Jounce Therapeutics can’t seem to find its clinical bounce, announcing that another phase 2 trial has missed the mark, prompting the company to reevaluate one of its lead programs.
The company said that a combo therapy of its top two assets, vopratelimab and pimivalimab, did not significantly reduce tumor size in a subset of non-small cell lung cancer patients compared to pimivalimab alone. The Tuesday news was the latest stinger to Jounce’s already-reeling pipeline following phase 2 failure back in 2020, prompting CEO Richard Murray, Ph.D., to say the company won’t be pursuing a future registrational trial and will instead be reevaluating vopratelimab.
“We will re-evaluate the vopra program in the context of our broader pipeline in the coming months,” he said in a release.
Vopratelimab—vopra for short—is a monoclonal antibody targeting a specific protein on the outside of T cells the researchers hope can further stimulate the immune system to attack cancer cells. Pimivalimab—or pimi—is PD-1 inhibiting monoclonal antibody that the company has specifically designed to use in combination with other drugs. The only other phase 2-stage asset that Jounce is developing is macrophage-focused JTX-8064.
The trial recruited 75 patients and tested two different dose levels of vopra in combination with pimi, assessing the average percent change in tumor size between the two groups. The goal was for the combo therapy to spur 20% smaller tumors than the monotherapy, but it ultimately only spurred a 7% difference.
It was the second failure in almost two years, coming after an interim analysis of vopratelimab in combination with Bristol Myers Squibb’s aging checkpoint inhibitor Yervoy was shown to not be good enough to continue enrollment. Ironically, that November 2020 update was coupled with the company announcing that it had begun dosing in the SELECT trial that just failed.
Although the vopra program appears on the chopping block, Murray says in the release that the company remains “pleased with pimi’s activity,” which supports continuing to use it in combo trials. As for JTX-8064, which arguably is now the company’s most promising asset, Jounce plans to present interim clinical data at an oncology conference in December.
Jounce’s shares fell more than 15% Tuesday in light of the news, down from $4.29 to $3.61. Nonetheless, the company still has more than $160 million on hand according to its second-quarter earnings report. But its spend rate is high, burning through nearly $60 million in cash in the first six months of 2022.