The U.S. Food and Drug Administration has granted Fast-Track Designation this week to ONCOS-102, an immunotherapy vaccine that targets malignant mesothelioma and other hard-to-treat tumors.
This designation is expected to expedite the regulatory approval process. The vaccine’s developer, Targovax, a small biotech company that focuses on oncolytic viruses, sees this as an early endorsement from the FDA.
“Yes, this opens the door for us,” Dr. Magnus Jaderberg, chief medical officer of Targovax, told The Mesothelioma Center at Asbestos.com. “It validates what the FDA believes is a potentially promising drug for this disease. That’s important.”
The designation stems in part from interim results in February of the ongoing phase II clinical trial that showed increased survival of patients receiving the vaccine in combination with standard chemotherapy.
Median overall survival was 20.5 months, compared to 13.5 months for the control group receiving only the chemotherapy.
ONCOS-102 demonstrated a broad immune system activation with favorable tolerability and safety, according to investigators. A trial follow-up will be announced in the coming months with the median overall survival expected to rise within the combination cohort.
At the latest update, half of the 20 patients in the experimental group were still alive.
“It’s too early to say I’m confident [that this is the answer to mesothelioma],” Jaderberg said. “But when the most important regulator in the world [the FDA] is telling you they will provide extra resources to help you through the regulatory process, that’s meaningful.”
In 2020, the FDA approved – for the first time in 16 years – a new systemic treatment for mesothelioma. The immunotherapy combination of Opdivo and Yervoy was approved last May after showing a similar four-month, improved median survival.
The fast-track designation involves more frequent interactions with the FDA, access to more FDA resources and a priority review status that can shorten the regulatory process significantly. It is used mostly for new drugs aimed at unmet medical needs.
Mesothelioma, a rare cancer predominantly associated with asbestos exposure, has no known cure. The most effective treatment has been aggressive surgery, but less than a third of those diagnosed with the disease are eligible for the procedure.
ONCOS-102 had already received the FDA’s Orphan Drug Designation, which allows doctors earlier usage in treating rare diseases.
Targovax, in partnership with Merck & Co., will soon be opening a mesothelioma clinical trial combining ONCOS-102 with Keytruda, known generically as pembrolizumab.
Both companies believe a combination of the two different types of immunotherapy could spark an effective synergy. The FDA in 2020 granted an approval of Keytruda, but only for a small percentage of mesothelioma patients expressing high levels of a particular cell-surface protein.
Keytruda alone has shown impressive results with mesothelioma, but only for a small percentage of those patients, and its staying power has been lacking. Jaderberg believes that ONCOS-102 can increase a tumor’s sensitivity to Keytruda.
“We could end up with a very powerful immunotherapy combination,” Jaderberg said in 2020. “Standard of care [for mesothelioma] likely will change in the next couple years. There is a good chance ONCOS-102 could be part of that.”
ONCOS-102 is the company’s lead product. It is a genetically modified adenovirus and engineered to selectively infect cancer cells while activating a patient’s immune system. It is also being tested for use with colorectal cancer and melanoma.
The upcoming mesothelioma trial is expected to involve at least 10 U.S. cancer centers with more than 100 patients participating.
It will compare the combination of ONCOS-102, Keytruda and chemotherapy to the use of just Keytruda and chemotherapy.