The following article features coverage from the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

Adding relatlimab to nivolumab improved progression-free survival (PFS) in patients with advanced melanoma, according to a phase 3 trial being presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting.

Relatlimab is a novel checkpoint inhibitor that binds to LAG-3. In the phase 3 RELATIVITY-047 trial ( Identifier: NCT03470922), researchers compared the safety and efficacy of relatlimab plus nivolumab to nivolumab monotherapy in patients with advanced melanoma.

The study included 714 patients who were randomly assigned 1:1 to receive nivolumab alone or a fixed-dose combination of relatlimab and nivolumab. All patients had previously untreated, unresectable, or metastatic disease.

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The median PFS was 10.1 months in the combination group and 4.6 months in the monotherapy group (hazard ratio, 0.75; P =.0055). The 1-year PFS rates were 47.7% and 36.0%, respectively.

Grade 3 to 4 treatment-related adverse events were more common in the combination group than in the monotherapy group (18.9% and 9.7%, respectively), as were all-grade treatment-related adverse events leading to discontinuation (14.6% and 6.7%, respectively).

There were 3 treatment-related deaths in the combination group (hemophagocytic lymphohistiocytosis, acute edema of the lung, and pneumonitis) and 2 in the monotherapy group (sepsis and myocarditis in 1 patient and worsening pneumonia in 1 patient).

Data on overall response rate and overall survival are forthcoming.

“This is the first phase 3 study to validate inhibition of the LAG-3 immune checkpoint as a therapeutic strategy for patients with cancer,” investigator Evan J. Lipson, MD, associate professor of oncology at the Johns Hopkins Kimmel Cancer Center and Bloomberg-Kimmel Institute for Cancer Immunotherapy in Baltimore, Maryland, said in a press release.

“Our findings establish the LAG-3 pathway as the third immune checkpoint pathway in history, after CTLA-4 and PD-1, for which blockade has clinical benefit,” Dr. Lipson added.

Disclosures: This research was supported by Bristol-Myers Squibb. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Read more of Cancer Therapy Advisor’s coverage of the 2021 ASCO Annual Meeting by visiting the conference page.


Lipson E, Tawbi H, Schadendorf D, et al. Relatlimab (RELA) plus nivolumab (NIVO) versus NIVO in first-line advanced melanoma: Primary phase III results from RELATIVITY-047 (CA224-047). J Clin Oncol 39, 2021 (suppl 15; abstr 9503).