Treatment with TARA-002 at 3 different dose levels was generally well-tolerated, and no dose limiting toxicities were observed among patients with high-grade non-muscle invasive bladder cancer.
TARA-002, a novel intravesical monotherapy, was generally well-tolerated and showed antitumor activity in patients with high-grade non-muscle invasive bladder cancer (NMIBC), according to positive preliminary data from the phase 1a dose-escalation portion of the ongoing ADVANCED-1 trial.1
Findings showed that anti-tumor activity was seen in all 3 of the evaluable patients with carcinoma in situ (CIS), including 1 heavily pre-treated Bacillus Calmette-Guérin (BCG)-unresponsive patient who achieved a complete response.
At all 3 dose levels of TARA-002 assessed in the study, the treatment was generally well tolerated, and no dose limiting toxicities were observed. However, a maximum tolerated dose was not determined. The dose-escalation portion of the trial remains ongoing in exploratory cohorts.
“These promising results suggest TARA-002 may provide meaningful benefit to patients with NMIBC, who currently have limited treatment options,” said Neal Shore, MD, medical director, Carolina Urologic Research Center, chief medical officer, GenesisCare US, and study investigator, in the press release. “These data show favorable tolerability and initial evidence of anti-tumor activity, thus serving as an impetus to advance TARA-002 into larger, later-stage trials.”
The phase 1 dose-finding, open-label ADVANCED-1 trial is assessing TARA-002 in patients with treatment-naïve and treatment-experienced NMIBC with CIS and high-grade papillary tumors (Ta).
The initial dose-escalation phase of the trial administered patients 6 weekly intravesical doses of TARA-002 up to 3 doses of 10KE, 20KE and 40KE.2
Patients aged 18 years and older with a histologically confirmed, high-grade Ta or CIS urothelial cell carcinoma of the bladder on central review who were treatment naïve, unable to obtain intravesical BCG for the treatment of NMIBC, and have received at least 1 dose of intravesical BCG, or at least 1 dose of intravesical chemotherapy were eligible to be included in the study.
The primary end point of the study was to evaluate the safety, tolerability, preliminary signs of anti-tumor activity of TARA-002, and incidence of dose-limiting toxicities. Investigators also aimed to establish a recommended dose for a future phase 2 clinical trial of the agent.
There were 9 patients enrolled in the study, including 3 patients with CIS who reached the 3-month efficacy assessment. Among those 3 patients with CIS, 1 patient who was heavily pre-treated and BCG-unresponsive reached a complete response at the 20KE dose. The other 2 patients had tumor regression.1
Additional findings from the study showed that most of the adverse events (AEs) reported were deemed grades 1 and 2 across all dose levels. Treatment-related AEs were also in line with typical responses to bacterial immunopotentiation. These AEs included fatigue, headache, fever, and chills.
Urinary urgency, urinary frequency, urinary tract pain/burning, incomplete emptying, and bladder spasm were the most common urinary symptoms, and most bladder irritations were resolved soon after administration or in a few hours to a few days.
“We are highly encouraged by preliminary results from the dose-escalation component of ADVANCED-1 and look forward to deepening our understanding of TARA-002’s potential in the ongoing expansion trial, which is currently enrolling NMIBC patients with carcinoma in situ,” said Jathin Bandari, MD, chief medical officer of Protara Therapeutics, in the press release. “We plan to initiate larger clinical trials in NMIBC patients with CIS who are Bacillus Calmette-Guérin-naïve and BCG-unresponsive in the second half of this year.”