Protara touts positive mid-stage findings for cell therapy in bladder cancer

Protara Therapeutics announced positive results from its ongoing phase 2 assessing its investigational cell-based therapy, intravesical TARA-002, in high-risk non-muscle invasive bladder cancer (NMIBC).

The open-label ADVANCED-2 trial is evaluating TARA-002 in NMIBC patients with carcinoma in situ or CIS who are Bacillus Calmette-Guérin (BCG)-unresponsive or BCG-naïve. BCG is currently the standard of care treatment for bladder cancer.

TARA-002 elicited a 72% complete response rate across BCG exposures at six months and 70% at any time with 100% (9/9) of patients maintaining a complete response from three months to six months. In addition, two of three patients maintained a complete response at nine months.

According to Protara, when TARA-002 is administered, it is hypothesized that innate and adaptive immune cells within the cyst or tumor are activated and produce a pro-inflammatory response with release of cytokines such as tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, IL-1b, IL-6, IL-12, granulocyte-macrophage colony-stimulating factor (GM-CSF) and natural killer cells. TARA-002 also directly kills tumor cells and triggers a host immune response by inducing immunogenic cell death, which further enhances the antitumor immune response.

The treatment, which has been granted Rare Pediatric Disease designation by the U.S. FDA, was developed from the same master cell bank of genetically distinct group A Streptococcus pyogenes as OK-432, a broad immunopotentiator marketed by Chugai Pharmaceutical as Picibanil. Protara has successfully shown manufacturing comparability between TARA-002 and OK-432.

The latest trial results were featured yesterday during a poster session at the 25th Annual Meeting of the Society of Urologic Oncology in Dallas, Texas. Protara plans to report initial data from 12-month evaluable patients in mid-2025.