At six months, Protara Therapeutics’ investigational cell therapy elicited a complete response (CR) rate of 72% among 18 patients with bladder cancer, data that sent the biotech’s shares surging.
After nine months, two of out of three evaluable patients maintained their CRs, according to a Dec. 5 company release. In the phase 2 trial, no severe treatment-related adverse events had been reported by the data cutoff of Nov. 19.
The open-label study, known as ADVANCED-2, enrolled patients with high-risk non-muscle invasive bladder cancer (NMIBC) who had not received or were unresponsive to Bacillus Calmette-Guérin (BCG), an immunotherapy used as the standard of care in the indication.
The trial is testing Protara’s lead asset TARA-002, a cell therapy designed to activate immune cells within the tumor and generate a pro-inflammatory response.
The data show that 13 of 18 patients (72%) across BCG exposures experienced CRs at six months, findings that are being shared today at the Society of Urologic Oncology’s annual meeting in Dallas.
When zooming in on the patient population by BCG exposure, the pivotal cohort of BCG-unresponsive patients saw a 100% (4/4) CR rate at six months and an 80% (4/5) CR rate at any time. The cohort is designed to be registrational and aligns with FDA draft guidance for the specific patient population, according to Protara.
In the proof-of-concept arm of BCG-naive patients, the CR rate was 64% (9/14) at six months and 67% (10/15) at any time.
No patients discontinued due to adverse events, and there weren’t any treatment-related adverse events at or above a grade 2 level, the company said. In general, most adverse events were grade 1 and transient, according to the New York-based biotech, with the most common symptoms in line with typical responses to bacterial immunopotentiation.
“These impressive TARA-002 results demonstrate meaningful activity in a difficult to treat patient population,” Brian Mazzarella, M.D., study investigator and vice president of research for Urology America, said in the release. “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.”
The biotech is expected to report 12-month data from the trial in mid-2025, according to Protara CEO Jesse Shefferman.
Since yesterday, Protara’s stock has skyrocketed, jumping from $3.54 per share at market close to $6.76 at 2:13 p.m. ET today.
NMIBC makes up about 80% of bladder cancer cases, with around 65,000 Americans diagnosed with the form of bladder cancer every year.
Earlier this year, ImmunityBio landed an FDA approval for its immunotherapy Anktiva in conjunction with BCG for BCG-unresponsive patients.
Pharma data intelligence outlet Evaluate recently listed the interleukin-15 superagonist as one of the top 10 drug launches expected this year, forecasting that the immunotherapy could reach nearly $900 million in 2028 sales.
The standard-of-care BCG is a vaccine supplied to the U.S. by Merck & Co. The med is used as to protect against tuberculosis and to stop or slow bladder cancer's growth.