Journal of Clinical Pathways spoke with Houston Holmes, MD, MBA, FACP, Texas Oncology, about the utility and accessibility of chimeric antigen receptor (CAR) T-cell therapies for patients with hematologic malignancies in the community setting. Dr Holmes also explained the toxicities associated with these therapies and how the next generation of products aim to decrease such toxicities.
In your presentation at the Community Oncology Alliance (COA) annual meeting, you mentioned that CAR-T therapy is relatively rare in the community setting. What are the largest barriers to CAR-T administration in your practice?
Dr Holmes: There are several barriers to consider. The first is that CAR-T therapy is new and by definition limited to certain sites by the manufacturers or the clinical trial sites. Because it is still a new therapy, it has not been widely disseminated in the community setting.
In addition, at least with anti-CD19 CAR-T cells, the toxicity can be substantial. Therefore, treatment centers that have infrastructure and experience to manage the toxicities are most capable of offering the therapy.
Yet another hurdle is the reimbursement issue, which is an ongoing moving target that has some centers wary of moving ahead with the therapy. My belief is that these practices are hesitant because CAR-T is considered new technology and most patients are being treated with CAR-T therapies in clinical trials rather than in a real-world setting. It is mostly academic centers that are running the trials.
When do you believe CAR-T products will become more commonplace in the community setting?
Dr Holmes: They will likely become more commonplace sooner rather than later. As of right now, most oncologists believe that the next wave of CAR-T products will be much more manageable and have significantly less toxicity. Additionally, the new CAR-T products will likely be accompanied with more manageable side effects because incidence and severity of cytokine release syndrome (CRS) has been less frequent with some of the products in development now compared with what we have seen in the past. If that experience and data remains true, I believe widespread availability of these products could progress even faster than expected. It is difficult to offer a specific prediction on the timeline, but it is amazing how quickly the process is moving along.
Do clinical trial eligibility standards have an impact on the rate of CAR-T Food and Drug Administration approvals? What other factors are at play?
Dr Holmes: I believe that the number one influential factor is safety. The FDA usually looks at safety first, followed by efficacy. For a number of malignancies there are documented impressive responses from CAR-T therapy. As I have mentioned, the safety of these products appears to be improving. The generation of products in development and under study now have demonstrated less toxicity, at least in the early reported data.
Patients with experience and better management of toxicities with the newer products appear as if they will have less side effects and be easier to manage. Some trials are being done currently with the primary intention of treating patients as outpatients. These trials look promising.
What are the current standards for treating CAR-T-related toxicities?
Dr Holmes: For the anti-CD19 products which are commercially available, the standard of care is mostly supportive care for CRS with cardiovascular and respiratory support as needed, as well as monitoring for infections or other complicating factors.
In some cases corticosteroids are used and in other an anti-seizure prophylaxis. But in most cases, it is mostly supportive care that is being used as well as monitoring for any other underlying complicating factors (ie, infection). But as far as specific guidelines, the recommendations call for tocilizumab and/or steroids.
Do you believe there is a need for more advanced options to treat these toxicities or do you believe it is more likely that the focus will be on the newer products which require significantly less toxicity management?
Dr Holmes: I believe there is a need for both. CRS or neurologic toxicity, even when severe, tends to be reversible for the majority of patients and often disappears completely over time. We always like to see improvement, even for the patients that are being actively treated for these severe side effects. It would be even better if some of the newer products were associated with less side effects to begin with.
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