Keytruda Cancer Vaccine Shows Promise
The experimental personalized cancer vaccine developed by Moderna and Merck has raised hopes for a new approach to cancer treatment.
The vaccine uses mRNA technology to help the immune system recognize cancer cells.
Early trial results are encouraging, but researchers still need more evidence before doctors can determine how widely the treatment could be used.
The treatment combines Moderna’s personalized vaccine with Merck’s cancer immunotherapy Keytruda.
An ongoing large trial found that the combination reduced the risk of melanoma returning or spreading in patients who had surgery to remove their tumors.
How Does the Keytruda Cancer Vaccine Work?
The treatment is known as intismeran autogene.
Doctors first remove a patient’s tumor or cancerous lesion through surgery.
The companies then analyze the tumor’s genetic material.
Researchers look for mutations that are unique to that patient’s cancer.
They use this information to design a personalized mRNA vaccine.
The vaccine can target up to 34 mutations from an individual patient’s tumor.
The treatment aims to teach the immune system to recognize those mutations.
It can then help the body’s defenses identify and attack cancer cells carrying the targeted mutations.
Patients in the trial received the personalized vaccine alongside Keytruda.
The treatment included up to nine doses of each therapy.
Which Cancers Could Benefit?
Researchers are also testing the treatment against other cancers.
Experts believe highly mutated cancers could offer promising targets.
Melanoma contains many tumor-specific mutations, which could give a personalized vaccine more targets to recognize.
Lung and colon cancers also have relatively high mutation rates.
Dr. Michael Atkins of the Georgetown Lombardi Comprehensive Cancer Center said those cancers could be promising areas for research.
However, researchers do not yet know whether the technology will work equally well against different cancer types.
Merck and Moderna are running large trials involving patients with non-small cell lung cancer.
The companies are studying patients whose tumors have already been surgically removed.
Moderna is also testing the treatment in bladder and kidney cancer.
Early-stage studies are underway for pancreatic and stomach cancers.
More trial results are expected over the next several years.
Why Is Manufacturing Difficult?
Personalized cancer vaccines create a major manufacturing challenge.
Traditional vaccines can be produced in large batches.
This treatment requires an individual vaccine for each patient.
Doctors must collect tumor samples and send them for genetic sequencing.
Researchers then identify suitable mutations and design the vaccine.
Manufacturers must produce the customized treatment and deliver it to the correct patient.
Dr. Ryan Sullivan of Mass General Brigham Cancer Institute said the entire process requires careful tracking.
He also said manufacturers would need to dramatically increase production capacity if the treatment reaches the commercial market.
Moderna President Stephen Hoge has said the company believes it can expand production to meet demand.
More Data Is Still Needed
The latest interim results provide encouraging evidence, but important questions remain.
Results released on August 19 showed that the combination met the trial’s primary goal of reducing cancer recurrence.
It also met a secondary goal involving the spread of cancer to other parts of the body.
However, researchers have not yet released all the detailed results.
Overall survival data are also unavailable.
That information will help determine whether the treatment allows patients to live longer.
Earlier five-year data from a mid-stage trial offered additional encouragement.
Those results showed that the vaccine combination cut the risk of cancer relapse by about half.
It also reduced the risk of cancer spreading to new locations by 59% compared with Keytruda alone.
Researchers will need longer follow-up and results from larger trials before the personalized vaccine can become a widely used cancer treatment.
