Evaxion's Melanoma Vaccine Data Are Durable, but Still Small

Evaxion's latest EVX-01 update is encouraging because it combines a durable clinical signal with evidence that the personalized vaccine is doing what it was designed to do. It is not yet proof that the treatment works in a broader melanoma population.

The company reported that every patient who reached the three-year follow-up maintained the response seen at two years, with no tumor progression during the extension period. Six patients from the original 16-person Phase 2 study entered that one-year extension. They received EVX-01 alone in the third year after receiving the vaccine with Merck's Keytruda during the first two years.

That distinction matters. The three-year result concerns a small, selected group that had already remained in the study. It does not come from a randomized comparison, and the earlier use of Keytruda makes it difficult to isolate how much of the durable response came from EVX-01.

The immune data are more precise than the headline

Evaxion said EVX-01 generated an immune response in every treated patient. Across the personalized vaccine targets, 89% of selected neoantigens produced a tumor-specific T-cell response, up from 86% at the two-year analysis after additional samples were included.

The 89% figure is not a tumor response rate and should not be read as diagnostic accuracy. It measures how often the vaccine's selected targets generated the intended immune response. Clinically, the company previously reported a 75% objective response rate at two years, including complete responses in 25% of patients. Tumor reduction was observed in 15 of the 16 enrolled patients, and 54% deepened their response after treatment began.

Together, those findings support the premise that Evaxion's AI-based process can select biologically active targets. The unanswered question is whether that immune precision will translate into a reproducible clinical benefit in a larger, controlled trial.

Financing is part of the development risk

EVX-01 remains an investigational Phase 2 program. Moving a personalized cancer vaccine into a larger study would require more patients, manufacturing capacity and additional capital or a partner. Evaxion has described the data package as a foundation for partnership discussions, but it has not announced a Phase 3 agreement in the materials reviewed.

The company's cash position makes that next step important. Evaxion reported $14.0 million of cash and cash equivalents at June 30, down from $18.4 million at March 31. Management said its plans and forecast cash burn should fund operations into the second half of 2027. That runway is a company estimate, not a guarantee that a pivotal program can be financed without new capital.

The stock's rally reflects legitimate scientific progress, but the evidence still has two limits: only six patients reached the extension analysis, and the trial did not separate EVX-01's effect from prior Keytruda treatment. The next value-changing development will be a credible path to a larger controlled study, including who pays for it and how the personalized manufacturing process scales.