Survival Benefits With CAR-T Therapy Higher Than With Chemotherapy in Leukemia

The survival benefits seen with tisagenlecleucel seems to be worth the high cost in pediatric patients with relapsed or refractory B-cell acute lymphoblastic leukemia (ALL), according to the results of a recent study, with researchers suggesting that payers create payment models that increase access to this high-value care (JAMA Pediatr. 2018 Oct 8. Epub ahead of print).

CAR-T Therapy Beneficial but Costly

“Among children and young adults with relapsed or refractory B-cell acute lymphoblastic leukemia, the rate of 5-year disease-free survival is 10% to 20%. Approval of tisagenlecleucel…represents a new and potentially curative treatment option,” explained lead investigator Melanie D. Whittington, PhD, Research Instructor, Department of Clinical Pharmacy, University of Colorado Anschutz Medical Campus, Aurora, and colleagues.

“However, tisagenlecleucel is expensive, with a current list price of $475 000 per one-time administration,” they added.

To determine an approximation of the long-term survival and value of tisagenlecleucel in pediatric patients with B-cell ALL, Dr Whittington and colleagues conducted a cost-effectiveness analysis by using a decision analytic model created to extrapolate trial data to a patient lifetime horizon.

Cost-Effective Analysis and Patient Data

Data from 3 clinical trials were used to provide survival evidence for the study; these trials included B2202, which enrolled patients from April 8, 2015, to November 23, 2016; B2205J, which enrolled patients from August 14, 2014, to February 1, 2016; and B2101J, which enrolled patients from March 15, 2012, to November 30, 2015.

The investigators derived long-term survival and outcomes of patients aged <25 years with relapsed or refractory B-cell ALL using flexible parametric modeling. These data were the result of direct extrapolation of event-free survival and overall survival curves. Analysis of data was conducted from December 1, 2017, to March 31, 2018, and outcomes included life-years gained, quality-adjusted life-years (QALYs) gained, and incremental costs per life-year and QALY gained.

Of note, Dr Whittington and colleagues focused their analysis on patients who received tisagenlecleucel or clofarabine.

Tisagenlecleucel Leads to Better Survival

Among patients receiving tisagenlecleucel, 40% are expected to be long-term survivors (ie, alive and responding to therapy after 5 years).

“Tisagenlecleucel had a total discounted cost of $667 000, with discounted life-years gained of 10.34 years and 9.28 QALYs gained. The clofarabine comparator had a total discounted cost of approximately $337 000, with discounted life-years gained of 2.43 years and 2.10 QALYs gained,” the investigators reported.

According to them, this difference led to an incremental cost-effectiveness ratio of approximately $42,000 per life-year gained and $46,000 per QALY gained for tisagenlecleucel versus clofarabine.

When analysis scenarios were altered to include more conservative assumptions regarding long-term relapse and survival, the incremental cost-effectiveness ratio ranged from $37,000 to $78 000 per QALY gained.

“[W]e estimated that more than 40% of pediatric patients who undergo leukapheresis in preparation for tisagenlecleucel therapy will be considered long-term survivors, compared with approximately 10% of pediatric patients considered long-term survivors after receiving comparator therapy,” Dr Whittington and colleagues concluded.

“Financing cures in the United States is challenging owing to the high up-front price, rapid uptake, and uncertainty in long-term outcomes; however, innovative payment models are an opportunity to address some of these challenges and to promote patient access to novel and promising therapies,” they said.—Hina Khaliq