Purpose: Cemiplimab, a PD-1 inhibitor, is indicated for treatment of cutaneous squamous cell carcinoma (CSCC) in patients with metastatic (mCSCC) or locally advanced (laCSCC) disease not eligible for curative surgery/radiation. Cemiplimab resulted in RECIST objective response rate (complete+partial response) of 44.0%, median times to tumour response of 2.0 months and progression-free survival (PFS) of 18.4 months safety profile was consistent with other anti–PD-1 agents. Cemiplimab-treated patients achieved clinically meaningful (CM) pain reductions (measured using the patient-reported EORTC QLQ-C30 pain domain), which was further characterised by the relationship between time to a CM change in pain and tumour response.
Methodology: Adults (N=193) with confirmed diagnosis of invasive CSCC received IV cemiplimab 3 mg/kg Q2W (mCSCC n=59; laCSCC n=78) or 350 mg Q3W (mCSCC n=56). The QLQ-C30 was administered at baseline and day 1 of each treatment cycle. Kaplan–Meier survival analysis (with censoring at drop-out) was used to estimate time to 1st CM (≥10-point) reduction (improvement) or increase (worsening) in QLQ-C30 pain scores. Pain medication use was captured over the treatment period.
Results: For pain score at 1st tumour response (cycle 2), the least squares mean change from baseline of responders (–13.8 ±1.7; n=81) differed from that of non-responders (–3.3 ±2.1; n=71) by –10.5 (95% CI: –15.6 to –5.3; P<0.0001); pain reduction was maintained at least through cycle 5 and was independent of opioid pain medication use. For responders, Kaplan–Meier estimated median time to 1st CM pain improvement (2.1 months; n=51) and 1st CM pain worsening (14.8 months; n=77) approximated median times to tumour response (2.0 months; n=85) and PFS (18.4 months; n=193), respectively.
Conclusion: In cemiplimab-treated CSCC patients, early pain reduction tracked with 1st tumour response and pain worsening with PFS. These results suggest that changes in pain may correlate with tumour response.