FDA Grants Fast Track Designation to UV1 Cancer Vaccine for Unresectable/Metastatic Mesothelioma


The UV1 cancer vaccine received fast track designation for use in combination with ipilimumab and nivolumab for patients with unresectable malignant pleural mesothelioma.



The FDA has granted fast track designation to the UV1 cancer vaccine as an add-on therapy in combination with ipilimumab (Yervoy) and nivolumab (Opdivo) for the treatment of patients with unresectable malignant pleural mesothelioma, according to an announcement from Ultimovacs.1

This designation was supported by data from the phase 2 NIPU trial (NCT04300244) which were presented at the 2023 ESMO Congress.Results from the trial showed that the addition of UV1led to a statistically significant and clinically meaningful overall survival (OS) benefit vs nivolumab and ipilimumab alone (HR, 0.73; 80% CI, 0.53-1.00; 1-sided P = .0985; 2-sided P = .197).1,2

The median OS was 15.4 months (95% CI, 11.1-22.6) in patients treated with UV1 plus ipilimumab and nivolumab vs 11.1 months (95% CI, 8.8-18.1) for patients treated with ipilimumab and nivolumab alone. The median observation time was 17.3 months.2

“We are pleased that the FDA has granted fast track designation for UV1 in 2 separate advanced indications, which underlines the potential of our cancer vaccine approach,” Carlos de Sousa, chief executive officer of Ultimovacs, stated in the news release.1 “UV1 demonstrated a positive safety profile and encouraging signs of improvement in OS in combination with the checkpoint inhibitors, ipilimumab, and nivolumab, in malignant mesothelioma, a hard-to-treat cancer indication with significant unmet need.”

Notably, in October 2023, Ultimovacs announced that the regulatory agency granted UV1 orphan drug designation based on data from the same trial for patients with malignant mesothelioma.3

The randomized, open-label, multi-center trial evaluated 118 participants across Australia, Denmark, Norway, Spain, and Sweden with malignant mesothelioma post platinum-based chemotherapy.2

Treatment with the cancer vaccine in combination with the study drugs also resulted in a benefit in objective response rate (tumor reduction by at least 30%). Notably, of the patients treated with UV1, 31% experienced an objective response compared with 16% of patients who received the immunotherapy doublet alone (OR, 2.44; 80% CI, 1.35-4.49; 1-sided P = .028).2

Patient characteristics at baseline were evenly distributed between the 2 treatment groups. The study predominantly included patients with the epithelioid subtype of malignant pleural mesothelioma (77.1% of patients enrolled), which was consistent with the prevalence of this subtype in the general patient population. Notably, there was a relatively elevated proportion of patients with PD-L1–negative tumor biopsies (53.4%) enrolled, a marker associated with lower responsiveness to checkpoint inhibitors.2

Furthermore, UV1 plus ipilimumab and nivolumab had a consistent safety profile with that of ipilimumab and nivolumab alone, confirming the acceptable safety profile for the agent. Patients will continue to be monitored for efficacy and safety end points over the next few years.2

“We expect to announce topline results from our randomized phase 2 trial INITIUM in the coming month of March, and we are looking forward to reporting important data from our broad UV1 phase 2 clinical trial program with UV1 over the course of 2024 and beyond,” de Sousa concluded.


  1. Ultimovacs receives FDA fast track designation for UV1 cancer vaccine for the treatment of patients with unresectable mesothelioma. News release. Ultimovacs. February 5, 2024. Accessed February 5, 2024. https://ultimovacs.com/investors/news/ultimovacs-receives-fda-fast-track-designation-for-uv1-cancer-vaccine-for-the-treatment-of-patients-with-unresectable-mesothelioma
  2. Ultimovacs provides complete phase II NIPU results presented at ESMO 2023: significant and clinically meaningful improvement in overall survival for patients with malignant mesothelioma receiving UV1 cancer vaccine. Ultimovacs. October 23, 2023. Accessed February 5, 2024. https://tools.eurolandir.com/tools/Pressreleases/GetPressRelease/?ID=4405256&lang=en-GB&companycode=no-ulti&v=
  3. Ultimovacs receives FDA orphan drug designation for the UV1 cancer vaccine for treatment of mesothelioma. News release. Ultimovacs. October 9, 2023. Accessed February 5, 2024. https://ultimovacs.com/investors/news/ultimovacs-receives-fda-orphan-drug-designation-for-the-uv1-cancer-vaccine-for-treatment-of-mesothelioma
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