The freeze-dried formulation provides flexibility with regard to storage and shelf life.
The Food and Drug Administration (FDA) has approved a new freeze-dried formulation of Jynneos® (smallpox and mpox vaccine, live, non-replicating). Prior to this approval, Jynneos had only been available as a liquid-frozen formulation.
Jynneos was approved in 2019 for the prevention of smallpox and mpox disease in adults 18 years of age and older at high risk for smallpox or mpox infection. The live vaccine is produced from the strain Modified Vaccinia Ankara-Bavarian Nordic (MVA-BN), an attenuated, non-replicating orthopoxvirus; this modified form of the vaccinia virus does not cause disease in humans and cannot reproduce in human cells.
According to Bavarian Nordic, the freeze-dried formulation has advantages in terms of transportation, storage, and shelf life compared with the liquid-frozen formulation, allowing for more efficient stockpiling.
The supplemental Biologics License Application approval was supported by clinical data from a lot consistency phase 3 study (ClinicalTrials.gov Identifier: NCT03699124), a phase 2 study (ClinicalTrials.gov Identifier: NCT01668537), as well as non-clinical and manufacturing data.
The comparative phase 2 study enrolled 651 vaccinia-naïve participants to receive either the liquid-freeze formulation or the freeze-dried formulation of the MVA-BN smallpox vaccine. Results demonstrated bioequivalence between the 2 formulations based on vaccinia-specific humoral response.
The phase 3 study evaluated the immunogenicity and safety of the freeze-dried MVA-BN smallpox vaccine in 1129 vaccinia-naïve individuals. The study participants were randomly assigned to receive 1 of 3 lots of freeze-dried MVA-BN as a 2-dose regimen 4 weeks apart.
Results showed 2 weeks after receiving the second dose, neutralizing antibody geometric mean titers (GMT) increased from non-detectable to 252.7, 269.9, and 242.0 for lots 1, 2, and 3, respectively. The GMT ratios between the lot group pairs (range, 0.936-1.115) all fell within the prespecified interval of 0.5 to 2.0, demonstrating equivalence between all lots. Total antibody GMTs showed similar results as well. Seroconversion rates were all above 98% for both neutralizing and total antibodies following 2 weeks after the second dose; no statistically significant differences were observed among the 3 lots (neutralizing antibodies: P =.7102 and total antibodies: P =.6916).
No serious adverse events were reported in the trial. Notably, no inflammatory cardiac disorders were identified. The most common local adverse events were injection site pain and erythema. The most common general adverse events were myalgia, fatigue and headache.
“Today’s FDA approval represents a significant milestone in our development of this next generation of Jynneos and in our collaborative efforts with the US government to strengthen public health security,” said Paul Chaplin, President and CEO of Bavarian Nordic. “As a long-term supplier of Jynneos to the US biological preparedness, we are committed to continue supporting the government’s efforts to protect its citizens against current and future public health threats.”
By Jaymin Kang, PharmD
References:
- Bavarian Nordic receives US FDA approval of freeze-dried smallpox and mpox vaccine. News release. Bavarian Nordic. March 31, 20205. https://www.globenewswire.com/news-release/2025/03/31/3052817/0/en/Bavarian-Nordic-Receives-U-S-FDA-Approval-of-Freeze-Dried-Smallpox-and-Mpox-Vaccine.html.
- Bavarian Nordic submits supplemental BLA seeing US FDA approval of freeze-dried formulation of smallpox and mpox vaccine. News release. Bavarian Nordic. May 31, 2024. https://www.bavarian-nordic.com/investor/news/news.aspx?news=6959.
- Greenberg RN, Schmidt D, Reichhardt D, et al. Equivalence of freeze-dried and liquid-frozen formulations of MVA-BN as smallpox and mpox vaccine. Human Vaccines & Immunotherapeutics. Published online August 22, 2024. doi:10.1080/21645515.2024.2384189
- Turner Overton E, Schmidt D, Vidojkovic S, et al. A randomized phase 3 trial to assess the immunogenicity and safety of 3 consecutively produced lots of freeze-dried MVA-BN® vaccine in healthy adults. Vaccine. Published online January 9, 2023. doi:10.1016/j.vaccine.2022.10.056
Source : MPR
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