February 8, 2006
The only manufacturer of U.S.-licensed VZIG, Massachusetts Public Health Biologic Laboratories (Boston, MA), has discontinued production of this product, which is indicated for patients in need of passive immunization to prevent severe varicella zoster infection. The supply of the licensed VZIG product is nearly depleted. However, an investigational (not licensed) VZIG product (manufactured and currently under development by Cangene Corporation Winnipeg, Canada) is available under an investigational new drug application (IND) protocol. This product may be requested through FFF Enterprises (Temecula, CA) for individuals who have been exposed to varicella and who are at increased risk of complications from varicella (see below - "What Patients Are Eligible to Participate" section).
The investigational VZIG, like licensed VZIG, is a purified human immune globulin preparation made from high anti-varicella antibody-containing plasma. The investigational product is lyophilized. When properly reconstituted, it is a 5% solution of IgG, which is intended to be administered intramuscularly. As with any product used under IND, patients must be informed of potential risks and benefits and give informed consent before receiving the product.
If a decision is made to use VZIG, it should be administered as soon as possible after exposure, and within 10 days of exposure.
What patients are eligible to participate in the IND protocol for VZIG?
At-risk, susceptible patients who have been exposed to varicella1, and for whom informed consent is obtained, are eligible to receive the IND product under an expanded access protocol. The patient groups include:
- Immune compromised pediatric and adult patients
- Neonates and infants < 1 year of age
- Premature infants
- Pregnant women
- Newborns whose mothers had varicella infection < 5 days prior to delivery, to <2 days after delivery
Note: Licensed VZIG is not indicated for prophylactic use in immunodeficient children or adults who have a known past history of varicella, unless the patient has undergone bone marrow transplantation. The expanded access protocol also does not include this use.
If I have a patient who may be eligible, how can I find out more about the expanded access protocol?
There is an expanded access protocol that enables use of investigational VZIG for patients who meet the protocol's enrollment criteria and who choose to participate in the protocol (see attached sample release form). You can obtain information by calling the 24-hour number at FFF Enterprises: 1-800-843-7477. You will be asked to provide preliminary information to determine patient eligibility. If your patient is eligible, investigational VZIG will be shipped to you with the informed consent form, case report forms, Investigator's Brochure, and contact information for Cangene Corporation. Under normal circumstances, investigational VZIG can be delivered from the distributor to its destination within 24 hours of request.
To assist you in determining whether your patient is eligible, a sample release form is attached, below. If you request investigational VZIG, FFF Enterprises will provide this form directly to you for completion.
How should I report difficulties in obtaining investigational VZIG?
You may report any difficulties by sending an email to CBERshortages@fda.hhs.gov. Also, during business hours, healthcare personnel may report a real or suspected supply concern by calling (301) 827-4239.
The CDC has defined varicella exposure as follows (MMWR July 12, 1996; 45 (RR11): 1-25): "Several types of exposure can place susceptible persons at risk for varicella. Direct contact exposure is defined as greater than 1 hour of direct contact with an infectious person while indoors; substantial exposure for hospital contacts consists of sharing the same hospital room with an infectious patient or prolonged, direct, face-to-face contact with an infectious person (e.g., health-care workers). Brief contacts with an infectious person (e.g., contact with x-ray technicians or housekeeping personnel) are less likely to result in VZV transmission than are more prolonged contacts. Persons with continuous exposure to household members who have varicella are at greatest risk for infection. Varicella develops in approximately 90% of susceptible household contacts." The risk for varicella following close contact (e.g., contact with playmates) or hospital exposure is approximately 20% of the risk occurring from household exposure.