TARA-002 Shows Potential in BCG-Naive NMIBC Treatment

TARA-002 may offer meaningful benefits for patients with non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS), including those who have never received Bacillus Calmette-Guérin (BCG), a standard therapy for bladder cancer, and who have limited treatment options, according to updated interim data from the phase 2 ADVANCED-2 clinical trial, as shared in a news release from Protara Therapeutics, Inc.

“These positive results continue to support TARA-002’s potential in the NMIBC treatment landscape, and we look forward to finalizing a regulatory pathway for TARA-002 in BCG-Naïve patients,” Jesse Shefferman, CEO of Protara Therapeutics, said in the news release. “We remain on track to provide an update on the registrational BCG-Unresponsive patient cohort in the ADVANCED-2 trial in the first quarter of 2026 and expect to complete enrollment of this cohort in the second half of 2026.”

“These encouraging TARA-002 results demonstrate meaningful and durable activity in BCG-naïve NMIBC patients,” added Dr. Mark Tyson, vice chair for research and a professor in the Department of Urology with the Mayo Clinic in Phoenix, Arizona, and ADVANCED-2 study investigator. “The clinically meaningful response rates at six and 12 months, coupled with a favorable safety and tolerability profile and simple administration that is even more streamlined than BCG, make TARA-002 a compelling potential treatment option in the BCG-naïve setting.”

TARA-002 Shows High Complete Response Rates in BCG-Naïve Patients

Interim findings from 31 BCG-naïve patients who received at least one dose of TARA-002 indicate strong anti-cancer activity. Among the 29 patients evaluable for efficacy, 72% achieved a complete response (CR) at any time during the study, 69% maintained a CR at six months, and 50% maintained a CR at 12 months. Among initial responders, 88% maintained their response at six months and all patients who reached 12 months maintained their CR.

Patients who did not initially respond underwent re-induction therapy, which converted 80% to a CR at six months and 100% maintained it at 12 months.

The treatment schedule involved six weekly bladder instillations, followed by maintenance courses of three weekly instillations every three months. Eligible patients with persistent or recurrent disease could receive re-induction therapy.

Favorable Safety and Tolerability Observed with TARA-002

TARA-002 appears to be well tolerated. Most treatment-related side effects were grade 1 (mild) and temporary. The most common treatment-related side effects included dysuria (painful urination; 13%), fatigue (13%), and hematuria (blood in urine; 6%).

No patients experienced grade 3 or higher (severe) side events, and no participants discontinued treatment due to side effects. These results suggest TARA-002 may provide a safer, more manageable alternative to BCG for patients new to therapy.

Regulatory Progress and Next Steps for TARA-002

Protara Therapeutics is actively engaging with the U.S. Food and Drug Administration (FDA) to define a path forward for TARA-002 in both BCG-naive and BCG-unresponsive patients. The FDA has provided feedback supporting a registrational trial design for BCG-naive patients; the primary end point for this trial is the six-month CR rate, with duration of response as a key secondary measure.

The clinical-stage company remains on track to report interim results for approximately 25 BCG-unresponsive patients in the first quarter of 2026 and expects to complete enrollment in this cohort by the second half of 2026.

Understanding TARA-002 and Its Mechanism of Action

TARA-002 is a first-in-class immunotherapy and is designed to activate both innate and adaptive immune responses within the bladder wall. By stimulating immune cells, TARA-002 can trigger a pro-inflammatory response, release tumor-fighting cytokines such as tumor necrosis factor-alpha and interferon-gamma, and directly kill tumor cells. Additionally, the therapy may induce immunogenic cell death, further enhancing the body’s anti-cancer response.

This approach is being tested for NMIBC as well as other rare cancers and has received Rare Pediatric Disease Designation from the FDA.

What Patients Should Know About Non-Muscle Invasive Bladder Cancer

NMIBC accounts for roughly 80% of bladder cancer diagnoses in the United States, with approximately 65,000 new cases annually. The cancer is limited to the inner lining of the bladder and has not invaded the muscle layer, making it highly treatable when detected early.

Standard therapy typically involves BCG instillations, but not all patients can tolerate or access this treatment, highlighting the need for effective alternatives like TARA-002.

Reference

1. “Protara Therapeutics Announces Updated Interim Data from Phase 2 ADVANCED-2 Trial of TARA-002 in BCG-Naïve NMIBC Patients,” by Protara Therapeutics, Inc. News release; Dec. 3, 2025.

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