Protara Therapeutics Highlights Phase 2 TARA-002 Data in NMIBC, Cites Strong Response Rates at ASCO GU

Key Points

• Phase 2 ADVANCED-2 efficacy: Protara reported strong complete response rates—BCG‑unresponsive cohort CR at any time 66% (six‑month 68%, 12‑month 33% with management expecting the 12‑month rate to rise into the 40s) and BCG‑naïve cohort CR at any time 72% (six‑month 67%, 12‑month 58%).
• Favorable safety and simple administration: TARA‑002 was generally well tolerated with mostly grade 1 transient adverse events, no grade ≥3 or related serious AEs or discontinuations, and is delivered via an office‑based intravesical instillation without special handling.
• Regulatory and enrollment progress: The registrational BCG‑unresponsive cohort was designed to align with FDA 2024 guidance (including a mandatory month‑3 biopsy), global enrollment is expanding and Protara expects to complete that cohort in H2 2026 while initiating ADVANCED‑3 in BCG‑naïve patients later this year.

Protara Therapeutics NASDAQ: TARA shared updated interim data from its ongoing Phase 2, open-label ADVANCED-2 trial evaluating intravesical TARA-002 in patients with high-risk non-muscle invasive bladder cancer (NMIBC) with carcinoma in situ (CIS), with or without papillary disease. Management said the updated results, which will be presented in a poster session at ASCO GU, continue to show what the company described as compelling response rates alongside favorable safety and tolerability in both BCG-unresponsive and BCG-naïve cohorts.

Trial design and regulatory alignment

According to Protara, ADVANCED-2 includes two cohorts: a BCG-unresponsive cohort designed to align with the FDA’s updated 2024 guidance, and a fully enrolled BCG-naïve cohort. Patients receive six weekly intravesical instillations of TARA-002 followed by maintenance dosing of three weekly instillations every three months. Participants may receive reinduction if they have residual CIS and/or recurrent high-grade Ta disease at 12 weeks, but are not eligible for reinduction in cases of progression or treatment failure, defined as progression or recurrent T1 disease.

Protara added that, at the FDA’s request, the registrational BCG-unresponsive cohort includes a mandatory biopsy at month three, including bladder mapping, which management said can identify microscopic disease.

Updated efficacy: BCG-unresponsive cohort

With a data cutoff of January 2026, Protara reported the following complete response (CR) outcomes in the BCG-unresponsive cohort:

• CR at any time: 66%
• Six-month CR rate: 68%
• 12-month CR rate: 33%

Head of Clinical Development for the program Dr. Carla Beckham called the initial durability “encouraging,” while noting the small sample size and shorter follow-up inherent in landmark analyses. She cited a Kaplan-Meier estimated probability of maintaining a CR for six months of 71%, and said 100% of evaluable responders maintained their CRs from month nine to 12. Beckham also highlighted that 62% of participants converted from non-CR to CR at six months with reinduction.

CEO Jesse Shefferman said the company believes its six-month landmark CR rate is “just about the best” published among peers at that time point, and argued that the 12-month figure is currently influenced by small numbers and early non-responders. He said Protara expects the 12-month CR rate to strengthen as additional patients reach the 12-month evaluation, adding that the company is “very confident” the 12-month CR rate will be “in the 40s” once the dataset is complete.

Protara said enrollment has increased as the company executes a global expansion and it expects to complete enrollment in the registrational BCG-unresponsive cohort in the second half of 2026.

Updated efficacy: BCG-naïve cohort

In the fully enrolled BCG-naïve cohort, Beckham reported:

• CR at any time: 72%
• Six-month CR rate: 67%
• 12-month CR rate: 58%

Beckham said the 12-month CR rate represents a “significant improvement” versus previous data cutoffs and has increased with longer follow-up. She also cited a Kaplan-Meier estimated probability of maintaining a CR for six months of 73%, with 100% of evaluable responders maintaining CR from month nine to 12. Additionally, 67% of reinduced patients converted to CR at month six, according to Beckham.

Looking ahead, Beckham said Protara expects to begin ADVANCED-3, a registrational trial in BCG-naïve patients, later in the year.

Safety, administration, and real-world considerations

Management repeatedly emphasized ease of administration and tolerability as differentiators. Shefferman said TARA-002 is administered via a simple, office-based intravesical instillation without viral handling, special preparation, or burdensome post-administration protocols. Beckham said treatment-related adverse events including dysuria, bladder spasms, fatigue, and urgency were mostly grade 1 and transient, with no grade 3 or greater events. The company reported no treatment discontinuations due to related adverse events and no related serious adverse events.

In the Q&A, Shefferman said about 35% of BCG-unresponsive patients in the current dataset had received other investigational or approved therapies, mentioning examples such as JELMYTO, checkpoint inhibitors, targeted immunotherapies, and enhanced chemotherapeutic agents, while noting the dataset was too small to draw conclusions on differential responses by prior therapy. He also said the trial follows FDA guidance in defining a high-grade CR as no high-grade recurrence (including CIS, Ta, T1, or combinations), with low-grade recurrence not considered a high-grade recurrence.

Guest physician Dr. Neal Shore, Medical Director of START Carolinas’ Carolina Urologic Research Center, said the reinduction (“salvage”) rates looked “remarkably impressive” and argued that tolerability and operational simplicity could support adoption, particularly in community settings where he said most NMIBC care occurs. He also pointed to operational barriers for some competing therapies, such as safety equipment requirements and storage constraints, and characterized TARA-002 as an off-the-shelf option without “just-in-time delivery” challenges.

Protara said it is not yet providing guidance on the timing of the next ADVANCED-2 data update, but indicated it has historically shared updates at major urologic conferences including ASCO GU and AUA.

About Protara Therapeutics NASDAQ: TARA

Protara Therapeutics, Inc is a clinical-stage biopharmaceutical company focused on developing novel immunotherapies for virus-driven cancers. The company's primary areas of research include human papillomavirus (HPV)–associated malignancies, where it seeks to harness and enhance the body's immune response to target tumor cells. Protara's therapeutic strategy combines antigen-specific vaccination approaches with modulators of T-cell activation to improve clinical outcomes in patients with HPV-mediated disease.

Protara's lead immunotherapy candidate is PTX-35, an investigational monoclonal antibody designed to agonize OX40, a co-stimulatory receptor on T cells.

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