TCR2 Therapeutics has reported updated data from a phase 1 clinical trial of gavo-cel, linking the T-cell therapy to a 22% response rate in solid tumor patients who received the treatment after chemotherapy depletion.
As of the data cutoff, 32 solid tumor patients had received a single infusion of the autologous cell therapy. The therapy consists of T cells that express an anti-mesothelin fused to the CD3-epsilon subunit of the T-cell receptor. Because mesothelin is overexpressed by multiple cancers, TCR2 and other biotechs including Adaptimmune have identified it as a way to go after solid tumors.
TCR2 saw six partial responses among the 30 evaluable recipients of gavo-cel. One year ago, the biotech reported four responses in 16 patients. On average, participants had received five prior lines of therapy. After removing patients who didn’t receive lymphodepletion from the analysis, the biotech calculated the response rate to be 22%.
Four mesothelioma patients and two ovarian cancer patients responded in line with the criteria used. Breaking the data down by indication, TCR2 reported response rates in mesothelioma and ovarian cancer of, respectively, 21% and 29%. The overall and progression-free survival in mesothelioma were 11.2 months and 5.6 months.
The data drop delivered a boost to TCR2’s share price, bumping it up 7% to $1.80 in premarket trading. However, the biotech is still a long way from recovering from the slump it entered into after the release of an earlier slice of data from the trial around one year ago. The stock closed at $18 on Sept. 10, 2021, but fell thereafter, first precipitously and then steadily.
TCR2 has retained its confidence in gavo-cel as investor enthusiasm has waned. In conjunction with the phase 1 data drop, the biotech named gavo-cel alongside TC-510 and TC-520 as one of three assets it will focus on in the near term.
The phase 2 portion of the gavo-cel trial is already underway. TCR2 is studying its cell therapy with Bristol Myers Squibb checkpoint inhibitors Opdivo and Yervoy. The biotech is looking to the combination, plus the ability to give multiple doses of gavo-cel, to potentially increase the response rate and durability.
TCR2 had $206.2 million in the bank at the last count, giving it the cash to keep going into 2024.