Theratechnologies assembles science team to retool solid tumor trial after clinical hold

Theratechnologies has formed a science advisory committee to try and come up with ways to overcome an imbalance between adverse events and efficacy seen in early results from a phase 1 solid tumor trial of the Canadian biotech’s lead asset.

The trial was expected to enroll 70 participants with a range of solid tumors and cancers, but Theratechnologies pumped the brakes in December after getting a glimpse at initial data from the peptide-drug conjugate TH1902. “Efficacy results observed thus far were not convincing enough to pursue enrolling patients and did not outweigh the adverse events seen in some patients,” the company said at the time. The adverse events were mainly neuropathy and eye toxicity. The FDA later placed a partial clinical hold on the study. 

Now, Theratechnologies says they have formed the advisory committee and will consider ways to amend the protocol to overcome the issues, according to a Thursday press release. The goal will be to complete a timely re-submission to the FDA to get the trial back underway.

Theratechnologies has brought on three key experts in oncology drug development. They are: Erika Hamilton, M.D., director of breast cancer and gynecologic cancer research for the Sarah Cannon Research Institute at Tennessee Oncology; Daniel Petrylak, M.D., professor of medicine in medical oncology and urology and chief of genitourinary oncology at Yale School of Medicine; and Anthony Tolcher, M.D., medical oncologist at Texas Oncology-San Antonio Medical Center. The company will also engage its existing scientific advisor Mace Rothenberg, M.D.

“We are eager to resume patient enrollment with a revised protocol for TH1902 and have pulled together some of the best scientists in the field of oncology drug development to ensure an optimal amendment,” said Christian Marsolais, Ph.D., Theratechnologies’ Chief Medical Officer.

In an early January letter to shareholders, CEO Paul Lévesque said the FDA ultimately agreed with the decision to voluntarily pause the early-stage trial and later issued the partial clinical hold.

“We were disappointed to voluntarily pause enrollment in the phase 1 clinical trial of TH1902; however, we believe it was the right decision for patients, the company and our shareholders,” he wrote.

Theratechnologies is working to respond to questions received from the FDA. The experts will examine different dosing strategies and consider patient selection, Marsolais said. The advisory board will meet in March when they will consider the FDA response and provide analysis for the protocol amendment.

The FDA has promised to respond to the revised protocol amendment within 30 days once received, according to Lévesque's letter.

Meanwhile, Theratechnologies is taking a restrained approach to funding further investment in TH1902, with a stage-gated approach that will depend on the data generated. Once the phase 1 is back underway, the company plans to seek a partner for the therapy.

“While we refine our plans around TH1902, our priority will be to rein in costs associated with its development and deploy those resources towards the company’s path to positive cash flow from operations in 2023,” Lévesque wrote.

Theratechnologies has two approved medicines: Trogarzo for HIV-1 infection and Egrifta for the reduction of excess abdominal fat in people with HIV who have lipodystrophy. Lévesque told shareholders that he had tasked his business development team with finding commercialized assets to bring into the portfolio.

TH1902 was previously granted a fast-track designation by the FDA for all sortilin-positive recurrent advanced solid tumors that are refractory to standard therapy.