SUO 2018: Long-Term IO Alone for Muscle Invasive Bladder Cancer

Phoenix, Arizona ( As part of the bladder cancer session at the 2018 annual meeting of the Society of Urologic Oncology, Dr. Guru Sonpavde from the Dana-Farber Cancer Institute discussed the role of systemic monotherapy in the treatment of muscle invasive bladder cancer (MIBC), with a focus on immune-oncologic (IO) agents, such as PD-1 / PDL-1 inhibitors. Dr. Sonpavde began his discussion noting that at the present time, systemic chemotherapy or immunotherapy alone are rarely used in the treatment of MIBC, however there are several reasons that patients may not be candidates for adjuvant surgical or radiologic interventions, such as medical comorbidities, prior surgery, prior radiotherapy, or poor bladder function.

Dr. Sonpavde reviewed the data regarding the use of systemic chemotherapy as monotherapy for patients with muscle-invasive urothelial carcinoma in order to set a historical benchmark to compare any future immunotherapy trials. He showed retrospective data that showed the 5-year survival rate for patients who underwent TURBT followed by systemic chemotherapy alone was on 32.5%. This indicates that while a small fraction of patients may be curable with systemic chemotherapy alone, the majority of patients likely require additional treatment modalities for a chance of cure.

Sonpavde then went on to discuss the challenges of identifying those patients who may have a complete and durable response to adjuvant chemotherapy or immunotherapy. The benefit of developing a biomarker in this setting is that it would allow some patients to avoid a consolidative radical cystectomy after neoadjuvant therapy. He questions if, in the future, PD-L1 expression in tumor cells could be employed to select those patients who may be managed with IO therapy alone if they appear to achieve a pathologic complete response and reviewed the data of some trials that address this question.

He then reviewed a phase Ib/II study evaluating the efficacy of neoadjuvant pembrolizumab and chemotherapy in patients with locally-advanced urothelial cancer and showed that there was a 44.4% rate of complete response in these patients.

Dr. Sonpavde concluded that IO therapy alone at this point for MIBC is not a reality in 2018. He believes that given the roughly 25% rate of durable responses, there may be a defined role for IO monotherapy in appropriately selected patients in the future, however extensive validation would first be required. He believes that further investigation into predictive biomarkers and improved imaging technologies are going to be required before we can accurately predict those patients who will have good outcomes with IO monotherapy.

Presented By: Guru P. Sonpavde, MD, Dana-Farber Cancer Institute

Written by: Brian Kadow, MD, Society of Urologic Oncology Fellow, Fox Chase Cancer Center, Philadelphia, PA, at the 19th Annual Meeting of the Society of Urologic Oncology (SUO), November 28-30, 2018 – Phoenix, Arizona