Protara Therapeutics has reported updated 12-month data from its ongoing Phase 2 Advanced-2 trial, showing durable responses and a favourable safety profile for TARA-002 in patients with BCG-naïve non-muscle invasive bladder cancer (NMIBC).

The investigational therapy achieved a complete response rate of 72.4% at any time point, with 66.7% of patients maintaining complete response at six months and 55% remaining in complete response at the 12-month landmark.

The updated data from Cohort A of the Advanced-2 study were presented at the American Urological Association annual meeting in Washington DC.

TARA-002 is being evaluated in patients with carcinoma in situ, with or without Ta or T1 disease, a form of high-risk NMIBC that can recur or progress despite treatment.

Mark Tyson, professor of urology at Mayo Clinic Phoenix and an Advanced-2 study investigator, said: “Today’s presentation demonstrates TARA-002’s impressive 12-month durability data and excellent safety profile for patients with BCG-Naïve NMIBC.

“The NMIBC patient community faces a critical unmet need for safe, effective and bladder-sparing treatment options for this devastating disease.”

The efficacy analysis included 29 evaluable patients, with 20 patients available for 12-month assessment at the April 2026 data cut-off.

Among patients who responded to treatment, the Kaplan-Meier estimated probability of maintaining complete response for six months was 73.1%, while 91.7% maintained their response from nine to 12 months.

The company also reported encouraging results among patients who underwent re-induction therapy, with four of six converting to complete response at six months.

TARA-002 demonstrated a favourable safety profile, with most treatment-related adverse events reported as Grade 1 and transient. No Grade 3 or higher treatment-related adverse events were observed, and no patients discontinued treatment because of side effects. The most commonly reported adverse events were dysuria, fatigue and haematuria.

Jesse Shefferman, chief executive officer of Protara Therapeutics, said: “These data continue to support our conviction that TARA-002 has the potential to make a meaningful difference in the lives of patients with BCG-Naïve NMIBC.”

The company said it remains on track to begin the registrational Advanced-3 trial in the second half of 2026, comparing TARA-002 with intravesical chemotherapy in BCG-naïve and potentially BCG-exposed patients.

Non-muscle invasive bladder cancer accounts for around 80% of bladder cancer diagnoses in the United States, affecting approximately 65,000 patients each year.