New drug combination before bladder surgery for small cell bladder cancer

Plain-English translation of NCT05312671 on ClinicalTrials.gov ↗ · Source last updated June 2026 · Translation generated June 2026 · How we translate trials

Phase 2 — Testing in a bigger group (up to a few hundred people) to see if the treatment actually works and is still safe.

What is this trial?

This trial is testing whether —a drug that helps your immune system fight cancer—works better when combined with two chemotherapy drugs ( and either or ) before surgery to remove the bladder in patients with a rare type of bladder cancer called small cell neuroendocrine carcinoma. All participants will receive four cycles of this three-drug combination, then have surgery to remove their bladder, followed by additional doses of the medication to help prevent cancer from returning.

Small cell neuroendocrine bladder cancer is aggressive and hard to treat. Doctors want to see if combining this newer immunotherapy drug with standard chemotherapy can help shrink the cancer before surgery and improve long-term survival.

Do you qualify?

You likely qualify if…

you have been diagnosed with invasive small cell or neuroendocrine bladder cancer
you are 18 years old or older
you are physically healthy enough to receive chemotherapy, immunotherapy, and surgery
you have adequate liver, kidney, and bone marrow function based on blood tests
you have a tumor sample available for testing, either from a previous procedure or a new biopsy

You likely don't qualify if…

you have untreated HIV, hepatitis B, or other active infections
you have severely reduced kidney function (unless it's only mild-to-moderate and you'll receive carboplatin instead of cisplatin)
you are pregnant, breastfeeding, or unwilling to use effective contraception during and after treatment
you have other serious medical conditions that would make chemotherapy or surgery unsafe

What participation looks like

You will come to the hospital or clinic every three weeks for four cycles of treatment, where you'll receive intravenous (IV) infusions of three drugs on the first day of each cycle. After four cycles, you'll have surgery to remove your bladder. Following surgery, you'll continue receiving the immunotherapy drug as an IV infusion every three weeks for up to one year, as long as it's helping and you're tolerating it well. Throughout the trial, you'll have blood tests and imaging scans to monitor how you're doing.

AI-generated summary from trial data · Jun 27, 2026 · Not medical advice

Trial locations(2 sites)

United States

Johns Hopkins University: Sibley Memorial Hospital, Washington D.C., District of Columbia

Johns Hopkins University: Sidney Kimmel Comprehensive Cancer Center, Baltimore, Maryland