Potential Impact of CAR T-Cell Therapy on Specialty Pharmacy

Chimeric antigen receptor (CAR) T-cell therapy has generated a lot of buzz in the drug development world.

The results of early-stage clinical trials in certain hematologic malignancies, as well as the potential in solid tumor cancers, has captured the attention of those interested in pipeline therapeutics. Quotes from key opinion leaders about the great potential of these treatments can be found in numerous articles. Not surprisingly, biotech investors have noticed CAR T-cell immunotherapy, too.

Juno Therapeutics, one of leaders in CAR T-cell development, had an initial public offering (IPO) of $264.6 million in 2014, the largest biotech IPO that year. The company’s value later increased into the billions.¹

What Is CAR T-Cell Therapy?

CAR T-cell therapy is not so much a drug as it is a medical procedure. Creating it involves engineering cells to contain unique CAR receptors.

First, T-cells are extracted from a patient, genetically modified, replicated in the lab, and then infused back into the patient. The re-introduced CAR cells then multiply and spread within the patient’s body, seeking out cancer cells.

CARs enable T-cells to recognize cancer cells and attack them. Therefore, this approach uses the patient’s own newly trained immune system to attack cancerous cells.²

Also being explored is “off the shelf” CAR T-cell therapy, which doesn’t require T-cells used in its production to come from the same patient being treated.³

CAR T-Cell Clinical Trials

To date, clinical trials of CAR T-cell therapy have mainly involved patients with B-cell malignancies such as acute lymphoblastic leukemia (ALL), non-Hodgkin lymphoma, and chronic lymphocytic leukemia.⁴

One study evaluated the therapy in 30 relapsed/refractory ALL patients, some of whom had received blinatumomab (Blincyto) or a stem-cell transplant. Complete remission was reached in 90% of patients, and sustained remission with a 6-month event-free survival was achieved in 67% of patients.

Impressive results like these have led to a great deal of optimism for the future of CAR T-cell treatment. However, there are some concerns involving adverse drug events (ADE).

For instance, all patients in the study developed cytokine-release syndrome (CRS), with 27% of these cases classified as severe.⁵ CRS can lead to severe high fever and low blood pressure.² Etanercept (Enbrel) and tocilizumab (Actemra) were some of the treatment options used to help control CRS, which is thought to be manageable in most patients. However, there have been at least 2 patient deaths in CAR T-cell studies as a result of an ADE.⁶

Implications for Specialty Pharmacy

Thus far, study results have conveyed optimism about the future of CAR T-cell therapy as a treatment for B-cell hematological malignancies and potentially other types of cancer. Performing CAR T-cell treatment is expected to take place in a hospital or clinic setting, and pharmacy involvement with administration seems unlikely, with the potential exception of the distribution of certain drugs for the treatment of ADEs associated with the procedure.

From a specialty pharmacy business perspective, this raises the question of what impact CAR T-cell therapy will have on currently available treatments for hematological malignancies. Drugs such as imatinib (Gleevec), ibrutinib (Imbruvica), and idelalisib (Zydelig) are currently used in this space and represent significant business for specialty pharmacies involved in oncology/hematology.

Does CAR T-cell therapy represent a new era in the treatment of hematological malignancies, similar to how drugs like sofosbuvir (Sovaldi) effectively replaced boceprevir (Victrelis) and telaprevir (Incivek) in hepatitis C? Will drugs currently used for hematological malignancies will meet the same fate? It’s too early to tell, but while it seems probable that CAR T-cell therapy will have some impact on existing standards of care, it appears unlikely that current treatments for hematological malignancies will become obsolete.

Cost Concerns

One of the main reasons currently available treatments are likely to continue to be used for hematological malignancies is that CAR T-cell therapy is expected to be very expensive.

Although no formal price announcement has been made by any manufacturers, Citigroup estimates that the treatment could cost more than $500,000 per patient, or roughly the cost of a stem cell transplant.⁶ Because of this high cost, it seems probable that payers would make CAR T-cell therapy a late-line therapy and require patients to try less expensive treatments first.

The wholesale acquisition cost of Gleevec, Imbruvica, and Zydelig, which are targeted B-cell malignancy drugs typically dispensed by specialty pharmacies, is in the range of approximately $8700 to $13,700 per month. Notably, a patient would have to take one of those treatments continuously for roughly 4 years to equal the cost of a CAR T-cell treatment.

As the issue of health care costs becoming increasingly critical, insurers are unlikely to pay for CAR T-cell treatment unless a patient has tried and failed multiple prior therapies that are less expensive.

Closing Thoughts

CRS can be a serious ADE as evidenced by patient deaths during studies of CAR T-cell treatment. Prescribers and patients may also be reluctant to use a newer therapy in an early-line setting that has shown the potential for severe ADEs in trials.

CAR T-cell therapy may prove to be a valuable treatment option for patients in the future, but it seems unlikely to turn the market upside down on currently available treatments that are dispensed through specialty pharmacies.

Nevertheless, CAR T-cell therapies are worth watching as they continue to be studied in clinical trials and eventually make their way through the regulatory review process.

References

1. Brower V. The CAR T-cell race. The Scientist. the-scientist.com/?articles.view/articleNo/42462/title/The-CAR-T-Cell-Race/. Accessed May 12, 2016.

2. National Cancer Institute. CAR T-cell therapy: engineering patients’ immune cells to treat their cancers. National Cancer Institute website. cancer.gov/about-cancer/treatment/research/car-t-cells. Accessed May 5, 2016.

3. Adler MJ. CAR T cells: a look under the hood and down the road. Medscape. medscape.com/viewarticle/831551#vp_3. Accessed May 5, 2016.

4. Chustecka Z. Extraordinary results with CAR-T making headlines again. Medscape. medscape.com/viewarticle/858941. Accessed May 5, 2016.

5. Maude SL, Frey N, Shaw PA, et al. Chimeric antigen receptor T cells for sustained remission in leukemia. N Eng J M. 2014 Oct 16;371(16):1507-1517.

6. Plumridge H. New costly cancer yreatments face hurdles getting to patients. Wall Street Journal. wsj.com/articles/new-costly-cancer-treatments-face-hurdles-getting-to-patients-1412627150. Accessed May 5, 2016.