In a statement, the company said that their exploratory analysis found that in patients with PD-L1 expression of 1%, patients treated with Opdivo with Yervoy were alive at six years, more than three times as many as those treated with chemotherapy (16% vs. 5%, respectively).

The follow-up results are to be presented in an oral presentation at the IASLC 2023 World Conference on Lung Cancer on September 11, 2023.

Patients who responded to Opdivo plus Yervoy treatment showed a higher proportion of 80% tumour burden reduction compared to chemotherapy in both PD-L1 1% and 1% subgroups. Additionally, patients with 80% tumour burden reduction had higher six-year overall survival rates compared to chemotherapy, Bristol Meyers said in a statement.

Dr Solange Peters, professor and chair of medical oncology and the thoracic malignancies programme in the Department of Oncology at the University Hospital of Lausanne in Lausanne, Switzerland, commented on the findings, saying, "Immunotherapy has transformed the treatment of advanced lung cancer, and thankfully, a diagnosis no longer means the same thing as it used to for many patients.

"With these six-year results, we are seeing remarkably sustained and durable clinical survival benefits with nivolumab plus ipilimumab year-over-year," he added.

"The long-term efficacy seen with the dual immunotherapy regimen in CheckMate-227 reinforces the importance of nivolumab plus ipilimumab to transform outcomes for appropriate patients with metastatic non-small cell lung cancer," Dr Peters said.

"We are ecstatic to see Opdivo plus Yervoy continue to demonstrate almost double the overall survival rates as chemotherapy after six years of follow-up—the longest-ever for a Phase 3 trial with immunotherapy in metastatic non-small cell lung cancer. Further, the Opdivo plus Yervoy regimen more than tripled survival for patients with PD-L1 expression <1%, a population that is difficult to treat and faces high unmet needs," said Dr. Abderrahim Oukessou, M.D., vice president, thoracic cancers global programme lead at Bristol Myers Squibb.

"Our results presented at WCLC 2023 build on our legacy of transforming survival expectations with immunotherapy combinations. Looking ahead, we are excited to expand our research into targeted and small molecule therapies, as well as additional immunotherapy combinations, in the hope of potentially finding solutions for as many people living with thoracic cancers as possible," he added.