Phase 1 Trial Begins Dosing of TARA-002 Cell Therapy for NMIBC

A clinical trial investigating the safety and toxicity of TARA-002, a cell therapy agent, for non-muscular invasive bladder cancer (NMIBC), has started dosing, according to a press release from Protara Therapeutics.¹

The new immunopotentiator agent phase 1 ADVANCED-1 trial (NCT05085977) is now investigating a single-arm, open-label, dose-finding trial of TARA-002 for treatment-naive and previously treated patients with NMIBC with high-grade carcinoma in situ (CIS) and high-grade papillary tumors.

“NMIBC is one of the most recurrent and difficult to treat cancers with very limited treatment options,” Jesse Shefferman, chief executive officer of Protara Therapeutics, said in a statement. “We are thrilled to have dosed the first patient in our phase 1 study in NMIBC and look forward to exploring TARA-002’s full potential in this pressing area of high unmet need.”

TARA-002 is an immunopotentiator cell therapy based on group A Streptococcus pyogenes that cause immune cells to produce a local inflammatory cytokine reaction that destroys abnormal cells in a cyst or tumor. It was developed from the same genetic cell bank as OK-432 (Picibanil), a broad immunopotentiator that is approved in Japan and Taiwan.

The phase 1a of the ADVANCED-1 trial is enrolling an estimated 18 patients with NMIBC to receive 6 weekly intravesical doses of TARA-002. Patients are eligible if they are unable to receive intravesical Bacillus Calmette-Guérin (BCG), have received at least 1 dose of BCG, or have received at least 1 dose of intravesical chemotherapy.

Patients will receive up to 3 dose levels: 10 KE, 20 KE, and 40 KE, which will be tested sequentially starting with the lowest dose. The goal of the study is to determine the agent’s safety and tolerability as well as observe for preliminary signs of antitumor activity. The primary end points for the dose escalation phase are dose-limiting toxicities, maximum tolerated dose, and recommended phase 2 dose (RP2D).

The phase 1b dose expansion part of the trial (NCT05085990) is planned to enroll patients with CIS NMIBC in 2023 to receive 6 weekly doses of the RP2D. Its primary end point is the incidence of adverse events in these patients.

In 2021, TARA-002 was granted a rare prediatric disease designation by the FDA for lymphatic malformations, a rare condition affecting young children.² Protara stated its intention to begin a clinical trial of TARA-002 in a clinical trial in this setting. While OK-432 is the standard-of-care agent to treat lymphatic malformations in Japan and Taiwan, there is no FDA-approved agent for this disease.

“While bladder cancer is the 6th most common cancer in the United States today, with NMIBC representing approximately 80% of diagnoses, treatment options for these patients remain limited,” Edward M. Messing, MD, a principal investigator of the ADVANCED-1 study and a professor of urology, oncology, and pathology at the University of Rochester said in a statement.¹ “There is an urgent need for new therapeutic interventions for these patients, as there continues to be an increase in recurrence, progression and an escalated number of patients needing cystectomies.”

_References:

_{1. Protara Therapeutics doses first patient in ADVANCED-1 phase 1 study of TARA-002 in non-muscle invasive bladder cancer. Protara Therapeutics. March 24, 2022. Accessed April 1, 2022. https://bit.ly/376E9TY}

_{2. Protara Therapeutics provides regulatory update for TARA-002 for the treatment of lymphatic malformations. Protara Therapeutics. April 23, 2021. Accessed April 1, 2022. https://bit.ly/37cE5lG}