Cyfendus FDA Approval History
Last updated by Judith Stewart, BPharm on July 24, 2023.
FDA Approved: Yes (First approved July 20, 2023)
Brand name: Cyfendus
Generic name: anthrax vaccine adsorbed, adjuvanted
Dosage form: Injection
Company: Emergent BioSolutions Inc.
Treatment for: Anthrax Prophylaxis
Cyfendus (anthrax vaccine adsorbed, adjuvanted) is a vaccine indicated for post-exposure prophylaxis of disease following suspected or confirmed exposure to Bacillus anthracis in persons 18 through 65 years of age when administered in conjunction with recommended antibacterial drugs.
- Anthrax is an infection caused by the Gram-positive, spore-forming bacteria called Bacillus anthracis, which occurs naturally in soil and commonly affects domestic and wild animals when they breathe in or ingest spores in contaminated soil, plants, or water. Humans can contract anthrax if they come in contact with infected animals or contaminated animal products.
- Cyfendus is an anthrax vaccine that works by inducing antibodies against protective antigen protein that may contribute to protection by neutralizing the activities of the cytotoxic lethal toxin and edema toxin of Bacillus anthracis.
- The first anthrax vaccine was licensed in 1970 and was recommended for use by a small population of workers with an occupational risk of exposure to anthrax. In the 1990s, the Department of Defense (DoD) started vaccinating U.S. military personnel due to increased concern about the use of anthrax as a biological weapon. The vaccine was offered to civilians who had been exposed to anthrax after intentional mailings of anthrax spores caused an outbreak in 2001.
- Cyfendus vaccine is comprised of Anthrax Vaccine Adsorbed (AVA) and an additional adjuvant so that two doses administered over 14 days provides protective levels of immune response. The previous anthrax vaccine required administration at 0, 2, and 4 weeks for post-exposure prophylaxis.
- FDA approval for Cyfendus was based on data from a pivotal Phase 3 clinical study that evaluated immunogenicity and safety, a Phase 2 study that evaluated non-interference between the vaccine and antibacterial drugs, and non-clinical studies that assessed protective efficacy of the vaccine against lethal challenge with anthrax spores. The efficacy of Cyfendus vaccine for post-exposure prophylaxis is based solely on studies in animal models of inhalational anthrax.
- Cyfendus is administered by intramuscular injection as two doses (0.5 mL each), two weeks apart.
- Warnings and precautions associated with Cyfendus include fetal harm when administered to a pregnant individual.
- Common injection-site adverse reactions include tenderness, pain, arm motion limitation, warmth, induration, itching, swelling, and erythema/redness.
Common systemic adverse reactions include muscle aches, tiredness, and headache.
Development timeline for Cyfendus
Further information
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