Dr Karl Kilgore: Updated Data Suggest CAR T Costs, Adverse Events Are Decreasing

December 8, 2020

As more data have become available, we are seeing more and more patients receiving chimeric antigen receptor (CAR) T-cell therapy in the community setting, noted Karl Kilgore, PhD, senior research scientist at Avalere Health.

As more data have become available, we are seeing more and more patients receiving chimeric antigen receptor (CAR) T-cell therapy in the community setting, and we know these outpatient costs are significantly lower vs receiving the treatment as an inpatient, noted Karl Kilgore, PhD, senior research scientist at Avalere Health.


How do data presented last year at ASH compare with updated data you presented this year, which includes Medicare Part D?

Either in terms of the utilization or the costs, you may recall from the last time we spoke, our CAR T sample that we used a year ago at ASH [American Society of Hematology annual meeting] was literally the first year of real-world CAR T experience. And we used the Medicare fee-for-service database the same as we used the claims database, same as we used for this study here.

More data [are] becoming available rapidly, both in terms of the frequency of CAR T occurring and it appearing in our data assets that we have. This study, however, because of the design, we decided it was best to stay with our initial CAR T sample.

So the CAR T sample is still that original sample of a little over 200 patients that represent the initial CAR T experience. Then we took our other samples for the same time period to make them comparable in terms of the timing. So at this time, I don't have any data that I can share with you, unfortunately, on changes over time. I have heard, and we are talking to our CAR T clients, about those very questions.

The number of CAR T events that we are seeing in our data is doubling about every 6 months. And if we were to do this study again now with fresh data, we would probably have 1000 patients that we could use and be able to trend that over time. One of the limitations of the earlier study was we didn't have any [Medicare] Part D data, prescription drug data, at all. Now we do, all the way up through 2019. And so while I unfortunately don't have any trend data on cost for utilization to share with you today, it's definitely a focus on the Avalere side. We are designing studies, talking to our clients just to try to address those very questions, because our clients and we are hearing exactly the same thing.

Costs are going down, adverse events are going down. We're having those same discussions, and I can't wait to get my hands on some data that I can share with the community that quantify what people are observing, kind of idiosyncratically.

Can we anticipate costs for CAR T in the community practice setting once it becomes more widely available?

We can, I think, for a couple reasons. One, for what you just said. In our initial CAR T study, we had 11 patients of the 200 that received CAR T in the outpatient setting. This study uses the same sample, and so we don't have any more data to share. But we do know, from looking at our data, that if we were to redo the study now, we have several hundred patients in our database who have received CAR T in the outpatient setting.

And we know from our own cost data that the costs associated with CAR T, and it's true for stem cells, for transplants as well, a lot of the costs that occur in the inpatient setting for the procedure itself, they go beyond the cost of the drug itself. And so if we hold that kind of constant, we know that just from studies more broadly, that outpatient costs are significantly lower than a stay in the hospital.

One of the things we do want to look at is, of course, the rates of adverse events and side effects and complications of the therapy. And so from talking to my colleagues who are practitioners, even when the procedure is done in the outpatient setting, they might want the patients to stay close to the hospital for the first week or so while we can monitor them for the signs of cytokine release syndrome, for example, or for the neurological side effects. But we can anticipate a reduction in costs from the outpatient setting.

That reminded me of one thing. I want to go back to your prior question about seeing costs go down. There is one piece of data that we do have in this study, and that is a variation in costs. For the procedure itself, the costs of a CAR T procedure, of a CAR T stay, are greater than the cost of an auto [autologous] or allo-HCT [allogeneic hematopoietic stem cell transplant] stay. We know that.

Another thing our data shows—I'm speaking to you as a data person now—is that the variance in costs of the stay [are] much higher in CAR T than in auto-HCT. And we know—while technically, of course, a mean cost and a standard deviation, while they're technically uncorrelated with each other—from practical experience, and all outcomes research and health economists know, that as time goes on, we would very much expect that high variation in costs associated with CAR T to decrease and that will lead to a practical decrease in the overall population-level costs of treating people with CAR T. Because we get the variation under control.

And think of ICU [intensive care unit] stays, per se. We know from this study, for example, that ICU stays are slightly more likely in the CAR T patient than in the stem cell transplant patient—although the length of stay in the ICU tends to be longer for the transplant than for the CAR T patient. We know from our discussions with clinicians and from their own experience that they're seeing, as time goes on, that patients are much less likely to go to the ICU now during their stay, because the clinicians have become more used to seeing what the impact of CAR T is on the patient and knowing a little bit better not to be so quick to pull the trigger and transfer the patient to the ICU.

We'll definitely have data on that, as well, as we move forward. That's a key contributor to the cost of that stay over and above the cost of the drug itself. And our anecdotal evidence suggests that ICU stays are going down as well. And I do find it interesting that our data in this study do support that, in that ICU stays for the CAR T patients, while slightly higher in prevalence during the inpatient stay, they stayed in the ICU for a shorter period of time than for both auto- and allo- stem cell transplant patients.