatric protocol for management of
    extravasation injuries. Pediatr Nurs 1993;19:355-8, 424.

22. DeRuiter J, Holston PL. Review of Select New Molecular Entities. US
    Pharmacist, March, 2006, available at
    <http://www.uspharmacist.com/index.asp?page=ce/105220/default.htm>

23. Bruera E, Neumann CM, Pituskin E et al. A randomized controlled
    trial of local injections of hyaluronidase versus placebo in cancer
    patients receiving subcutaneous hydration. Ann Onc 1999;10:1255-8.

24. Thomas JR, Yocum RC, Haller MF et al. Assessing the role of human
    recombinant hyaluronidase in gravity-driven subcutaneous hydration:
    The INFUSE-LR Study. J Palliat Med 2007;10(6):1312-20.

25. Herndon CM, Fike DS. Continuous Subcutaneous Infusion Practices of
    United States Hospices. J Pain Symptom Manage 2001;22:1027-34.

26. INFUSE Morphine Study available at
    <http://clinicaltrials.gov/ct2/show/NCT00593281?term=infuse+morphine&rank=1>

27. Halozyme Therapeutics and Baxter Present Promising Results for the
    use of Hylenex® from the Infuse-Morphine Study, available at:
    <http://www.baxter.com/about_baxter/news_room/news_releases/2007/02-14-07-infuse_morphine.html>

28. Sarvela J, Nikki P. Hyaluronidase improves regional ophthalmic
    anaesthesia with etidocaine. Can J Anaesth 1992;39(9):920-4.

29. Gmyrek R. Local anesthesia and regional nerve block anesthesia,
    February 7, 2007, available at
    <http://www.emedicine.com/derm/topic824.htm>

30. Woodward DK, Leung ATS, Tse MWI et al. Peribulbar anaesthesia with
    1% ropivacaine and hyaluronidase 300 IU ml^-1^ ; comparison with
    0.5% bupivacaine/2% lidocaine and hyaluronidase 50 IU ml^-1^ . Br J
    Anaesth 2000;84:618-20.

31. Prosser DP, Rodney GE, Mian T et al. Re-evaluation of hyaluronidase
    in peribulbar anaesthesia. Br J Ophthalmol 1996;80:827-30.

32. Canavan KS, Dark A, Garrioch MA. Sub-Tenon's administration of local
    anaesthetic: a review of the technique. Br J Anaesth 2003;90:787-93.

33. Zahl K, Jordan A, McGroarty J et al. pH-Adjusted bupivacaine and
    hyaluronidase for peribulbar block. Anesthesiology 1990;72:230-32.

34. Kallio H, Paloheimo M, Maunuksela EL. Hyaluronidase as an adjuvant
    in bupivacine-lidocaine mixture for retrobulbar/peribulbar block.
    Anesth Analg 2000;91:934-7.

35. Aslam S, Sarker SJ, Tran-Dang M et al. Effect of hyaluronidase on
    ocular motility and eyelid function in sub-Tenon's anaesthesia:
    randomized controlled trial. Eye 2006;20:579-82.

36. AHRQ Evidence Reports and summaries, Numbers 1-60. Anesthesia
    Management During Cataract Surgery, Volume I: Evidence Report,
    Chapter 4. Conclusions. HSTAT (Health Services Technology Assessment
    Text), National Library of Medicine, available at:
    <http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat1.section.23954>

37. Zimmet SE. Hyaluronidase in the prevention of sclerotherapy-induced
    extravasation necrosis: a dose response study. Derm Surg
    1996;22:73-7.

38. Sokol DK, Dahlmann A, Dunn DW. Hyaluronidase treatment for
    intravenous phenytoin extravasation. J Child Neuro 1998;13(5).

39. Kumar MM, Sprung J. The use of hyaluronidase to treat mannitol
    extravasation. Anesth Analg 2003;97:1199-1200.

40. Vartanian AJ, Frankel AS, Rubin MG. Injected hyaluronidase reduces
    restylane-mediated cutaneous augmentation. Arch Facial Plast Surg
    2005;7:231-7.

41. Soparkar CNS, Patrinely JR. Managing inflammatory reaction to
    restylane. Ophthal Plast Reconstr Surg 2005;21:151-64.

42. Hirsch RJ, Brody HJ, Carruthers JDA. Hyaluronidase in the office: a
    necessity for every dermasurgeon that injects hyaluronic acid. J
    Cosmet Laser Ther 2007;9:182-5.

43. Vitreous hemorrhage available at
    <http://www.istavision.com/conditions/conditions_vitreous.asp>

44. Kuppermann BD, Thomas EL, deSmet MD, et al. Safety results of two
    phase III trials of an intravitreous injection of highly purified
    ovine hyaluronidase (Vitrase®) for the management of vitreous
    hemorrhage. Am J Ophthalmol 2005;140:585-597.

45. Simple model predicts treatment success with Vitrase® in vitreous
    hemorrhage associated with diabetes -- ISTA Pharmaceuticals reports.
    Medical News Today, May 2, 2006, available at:
    <http://www.medicalnewstoday.com/articles/42550.php>

46. Personal communication, ISTA Pharmaceuticals, Inc., August 28, 2008.

47. Ebo DG, Gossens S, Opsomer F. et al. Flow-assisted diagnosis of
    anaphylaxis to hyaluronidase. Allergy 2005;60(10):1333-4.

48. Yocum RC, Kennard D, Heiner LS. Assessment and implication of the
    allergic sensitivity to a single dose of recombinant human
    hyaluronidase injection. J Infus Nursing 30(5):293-9.

49. Gow JA, Aird BA, McNamara TR et al. The compatibility of Vitrase®
    combined with Kenalog®, abstract #688, Association for Research in
    Vision and Ophthalmology Annual Meeting, Ft. Lauderdale, FL, April
    30-May 4, 2006.

Prepared by Michael Chaffman, PharmD, BCPS

+------------+---------------------------------------------------------+
| ######     | INFUSE-LR                                               |
| # Citation |                                                         |
|            | Thomas, JR, Yocum, RC, Haller MF et al. Assessing the   |
|            | role of human recombinant hyaluronidase in              |
|            | gravity-driven subcutaneous hydration: the INFUSE-LR    |
|            | study. Journal of Palliative Medicine. 2007; 1312-1320. |
+------------+---------------------------------------------------------+
| ####### S  | ## To compare flow rate                                 |
| tudy Goals | , tolerability, and safety of gravity-driven subcutaneo |
|            | us fluid administration with and without human recombin |
|            | ant human hyaluronidase (rHuPH20) in healthy volunteers |
+------------+---------------------------------------------------------+
| #####      | INFUSE-LR conducted with paid volunteers in a contract  |
| ## Methods | research facility in Long Beach, California, USA.       |
|            |                                                         |
|            | **Study Design**                                        |
|            |                                                         |
|            | INFUSE-LR is a randomized, double-blind,                |
|            | placebo-controlled, within-subject trial with 54        |
|            | volunteer participants. Twenty-four gauge               |
|            | angiocatheters were placed subcutaneously in both upper |
|            | arms of participants. Each arm received rHuPH20 (150    |
|            | units, 750 units, or 1500 units), or an equal volume of |
|            | saline placebo. Immediately thereafter, 400ml of        |
|            | lactated Ringer's (LR) solution was gravity-infused     |
|            | from a 100cm height. In the pilot stage, 5 subjects     |
|            | also received a similar intravenous infusion. The       |
|            | primary outcome was time to infuse 400ml of LR.         |
|            | Secondary outcomes included discomfort assessments,     |
|            | edema, arm circumference, time to recover to baseline   |
|            | arm circumference, subject and investigator global      |
|            | preference, and adverse events. Secondary outcomes and  |
|            | upper arm photographs were obtained at                  |
|            | protocol-specified time points Investigators rated      |
|            | edema and obtained arm circumference at the catheter    |
|            | site, halfway between the catheter and the olecranon    |
|            | process, and halfway between the catheter and the       |
|            | inferoposterior aspect of the acromion at baseline,     |
|            | mid-infusion each arm (once 200ml had infused), at the  |
|            | end of infusion each arm, and then every 30 minutes     |
|            | until arm circumference in each arm returned to within  |
|            | 5% of the baseline measurement. Time to return to       |
|            | within 5% of baseline circumference was recorded.       |
|            | Subjects rated discomfort on a 100-mm visual analog     |
|            | scale (0 = no discomfort; 100 = worst discomfort).      |
|            | Subjects and the investigator separately ranked global  |
|            | preferences for the infusions. All adverse events were  |
|            | recorded from the time of initial exposure through 28   |
|            | days. Subjects underwent post-infusion evaluations at 1 |
|            | and 28 days.                                            |
|            |                                                         |
|            | **Data Analysis**                                       |
|            |                                                         |
|            | Statistical analyses were performed using McNemar's     |
|            | test for binomial variables, the sign rank test for     |
|            | global preferences, and paired t-tests for all other    |
|            | variables. Flow rate was determined on an as-treated    |
|            | basis; safety analysis was performed on an              |
|            | intent-to-treat basis. Continuous data were presented   |
|            | as mean ± SD. While the normality assumption was not    |
|            | rejected for any cohort, additional nonparametric       |
|            | paired analyses were also performed. Both the signed    |
|            | rank test and sign test confirmed results of the paired |
|            | t-test.                                                 |
+------------+---------------------------------------------------------+
| ######     | ####### Inclusion criteria                              |
| # Criteria |                                                         |
|            | Subjects aged 18 to 60, with normal vital signs, venous |
|            | access in one forearm, decision-making capacity, no     |
|            | fluid intake for 12 hours prior to study infusions,     |
|            | normal metabolic panel, and, if female, a negative      |
|            | pregnancy test.                                         |
|            |                                                         |
|            | ####### Exclusion criteria                              |
|            |                                                         |
|            | Subjects with edema, upper extremity pathology that     |
|            | could interfere with study outcomes, cardiovascular     |
|            | disease, rales, coagulopathy, and allergy to            |
|            | hyaluronidase, bee, or vespid venom.                    |
+------------+---------------------------------------------------------+
| #####      | Male and female volunteers participated in the study.   |
| ## Results | Fifty-two percent were female. Mean age was 28.9 ± 7.8  |
|            | years. Mean body mass index was 28.1 ± 6.1 kg/m^2^.     |
|            | Subjects were evenly distributed among the stages and   |
|            | cohorts of the study.                                   |
|            |                                                         |
|            | ####### [Stage 1 Pilot:]{.underline}                    |
|            |                                                         |
|            | In the 5 pilot subjects, mean subcutaneous flow rates   |
|            | with and without rHuPH20 were 313 ± 151 ml/h and 108 ±  |
|            | 59 ml/h, respectively (p = 0.049). The mean IV flow     |
|            | rate in the pilot subjects was 809 ± 295 ml/h. Four of  |
|            | the 5 pilot subjects stated a global preference fir SC  |
|            | infusion over IV infusion. SQ infusion with rHuPH20 was |
|            | their first choice or tied for first in 4 subjects.     |
|            |                                                         |
|            | #######                                                 |
|            |                                                         |
|            | ####### [Primary Endpoints]{.underline}:                |
|            |                                                         |
|            | *Time to infuse 400ml of LR:*                           |
|            |                                                         |
|            | -   150 units of rHuPH20: 301 ± 117 ml/h vs. placebo 82 |
|            |     ± 30ml/h; n = 16                                    |
|            |                                                         |
|            | -   750 units of rHuPH20: 518 ± 154 ml/h vs. placebo    |
|            |     148 ±57 ml/h; n = 16                                |
|            |                                                         |
|            | -   1,500 units of rHuPH20: 494 ± 136 ml/h vs. placebo  |
|            |     124 ± 50ml/h; n = 15                                |
|            |                                                         |
|            | p \< 0.001 for rHuPH20 vs. placebo in each group        |
|            |                                                         |
|            | ####### [Secondary Outcomes:]{.underline}               |
|            |                                                         |
|            | *% of subjects with moderate or severe edema:*          |
|            |                                                         |
|            | -   150 units of rHuPH20: 12% moderate, 0% severe vs.   |
|            |     placebo 65% moderate; 35% severe; n = 17            |
|            |                                                         |
|            | -   750 units of rHuPH20: 38% moderate, 0% severe vs.   |
|            |     placebo 100% moderate, 0% severe; n = 16            |
|            |                                                         |
|            | -   1,500 units of rHuPH20: 0% moderate, 0% severe vs.  |
|            |     placebo 47% moderate, 40% severe; n = 15            |
|            |                                                         |
|            | P ≤ 0.003 for each dose group pair-wise comparison      |
|            | (McNemar's test)                                        |
|            |                                                         |
|            | *Time (minutes) to recovery of baseline arm             |
|            | circumference:*                                         |
|            |                                                         |
|            | -   150 units of rHuPH20: 339 ± 139 min vs. placebo 507 |
|            |     ± 172 min; n = 18                                   |
|            |                                                         |
|            | -   750 units of rHuPH20: 268 ± 121 min vs. placebo 424 |
|            |     ± 114 min; n = 16                                   |
|            |                                                         |
|            | -   1,500 units of rHuPH20: 352 ± 137 min vs. placebo   |
|            |     442 ± 101 min; n = 15                               |
|            |                                                         |
|            | *Discomfort:*                                           |
|            |                                                         |
|            | Overall, subjects rated only minimal pain in both arms  |
|            |                                                         |
|            | -   Without rHuPH20 (placebo), pain score was 9.6 ±     |
|            |     15.3 mm                                             |
|            |                                                         |
|            | -   With rHuPH20, pain score was 5.8 ± 10.7 mm (p \<    |
|            |     0.002 for rHuPH20 vs. placebo                       |
|            |                                                         |
|            | *Global preference rHuPH20 vs. placebo:*                |
|            |                                                         |
|            | -   150 units of rHuPH20: 88%, p \< 0.002               |
|            |                                                         |
|            | -   750 units of rHuPH20: 100%, p \< 0.001              |
|            |                                                         |
|            | -   1,500 units of rHuPH20: 87%, p \< 0.007             |
+------------+---------------------------------------------------------+
| ####### C  | The authors concluded that human recombinant            |
| onclusions | hyaluronidase (rHuPH20) enabled the gravity-driven      |
|            | subcutaneous infusion of a clinically relevant volume   |
|            | of an isotonic solution in a clinically relevant time   |
|            | frame in a well-tolerated manner, thus supporting the   |
|            | possibility of using gravity-driven rHuPH20-enabled SC  |
|            | infusions as a replacement for pump-driven IV fluid     |
|            | therapy.                                                |
+------------+---------------------------------------------------------+

+------------+---------------------------------------------------------+
| ######     | Kuppermann BD, Thomas EL, de Smet MD et al. Pooled      |
| # Citation | efficacy results from two multinational randomized      |
|            | controlled clinical trials of a single intravitreous    |
|            | injection of highly purified ovine hyaluronidase        |
|            | (Vitrase®) for the management of vitreous hemorrhage.   |
|            | American Journal of Ophthalmology 2005; 140(4):         |
|            | 573-584.                                                |
+------------+---------------------------------------------------------+
| ####### S  | ## To evaluate the efficacy o                           |
| tudy Goals | f a single intravitreous ovine hyaluronidase injection  |
|            |                                                         |
|            | ## for the management of vitreous hemorrhage            |
+------------+---------------------------------------------------------+
| #####      | The study was conducted in 131 centers in the United    |
| ## Methods | States, Canada, Mexico (North American, Vit-02) and in  |
|            | Hungary, Italy, the Netherlands, Poland, Spain, United  |
|            | Kingdom, Australia, Brazil and South Africa (ex-North   |
|            | American, Vit-03; 1306 patients were screened and       |
|            | randomized.                                             |
|            |                                                         |
|            | **Study Design**                                        |
|            |                                                         |
|            | The data from two randomized, parallel-group            |
|            | double-blinded clinical trials were integrated; Vit-02  |
|            | where 3 dosages of hyaluronidase were evaluated: 7.5    |
|            | IU, 55IU, and 75IU, and Vit-03, where 2 dosages were    |
|            | evaluated, 55 IU and 75 IU.                             |
|            |                                                         |
|            | Treatment consisted of a single intravitreous injection |
|            | of 7.5 IU, 55 IU, or 75 IU ovine hyaluronidase          |
|            | (equivalent to 9.3, 68, or 93 USP units, respectively)  |
|            | or saline (0.9% sodium chloride solution) through the   |
|            | pars plana using a 30-gauge needle and local            |
|            | anesthesia. To ensure the integrity of the study        |
|            | masking procedures, an unmasked person not involved in  |
|            | the treatment or evaluation of the subject was chosen   |
|            | in advance at each site to select the appropriate test  |
|            | agent vial as determined by the randomization sequence, |
|            | prepare the test agent, and deliver the test agent to   |
|            | the masked injecting investigator. Masking of the       |
|            | investigator and subject was maintained throughout the  |
|            | duration of the study.                                  |
|            |                                                         |
|            | Clinical ocular assessments were performed at day 1,    |
|            | week 1, and months 1,2 and 3 following injection for    |
|            | efficacy and safety outcomes, and at month 6, and every |
|            | 6 months thereafter for safety outcomes. Assessments    |
|            | performed at each visit during the study consisted of   |
|            | medical/ophthalmic history, ocular symptoms, adverse    |
|            | events, concomitant medications, best corrected visual  |
|            | acuity (BCVA), intraocular pressure (IOP), external eye |
|            | examination, slit-lamp biomicroscopy, dilated fundus    |
|            | examination, B-scan ultrasonography, and fundus         |
|            | photography.                                            |
|            |                                                         |
|            | The primary efficacy endpoint was defined by clearance  |
|            | of the vitreous hemorrhage sufficient to see the        |
|            | underlying pathology and to complete treatment, when    |
|            | indicated, by the month 3 visit. A patient was          |
|            | classified as a treatment success if the patient's      |
|            | vitreous hemorrhage in the study eye had cleared        |
|            | sufficiently for diagnosis of the underlying pathology  |
|            | and one of the following criteria were met within the   |
|            | month 3 visit window: 1) laser treatment of the         |
|            | underlying condition was completed; 2) visualization of |
|            | the retina revealed that surgery was required and was   |
|            | performed to correct the underlying pathology; or 3)    |
|            | visualization of the macula and a minimum of 180        |
|            | degrees of the vitreous base was performed and the      |
|            | underlying cause of the hemorrhage was documented,      |
|            | through a fundus photograph, to have been resolved      |
|            | without the need for further therapy.                   |
|            |                                                         |
|            | The key secondary endpoints evaluated were the          |
|            | proportion of patients with: at least a 3-line          |
|            | improvement in BCVA in the study eye; reduction in      |
|            | vitreous hemorrhage density; and clinical assessment of |
|            | therapeutic utility by the investigator (clearance of   |
|            | hemorrhage sufficient to diagnose the underlying        |
|            | pathology).                                             |
|            |                                                         |
|            | **Data Analysis**                                       |
|            |                                                         |
|            | Baseline characteristics were analyzed using either a   |
|            | one-way analysis of variance (ANOVA) for numeric        |
|            | response variable, or an appropriate categorical        |
|            | analysis                                                |
|            |                                                         |
|            | (for example, χ2 and/or Fisher's exact test) for        |
|            | categorical response frequencies. Adverse event         |
|            | summaries were provided using descriptive statistics.   |
|            | Statistical significance was on the basis of a          |
|            | generalized Fisher's exact test that compared incidence |
|            | among and between the saline and ovine hyaluronidase    |
|            | treatment groups.                                       |
+------------+---------------------------------------------------------+
| ######     | ####### Inclusion criteria                              |
| # Criteria |                                                         |
|            | Male and female subjects were eligible for enrollment   |
|            | if they were 18 years or older and had a vitreous       |
|            | hemorrhage in the study eye which had been present for  |
|            | at least 1 month, and which was dense enough at entry   |
|            | to obscure visualization of the fundus on indirect      |
|            | ophthalmoscopy such that no retinal detail was visible  |
|            | posterior to the equator. Eligible subjects had BCVA    |
|            | worse than 20/200 in the study eye.                     |
|            |                                                         |
|            | ####### Exclusion criteria                              |
|            |                                                         |
|            | Candidates were excluded if they had corneal            |
|            | abnormalities that would have precluded fundus          |
|            | observation or accurate IOP readings; ocular infection  |
|            | or inflammation or a history of herpetic corneal        |
|            | lesion; current or prior retinal detachments, retinal   |
|            | tears or breaks, or intraocular tumor; more than one    |
|            | severe vitreous hemorrhage within the 6 months before   |
|            | the onset of the present hemorrhage; vitreous           |
|            | hemorrhage associated with ocular trauma, previous      |
|            | vitrectomy; hemorrhage that was old and organized; no   |
|            | light perception (NLP) in either eye before or at       |
|            | screening; or a history of sickle cell disease.         |
+------------+---------------------------------------------------------+
| #####      | A total of 1125 patients with persistent vitreous       |
| ## Results | hemorrhage were randomized to 55 IU (n = 365) or 75 IU  |
|            | (n = 377) of hyaluronidase, or saline (n = 383). Data   |
|            | from pa-tients who received 7.5 IU was not utilized for |
|            | this pooled analysis. Pooled demo-graphic data: 51.6%   |
|            | of all participants were male; mean age of all patients |
|            | was 62. Seventy-six percent of pooled patients were     |
|            | diabetic (59.4% type I). Most patients in the pooled    |
|            | group (90.4%) were unable to read any letters on the    |
|            | eye chart with their study eye. Mean duration of the    |
|            | vitreous hemorrhage was 120.4 days.                     |
|            |                                                         |
|            | ####### [Primary Endpoints]{.underline}:                |
|            |                                                         |
|            | *Cumulative % of patients achieving clearance of        |
|            | vitreous hemorrhage sufficient to see underlying        |
|            | pathology and complete treatment by month 3 visit:*     |
|            |                                                         |
|            | -   Month 1: saline control 5.5%; hyaluronidase 55 IU   |
|            |     13.2% (p , 0.001)                                   |
|            |                                                         |
|            | > 75 IU 10.6% (p = .010)                                |
|            |                                                         |
|            | -   Month 2: saline control 16.2%; hyaluronidase 55 IU  |
|            |     25.5% (p = 0.02)                                    |
|            |                                                         |
|            | > 75 IU 21.2% (p = .083)                                |
|            |                                                         |
|            | -   Month 3: saline control 25.6%; hyaluronidase 55 IU  |
|            |     32.9% (p = .025)                                    |
|            |                                                         |
|            | > 75 IU 30.5% (p = .144)                                |
|            |                                                         |
|            | ####### [Secondary Outcomes:]{.underline}               |
|            |                                                         |
|            | *% of subjects attaining ≥ 3-line improvement in BCVA   |
|            | by month 3 visit:*                                      |
|            |                                                         |
|            | -   Month 1: saline control 20.1%; hyaluronidase 55 IU  |
|            |     30.7% (p \< .001)                                   |
|            |                                                         |
|            | > 75 IU 27.9% (p = .013)                                |
|            |                                                         |
|            | -   Month 2: saline control 27.4%; hyaluronidase 55 IU  |
|            |     41.1% (p \< .001)                                   |
|            |                                                         |
|            | > 75 IU 38.2% (p = .002)                                |
|            |                                                         |
|            | -   Month 3: saline control 34.5%; hyaluronidase 55 IU  |
|            |     44.9% (p \< 004)                                    |
|            |                                                         |
|            | > 75 IU 43.5% (p = .011)                                |
|            |                                                         |
|            | *Cumulative % of subjects reaching the reduction in     |
|            | vitreous hemorrhage density endpoint by month 3 visit:* |
|            |                                                         |
|            | -   Month 1: saline control 11.0%; hyaluronidase 55 IU  |
|            |     20.3% (p \< .001)                                   |
|            |                                                         |
|            | > 75 IU 19.1% (p = .002)                                |
|            |                                                         |
|            | -   Month 2: saline control 21.4%; hyaluronidase 55 IU  |
|            |     32.9% (p \< .001)                                   |
|            |                                                         |
|            | > 75 IU 30.2% (p = .006)                                |
|            |                                                         |
|            | -   Month 3: saline control 28.5%; hyaluronidase 55 IU  |
|            |     38.6% (p = .003)                                    |
|            |                                                         |
|            | 75 IU 38.2% (p = .005)                                  |
|            |                                                         |
|            | *Cumulative % of subjects attaining clearance of        |
|            | hemorrhage sufficiently for investigator to diagnose    |
|            | and treat by month 3 visit (clinical assessment of      |
|            | therapeutic utility endpoint):*                         |
|            |                                                         |
|            | -   Month 1: saline control 11.2%; hyaluronidase 55 IU  |
|            |     23.3% (p \< .001)                                   |
|            |                                                         |
|            | > 75 IU 22.5% (p \< .001)                               |
|            |                                                         |
|            | -   Month 2: saline control 21.4%; hyaluronidase 55 IU  |
|            |     35.3% (p \< .001)                                   |
|            |                                                         |
|            | > 75 IU 32.1% (p = .001)                                |
|            |                                                         |
|            | -   Month 3: saline control 28.5%; hyaluronidase 55 IU  |
|            |     40.8% (p \< .001)                                   |
|            |                                                         |
|            | 75 IU 39.3% (p = .002)                                  |
+------------+---------------------------------------------------------+
| ####### C  | Fifty-five IU ovine hyaluronidase showed statistically  |
| onclusions | significant efficacy as early as months 1 and 2. These  |
|            | results were supported by outcomes for 3 key secondary  |
|            | endpoints. These results suggest a therapeutic utility  |
|            | of ovine hyaluronidase in the management of vitreous    |
|            | hemorrhage.                                             |
+------------+---------------------------------------------------------+