By Julie Steenhuysen and Michael Erman
Oct 22 (Reuters) – Moderna and Merck said on Thursday that their mRNA cancer vaccine when combined with Merck’s widely used immunotherapy cut the risk of melanoma death or recurrence by 42% in a large trial, potentially paving the way for a new era of personalized treatment.
Moderna shares have soared since the companies in August announced the trial’s success without the actual data, nearly quadrupling through Wednesday’s close. They closed more than 17% lower after the results leaked on an oncology website earlier on Thursday. Merck shares closed down about 1.8%.
The data from the Phase 3 trial of more than 1,100 patients also showed that the combination cut the risk of the cancer’s spread by 38%.
It is the first data to show that the combination of a vaccine based on mutations unique to each patient’s tumor plus a drug that helps the immune system fight cancer can keep the disease at bay. The vaccine was tested along with Merck’s blockbuster immunotherapy Keytruda, among the world’s biggest-selling medicines.
Keytruda works by removing a natural brake cancer cells use to hide from immune system attack, while the vaccine instructs the patient’s cells to produce copies of specific mutations for the immune system to seek and destroy.
Moderna CEO Stephane Bancel said the data signaled a new chapter in cancer treatment.
“With this ability to create new T cells that are specific to your tumor… the clinical impact is very profound, and as we saw in the Phase 2 (trial), very lasting,” Bancel said in an interview.
The companies are preparing to file for US approval and expect the cancer vaccine to launch in 2027, Bancel said.
The results, based on patient data for the first two years after treatment, are scheduled to be presented on Saturday at the European Society for Medical Oncology meeting in Madrid.
Among those who received the vaccine in addition to Keytruda, 82.2% were still cancer-free after two years, compared with 70% of patients who received Keytruda alone.
“This is highly statistically significant. It is not by chance,” Dr. Hussein Tawbi, a melanoma expert and trial investigator at the University of Texas MD Anderson Cancer Center, said of the results.
Several Wall Street analysts said before the meeting that investors were looking for the combination to cut the risk of recurrence by 40% or more.
“There appears to be a sell-on-the-news reaction playing out here,” William Blair analyst Myles Minter wrote in a research note, adding that Moderna shares were up 525% this year including Thursday’s downward move.
Minter said the results were “great data, in our view, but investors will continue to debate the fundamental valuation.”
The trial tested nine doses of the vaccine, known as intismeran, along with Keytruda, beginning 13 weeks after surgery to remove melanoma lesions. The response to the combination treatment was compared with the patients treated with just Keytruda, a standard therapy for melanoma.
(Reporting by Julie Steenhuysen in Chicago and Michael Erman in New York; Editing by Bill Berkrot)
