Allogene Therapeutics announced Monday that the FDA has lifted a clinical hold on all five of its AlloCAR T studies, clearing the way for resumption of trials involving the company's off-the-shelf CAR-T cell therapies for blood cancers. The regulatory action follows a comprehensive three-month safety investigation that determined a chromosomal abnormality observed in a single patient was unrelated to the company's manufacturing process.
Clinical Hold Background and Investigation
The FDA initially imposed the clinical hold on October 7, 2021, after detecting a chromosomal abnormality in a patient treated with ALLO-501A in the ALPHA2 study. The hold affected all five of Allogene's ongoing AlloCAR T clinical trials, representing a significant setback for the company's allogeneic CAR-T platform.
The ALPHA2 study is evaluating ALLO-501A, an allogeneic CD19-targeting CAR T-cell product, in combination with ALLO-647 and lymphodepleting chemotherapy for patients with relapsed or refractory large B-cell lymphoma (LBCL) who have not previously received autologous CAR T-cell therapy.
During the investigation period, Allogene conducted extensive analyses to determine the root cause of the chromosomal abnormality. The company's findings revealed that the abnormality was not connected to its manufacturing processes and posed no clinical significance to the affected patient.
Regulatory Clearance and Trial Resumption
The FDA's decision to remove the clinical hold validates Allogene's safety investigation conclusions. This regulatory clearance allows the company to resume enrollment and dosing across its AlloCAR T platform, which represents a critical milestone for the development of off-the-shelf CAR-T therapies.
The company plans to initiate its pivotal phase II trial of ALLO-501A in relapsed/refractory large B-cell lymphoma in mid-2022. This trial will be crucial for advancing the therapy toward potential regulatory approval and establishing the clinical utility of allogeneic CAR-T approaches in hematologic malignancies.
Market Impact and Clinical Significance
The clinical hold removal had an immediate positive impact on Allogene's stock performance, with shares rising over 4% to $12.80 in premarket trading. The stock had previously traded in a range of $11.54 to $39.12 over the past year, closing Monday's regular session at $12.20, down 9.36%.
The resumption of Allogene's clinical trials represents a significant development in the allogeneic CAR-T field, where off-the-shelf therapies could potentially address manufacturing and accessibility challenges associated with autologous CAR-T treatments. Large B-cell lymphoma affects thousands of patients annually, with many experiencing relapsed or refractory disease despite available therapies.
Allogene is scheduled to present at the 40th Annual J.P. Morgan Healthcare Conference, providing an opportunity to discuss the clinical hold resolution and future development plans for its AlloCAR T platform.
