Evaxion reports sustained clinical responses at three years with EVX-01 in advanced melanoma. Explore Phase 2 results, response durability and study limitations.
Written By: Malavatu Satvika, PharmD
Reviewed By: Pharmacally Editorial Team
Evaxion A/S reported sustained clinical responses at three-year follow-up in its Phase 2 trial evaluating EVX-01, a personalized cancer vaccine, in patients with advanced melanoma. According to the company’s October 19, 2026, announcement, patients assessed at three years maintained their clinical responses observed at two years, with no tumour progression reported. During the third year, patients received EVX-01 as monotherapy rather than alongside pembrolizumab. The findings are scheduled for presentation at the European Society for Medical Oncology (ESMO) Congress 2026 on October 24.
Phase 2 Trial and Treatment Approach
EVX-01 is a personalized peptide-based cancer vaccine designed using Evaxion’s AI-Immunology™ platform. It is tailored to individual tumour profiles and aims to stimulate T-cell responses against tumour-specific neoantigens, which can help the immune system recognise cancer cells.
The Phase 2 study enrolled 16 patients with advanced melanoma. During the first two years, participants received EVX-01 in combination with pembrolizumab, an anti-PD-1 immunotherapy. Six of the 12 patients who achieved an objective response continued into the trial’s one-year extension, receiving EVX-01 alone.
This extension provides an opportunity to examine whether responses are maintained after pembrolizumab is discontinued. However, the small follow-up group limits the conclusions that can be drawn about the vaccine’s independent clinical activity.
Three-Year Follow-Up Builds on Earlier Clinical Results
At the two-year assessment, 12 of the 16 enrolled patients had achieved an objective response, corresponding to an objective response rate (ORR) of 75%. Four patients achieved a complete response, representing 25% of the original study population.
Evaxion also reported that 92% of patients remained in response at two years, with no relapses observed. Additionally, 54% experienced a deepening of response after starting EVX-01, improving from stable disease or partial response to partial or complete response. Tumour reduction in target lesions was observed in 15 of the 16 participants.
The three-year update extends these observations by reporting maintenance of the responses documented at two years among patients assessed during the extension. The company reported no tumour progression in this group.
Importantly, the three-year finding should not be interpreted as evidence that all 16 original participants remained progression-free for three years. Six of the 12 responders continued into the extension, and the reported outcome applies to the patients assessed at the three-year follow-up.
Personalized Vaccine Design and Immune Activity
EVX-01 is designed to stimulate T cells against neoantigens specific to each patient’s tumour. At the two-year assessment, Evaxion reported that 86% of vaccine neoantigens generated specific T-cell responses. The company also reported vaccine-induced immune responses in all patients.
These findings support the biological rationale for personalized vaccination, in which treatment is tailored to an individual tumour rather than using an identical vaccine for every patient. Nevertheless, vaccine-specific T-cell activity is a biological measure and does not, by itself, establish the magnitude or durability of clinical benefit.
Further research is needed to determine how reliably these immune responses predict clinical outcomes and whether they can help identify patients most likely to benefit.
Clinical Interpretation
The three-year findings provide an encouraging signal of response durability in patients with advanced melanoma who continued into the extension and received EVX-01 alone. The earlier 75% ORR, four complete responses and maintenance of responses at two years provide context for the longer follow-up.
However, the evidence remains preliminary. Only six responders continued into the extension, limiting the generalisability of the observations. Furthermore, because EVX-01 was initially administered with pembrolizumab, the earlier responses cannot be attributed to the vaccine alone. The extension offers insight into response maintenance during monotherapy, but it does not establish the vaccine’s independent efficacy or superiority over other treatments.
Larger controlled studies and longer follow-up will be needed to establish the durability and clinical significance of these findings and clarify EVX-01’s potential role in melanoma treatment.
Reference
Evaxion reports sustained clinical responses for all patients at three-year follow-up in Phase 2 trial with personalized cancer vaccine EVX-01, Evaxion A/S, October 19, 2026.
A Single Arm Trial Evaluating the Efficacy and Safety of EVX-01 in Combination with Pembrolizumab in Adults with Unresectable or Metastatic Melanoma, ClinicalTrials.gov ID NCT05309421
About the Writer
Malavatu Satvika (Linkedin) is a Pharm.D professional and aspiring healthcare medical writer with clinical exposure and research experience. Her interests include medical writing, drug safety, pharmaceutical research, and evidence-based healthcare communication. She has contributed to two research publications in pharmaceutical journals and has gained practical experience in prescription review, patient counselling, medication review, adverse drug reaction monitoring, drug information services, literature review, and clinical documentation through regular hospital training.
She has completed certifications in clinical research, ICH-GCP E6(R3), data management for clinical research, and congenital hypothyroidism. With a strong foundation in pharmacy, clinical practice, and scientific research, she aims to translate complex medical and pharmaceutical information into accurate, clear, and evidence-based healthcare content. She is also preparing to pursue a PhD and further develop her expertise in medical writing and pharmaceutical research.