HEMO-CAR-T IND Gets Clinical Hold for Manufacturing Issue

The FDA has placed Hemogenyx’s HEMO-CAR-T investigational new drug application (IND) for treating acute myeloid leukemia (AML) on clinical hold and has provided more details about the hold in a full review letter.¹

In the letter, the FDA shared the reasoning behind the hold, which relates to a splicing that occurs during the manufacturing process of the lentivirus vector. Hemogenyx stated that it has identified the source of the splicing issue, has developed a method to eliminate it, and is remanufacturing the lentivirus. The FDA's letter also includes several suggestions on how to improve the safety of HEMO-CAR-T that are not related to the hold but Hemogenyx plans to deal with promptly.

"We are confident that we will be able to address the FDA's questions and concerns regarding the IND. AML has poor survival rates and we are eager to resolve this hold and continue down the treatment development pathway toward saving lives,” Vladislav Sandler, PhD, cofounder and chief executive officer, Hemogenyx Pharmaceuticals, and Research Assistant Professor, State University of New York Downstate, said in a statement.¹

Hemogenyx submitted the IND for HEMO-CAR-T in May 2023 and was first notified of the clinical hold in June.² HEMO-CAR-T is an autologous chimeric antigen receptor (CAR) T-cell therapy.

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“We are pleased to have reached this milestone with HEMO-CAR-T. We are committed to advancing therapies for blood diseases, and our work to address AML, which currently has poor survival rates, is an essential part of that commitment,” Sandler said in a statement at that time.²

Hemogenyx is also developing another cell therapy, Hu-PHEC, made from postnatal human hemogenic endothelial cells, which the company states require less manipulation before use compared to other types of celltherapy. Hu-PHEC is being investigated in preclinical studies for bone marrow or hematopoietic stem cell transplant (HSCT). The company is also developing a bispecific antibody indicated for patient conditioning for bone marrow or HSCT and/or patients with relapsed/refractory AML.

HEMO-CAR-T joins another CAR T-cell therapy for AML, 2seventy bio’s SC-DARIC33, to be put on clinical hold in June. Seattle Children’s announced that it was pausing the phase 1 PLAT-08 clinical trial (NCT05105152) evaluating the CD33-directed CAR T-cell therapy following the death of the first patient treated at the study’s second dose level (5x10⁶ SC-DARIC33 T-cells/kg).³ Investigators are looking into the grade 5 serious adverse event that led to the death.

“Importantly, I’d like to offer that our thoughts are with the family during this time,” Steve Bernstein, MD, chief medical officer, 2seventy bio, said in a statement at that time.³ “The safety of every patient who participates in our studies or is treated with our therapies is the utmost priority for us, and we are in communication with FDA while we assess the data surrounding this SAE, and the potential next steps for the study."

REFERENCES
1. Hemogenyx Pharmaceuticals PLC Announces Full FDA Review for HEMO-CAR-T IND. News release. Hemogenyx Pharmaceuticals. July 10, 2023. https://www.biospace.com/article/releases/hemogenyx-pharmaceuticals-plc-announces-full-fda-review-for-hemo-car-t-ind/
2. Submission of IND for HEMO-CAR-T. News release. Hemogenyx Pharmaceuticals. May 9, 2023. https://hemogenyx.com/wp-content/uploads/2023/05/20230509-Submission-of-IND-for-HEMO-CAR-T.pdf
3. 2seventy bio announces clinical study pause of PLAT-08 trial of SC-DARIC33 in acute myeloid leukemia. News release. 2seventy bio, Inc. June 14, 2023. Accessed June 14, 2023. https://ir.2seventybio.com/news-releases/news-release-details/2seventy-bio-announces-clinical-study-pause-plat-08-trial-sc