Moderna and Merck’s positive preliminary cancer vaccine results could signal a ‘new era’ of cancer treatment, expert says

The future of cancer treatment could be vaccines.

Two large pharma companies, Moderna and Merck, announced on Aug. 19 positive initial results from a Phase 3 clinical trial testing an mRNA-based vaccine that could prevent recurrence or distant metastasis of melanoma in certain patients when combined with Merck’s Keytruda immunotherapy.

It marks the first time this kind of treatment, called an individualized neoantigen therapy, has shown such promise, according to Moderna.

“I think it is the start of a new era to a degree,” Hussein Tawbi, professor of melanoma medical oncology at the University of Texas MD Anderson Cancer Center, told Healthcare Brew. “People have been trying to do this for decades, and this is the first technology and setting that allowed us to make this highly effective.”

Tawbi was the principal investigator for the Phase 3 trial at MD Anderson, one of the 165 trial sites. He also serves as executive director of the immuno-oncology clinical drug development program at the center.

Following the announcement, Moderna’s stock shot up 177% to $174.38 per share, raising the company’s valuation from $25 billion to $69 billion in a single day, Inc. reported. The stock has dipped since, and was $134.34 as of late morning on Aug. 28. That’s still up 113% from $62.96, the price at which Moderna closed on Aug. 18, the day before the trial news was released.

Merck’s stock had a much more modest reaction, closing up 13% at $152.20 on Aug. 19. As of late morning Aug. 28, it was $147.81, a slight dip but still up 9% from its price before the news.

Target reached. The primary endpoint of the trial, which included 1,137 participants, was recurrence-free survival, and a secondary endpoint was distant metastasis-free survival.

Moderna said in its press release the treatment met those endpoints but has not released the full study data, so it’s unclear how long the treatment can prevent recurrence or metastasis, or just how effective the vaccine was compared to treatment with only Keytruda. The company said it plans to release the full data at an “upcoming international medical meeting” but didn’t specify the name or date.

Earlier trial results were also promising. Moderna and Merck announced in early June a five-year follow-up analysis of Phase 2 trial results, in which the treatment showed a 49% reduction in the risk of recurrence or death and a 59% reduction in the risk of distant metastasis or death compared to Keytruda alone.

How it works. The treatment, known as intismeran autogene, is specifically for patients with Stage 2 to Stage 4 melanoma who’ve undergone a cancer resection.

Researchers first identify the unique neoantigens in each patient’s tumor, and then use those sequences as a template to make a personalized mRNA vaccine that helps train the patient’s immune system to fight their specific cancer.

Patients get a shot of Moderna’s cancer vaccine every three weeks for up to nine doses and an infusion of Keytruda every six weeks for roughly a year.

Each vaccine takes approximately six weeks to make, Jane Healy, VP of oncology early clinical development at Merck, told Healthcare Brew in an emailed statement.

Moderna did not respond to a request for comment on what its next steps toward FDA approval are. In the announcement press release, the company said it plans to “engage with regulators on filing submissions” for the treatment. It didn’t specify when.

Potential challenges. Moderna and Merck have been working together to create a cancer vaccine for a decade.

Beyond melanoma, the drugmakers are studying the potential treatment for other types of cancers, including non-small cell lung cancer, bladder cancer, and renal cell carcinoma, according to Moderna’s release.

If the treatment is approved for melanoma, scaling up manufacturing could be a challenge, as the vaccine is tailored to each patient.

However, Tawbi said it may be easier to do than some may think because sequencing tumors has become commonplace in cancer treatment.

“My assessment is that I think they’re prepared for the scaling…I suspect our patients are going to have access to it as soon as it is approved, and I doubt that’s going to be a major issue,” he said.

Healy said that “scalability is an important question, and one we’ve thought about from the beginning with Moderna.”

“What gives us confidence is that we’ve successfully integrated the entire process in clinical studies—from sequencing a patient’s tumor to designing, manufacturing, and delivering an individualized therapy…We are working closely with Moderna to ensure timely supply of intismeran,” she added.

The customized treatment could also be quite costly. For instance, Kymriah, a CAR T-cell therapy for certain blood cancers, is tailored to each patient and comes with a list price of $475,000.

Neither Moderna nor Merck responded to questions from Healthcare Brew about how much the treatment may cost.

Future outlook. Tawbi said he expects the cancer vaccine to “have a dramatic impact” on melanoma treatment.

However, there’s still a lot to learn, he added. For instance, in patients who still see their melanoma recur after receiving the vaccine, will the vaccine change the cancer? The tumors that come back post-treatment probably wouldn’t have the neoantigens included in the vaccine, which would likely make them different from the patient’s original tumor, according to Tawbi.

“It almost generates a new population of patients, once they start recurring, that we need to understand as well,” Tawbi said. “It definitely will have ripple effects, and we’ll have to change the way we do things in melanoma.”

The positive trial results also suggest more personalized cancer care in the future, he added.

“The evolution of technology, and especially the mRNA technology, has really kicked things off in an entirely different pace,” Tawbi said. “I think it really puts us in a place where this is now a reality, and that’s really exciting. I do think that over time, we’re going to be more specific in how we treat our patients.”