Final PFS Analysis Shows Promise of Sugemalimab in Stage III Non–Small Cell Lung Cancer

Final end point analysis of the GEMSTONE-301 trial confirmed that patients with stage III non–small cell lung cancer experienced significant clinical benefit and promising efficacy following consolidation therapy with sugemalimab monotherapy.

Final analysis of consolidation therapy with single-agent sugemalimab (Cejemly) indicated robust efficacy and promising clinical benefit in patients with stage III non–small cell lung cancer (NSCLC) without disease progression following concurrent or sequential chemoradiotherapy, according to a press release from developer CStone Pharmaceuticals.

The agent, which is being assessed as part of the phase 3 GEMSTONE-301 trial (NCT03728556), was found to maintain a statistically significant and clinically meaningful improvement in progression-free survival (PFS) by blinded independent central review in the designated patient population. Additionally, findings from the subgroup analysis indicated that sugemalimab was clinically beneficial in patients who were receiving either concurrent or sequential chemoradiotherapy before sugemalimab. The agent was well tolerated, and investigators did not report any new safety findings.

Data from the clinical trial will be presented at an upcoming international academic conference.

“Following positive data from last year’s interim PFS analysis, [the] final PFS analysis results showed that sugemalimab as a consolidation therapy demonstrated more durable PFS and overall survival in patients with stage III NSCLC following concurrent or sequential chemoradiotherapy. The 2022 Chinese Society of Clinical Oncology (CSCO) guidelines have recommended sugemalimab as consolidation therapy for patients with stage III NSCLC after chemoradiotherapy. The updated data will further support sugemalimab to become a standard-of-care for this patient population,” principal investigator Yi-Long Wu, MD, a tenured director of Guangdong Provincial People’s Hospital, said in the press release.

The trial had an actual enrollment of 381 patients for randomization to either 1200 mg of intravenous sugemalimab every 3 weeks for up to 24 months or a matched placebo. The primary end point was PFS.

To enroll on the trial, patients were required to have histologically confirmed locally advanced/unresectable stage III NSCLC and have previously received treatment with platinum-containing chemotherapy. Absence of progression following concurrent or sequential chemoradiotherapy, as well as an ECOG performance status of 0 or 1 were required. Patients with a histologically identified small cell lung cancer component, disease progression after concurrent or sequential chemoradiotherapy, or who had a major surgical procedure within 28 days of the first dose of sugemalimab were not eligible for enrollment.

“We are glad that the final PFS analysis of the GEMSTONE-301 study further demonstrated a statistically significant improvement in PFS and clinical benefits were observed in patients receiving either concurrent or sequential chemoradiotherapy. Based on the positive results of the interim PFS analysis, the [new drug application] of sugemalimab for the treatment of stage III NSCLC is under review by the [National Medical Products Administration]. Sugemalimab is expected to become the first anti–PD-(L)1 antibody worldwide for patients with stage III NSCLC following prior concurrent or sequential chemoradiotherapy if approved. We are also excited about sustained overall survival benefits. We hope sugemalimab will be approved globally to benefit more and more lung cancer patients with excellent efficacy and safety data,” Jason Yang, chief medical officer at CStone, concluded.


CStone announces final PFS analysis of a registrational study of sugemalimab in patients with stage III NSCLC further demonstrates its robust efficacy and significant clinical benefits shown in interim analysis. News release. CStone Pharmaceuticals. May 17, 2022. Accessed May 18, 2022.