463P - Cost effectiveness of palbociclib and ribociclib in metastatic breast cancer in India using ICER and QALY

Background

Cyclin dependent kinase inhibitors (CDK 4/6) are the mainstay of treatment in metastatic Hormone receptor positive (HR+) HER-2 negative breast cancer, having impressive Progression free survival (PFS) and overall survival (OS) results. The approved agents are Palbociclib, Ribociclib and Abemaciclib. OS data are not yet mature for Abemaciclib. Cost effectiveness of these drugs has not been studied in the Indian context, where most patients resort to out of pocket expenditure (OOP). This study was undertaken to analyse the cost effectiveness of Palbociclib and Ribociclib by calculating the quality adjusted life years (QALY) and Incremental cost effective ratio (ICER).

Methods

Maximum retail price (MRP) of these drugs was obtained. PFS and OS were collected from the pivotal studies of these drugs. OS data not mature for Abemaciclib, hence not included. QALY and ICER was calculated using the formula QALY= [m PFS (years) x utility value (PFS)] + [ {m OS- m PFS} X utility value (PD)], where PD is progressive disease. QALY was calculated for CDK 4/6 inhibtor and control. Utility value for PFS and PD taken as 0.715 and 0.443 respectively, based on earlier studies. Gain of QALY= QALY of CDK 4/6- QALY of control Incremental cost= total cost of drug till PD or death ICER= Incremental cost/ gain of QALY Cost effectiveness was based on the WHO criteria - which is less than 3 x Gross domestic product (GDP) per capita India GDP per capita in 2020 is USD 1900 Hence cost effectiveness from an Indian perspective ought to be less than USD 5700.

Results

For Palbocilib QALY, gain of QALY, incremental cost and ICER/QALY were 2.53, 0.32, Rs 855000 (USD 11400) Rs 26, 41,334 (USD 35217) For Ribociclib QALY, gain of QALY, incremental cost and ICER/QALY were 2.92, 0.67, Rs 81000 (USD 10800) and Rs 12, 08,576 (USD 16,114).

Conclusions

Both Palbociclib and Ribociclib are not cost effective based on the WHO benchmark (six and three times higher respectively). Ribociclib has lower ICER/QALY compared to Palbociclib (USD 19103 lower), making it cost effective among the two. Based on its recent OS advantage and favourable ICER/QALY Ribocicilib can be preferred. Considering the clinical benefit of these drugs, cost effectiveness has to be improved to benefit the larger patient populace.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.