Several new checkpoint inhibitors — a class of immunotherapy drugs used in cancer — continue to show beneficial effects in numerous cancer types, according to data presented at the recent American Association for Cancer Research Annual Meeting in New Orleans.
Investigated checkpoint inhibitors confirmed earlier results showing evidence of efficacy in melanoma, and also suggested that this class of immunotherapies, which trigger a person’s immune system to attack cancer, might work in patients suffering from certain head and neck cancers.
One of the studies, CheckMate-141, exploring the checkpoint blocker nivolumab (Opdivo) in patients with squamous cell carcinoma of the head and neck, was stopped early after 36 percent of the 361 patients survived for one year — an increase of more than 100 percent compared to patients receiving other treatments.
Squamous cell carcinoma is usually treated with platinum-based chemotherapy, but the effects are often temporary as the cancer tends to return. Moreover, patients who fail to fully recover after chemotherapy are generally resistant to further treatment.
Maura Gillison from Ohio State University, who presented the CheckMate-141 data, said that no effective treatments have been approved for patients with this kind of cancer in over a decade. “I’ve treated head and neck cancers for more than twenty years, and this is the first time I’ve had a drug to go to for patients that have become resistant to first-line treatment,” she said in a press release.
Dr. Emma King, a Cancer Research UK-funded head and neck cancer expert, added that the findings are likely to have a “significant impact” for these cancer patients. “They also reinforce the important shift that we are seeing towards using immunotherapies for cancer treatment.”
“Before nivolumab can be used routinely to treat head and neck cancer in the UK, it will need to approved by the National Institute for Health and Clinical Excellence (NICE),” she added.
Nivolumab was investigated in the CheckMate-069 trial, where its efficiency in advanced melanoma was tested in combination with another checkpoint inhibitor, ipilimumab (Yervoy).
Data presented showed that 60 percent of patients on the combination therapy survived for two years. But the benefit can come with a high price, as severe side effects forced one-third of patients to stop the treatment.
“Both nivolumab and ipilimumab have changed survival expectations in advanced melanoma over the last few years, and these latest data show us that combining these two immunotherapies is an effective two-pronged attack against the cancer,” said Dr. James Larkin, a medical oncologist at the Royal Marsden Hospital.
Yet another study found nivolumab to increase five-year survival in advanced melanoma patients to one-third — again, a doubling compared to what can be achieved by conventional treatment.
Merkel cell carcinoma, a rare skin cancer linked to exposure to a common virus, was also among the cancer types showing benefits from checkpoint inhibitor treatment. Once the cancer spreads, no treatments are effective in holding it back. The checkpoint blocker pembrolizumab (Keytruda) caused tumors to shrink in about half of the 26 patients in the trial.
“The trial also suggests that patients whose Merkel cell carcinoma is linked to a virus may be more likely to benefit from this treatment, which fits with the idea that the more danger signals there are in a cancer, the easier it is for the immune system to recognise it,” said Peter Johnson, Cancer Research UK’s chief clinician.
Early data of checkpoint inhibition in liver and advanced bowel cancer, used in combination with radiofrequency ablation treatment, also showed promising results.