Ultimovacs has announced encouraging overall survival (OS) data from cohort 1 in the UV1-103 Phase I clinical trial in malignant melanoma.

Among the patients in cohort 1 who were alive at the 3-year follow-up, no further deaths have been reported, reaffirming an encouraging trend of durable overall survival benefit from UV1 vaccination.

“We are very encouraged to report a durable and long-term overall survival rate at the 4-year follow-up in the UV1-103 study. The data further strengthen the previously reported results from the study, including good safety for UV1 and the high number of complete responses in patients with metastatic malignant melanoma where surgery is not an option,” says Jens Bjørheim, Chief Medical Officer at Ultimovacs. “The UV1-103 study treats the same patient population as our Phase II study INITIUM. As we await data from the first three randomized UV1 Phase II trials in the near-term, we are increasingly optimistic about UV1’s potential to benefit cancer patients.”

The UV1-103 study

The UV1-103 study evaluates Ultimovacs’ universal cancer vaccine, UV1, in combination with the anti-PD-1 checkpoint inhibitor pembrolizumab, as first-line treatment in patients with advanced non-resectable or metastatic malignant melanoma. The study enrolled 30 patients in the U.S. in two cohorts that differed only in the concentration of GM-CSF used as vaccine adjuvant.

Three patients in cohort 1 chose not to be followed up after 2 years. Measured in absolute numbers, the overall survival in cohort 1 after 3-year follow-up was 71% (12 out of 17 patients). Out of the 17 patients included in the 4-year follow-up, one patient could not be reached temporarily, and the status is pending. Employing a conservative approach, 11 out of 16 patients were confirmed alive after 4 years, indicating an overall survival of 69% based on absolute numbers. Overall survival from the trial based on Kaplan-Meier estimates is described below. The 4-year survival across both cohorts is expected to be announced in Q2 2024.

Ultimovacs has previously reported data showing a complete response rate in the UV1-103 study of 33% (complete disappearance of tumors) and an objective response rate of 57% (complete or partial disappearance of tumors). Biomarker analyses reported in October 2022 showed robust clinical responses in patients treated with the combination of UV1 and pembrolizumab, regardless of patients’ PD-L1 status. The safety profile of UV1 in combination with pembrolizumab is comparable to that of pembrolizumab alone.

Ultimovacs is investigating UV1 in malignant melanoma in its randomized Phase II INITIUM trial of UV1 in combination with ipilimumab and nivolumab. The trial completed enrollment of 156 patients with advanced non-resectable or metastatic malignant melanoma in July 2022. The top-line results will be disclosed after cancer progression has been verified in 70 patients, which has not yet occurred due to patients taking longer than estimated to experience cancer progression. The outcome of the study is now expected to be announced in the first half of 2024.

Photo of Jens Bjørheim: Anton Soggiu/Ultimovacs