FDA eases hold as Marker Therapeutics T-cell manufacturing issues addressed 

Marker Therapeutics technology is designed to selectively expand a patent’s own T cells, which the biotech expects will make manufacturing less expensive. (Marker Therapeutics)

Marker Therapeutics says it has overcome an issue in its MultiTAA-specific T cell manufacturing process that led the FDA to stymie its trial in patients with acute myeloid leukemia (AML) who have had stem cell transplant. With new reagent suppliers on board it says the FDA has now lifted the hold. 

There is still a partial hold until the Houston, Texas-based biotech can get FDA all of the additional data and technical specifications about the manufacturing process, which the company expects to complete in the second half of 2020. Marker has what it needs on one reagent but is awaiting info on a second. 

“With a clear path identified for getting our study of MultiTAA-specific T cell therapy underway in patients with AML, we’re focused on addressing the remaining requirements from the FDA and enrolling up to 20 clinical centers to conduct our Phase 2 trial,” CEO Peter L. Hoang said in a statement. 

Marker’s technology is designed to selectively expand a patient’s own T cells. It contends that because it does not genetically engineer its T cell therapies, the candidates will be easier and less expensive to manufacture, 

The process was halted in November, however, when the FDA asked for information and specifications for two legacy reagents that were used in the MultiTAA-specific T cell manufacturing process. Since the initial suppliers were unable to produce the info, Marker went on the hunt for alternatives. 

RELATED: TapImmune to merge with Baylor adoptive T-cell startup Marker

The partial hold allows Marker to move ahead with the safety lead-in portion of the trial with an amended trial design. Marker says it expects to enroll about six patients, dosing three patients with T cells manufactured using the legacy reagent, and three patients with T cells manufactured using the reagent from the alternative supplier.

After the safety lead-in, Marker says it will do a 160-patient randomized portion of the study through about 20 transplant centers. One group will include 120 disease-free patients, with a primary endpoint of relapse-free survival of patients receiving the T cell therapy compared to a control group. The second group will include the remaining 40 active disease patients in a single arm. The primary endpoints for that portion is for patients to achieve complete remission and then maintain it. 

T-cell drugs offer the hope of cures for patients with certain conditions but the FDA has set a high bar for their manufacturing—which in some cases is proving tricky to achieve.

RELATED: Novartis' AveXis opens Zolgensma plant in Colorado with 350 employees

Novartis has had difficulty meeting the specifications for cell variability for its first gene therapy, CAR-T drug Kymriah, which the FDA set higher for the commercial release than the drugmaker achieved in trials. Novartis has been making manufacturing tweaks to address the issues but is also trying to convince the FDA to set the standards to those achieved during trials. 

During the recent ASH meeting, the Swiss company released data that showed the effectiveness of the drug was unaffected when there were viable cells of 60% to up to 80%. The FDA set the threshold at 80%.