A Biologics License Application has been submitted to the Food and Drug Administration (FDA) for obe-cel (obecabtagene autoleucel), a CAR-T cell therapy for patients with relapsed/refractory (r/r) adult B-cell acute lymphoblastic leukemia (ALL), according to a news release from biopharmaceutical company Autolus Therapeutics, the manufacturers of obe-cel.
Obe-cel previously received Orphan Drug Designation and Regenerative Medicine Advanced Therapy designation by the FDA for the treatment of adult r/r B-ALL, according to the news release.
“We are looking forward to continuing working with the FDA through the regulatory approval process,” Dr. Christian Itin, chief executive officer of Autolus, said in the news release. “I would like to thank the treating physicians, patients, caregivers and the dedicated team at Autolus for their support, trust and commitment for the program to reach this important milestone.”
The submission was based on findings from the FELIX study which, according to its listing on clinicaltrials.gov, enlisted 153 adult patients with r/r B-ALL, launched in 2020 and is estimated to be completed in 2025.
Findings from the FELIX study were previously published in the Journal of Clinical Oncology and were presented at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting, and updated data are expected to be presented during the upcoming American Society for Hematology (ASH) Meeting.
More than three-fourths (76%) of patients experienced an objective response (meaning their disease shrank or became untraceable), with 54.3% of patients displaying a complete response (the disappearance of their disease) and 21.3% experiencing a complete response with incomplete blood count recovery, while 97% of patients who responded and had evaluable samples were minimal residual disease (MRD)-negative, meaning traces of their cancer were undetectable after treatment, according to study findings presented at ASCO.
“We are dealing with a very difficult patient population here. They are heavily pretreated, they’re older, they’re comorbid, they have got a lot of extra disease on board; there was a lot of extramedullary disease,” lead study author Dr. Claire Roddie, associate professor in haemato-oncology in the research department of haematology of University College London Cancer Institute, said in an oral presentation of the data at ASCO. “But despite all of these odds being stacked against the product, obe-cel was able to achieve (complete response) or (complete response with incomplete count recovery) in 76% of those infused patients, and what’s more is those responses were deep, MRD-negative responses.”
Obe-cel, according to the news release, is “designed to overcome the limitations in clinical activity and safety compared to current CD19 (a protein found on some blood cancer cells) CAR-T cell therapies. Obe-cel is designed with a fast target binding off-rate to minimize excessive activation of the programmed T cells. Clinical trials of obe-cel have demonstrated that this ‘fast off-rate’ profile reduces toxicity and T cell exhaustion, resulting in improved persistence and leading to high levels of durable remissions in r/r Adult ALL patients.”
Writing in the Journal of Clinical Oncology, researchers noted that obe-cel for adult r/r B-ALL was safe, with low rates of cytokine release syndrome (CRS; a systemic inflammatory response) higher than grade 3 and/or immune effector cell-associated neurotoxicity syndrome (ICANS; a neurotoxicity associated with CAR-T cell therapy), even among patients with high-burden disease.
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