Immunotherapy: The Most Significant Cancer Treatment Since Chemotherapy?
New drugs which unleash the body’s immune system on cancer cells have been shown in clinical trials to boost the survival chances of patients with advanced forms of cancer. This new development serves to show that immunotherapy has the potential to be the most exciting cancer treatment option since chemotherapy.
Two separately-run clinical trials on different types of cancers have shown that drugs which inhibit the natural “checkpoints” of the immune system can result in the destruction and shrinking of tumor cells by the body’s own defense mechanisms to “effectively cure” even the sickest cancer patients.
In one of the trials, researchers gave nivolumab (Opdivo) - an immunotherapy produced by Bristol-Myers Squibb – to patients with “advanced non-squamous non-small cell lung cancer” which was unresponsive to the normal treatments. They discovered that the drug reduced the risk of death by 27% compared to patients who were on chemotherapy.
The data was published at the recently concluded American Society for Clinical Oncology (Asco) meeting held in Chicago – an annual gathering which brings together more than 35,000 cancer experts from around the world. Bristol-Myers is in the process of seeking FDA approval to administer the drug to 60,000 Americans suffering from lung cancer.
Lung cancer is the most prevalent form of cancer, with 1.8 million diagnoses being made worldwide every year.
In a separate, British-led trial on a group of 945 patients suffering from advanced melanoma, doctors assigned a combination of nivolumab and ipilimumab (Yervoy) to see if this compounding would stop the skin cancer from deteriorating. It did in 58% of the cases, as reported in the New England Journal of Medicine by Dr. Jedd Wolchock and his team from the Memorial Sloan Kettering Cancer Center in New York. According to this research, the tumors stabilized or reduced in size for an average period of 11.5 months. This period is longer compared to 6.9 months for patients on nivolumab alone, and 2.9 months in the ipilimumab-only set.
While combining these two immunotherapy treatments has drastic results, serious side effects were reported by more than half of the patients under study (55%), with about 36% of them opting out.
“This research shows that two immunotherapy drugs can deliver a serious blow to cancer, but side-effects become even more pronounced. We need to identify the patients who are most likely to do well, which will enable us to bring our best weapons against this terrible illness,” said Dr. Alan Worsley from Cancer Research UK.
Tests can show which patients are likely to respond better to each of the treatments which will help doctors to determine whether a patient will be given each drug alone or in combination.
Nivolumab and ipilimumab are called checkpoint inhibitors since they block a chemical “handshake” between the killer T-cells of the immune system and the cancer cells. The cancer cells usually exploit this handshake to hide and evade detection but the treatments counteract this. They release the brakes on the T-cells giving them the green light to destroy the tumor cells.
While immunotherapy has shown to be potent against cancer, the big question is whether the drugs will prevent the disease from returning since they haven’t been used for long enough. However, there is genuine hope that the drugs will teach the immune system to identify and destroy cancer cells, thereby banishing cancer for good. This is a very exciting prospect.
Image source: The Guardian