A group of Australian patients receiving Checkmate743 therapy saw higher levels of toxicity compared to CheckMate743 clinical trial patients. Checkmate743 consists of a dual treatment of ipilimumab and nivolumab and is the standard of care for patients with unresectable pleural mesothelioma. Unresectable means patients are not able to receive surgery to remove their cancer. Patients in Australia saw higher levels of toxicity when treated with the immunotherapy combination than what was reported in clinical trial results. Australia has particularly high levels of asbestos-related diseases, with mesothelioma being an unmet need with a five-year survival rate being only 10 percent.
Thanks to the Checkmate 743 trial, immunotherapy with ipilimumab and nivolumab is a first line treatment option for pleural mesothelioma. Other data from the MAPS2 trial supports the Checkmate743 data.
Researchers at the Kinghorn Cancer Centre & St. Vincent’s Hospital in Darlinghurst, Australia collected demographic and clinicopathological data from 119 Australian patients at 11 different medical centers. These patients underwent treatment with ipilimumab and nivolumab in first line and later settings for pleural mesothelioma. Survival outcomes were measured using the Kaplan-Meier method and toxicity was measured using the CTCAE v5.0.
The median age of patients was 72 while 83 percent were male. Ninety-two percent were ECOG≤1, 50 percent of patients were past or current smokers, and 78 percent had known asbestos exposure. Types of mesothelioma included: 50 percent epithelioid, 19 percent sarcomatoid, 14 percent biphasic, and 17 percent unknown. Ipilimumab and nivolumab were used together as a therapy in a first line setting in 75 percent of patients. The median overall survival for patients was 14.5 months. When the treatment was used as a second or later-line therapy, the median overall survival was 15.4 months. Around 24 percent of patients had CTCAE grade ≥ 3 adverse events, colitis being the most common.
This is the first time that real world results related to survival and toxicity outcomes in Australian patients taking ipilimumab and nivolumab for pleural mesothelioma have been reported. This shows that in real world settings, combination immunotherapy may have worse outcomes and can be more toxic than clinical trial data makes it appear. It is important to understand the treatment landscape beyond just trial settings though. The most important takeaway is that the non-chemotherapy option is not necessarily less toxic.
