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Soo Park, MD
Soo Park, MD
Posted: Thursday, June 6, 2024
Rahul Ladwa, MBChB, BSc, FRACP, MPhil, of the University of Queensland, Brisbane, Australia, and colleagues evaluated a risk-adapted surgical de-escalation approach guided by clinical, radiologic, and pathologic responses in patients with resectable, locally advanced cutaneous squamous cell carcinoma who were undergoing neoadjuvant therapy with the PD-1 inhibitor pembrolizumab. The results of the multicenter phase II De-Squamate study were presented during the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 9514).
“Pembrolizumab led to a high rate of pathologic complete and clinical complete responses,” the investigators commented. “The study design effectively selected patients for surgical and postoperative radiation therapy de-escalation and demonstrated a sustained response in this cohort.”
A total of 27 immunocompetent patients with stage II to IV disease were treated with two to four cycles of 200 mg of intravenous pembrolizumab every 3 weeks. They underwent CT/MRI and 18F-fluorodeoxyglucose–PET imaging at baseline and after completing neoadjuvant therapy. In those with a complete metabolic response, mapping biopsies of the target sites were performed. A clinical complete response warranted omission of surgery and postoperative radiation therapy; patients with clinical or radiologic residual disease underwent surgical resection. Postoperative radiation therapy was de-escalated in the event of a pathologic complete or major pathologic response. The population received 13 cycles of maintenance therapy with pembrolizumab.
The combined pathologic complete, major pathologic, and clinical complete response rate was 63% (individually: 15%, 0%, and 48%, respectively). De-escalation of both surgery and postoperative radiation therapy was achieved in 48% of patients; an additional 15% avoided postoperative radiation therapy alone. With a minimum duration of follow-up of 6 months, none of the patients who achieved a pathologic complete, major pathologic, or clinical complete response experienced disease recurrence. Investigator-assessed treatment-related adverse events of grade 3 or higher were reported in 7% of the treated population.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
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