Trial for a New CAR-T Has Been Paused

The phase 1 clinical trial for a new CAR-T treatment has been paused (not cancelled) while the FDA tries to figure out why one patient is having some problems.

Quick review -- CAR-T involves removing a patient's T cells (a type of immune cell), changing them in a laboratory so they can recognize cancer cells as something to be eliminated, and then putting them back into the patient. Ideally, they do their job of killing off the cancer cells, and the stay in the body (like any other T cell) until they recognize any return of the cancer cells, and take care of them.

This clinical trial involves a different kind of CAR-T, an "off the shelf" version called ALLO-501A. In other words, instead of using the patient's own T cells, ALLO-501A uses the same T cells for every patient. If it works, it should be much easier and less expensive -- there is no lab involved in the process of removing and changing the T cells.

The trial is small (which is usually the case for phase 1 trials), and involves patients with Diffuse Large B Cell Lymphoma and transformed Follicular Lymphoma. (These were the same patient populations that were in trials that led to the first round of CAR-T treatments for lymphoma patients.)

One of the patients in the trial has bone marrow biopsy after the treatment to look into low blood counts, and the cells were found to have a chromosomal abnormality. Chromosomal changes in cells can lead to a whole bunch of issues, including other cancers. The researchers are pausing to do some investigating, to figure out if the CAR-T treatment caused the abnormality, and if the abnormality might lead to more problems for the patient (and for future patients).

As the article linked above points out, the patient had a partial response to the CAR-T treatment, and after finding the issue from the bone marrow biopsy, was given an allo stem cell transplant, something that happens with certain patients after other CAR-T treatments, too. 

Aside from the issue with this patient, the data fro the trial has been positive, and seemed like the effectiveness was good enough to justify a larger phase 2 trial. However, trials are about both effectiveness and safety, and the pause makes that clear. One patient's safety is important.

"Off the shelf" CAR-T will be a huge benefit to lymphoma patients, if they are shown to be as safe and effective as other treatments. I hope the patient with the issue is doing OK, and I hope researchers can determine that the treatment is safe enough to continue.

The company that makes the treatment is holding a press conference later today (Oct 8). If anything important comes out of it (more than just repeating what we know already), I'll update.