Cancer Vaccine Candidate Shows Enhanced Efficacy

A clinical-stage company based in Norway developing vaccines for cancer presented today clinical endpoints and biomarker results from patients in the U.S.-based UV1-103 phase I trial at the 19th International Conference of the Society for Melanoma Research.

Ultimovacs ASA's UV1-103 study evaluated the universal cancer vaccine, UV1, in combination with the anti-PD-1 checkpoint inhibitor pembrolizumab, as first-line treatment in 30 patients with advanced non-resectable and metastatic malignant melanoma.

Clinical analyses from the UV1-103 study indicate efficacy in patients with low levels of PD-L1, a key predictive biomarker associated with lower efficacy for pembrolizumab, and other anti-PD-1 therapies, in some tumor types.

The analyses showed robust responses in patients treated with the combination of UV1 and pembrolizumab, regardless of patients' PD-L1 status.

"The results from this phase I trial show that UV1 in combination with pembrolizumab has a good safety profile and encouraging signs of efficacy, particularly the 33% complete responses and the extended overall survival," said Jens Bjørheim, Chief Medical Officer at Ultimovacs, in a press release on October 18, 2022.

"The biomarker data provide a critical insight into the study population, showing that the combination treatment resulted in good clinical responses in patients considered less likely to respond to monotherapy checkpoint inhibition."

"This indicates potential broad applicability for UV1 as a combination therapy to anti-PD1 checkpoint inhibitors in the real-world setting."

As previously reported, the objective response rate in the study was 57%, with a complete response rate of 33%.

Median progression-free survival was 18.9 months.

Overall survival was 87% after one year and 73% after two years.

For the 20 patients in cohort 1, the overall survival after three years was 71%, as reported earlier this month.

The good safety profile of UV1 in combination with pembrolizumab has previously been reported.

In addition to the sub-analysis of the PD-L1 status, the study also evaluated four other key prognostic biomarkers, including baseline tumor mutational burden (TMB), predicted neoantigens, interferon-gamma (IFN-gamma) gene signature, and levels of tumor-infiltrating lymphocytes.

Objective responses were observed in patients with low TMB, in patients with low neoantigen tumors, and in patients with tumors that were not enriched for IFN-gamma.

These patients have tumors that previous clinical data have shown would be less responsive to treatment with pembrolizumab monotherapy in various cancer types.

Lastly, the study also showed that clinical responders did not have higher levels of tumor-infiltrating lymphocytes before treatment.

The analyses of these five biomarkers signal efficacy in patients treated with UV1 in combination with pembrolizumab, regardless of the tumor phenotype.

These results support the addition of UV1 to checkpoint inhibitors, with the potential for improving both efficacy in current target patient populations and extending the use of immunotherapy to broader patient populations in multiple cancer types underserved by existing therapies.

Carlos de Sousa, CEO of Ultimovacs, commented in the press release, "We are excited about the clinical data generated on UV1 so far, with indications of efficacy also in hard-to-treat cancer patients with low levels of PD-L1."

"The biomarker data strengthen the rationale of UV1 as a backbone therapy in combination with checkpoint inhibitors."

"These results provide a solid foundation for Ultimovacs' extensive program of five randomized phase II trials of UV1 in different cancer indications, including malignant melanoma."

"We look forward to further progressing these studies and generating more data on the ability of our vaccine to induce long-lasting, survival-associated immune responses."

Note: This announcement was manually translated and curated for mobile readers.