The UK’s National Institute for Health and Care Excellence (NICE) has issued a final draft guidance recommending that the PI3Kδ inhibitor idelalisib (Zydelig) be made available on the National Health Service (NHS) for some adults with chronic lymphocytic leukemia (CLL).
NICE is recommending idelalisib in combination with rituximab for adults with previously untreated CLL who have a 17p deletion or TP53 mutation and for adults with CLL who have relapsed within 24 months of their previous treatment.
This decision follows a preliminary decision earlier this year, when NICE asked Gilead Sciences, the company developing idelalisib, to provide further information on the cost-effectiveness of the drug.
Gilead responded by submitting new economic analyses and a simple discount agreement to the list price of idelalisib.
NICE’s recommendation for idelalisib is contingent upon the company providing the agreed upon discount.
NICE’s draft guidance is now with consultees, who have the opportunity to appeal against it. Until NICE issues a final guidance, NHS bodies should make decisions locally on the funding of specific treatments.
Patients whose treatment with idelalisib is not recommended in this NICE guidance but was started within the NHS before this guidance was published should be able to continue treatment until they and their NHS clinician consider it appropriate to stop.
Clinical effectiveness
The committee advising NICE concluded that idelalisib could not be recommended for patients whose disease had relapsed more than 24 months after previous treatment, as no evidence was submitted for this patient group.
For the other populations, the clinical effectiveness data from Study 116 showed that idelalisib plus rituximab produced a significant improvement in progression-free survival and overall survival, compared with rituximab alone, for patients with high-risk, relapsed or refractory CLL.
Cost-effectiveness
Idelalisib is priced at £3114.75 for sixty 150-mg tablets (British national formulary 2015). The mean cost of a 1-year treatment course is £37,922.
Gilead’s agreement provides a discount to the list price of idelalisib, but the level of the discount is currently confidential.
Analyses suggested that, at the discount agreement price, idelalisib plus rituximab was associated with higher costs and greater quality-adjusted life-year (QALY) gains when compared with rituximab alone.
The deterministic incremental cost-effectiveness ratio (ICER) for idelalisib plus rituximab compared with rituximab alone was £13,634 per QALY gained (incremental costs £26,128; incremental QALYs 1.92).
Compared with best supportive care, the ICER for idelalisib plus rituximab was £20,461 per QALY gained (incremental costs £39,211; incremental QALYs 1.92). And compared with ofatumumab, the ICER was £1527 per QALY gained (incremental costs £2926; incremental QALYs 1.92).
