Today, the allogeneic CAR-T company Allogene Therapeutics (NSDQ:ALLO) saw its stock dip to the lowest level since its IPO in 2018.
The company announced that FDA had placed a hold on its AlloCAR T clinical trials after the identification of a chromosomal abnormality in a patient enrolled in its ALPHA2 study (NCT04416984). That trial was a Phase 1/2 study involving 30 patients with relapsed/refractory large B-Cell lymphoma. The study related to the allogeneic CAR-T cell therapy ALPHA2 (ALL0-501A).
“The data generated from our past trials supports a favorable clinical profile for ALL0-501A in patients with large B-cell lymphoma, which underlies our mission to provide allergenic CAR-T therapies, faster and more reliably to patients suffering from some of the most difficult to treat cancers,” said David Chang, president and CEO of Allogene Therapeutics in an investor briefing.
The company stated that its lots of CAR-T cells undergo extensive testing, including assessment for chromosomal abnormalities, before release. “Certainly, all the lots that were used in the clinical trial passed the release test,” Chang said. “We are investigating every possibility that could have contributed to the observed finding in this single patient.”
Allogene noted that the chromosomal abnormality was of unclear clinical significance.
“This is still very early,” said Dr. Rafael Amado, executive vice president of R&D and chief medical officer in an investor briefing. “We are trying to understand, first of all, whether this is a clinically relevant finding.”
The company intends to “better characterize what exactly happened to the chromosome,” Amado said. “That may require some additional investigation. We are also looking to see when the changes may have occurred.”
Amado stressed that the issue related to a single patient “out of more than 100 patients that we have tried.” “Most patients do recover and CAR-T cells disappear from the patient’s body, so there are many unknown questions, and we are working diligently to answer these questions.”