Moderna’s ‘Off-the-Shelf’ Cancer Vaccine Shows Promise in Early Human Trial Data

The future of cancer treatment is continuing to look bright. Over the weekend, researchers in the UK announced encouraging results from an early trial testing an mRNA vaccine against advanced solid cancers. The vaccine, developed by Moderna, is designed to help people’s immune system better recognize and kill cancerous cells.

On Saturday, researchers at King’s College London and elsewhere presented the data at the annual conference of the European Society of Medical Oncology. The Phase I/II trial is the first to test the vaccine candidate—currently codenamed mRNA-4359—in people. The vaccine is supposed to sensitize the immune system to two specific proteins commonly featured on the cells of certain tumors as well as other cells that suppress the immune system, PD-L1 and IDO1. The hope is that a person’s retrained immunity can then more easily target cancers directly.

While vaccines are generally preventative, helping the body recognize threats before they arrive, cancer vaccines, including mRNA-4359, are typically therapeutic, used to help treat people’s existing cancer or prevent a recurrence. Many cancer vaccines are personalized to someone’s specific type of cancer, but Moderna expects that mRNA-4359 can be an “off-the-shelf” vaccine, one that can be used against a wide range of advanced solid tumor cancers.

The trial involves 19 patients with advanced lung cancer, melanoma, and other solid tumors. Phase I trials are primarily intended to test a drug or vaccine’s safety, but this trial is also meant to find the treatment’s optimal dosing. So people have been given anywhere from one to nine different doses of the vaccine. In their presentation, the researchers provided data on 16 patients who were able to have their responses to the vaccine measured.

According to the researchers, eight of these patients (50%) showed no signs of their tumors growing, as well as a lack of new tumors forming. Tests additionally found that the vaccine did seem to generate a noticeable increase in immune cells that could recognize PD-L1 and IDO1. The vaccine also appeared to be safe and well-tolerated, with common adverse events being fatigue, injection site pain, and fever.

“We are encouraged by the Phase 1 results of mRNA-4359, which demonstrate its potential to elicit strong antigen-specific T-cell responses while maintaining a manageable safety profile,” said Kyle Holen, Moderna’s Senior Vice President and Head of Development, Therapeutics and Oncology, in a statement provided by King’s College London.

The researchers caution their results are, of course, preliminary, and that much more data will be needed to know whether mRNA-4359 can work as hoped. The trial is continuing to recruit more patients with advanced cancers across the U.S., UK, Spain, and Australia. But there are dozens of other cancer vaccines in development, some of which are very close to the finish line. Moderna is currently testing another of their candidates, designed to target advanced melanomas specifically, in a large-scale Phase III trial, for instance. So with any luck, the first wave of these cancer vaccines will reach the public in a matter of years.