Camrelizumab Plus Nab-Paclitaxel Showcases Antitumor Activity in Platinum-Resistant Urothelial Carcinoma

The combination of camrelizumab and nab-paclitaxel (Abraxane) produced encouraging responses in patients with platinum-resistant, unresectable locally advanced or metastatic urothelial carcinoma, according to data from a multicenter, single-arm, phase 2 study (CTR2000033820) presented at the 2022 ESMO Congress.¹

The median progression­-free survival (PFS) achieved with the doublet was 5.81 months in evaluable patients (n = 20). Moreover, the combination elicited an objective response rate (ORR) of 25%, with 1 patient achieving a complete response. Further, the disease control rate was 75%, with 2 patients achieving durable responses that lasted for over 1 year.

“Camrelizumab in combination with nab-paclitaxel for platinum-resistant advanced urothelial carcinoma patients exhibited favorable antitumor activities and tolerable in the preliminary analyses,” lead study author Haifang Li, PhD, of State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, and colleagues, noted in their poster presentation.

Immune checkpoint inhibitors have become a standard-of-care treatment for patients with advanced urothelial carcinoma who have received platinum-based chemotherapy and experienced disease progression. In those with advanced disease, nab-paclitaxel is increasingly leveraged.

In the current phase 2 trial, investigators set out to evaluate the safety and efficacy of camrelizumab plus nab-paclitaxel in this patient population.

To be eligible for enrollment, patients must have been previously treated with and progressed on at least 1 platinum-based systemic therapy.

Study participants received 200 mg of camrelizumab on day 1 followed by 125 mg/m² of nab-paclitaxel on days 1 and 8 of a 21-day cycle. Treatment continued until patients experienced disease progression or intolerable toxicity.

The primary end point of the phase 2 study was PFS by RECIST v1.1 criteria.

By January 2020, the phase 2 trial had accrued a total of 20 patients. In these patients, the median age was 65 years (range, 54-74), with 55% of patients aged 65 years or older. Sixty-five percent of patients were male, and 60% had an ECOG performance status of 0; the remaining 40% of patients had a status of 1.

Eleven patients (55%) had a primary tumor site of the bladder and 9 patients (45%) had upper-tract urothelial carcinoma. Twenty percent of patients had locally advanced disease and 16 patients (80%) had metastatic disease.

In terms of safety, 90% of patients experienced adverse effects (AEs) of any grade; 50% of AEs were grade 3 or higher in severity. One patient experienced severe immune-related pneumonia while on the treatment combination.

Based on the study results, additional randomized trials are warranted to further explore the combination.

Reference

Li H, Chen M, Xue C, et al. Camrelizumab plus nab-paclitaxel in platinum-resistant patients with unresectable locally advanced or metastatic urothelial carcinoma: a multicentre, single-arm, phase II study. Ann Oncol. 2022;33(suppl 7):S1335. doi:10.1016/j.annonc.2022.07.1822