Protara Recasts Bladder Cancer Trial as Exploratory Study
Protara reported $161.9 million in cash and securities while broadening its bladder cancer research and maintaining its expected funding runway into 2028.
Protara Therapeutics, Inc. (TARA), a clinical-stage biotechnology company developing treatments for cancer and rare diseases, changed course on its ADVANCED-3 bladder cancer trial after describing it as a registrational study in its previous two quarterly updates. The company said it was redesigning the recently initiated trial as an exploratory study covering a broader patient population.
The change followed March and May announcements that Protara expected to initiate ADVANCED-3 as a registrational trial in patients who had not received Bacillus Calmette-Guérin, or BCG, in the second half of 2026. The new design covered multiple groups of patients with high-grade, high-risk non-muscle-invasive bladder cancer, including those with carcinoma in situ who were BCG-naïve or BCG-exposed, and patients with papillary tumors across BCG exposures.
The redesigned study was open-label and focused on evaluating the efficacy and safety of TARA-002, Protara’s investigational cell therapy. Chief Executive Jesse Shefferman said the company expects the revised protocol to accelerate and broaden the data available around a potential launch in BCG-unresponsive carcinoma in situ. The announcement therefore changed ADVANCED-3’s stated role in the program while retaining a separate registrational effort in patients unresponsive to BCG.
That effort remained in ADVANCED-2. Protara expects to complete enrollment of its BCG-unresponsive registrational cohort in the fourth quarter of 2026. The schedule specified a narrower window than the second-half target given in both preceding updates. The company’s latest announcement centered on enrollment timing and the companion trial’s redesign rather than a new bladder cancer response-rate readout.
The clinical work accompanied higher research spending. Second-quarter research and development expenses rose to $17.0 million from $10.8 million a year earlier. Protara attributed the increase primarily to direct clinical-trial costs, personnel expenses and research costs outside specific programs, chiefly chemistry, manufacturing and controls. Direct trial costs accounted for $3.2 million of the increase, making them the largest identified contributor. The company did not assign that increase to an individual trial.
The quarterly net loss widened to $21.7 million from $15.0 million a year earlier. The latest loss was $0.36 a share, and general and administrative expenses were $6.4 million. Protara attributed the administrative expense increase primarily to personnel costs, partly offset by lower other administrative expenses. Together, research and administrative spending totaled $23.3 million for the quarter.
Cash, cash equivalents and marketable debt securities declined across the three reporting dates, from approximately $198 million at December 31 to approximately $177 million at March 31 and $161.9 million at June 30. Protara nevertheless continues to expect those resources to support planned operations and milestones into 2028, maintaining the runway it had cited in both prior updates.
Beyond bladder cancer, Protara advanced TARA-002 in pediatric lymphatic malformations, rare congenital abnormalities of lymphatic vessels. Following discussions with the Food and Drug Administration, the company expects to submit a Biologics License Application in the second half of 2027 based on the pivotal STARBORN-1 trial. It also expects to provide an update and complete enrollment in that study in the fourth quarter of 2026.
Interim STARBORN-1 data showed clinical success in 10 of 12 participants who completed treatment and all 10 evaluable patients at the April 10 cutoff. All seven participants who reached the 32-week post-treatment assessment remained disease-free. Most adverse events were mild to moderate, and no serious adverse events were reported; swelling and fatigue were the most common.
Protara’s other registrational program, THRIVE-3, evaluated IV Choline Chloride in patients dependent on long-term parenteral support. The company now expects interim results in the fourth quarter, narrowing its earlier second-half window and placing another clinical readout alongside its year-end enrollment targets.
Stronger demand supports expansion as pricing diverges