Ultimovacs has announced positive results from the first cohort of 20 patients in its ongoing US-based Phase I clinical trial evaluating the company’s lead candidate, UV1, in combination with PD-1 checkpoint inhibitor, pembrolizumab, as a first line treatment in patients with metastatic malignant melanoma.

The results confirm achievement of the primary endpoints of safety and tolerability and indicate initial signs of clinical response.

Encouraging results

As per the cut-off date of September 30, 2020, every patient in the first cohort reached at least 12-months of follow-up post treatment with UV1 and pembrolizumab. At the one-year landmark, the overall survival (OS) rate was 85%. Median Progression-Free Survival (mPFS) was not reached at 12 months, indicating that more than half of the participating patients did not demonstrate disease progression. None of the patients experienced unexpected safety issues related to UV1 and the vaccine was well-tolerated. The safety events observed are in line with the established data on UV1 and pembrolizumab.

“The safety profile observed to date in this first cohort of the PD-L1 combination study is consistent with the promising safety profiles seen in our earlier Phase I trials. For the further development of our vaccine, it is important to demonstrate that UV1 can be combined with different classes of immunotherapies without compromising on safety,” says Jens Bjørheim, Chief Medical Officer at Ultimovacs. “From our perspective, an appropriate historical comparison for our trial is the cohort in the KEYNOTE006 trial in which patients with advanced melanoma without prior treatment history were treated with pembrolizumab only. Results from that study demonstrated a 68% OS and a mPFS of 11.6 months. Comparing this to our data presented today, we are encouraged by the results and look forward to additional data readouts over the next years that will demonstrate if the initial signs of efficacy in this cohort persist and mature into long-term added clinical benefit for the patients.”

Growing clinical data package

The Phase I trial in malignant melanoma is evaluating the safety, tolerability and initial signs of clinical response in patients treated with UV1 in combination with pembrolizumab. Pembrolizumab improves the ability of immune cells to kill tumor cells and is a current standard-of-care therapy for malignant melanoma. The 20 patients in the first cohort had no prior treatment history and received a 37.5 µg GM-CSF adjuvant dose per UV1 vaccination, combined to strengthen the ability of UV1 to stimulate the immune system. The study has completed full enrollment of 30 patients, as announced on August 18, 2020. The 10 patients in the second cohort have received the standard 75 µg GM-CSF adjuvant dose per UV1 vaccination. One-year of follow-up data on these patients will be available in the second half of 2021.

“In all four Phase I studies, UV1 has demonstrated a consistent and positive safety and tolerability profile. The topline results announced today complement our extensive and growing clinical data package, confirming that this strong safety profile holds when combining UV1 with a PD-1 checkpoint inhibitor,” stated Carlos de Sousa, Chief Executive Officer at Ultimovacs. “As an update on other clinical development progress, we had announced in May this year a collaboration with a leading Big Pharma company and a European oncology clinical trial group to evaluate UV1 in an additional Phase II study, which we had planned to confirm with all details in the third quarter. Ultimovacs, the sponsor and the Big Pharma partner have been making improvements to the trial protocol and due to the challenges of operating in the current pandemic environment, the agreement is still in the process of finalization. We look forward to announcing the collaboration and trial timelines during the fourth quarter.”

Photo of Carlos de Sousa, CEO, Ultimovacs