With 30 months additional follow-up on the EMPOWER-Cervical 1 trial, cemiplimab monotherapy showed efficacy in patients with metastatic cervical cancer.
Cemiplimab (Libtayo) continued to improve overall survival (OS) compared with chemotherapy for patients with recurrent or metastatic cervical cancer after first-line treatment with platinum-based chemotherapy, according to results presented from the long-term survival analysis of the phase 3 EMPOWER-Cervical 1 study (NCT03257267).
“Cemiplimab is the first immunotherapy agent to demonstrate significant and clinically meaningful OS benefit as a second-line monotherapy for patients with recurrent or metastatic cervical cancer previously treated with platinum-based chemotherapy but without prior immunotherapy,” said Ana Oaknin, MD, head of the gynecological tumor unit and full-time senior attending physician at the medical oncology department at the Vall d’Hebron University Hospital in Barcelona, Spain, during the presentation at the 2022 ESMO Congress.
In this study, investigators analyzed data from 608 patients with recurrent or metastatic cervical cancer after progression on first-line platinum-based chemotherapy. Patients were randomized to receive either 350 mg of cemiplimab intravenously once every 3 weeks (n = 304) or investigator’s choice of single-agent chemotherapy (n = 304).
The primary end point of the study was OS, which was analyzed hierarchically in patients with squamous cell carcinoma followed by the overall population. The analysis was performed after 363 OS events occurred over a median follow-up of 30.2 months (range, 18.0-50.2).
Compared with chemotherapy, treatment with cemiplimab significantly improved OS (11.7 months vs 8.5 months; HR, 0.656; 95% CI, 0.545-0.790; P <.00001). Cemiplimab reduced the risk of death by 34% in the overall population. This effect was also seen in patients with squamous cell carcinoma (10.9 months vs 8.8 months; HR, 0.69; 95% CI, 0.56-0.85; P = .00023), whose risk for death was reduced by 31%.
In patients with adenosquamous carcinoma, cemiplimab treatment reduced the risk of death by 45%, thus increasing OS compared with chemotherapy (13.5 months vs 7.0 months; HR, 0.545; 95% CI, 0.365-0.814). Of note, the OS analysis in patients with adenosquamous carcinoma were exploratory with no adjustments for multiplicity.
Investigators also assessed OS by PD-L1 status in patients assigned to either arm. Oaknin called the results from this exploratory analysis “very interesting,” as OS at both 12- and 24-month timepoints appeared improved for those assigned cemiplimab. In particular, the median OS for patients in the PD-L1–positive group was 12.1 months vs 7.7 months for those assigned chemotherapy (HR, 0.61; 95% CI, 0.45-0.83). For patients with PD-L1–negative status, the median OS was 10.8 months compared with 7.0 months, respectively (HR, 0.65; 95% CI, 0.43-0.98).
The overall response rate was 16.4 months in the cemiplimab group vs 6.3 months in the chemotherapy group (OR, 2.984; 95% CI, 1.707-5.215).
“This pattern was repeated regardless of PD-L1 status,” Oaknin said during the presentation.
There were no new safety signals in cemiplimab compared with chemotherapy. Oaknin mentioned that the safety profile of cemiplimab was consistent with other anti–PD-L1 agents.
Oaknin A, Monk BJ, Polastro L, et al. Phase III EMPOWER-Cervical 1/GOG-3016/ENGOT-cx9 trial of cemiplimab in recurrent or metastatic (R/M) cervical cancer: Long-term survival analysis. Ann Oncol. 2022;33(suppl 7):519MO. doi:10.1016/annonc/annonc1054