08:31 AM EDT, 09/03/2024 (MT Newswires) -- Vaxcyte ( PCVX ) said Tuesday it plans to launch by mid-2025 a phase 3 study for VAX-31 following "positive" topline results from a phase 1/2 trial assessing the immunogenicity, safety, and tolerability of the 31-valent pneumococcal conjugate vaccine candidate.

The investigational treatment was tested in 1,015 healthy adults aged at least 50 years, said the company, which found VAX-31 to be "well tolerated" and showing "robust opsonophagocytic activity immune responses for all 31 serotypes" at all dose levels.

Vaxcyte ( PCVX ), which expects topline data from the planned phase 3 study in 2026, also said it intends to launch the phase 2 trial in Q1 2025.

The company's shares were up over 34% in recent Tuesday premarket activity.

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