ONCOS-102 Vaccine Showing Impressive Results for Mesothelioma

The novel immunotherapy vaccine ONCOS-102 may become the answer for the large percentage of mesothelioma cancer patients who fail to respond to a recently approved checkpoint inhibitor combination of treatment.

ONCOS-102, a genetically modified oncolytic adenovirus, showed an overall survival rate of between 21.9 and 25 months in a randomized phase II clinical trial when combined with standard chemotherapy in a first-line setting.

By comparison, patients in the trial receiving only standard chemotherapy had a median survival of just 13.5 months.

The vaccine is the lead product of Targovax, a small Scandinavian biotech company specializing in hard-to-treat cancers.

“We now have the data for taking this further. We just have to be careful not blowing too many trumpets today and getting ahead of ourselves, but the results are impressive,” Dr. Magnus Jaderberg, chief medical officer at Targovax, told The Mesothelioma Center at Asbestos.com. “We’re excited about what we’ve seen.”

New ONCOS-102 Study Likely 

Targovax is expected to announce soon the launch of another study, potentially involving prominent mesothelioma specialty centers within the U.S. The study would pair ONCOS-102 with the immunotherapy combination of Opdivo and Yervoy, which was approved by the Food and Drug Administration in 2020 and the European Commission in 2021.

A combination of Opdivo and Yervoy, known generically as nivolumab and ipilimumab, was the first systemic treatment approved for mesothelioma in 16 years, but it has not been effective for an estimated 50% of the patients.

“Those are the ones we need to reach, those patients still not getting the treatment they need with what’s on the market today,” Jaderberg said. “That’s where the combination could be effective.”

The recent approval stemmed from an extensive phase III clinical trial that produced a median overall survival of 18.1 months, compared to 14.1 months for chemotherapy. It was a lesser improvement than what the ONCOS-102 vaccine showed in a much smaller study.

Better Long-Term Outcomes Predicted

The most recent study involved just 31 patients and was spread across five cancer centers in Spain and France. Of the 20 patients receiving the ONCOS-102 vaccine, half were still alive at the two-year mark, compared to none of those receiving only chemotherapy.

Progression-free survival was 9.8 months vs. 7.6 months when comparing the ONCOS-102 patients with those receiving only chemotherapy.

“Our numbers are small, but the data is pointing in the right direction,” Jaderberg said. “With mesothelioma, there is a huge need for a new treatment that can provide better long-term outcomes for patients.”

For years, the most effective treatment for mesothelioma has been a multidisciplinary approach based around aggressive surgery. Unfortunately, less than a third of those diagnosed even qualify for surgery, leaving the majority of patients with little hope.

ONCOS-102 Vaccine on FDA Fast Track

Earlier this year, the FDA granted fast-track status to ONCOS-102, hoping to expedite the regulatory approval process. The designation stemmed from earlier reports of increased survival for patients receiving the vaccine.

The vaccine also is being tested with melanoma and colorectal cancers. Its safety and tolerability profile has been good for each of the cancers.

As part of the most recent study, tumor tissue analysis done before and during treatment showed broad remodeling of the tumor microenvironment from the vaccine.

It included increased T-cell infiltration and a change in immune activity, considerably different from the control group receiving only chemotherapy.

Earlier studies of ONCOS-102 also showed a more robust immune response.

Jaderberg said the synergy between ONCOS-102 and drugs such as Opdivo and Yervoy could provide even better clinical benefits than either could alone, or even with chemotherapy, which was used in the recent study.

He believes ONCOS-102 eventually will be part of standard of care for mesothelioma.

“The recently approved treatment is going around the world. It’s very effective standard of care,” he said. “But half the patients don’t respond. At this point, those are the patients we can really help.”