New (Expanded) CAR-T Trial

Early results from a new trial for a CAR-T treatment look very promising. It's not actually a new trial, but an expanded one. Still, the results are promising and worth keeping a close eye on.

The treatment is called MB-106, and is manufactured by a company called Mustang Bio. The company has already been conducting a phase 1/2 clinical trial at a single location, Fred Hutch Cancer Center. I wrote about this in May, when they reported results at the European Hematology Association meeting. 

This CAR-T treatment is different from those already available. It targets CD20, the same protein that is found on B Lymphocytes that is the target for many other B Cell Lymphoma treatments (like Rituxan). That is important because it means that patients who tried other CAR-T treatments, which target CD19, may be able to use this one as a next-line treatment. (That's one of the things the clinical trial is testing.)

The early trial of just 12 patients at Fred Hutch found that 11 patients had a response. There were 9 patients with Follicular Lymphoma, and 6 of them had a Complete Response. Side effects were great --  none of the patients had serious Cytokine Release Syndrome, and none had ICAN (a type of nerve damage that is common in CAR-T treatments). Four patients have had a Complete Response that lasted for more than 24 months, with the CR lasting 33 months (and still going, as far as I can tell).

The results were good enough to expand the trial. It is still a phase 1/2 trial, but now it will happen at 6 different cancer centers, and involve up to 287 patients. The patients will be put into 3 groups: one for patients with aggressive lymphoma (including transformed FL), one for patients with indolent or slow-growing lymphoma (including other types of FL), and one for patients with CLL. As a phase 1 trial, one of the goals is "dose escalation," or figuring out how much of the treatment to give a patient that will be most effective while creating the most manageable side effects. Once that is figured out, they will add more patients to each of the three groups.

The treatment is in the news this week because the company announced the early results from the first patient enrolled in the expanded trial. The patient did not experience cytokine release syndrome or ICANS, much like many of the patients from the earlier version of the trial.

It will be very interesting to see more results from this trial. Perhaps there will be more data presented in a couple of months at ASH, and definitely next spring at ASCO.

All of this is just more proof that CAR-T is going to be an important part of our treatment lives in the future. We're at the point where new CAR-Ts are not only going after different targets on cells, but are being developed so previous CAR-T patients can try a different version. That tells me that CAR-T is an established part of the treatment landscape for us.

Lots of questions still to be answered about CAR-T. Can someone develop an allogeneic or "off the shelf" version that will be as safe and effective, but won't require a specific treatment made for each individual patient? In the meantime, are there other ways to keep costs down? Can new developments figure out how to make CAR-T effective for that 20-30% that don't get a response at all? 

Stay tuned. I;m sure there be lots more CAR-T research to report in a couple of months as ASH approaches.