Evaxion Biotech (EVAX) investor relations material

Study design and population

• 17 enrolled and 16 received EVX-01; treatment-naïve patients received a 12-week pembrolizumab run-in before EVX-01 priming and boosters. Six entered an extension year of EVX-01 monotherapy.

• Main-phase data cutoff was June 22, 2025, with median follow-up of 24 months; extension data cutoff was April 27, 2026, with median follow-up of 39.5 months.

• Primary endpoint assessed response conversion; secondary endpoints included ORR, PFS, OS, safety, tolerability and neoantigen-specific T-cell responses.

Clinical outcomes

• Best ORR was 75% (12/16), comprising 4 complete responses (25%) and 8 partial responses (50%); median PFS and OS were not reached.

• 4/6 patients with stable disease converted to partial response, and 3/7 with partial response converted to complete response.

• 11/12 responders maintained response at two years; all six extension patients remained in clinical response with no tumor progression through the additional follow-up year.

• Investigators described late response conversions after pembrolizumab run-in as suggestive of vaccine contribution, while noting treatment effects could not be separated conclusively.

Immunogenicity and safety

• EVX-01-specific T-cell responses were detected against 105/118 neoantigens (89%); 67/78 responses (86%) were de novo.

• Durable vaccine-specific T-cell responses were observed in all 15 patients who received at least six vaccinations; response magnitude and breadth were sustained during EVX-01 monotherapy.

• EVX-01-related adverse events were grade 1–2, mostly injection-site pain or swelling; no grade 3 or higher events were attributed to EVX-01. One grade 4 immune-related diabetes event was attributed to pembrolizumab.