Efficacy and Biomarker Exploration of Sintilimab Combined With Chemotherapy in the Treatment of Advanced Penile Squamous Cell Carcinoma-A Report of Two Cases

Atezolizumab With or Without Radiotherapy for Advanced Squamous Cell Carcinoma of the Penis (The PERICLES Study): A Phase II Trial

PURPOSE

Patients with advanced penile squamous cell carcinoma have a poor prognosis (21% 2-year overall survival [OS] from diagnosis). We assessed the activity of atezolizumab (anti-PD-L1) in patients with advanced penile cancer, with or without radiotherapy (RT).

PATIENTS AND METHODS

A single-center, nonrandomized phase II study with two treatment arms was conducted in 32 patients with histologically confirmed advanced penile cancer. All patients received atezolizumab (1,200 mg) once every 3 weeks. Twenty patients, who were expected to benefit from RT for locoregional disease control, received additional irradiation. The primary end point was 1-year progression-free survival (PFS) for the complete cohort and was reached if the actual 1-year PFS was at least 35%. Secondary end points included OS, objective response rate (ORR), and tolerability. Exploratory biomarker analyses were conducted in pretreatment specimens.

RESULTS

Median follow-up was 29.1 months (IQR, 18.1-33.5). Grade 3-4 adverse events related to atezolizumab or RT were observed in 3/32 (9.4%) and 13/20 (65%) patients, respectively. One-year PFS was 12.5% (95% CI, 5.0 to 31.3), which did not meet the study's primary end point. Median OS was 11.3 months (95% CI, 5.5 to 18.7). In the objective response-evaluable population (n = 30; 93.8%), the ORR was 16.7% (95% CI, 6 to 35), including 2 (6.7%) complete responders and 3 (10%) partial responders. Improved PFS was observed in patients with high-risk human papillomavirus (hrHPV)-positive tumors (P = .003) and those with high infiltration of intratumoral CD3+CD8+ T cells (P = .037).

CONCLUSION

Although the primary end point of 1-year PFS was not met, durable antitumor activity to atezolizumab was observed in a subset of patients. Biomarkers, such as hrHPV and intratumoral CD3+CD8+ T-cell infiltration, may help to better select responders.

Sintilimab-Induced Diabetic Ketoacidosis in a Patient with Radiation and Multichemorefractory Penile Cancer: A Case Report and Literature Review

Penile squamous cell carcinoma (PSCC) is a rare disease. The treatment options for advanced penile cancer are often limited, and the prognosis remains poor. We reported a 52-year-old male recurrent and metastatic PSCC patient with high PD-L1 expression (90%) and TMB (14.4 muts/Mb). He had undergone penectomy, bilateral inguinal lymph node dissection, and excision of the abdominal wall mass. Despite cisplatin-based concurrent chemoradiotherapy and sequential chemotherapy with docetaxel plus cisplatin then being carried out, the carcinoma still progressed. The patient then obtained progression-free survival with continuous sintilimab, although he experienced the new onset of ICI-induced diabetes after 24 cycles of sintilimab and required sustained insulin treatment. He had negative type 1 diabetes-associated autoantibodies and the susceptible HLA genotype DR3-DQ2 haplotype. This is the first patient with radiation and multichemorefractory PSCC who has obtained the remarkable anti-tumor effect of partial regression exceeding 32 months during continuous sintilimab and anlotinib treatment.