Dr Lee on Responses With Nivolumab in Resectable dMMR Endometrial Cancer

“In the 15 patients, we completed the 6 cycles of nivolumab. Twelve patients, which is 80.0% of patients, achieved a cCR.”

Yong Jae Lee, MD, PhD, of the Yonsei University College of Medicine, discusses findings from the single-arm, phase 2 trial NIVEC trial (NCT05795244) investigating the PD-1 inhibitor nivolumab (Opdivo) in patients with completely surgically resectable mismatch repair–deficient (dMMR) endometrial cancer.

This multicenter, prospective study enrolled patients with stage I to III surgically resectable dMMR or microsatellite instability–high endometrial cancer, including carcinosarcoma, who had an ECOG performance status of 1 or 0 and had not received prior immune checkpoint inhibition. Patients received intravenous nivolumab at 480 mg every 4 weeks for 6 cycles. Following imaging and biopsy, patients with residual disease underwent surgery and subsequently received adjuvant treatment, whereas patients who achieved a clinical complete response (CR) with nivolumab underwent nonoperative follow-up every 3 months. The primary end point was the rate of pathologic CR or clinical CR (cCR). Secondary end points included objective response rate, progression-free survival, overall survival, and safety.

Among 15 evaluable patients, the cCR rate was 80.0%; these patients displayed no evidence of tumor on imaging or biopsy. The remaining 3 patient had partial responses (PR). Seven of the 12 responders did not undergo surgery. Radiological best responses included CR (n = 7), PR (n = 2), not available (n = 1), and not evaluable (n = 5).

The most common any-grade adverse effects (AEs) observed in the trial included skin rash/dermatitis (30%); hypothyroidism/thyroiditis (15%); increased alanine aminotransferase/aspartate aminotransferase levels (15%); increased thyroid-stimulating hormone (TSH) levels (6%); and decreased TSH, anemia, anorexia, depression, limb edema, fatigue, gingival pain, infusion-related reaction, eyelid edema, mucositis ulcer, and vaginitis (3% each). Grade 3/4 skin rash/dermatitis and anemia occurred in 1 patient each. No AEs led to treatment discontinuation.

Disclosures: Lee reported lecture-related personal financial interests with AstraZeneca, MSD, and Takeda; as well as institutional financial interests with Corcept Therapeutics and ONO.