Dive Brief:
- An experimental pneumococcal vaccine from Vaxcyte succeeded in the first of three late-stage studies, sending the biotechnology company’s shares soaring and inching it closer to a potential regulatory submission.
- Called VAX-31, the shot met all of its main efficacy objectives in the study. Among adults 50 years or older, VAX-31 matched the effectiveness of Pfizer’s Prevnar 20 and Merck & Co.’s Capvaxive in protecting against 28 strains of the bacteria that causes pneumococcal disease and proved superior against three “unique” strains. VAX-31 was inferior compared to Capvaxive on two strains when using a more rigorous statistical threshold. But that finding surpassed analyst and investor expectations heading into the readout.
- Vaxcyte said its vaccine was “well tolerated” and demonstrated a safety profile similar to Prevnar 20 and Capvaxive across all ages studied. The most common adverse events were “generally mild-to-moderate,” and the majority resolved within two days of vaccination. Vaxcyte will report results from two additional late-stage trials next year and seek approval if the data are positive.
Dive Insight:
Vaxcyte’s study results were among the most eagerly anticipated readouts remaining this year. Salim Syed, an analyst with the firm Mizuho Securities, referred to them in June as a “‘must-play’ catalyst for biotech investors.”
The reason for the intense interest is that Vaxcyte’s shot is the most advanced challenger to a vaccine business that generates billions of dollars each year. Led by Pfizer’s dominant Prevnar franchise, these vaccines prevent pneumococcal diseases that can cause a variety of health problems, from mild sinus issues to life-threatening pneumonia and meningitis.
Pfizer’s business is largely built on a 13-strain shot that emerged in 2010 and has since expanded to include a 20-strain alternative. And while others such as Merck and GSK have invested heavily in their own competitors, Pfizer’s grip has held firm, with its franchise earning more than $6 billion last year.
Vaxcyte could pose a tougher threat, however. VAX-31 is designed to cover more than 30 bacterial strains and has advanced while other next-generation shots suffered setbacks. In earlier testing, it was able to match the effectiveness of Pfizer’s 20-strain shot. A trio of late-stage studies are now evaluating it against that vaccine and Merck’s 21-strain Capvaxive.
Some Wall Street investors became skeptical of VAX-31’s prospects after executives implied in May that the shot might miss against some strains covered by Capvaxive. Yet the results Vaxcyte ultimately reported show “best-in-class” potential in a market worth $8 billion annually and growing, according to Mizuho’s Syed.
“The data are very clean,” Syed wrote in a new note on Monday, calling the findings a “near best-case scenario” for the company.
Missing against two strains only when using a stricter-than-normal statistical framework for non-inferiority is “highly impressive and raises the bar for future adult pneumococcal vaccine candidate developers,” added Leerink Partners analyst David Risinger, in a separate note.
Risinger contended that those misses won’t lower VAX-31’s approval chances, either. Those strains are covered by both comparators in Vaxcyte’s trial, and VAX-31 only needed to match the effectiveness of one of those shots to claim success — an objective the company achieved.
“We expect physicians and patients to prefer VAX-31 over Prevnar 20 and Capvaxive since it offers the broadest protection against disease,” Risinger wrote.
Vaxcyte shares climbed about 50% in early trading, catapulting the company’s market value past $12 billion.
