Protara's Phase II trial of TARA-002 shows positive results in NMIBC

The trial is assessing intravesical TARA 002, the Company’s investigational cell-based therapy, in high-risk Non-Muscle Invasive Bladder Cancer (NMIBC) patients with carcinoma in situ or CIS (± Ta/T1) who are Bacillus Calmette-Guérin (BCG)-Unresponsive or BCG-Naïve. The complete response (CR) rate across BCG exposures was 72% (13/18) at six months and 70% (14/20) at any time with 100% (9/9) of patients maintaining a CR from three months to six months. In addition, two of three patients maintained a CR at nine months. These results will be featured during a poster session at the 25th Annual Meeting of the Society of Urologic Oncology (SUO) in Dallas, Texas.

The dataset includes 20 patients who were evaluable at three months, 18 patients who were evaluable at six months and three patients who were evaluable at nine months with a data cutoff of November 19, 2024. In the pivotal cohort of the ADVANCED-2 trial in BCG-Unresponsive patients, the CR rate was 100% (4/4) at six-months and 80% (4/5) at any time. In the proof-of-concept cohort of BCG-Naïve patients, the CR rate was 64% (9/14) at six months and 67% (10/15) at any time. TARA-002 demonstrated a favorable safety and tolerability profile with no Grade 2 or greater treatment-related adverse events (TRAEs), and no patients discontinued due to adverse events.

“These impressive TARA 002 results demonstrate meaningful activity in a difficult to treat patient population,” said Brian Mazzarella, MD, Vice President of Research for Urology America, and ADVANCED-2 study investigator. “The activity of TARA 002 across BCG exposures, coupled with its ease of use and low procedural burden for physicians, make it an exciting potential treatment option for NMIBC patients.”

“We are thrilled with these positive six-month data, which reinforce TARA 002’s potential in NMIBC, while offering a compelling product profile for physicians and patients,” said Jesse Shefferman, Chief Executive Officer of Protara Therapeutics. “We believe these encouraging data together with our international site expansion will accelerate patient enrollment, and we look forward to reporting initial data from 12-month evaluable patients in mid-2025.”

The majority of adverse events were Grade 1 and transient with no Grade 2 or greater TRAEs as assessed by study investigators. No patients discontinued treatment due to adverse events. The most common adverse events were in line with typical responses to bacterial immunopotentiation, such as flu-like symptoms. The most common urinary symptoms reflect urinary tract instrumentation effects, such as bladder spasm, burning sensation, and urinary tract infection. Most bladder irritations resolved shortly after administration or within a few hours to a few days.

The Phase II open-label ADVANCED-2 trial is assessing intravesical TARA 002 in NMIBC patients with carcinoma in situ or CIS (± Ta/T1) who are Bacillus Calmette-Guérin (BCG)-Unresponsive (n≈100) and BCG-Naïve (n=27). The BCG-Unresponsive cohort has been designed to be registrational in alignment with the FDA’s 2024 BCG-Unresponsive Non-muscle Invasive Bladder Cancer: Developing Drugs and Biological Products for Treatment Draft Guidance for Industry.