A team of international research researchers has found that their experimental treatment for cancer showed "promising" signs to fight the disease in early clinical trials of patients with advanced cancers.
The treatment involved administering tailor-made vaccines alongside immunotherapy drug atezolizumab, which boosts the body's natural defenses against cancer. The researchers said the personalized vaccine when given in combination with the drug was "well-tolerated" and the participants experienced "low-to-moderate" side effects.
The new findings from the phase one clinical trial which was designed to test the safety of the vaccine were presented in the AACR Virtual Annual Meeting II, a scientific conference running from June 22 to 25.
A Promising Cancer Treatment
The researchers are now focusing on their next step to understand more about the potential benefits of this vaccine for patients with earlier-stage cancers. Led by UK scientists, a team of international researchers investigated the effects of the personalized vaccines in 144 participants of the clinical trial who had different types of advanced cancers, including breast, lung, and bowel.
To develop the vaccine, scientists first looked at the biopsy results of a patient's tumor and then by using artificial intelligence they identified a group of proteins known as neoantigens, which are produced in tumor cells and have not been previously recognized by the immune system. The research allocated all this information to develop a cancer vaccine known as the messenger RNA vaccine that can target the "unique differences" in tumors of every cancer patient.
The lead of the clinical trial Dr. Juanita Lopez, a consultant medical oncologist at The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, London, said many cancers are able to successfully avoid the immune system, and "we are only starting to understand the myriad ways in which cancers can do this." She further added that as many mutations are not shared between cancers, a personalized treatment approach that targets individual tumor neoantigens could be a viable immunotherapeutic strategy for several cancer patients.
The Cancer Treatment Trial
During the early trial, patients received one of the different doses of the vaccines, ranging between 15 and 50 micrograms once per week, for six weeks. The seventh and eighth doses were given to the participants fortnightly, while the immunotherapy drug was given on a 21-day cycle.
The cancer patients received a booster dose of the vaccine during the seventh cycle of the immunotherapy medication along with a maintenance dose of the vaccine every 24 weeks following the induction phase. The researchers noticed that the experimental treatment was well tolerated with patients experiencing low to moderate side effects of the treatment.
Only eight percent of the patients saw their tumor to be reduced, while 49 percent noticed that their tumors were neither growing nor shrinking. As per De Lopez, the low rate of response is "likely because many of the patients treated in our study had very advanced disease, and were heavily pre-treated."
The analyses of blood samples from 63 patients have revealed that the immune system had been activated in 73 percent of them, which the medical experts believe is a response to the personalized vaccine treatment. But they add further studies with a larger patient population are needed to understand more about how this treatment will work.