Clinical outcomes and safety of nimotuzumab plus concurrent chemoradiotherapy in EGFR-expressing locally advanced cervical squamous cell carcinoma: a single-arm exploratory study

Concurrent chemoradiotherapy (CCRT) is the standard non-surgical treatment for locally advanced cervical cancer, but residual disease, recurrence, and distant failure remain clinically relevant. Patient-level data describing nimotuzumab plus CCRT in EGFR-expressing locally advanced cervical squamous cell carcinoma are limited. This single-center, open-label, single-arm exploratory study included treatment-naïve patients with institutional immunohistochemistry-defined EGFR-expressing FIGO 2018 stage IB3–IVA cervical squamous cell carcinoma. Nimotuzumab 200 mg was administered weekly for 8 planned doses with cisplatin-based CCRT, external beam radiotherapy, and brachytherapy when feasible. The main descriptive efficacy outcome was objective response rate approximately 12 weeks after the final radiotherapy fraction, including the final brachytherapy fraction when delivered, assessed according to RECIST 1.1 among response-evaluable patients. Progression-free survival, overall survival, and locoregional control were estimated by Kaplan–Meier methods; safety was assessed using CTCAE version 4.03. Among 58 screened patients, 36 were treated and included in the full analysis and safety sets; 34 were evaluable for 12-week response. Complete response was observed in 18 patients (52.9%), partial response in 12 (35.3%), stable disease in 3 (8.8%), and progressive disease in 1 (2.9%), yielding an objective response rate of 88.2% (95% CI, 73.4–95.3) and a disease control rate of 97.1% (95% CI, 85.1–99.5). Treating both non-evaluable patients as nonresponders in a conservative sensitivity analysis gave an objective response rate of 83.3% (95% CI, 68.1–92.1). After a median follow-up of 30.6 months (IQR, 24.2–38.4), progression or death occurred in 8 patients (22.2%). The 2-year progression-free survival, overall survival, and locoregional control rates were 83.2% (95% CI, 65.1–92.3), 97.2% (95% CI, 81.9–99.6), and 88.6% (95% CI, 71.2–95.8), respectively; median values were not reached. Excluding the 10 patients who received adjuvant chemotherapy, the 2-year progression-free survival estimate was 81.7%. Any-grade adverse events occurred in 33 patients (91.7%), grade ≥ 3 adverse events in 13 (36.1%), and serious adverse events in 3 (8.3%); 2 patients (5.6%) permanently discontinued nimotuzumab. In this small single-arm cohort, nimotuzumab plus CCRT was clinically deliverable, and the observed 12-week response and preliminary 2-year outcome estimates were descriptive. Without a concurrent CCRT-only control, no inference can be made about the incremental efficacy of nimotuzumab; the findings require confirmation in controlled studies.