- Pfizer's experimental pneumococcal vaccine has shown early clinical success in healthy infants, supporting the company's plans to advance the Prevnar 13 successor into Phase 3 testing, the pharma said Monday.
- Since 2014, Prevnar 13 has brought in more than $30 billion in global sales due to its leading position in the world's largest vaccine market. While revenue growth has plateaued recently, Pfizer plans to extend its share of the market with an improved, next-generation vaccine.
- Pfizer said Monday that experimental candidate spurred immune responses across the 20 serotypes it targets, showing a similar safety profile to Prevnar 13 in a Phase 2 proof-of-concept study that tested the two drugs in roughly 460 healthy infants. Pfizer said it would disclose detailed data after the infants receive their fourth and final dose in the study.
With Prevnar 13, Pfizer dominates the pneumococcal vaccine market. But rival Merck & Co. is also developing a vaccine that could compete in the near-term future.
Merck's vaccine, called V114, is further along in development than Pfizer's 20-serotype option. V114 has 11 ongoing Phase 3 clinical studies across a range of patient types, including adults, infants and immunocompromised patients.
In May, Merck said its 15-valent drug demonstrated non-inferiority to Prevnar 13 in a Phase 2 infant study.
That progress makes Pfizer's incremental update more important. The positive interim result "allays concerns" about Pfizer's vaccine for the infant population, Evercore ISI analyst Umer Raffat wrote Monday, noting "some nervousness" about a potential formulation issue.
A few months after starting this clinical trial, Pfizer began another Phase 2 study testing a back-up formulation. That study is testing a 7-valent vaccine in combination with Prevnar 13, which together generate the same serotype coverage. The combination may hedge against the risk that a 20-valent product could overwhelm the immune system, analysts for Cowen & Co. wrote earlier this year.
Even with the positive update, Raffat is looking to full data, specifically on "carrier suppression on additional serotypes, non-inferiority on first 13 serotypes," and immune response.
For Pfizer, the update will keep the 20-valent vaccine moving forward in infants.
"These findings are encouraging and should support the program's advancement to Phase 3," said Kathrin Jansen, Pfizer's head of vaccine R&D, in a Sept. 9 statement.
For the adult population, Pfizer noted it completed enrollment in a trio of pivotal Phase 3 studies for the vaccine. Those three trials enrolled more than 6,000 adults, including patients who have had prior pneumococcal vaccinations as well as vaccine-naive individuals.
Pending successful results, the pharma giant plans to submit a Biologics License Application to the Food and Drug Administration by the end of 2020.
The next-gen vaccine covers the same 13 serotypes as Prevnar 13 along with seven new ones associated with high case-fatality rates, antibiotic resistance and meningitis, according to Pfizer.
Prevnar 13 sales declined last financial quarter due to lower government purchases for pediatrics combined with continued revenue drops among adults. Pfizer also expects further impact on the rest of 2019 due to a recent revision to vaccination guidelines by a Centers for Disease Control and Prevention group.
In June, the CDC's Advisory Committee on Immunization Practices said adults 65 and older should make pneumococcal vaccination decisions at the individual level, between doctors and patients. That reversed a previous decision in 2014 recommending all adults in that age range receive the vaccine.
Pfizer expects that decision to weigh on 2019 revenues for Prevnar 13, according to the company's latest financial statement.