Protara is advancing a cell therapy that triggers both adaptive and innate antitumor immune responses, while CG Oncology’s approach makes use of an oncolytic immunotherapy that preferentially targets cancer cells and proliferates inside them, destroying them from the inside.
At the 25th annual meeting of the Society of Urologic Oncology in Texas on Thursday, Protara Therapeutics and CG Oncology unveiled new data for their respective treatment technologies, demonstrating encouraging efficacy outcomes in non-muscle invasive bladder cancer.
Protara presented Phase II findings for its investigational cell therapy TARA-002, which works by activating innate and adaptive immune players within the cyst or tumor, triggering a pro-inflammatory cascade.
According to the biotech’s press announcement on Thursday, TARA-002 elicited a 72% complete response (CR) rate across the 18 evaluable patients at six months, regardless of their prior exposure to Bacillus Calmette-Guérin (BCG) immunotherapy, which is currently the standard treatment for bladder cancer.
In the four patients classified as BCG-unresponsive, TARA-002 had a 100% CR rate at six months. This is a particularly important patient subgroup for Protara as this cohort was designed to be registrational, according to the biotech.
Protara surged 87% in premarket trading on Thursday in response to the readout, according to Seeking Alpha.
The biotech on Thursday also presented proof-of-concept data for TARA-002 in BCG-naïve patients, in whom the CR rate was 64% at six months. As for safety, the cell therapy had a favorable tolerability profile, with no treatment-related adverse event grade 2 and up. None of the study participants dropped out due to toxicities.
CEO Jesse Shefferman said in a statement that the company is “thrilled” by these results, adding that initial 12-month data from the trial should come in by mid-2025.
Also on Thursday, CG Oncology released Phase III data for its oncolytic immunotherapy cretostimogene grenadenorepvec, an investigational treatment designed to replicate preferentially in cells in which the retinoblastoma gene pathway is defective, thus breaking cancer cells from the inside. The remains of the lysed cells then attract immune mediators, triggering an antitumor immune response.
Results from the late-stage BOND-003 trial showed that cretostimogene grenadenorepvec achieved a CR rate of 74.5% in BCG-unresponsive patients. Median duration of response had not yet been reached at the time of readout, but exceeded 27 months as of September 30.
Like TARA-002, cretostimogene grenadenorepvec was also well-tolerated. BOND-003 did not detect any treatment-related adverse events grade 3 and above, nor were there any discontinuations due to side effects.
CG Oncology president and COO Ambaw Bellete in a statement said that the readout “underscores our novel investigational oncolytic immunotherapy’s unique product profile,” particularly its dual mechanism of action, which Belette says “differentiates it from current and investigational [non-muscle invasive bladder cancer] treatments.”
BOND-003’s data also indicate that cretostimogene grenadenorepvec is “well positioned to address an unmet need for patients as a potential backbone bladder-sparing therapeutic if approved by the FDA,” Belette added.
