Phase II Trial of Continuous Treatment with Sunitinib in Patients with High-Risk (BCG-refractory) Non-Muscle Invasive Bladder Cancer - Expert Commentary

Treatment of patients with non-muscle invasive bladder cancer (NMIBC) who are unable to receive intravesical with Bacillus Calmette Guerin (BCG) remains a challenge.

A recent study published by Zahoor et al. in Investigational New Drugs assessed the safety and effectiveness of sunitinib in BCG-refractory NMIBC patients. Between June 2011 and September 2011, the authors enrolled 19 BCG-refractory NMIBC patients in this single-arm open-label phase II clinical study conducted at Cleveland Clinic. Six (32%) patients had prior intravesical treatment with BCG only, 13/19 (68%) had exposure to other intravesical therapies in addition to BCG. Patients received a daily oral dose of sunitinib 37.5 mg 12 weeks. Patients underwent cystoscopy and surveillance for one year. The authors assessed the complete response at 12 months as the primary endpoint of the study and the safety, recurrence-free survival (RFS), progression-free survival (PFS), overall survival (OS) as the secondary endpoints.

They reported that 79% (15/19) patients received full 12 weeks of sunitinib, and 3/15 had related adverse events and could not continue the treatment. One patient withdrew consent after being on trial for 15 weeks and was not included in the endpoint analysis. At the 12-week cystoscopy, 44% (8/18) of patients has no evidence of disease (95% CI 20–67%, 50% (9/18) had disease progression, and 1/18 had disease recurrence. At 12-month, 22% (4/18) of patients were in remission, and 78% (14/18) had disease progression. In terms of safety, they reported that 13 patients had clinically significant toxicity (Grade3/4). Two out of the 19 patients had grade 4 toxicities (anemia and thrombocytopenia), and 11/19 experienced grade 3 toxicities.

Several intravesical and systemic therapy options are emerging for patients with BCG-refractory NMIBC. This is an area of unmet medical need that requires additional studies to improve clinical outcomes.

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine

Reference:

  1. Zahoor H, Mir MC, Barata PC, Stephenson AJ, Campbell SC, Fergany A, Dreicer R, Garcia JA. “Phase II trial of continuous treatment with sunitinib in patients with high-risk (BCG-refractory) non-muscle invasive bladder cancer.” Invest New Drugs. 2019 Dec;37(6):1231-1238. doi: 10.1007/s10637-018-00716-w. Epub 2019 Jun 24. PMID: 31231785 Clinical Trial.

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