Julian Andres Marin-Acevedo, MD from H. Lee Moffitt Cancer Center & Research Institute speaks about ASCO 2021 Abstract – Efficacy of cetuximab after immunotherapy (IO) in advanced cutaneous squamous cell carcinoma (CSCC).
Link to Abstract:
https://meetinglibrary.asco.org/record/197144/abstract
Background information:
For advanced CSCC that is not responsive to surgery or curative radiation, anti-PD1 (aPD1) monotherapy with cemiplimab-rwlc or pembrolizumab is currently considered standard of treatment. Chemotherapy or anti-EGFR medicines were previously utilized to treat these individuals, albeit with poor effectiveness and response durability. At 6 weeks, the overall response rate (ORR) to cetuximab was 28 percent, with a disease control rate (DCR) of 69 percent, according to a prospective study. After primary or acquired resistance to aPD1 therapy, the effectiveness of second-line treatment is unknown. Cetuximab’s efficacy in patients who had progressed on prior IO treatment was studied.
Methodologies:
Patients with locally advanced or metastatic CSCC who received cetuximab after previous IO treatment were reviewed retrospectively from 9/28/18 (US approval date of cemiplimab-rwlc for CSCC) through 11/30/20 at a single institution. We identified patients who received cetuximab either as a first-line treatment after IO therapy (cohort A) or as a second-line treatment after IO therapy (cohort B) (cohort B). ORR was the primary objective, with DCR, survival, and toxicity as supplementary outcomes. The Kaplan-Meier technique was used to establish the median follow-up and survival periods.
The following are the outcomes:
This study comprised 13 patients, all Caucasian, with a median age of 72 years (62-82), and 11 males (85%). Two patients underwent extra intervening therapy after IO progression before getting cetuximab. Eleven patients got cetuximab promptly after IO progression. Three patients got cetuximab together with palliative or final radiotherapy. The ORR with cetuximab was 54% (7/13) with 1 complete response and 6 partial responses. The DCR for the first six months was 77 percent. In cohort A, all responses were seen; in cohort B, both patients exhibited progressing illness as their greatest response. Six of the seven early responses are still being evaluated, including three in which cetuximab was stopped. The median PFS for the total group has not been attained after 9.1 months of follow-up. There were no unexpected side effects after cetuximab, with rash (77%) and hypomagnesemia (54%) being the most prevalent side effects.
Final Thoughts:
Cetuximab administered immediately after progression on aPD1 treatment produces a significantly greater and longer-lasting overall response in advanced CSCC than previously documented in the pre-IO treatment era. This should be the chosen therapy for second-line treatment in advanced CSCC if it can be validated in a bigger dataset. More research into the mechanism of anti-EGFR treatment’s high effectiveness after aPD1 treatment is needed.