SITC 2020: Checkpoint Inhibitor Pair Tested in Thyroid Malignancies
Posted: Monday, November 30, 2020
The results of a phase II basket trial investigating how well checkpoint inhibitors targeting PD-1 and CTLA-4 might work against rare tumors have shown the agents have some efficacy in thyroid cancers. Young Kwang Chae, MD, MPH, MBA, of Northwestern University in Chicago, and colleagues noted that the clinical benefit rate of treatment with ipilimumab plus nivolumab, including all partial responses and stable disease lasting longer than 6 months, was 59%. These results were presented during the 2020 Society for Immunotherapy of Cancer (SITC) Annual Meeting (Abstract 270) and published in the Journal for ImmunoTherapy of Cancer.
The primary endpoint was objective response rate by Response Evaluation Criteria in Solid Tumors v1.1—confirmed complete responses plus partial responses—and that was 12%. Of 17 patients who received therapy (median age, 59 years; 10 of 17 were male), 1 patient with papillary carcinoma and 1 with anaplastic carcinoma experienced partial responses, although none had a complete response. Another two patients had unconfirmed partial responses. A third, who withdrew early due to toxicities, had stable disease for more than 1 year but was not included in the response assessment; all three had the papillary subtype of thyroid cancer. The 17 patients represented the thyroid cohort of SWOG S1609 (also known as the DART trial).
Notably, the patient's partial response with anaplastic thyroid carcinoma lasted more than 2 years and wrote Dr. Chae and co-investigators. They also pointed out that nine participants in this prospective, open-label trial experienced grade 3 to 5 toxicities; one died while enrolled. The most common immune-mediated adverse events were acute kidney injury and elevated lipase levels, each affecting five patients.
Disclosure: For study authors’ disclosure information, visit jitc.bmj.com.