Pfizer is taking its Valneva-partnered Lyme disease vaccine into phase 3. With midphase data supporting a three-dose series, the allies plan to kick off a phase 3 clinical trial of the regimen in the third quarter.
Valneva sold Pfizer the rights to multivalent protein subunit vaccine VLA15 for $130 million upfront in 2020. At that time, Valneva had already started two phase 2 clinical trials of the vaccine candidate. Pfizer and Valneva initiated a third midphase trial to compare two- and three-dose VLA15 regimens last year, leading to the generation of the data that has now persuaded the partners to move into phase 3.
The phase 2 clinical trial found VLA15 was immunogenic in adults when given in either regimen, adding to similar evidence generated in earlier studies. However, adding a third VLA15 dose increased the level of antibodies against an outer surface protein.
Pfizer’s three-dose regimen gives VLA15 the second dose at two months and the third at six months. The two-dose regimen misses out the shot at two months. As the phase 2 trial found there is value in adding the third dose, the partners plan to test that regimen in the late-phase study.
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Phase 3 success could give Pfizer a clear run at a growing opportunity. The number of reported cases of Lyme disease in the U.S. has tripled since the late 1990s, potentially because of changes in land use that have brought more humans into close contact with tick hosts. Whatever the cause, the rise has led the Centers for Disease Control and Prevention to say new tools for preventing tick-borne diseases are needed urgently.
VLA15 is a rare example of such a tool. SmithKline Beecham won approval for a Lyme vaccine in the late 1990s but pulled it from the market a few years later. Pasteur Mérieux Connaught, now Sanofi, dropped its plans to seek approval for a Lyme vaccine around the same time.
According to Valneva, VLA15 is now the only Lyme vaccine in clinical development. That offers Pfizer the chance to add a growth driver to its mammoth vaccine unit, but it will need to overcome the legacy of the earlier commercial failure to do so.