A personalized messenger RNA (mRNA) cancer vaccine slowed the return and spread of melanoma when used alongside Merck & Co.’s checkpoint inhibitor Keytruda in a first for the nascent cancer vaccine space.
Moderna, which developed the vaccine, announced the results in a joint press release with Merck on Wednesday. The drugmakers have not released detailed data, but they will present them at an upcoming medical conference.
Moderna’s vaccine, intismeran, is a personalized neoantigen vaccine. It delivers mRNA that encodes tumor-specific mutations identified from a person’s previously removed tumor. That mRNA is bundled into a lipid nanoparticle before being delivered back into a patient to train their body to fight the tumor cells.
In the press release, Moderna and Merck say that the Phase 3 trial met its primary goal of recurrence-free survival, as well as a secondary end point of distant metastasis-free survival, in patients with completely resected stage IIB–IV melanoma. Those results mirror those of an earlier Phase 2 trial, in which the combination of intismeran and Keytruda reduced the risk of recurrence and distant metastasis by 49% compared with Keytruda alone, according to a presentation at an American Society of Clinical Oncology meeting in June.
“These Phase 3 findings represent a pivotal moment for the field of cancer research. For many years, the idea of creating an mRNA treatment designed specifically for an individual patient’s cancer was aspirational. We are now helping turn that vision into a reality,” Moderna CEO Stéphane Bancel says in the announcement.
Moderna signed a partnership with Merck in 2018 to develop an mRNA vaccine to be used in combination with Keytruda.
The first mRNA vaccines to be approved for use in humans were the COVID-19 vaccines, developed by Moderna and BioNTech/Pfizer. But scientists have long hoped that the technology could be used for personalized cancer treatments. Moderna and Merck say today’s results mark the first positive Phase 3 readout for a cancer vaccine.
The two companies will now work to file with drug regulators for approval of the intismeran/ Keytruda combination. The firms will split any profits if the vaccine does go to market.
The news comes at a rocky moment for mRNA vaccines. Last year, the US Department of Health and Human Services (HHS) announced it would stop funding mRNA vaccine research. But earlier this month, the US Food and Drug Administration approved Moderna’s mRNA-based flu vaccine for adults 50 years old and up.
Moderna’s stock price leapt at the news of the positive trial data. In a research note, Leerink Partners analyst Daina M. Graybosch estimates that intismeran could be a blockbuster drug, reaching an average revenue of $1.4 billion by 2032.
“We are incredibly excited to see the detailed outcomes and hope this success is one upon [which] Merck and others can build next-generation vaccines,” Graybosch writes.
Rowan Walrath is an associate editor and life sciences reporter at C&EN.
