The Association Between Average Sales Price Decline and Shortages in Small Molecule Injectable Oncology Therapies With Generic Competition
Author(s)
Joshua A. Roth, PhD, MHA1, Elizabeth Donckels, MSPH2, Iman Mohammadi, PhD2, Anthony Yu, PharmD2, Jennifer Dezet Deem, MS, PhD1, Yecheng Huang, MS2, Maja Isabelle Strecker, PhD1, Tigwa Davis, PhD2.
1Pfizer Inc., New York, NY, USA, 2Inovalon, Bowie, MD, USA.
1Pfizer Inc., New York, NY, USA, 2Inovalon, Bowie, MD, USA.
Presentation Documents
OBJECTIVES: There are currently 14 active shortages among oncology drugs in the U.S.—each with potential to disrupt patient treatment and reduce survival. The Food and Drug Administration (FDA) and other stakeholders have suggested that price erosion is a driver of oncology drug shortages, but evidence is limited. This study explored the association between Medicare Average Sales Price (ASP) decline and incidence of shortage for small-molecule injectable oncology therapies with generic competition in the U.S.
METHODS: Study data spanned 1/1/2018-12/31/2023 on a quarterly basis. Counts of National Drug Codes (NDC) and manufacturers, ASP, and shortage data were derived from the FDA NDC Directory, Medicare pricing files, and FDA Drug Shortage Database, respectively. We used a time-varying proportional hazards model to assess the hazard ratio (HR) and 95% confidence interval (CI) for the association between declining ASP (categorical) and FDA-reported 2-quarter lagged shortage, adjusting for indication and manufacturer count per drug. To address uncertainty resulting from the small number of shortages, a sensitivity analysis reran the model using unrestricted random sampling with a replacement sample size=20 and resamples=1,000.
RESULTS: Fifty drugs met inclusion criteria. Most drugs (65%) demonstrated an inflation-adjusted decline by 12/31/2023 (mean decline=19.0%). In 2019, 2021, and 2023 there were 2.8%, 5.6%, and 12.5% of NDCs in shortage, respectively. ASP decline from baseline was greater for drugs ever in shortage (-32.7%) vs. others (-13.6%). The base case adjusted analysis showed a non-significant trend toward association between price decline and shortage (HR=4.23, 95% CI=0.54-33.04, p=0.17), whereas the sensitivity analysis demonstrated a significant association (HR=7.23, 95% CI=4.39-11.92, p<0.0001).
CONCLUSIONS: In the U.S. from 2018-2023, drugs with ASP decline had several-fold increased risk of shortage vs. drugs without decline. Future research should generate additional evidence about price decline as cause of drug shortages, and should extend to oncology biosimilars given similar ASP decline and shortage risk.
METHODS: Study data spanned 1/1/2018-12/31/2023 on a quarterly basis. Counts of National Drug Codes (NDC) and manufacturers, ASP, and shortage data were derived from the FDA NDC Directory, Medicare pricing files, and FDA Drug Shortage Database, respectively. We used a time-varying proportional hazards model to assess the hazard ratio (HR) and 95% confidence interval (CI) for the association between declining ASP (categorical) and FDA-reported 2-quarter lagged shortage, adjusting for indication and manufacturer count per drug. To address uncertainty resulting from the small number of shortages, a sensitivity analysis reran the model using unrestricted random sampling with a replacement sample size=20 and resamples=1,000.
RESULTS: Fifty drugs met inclusion criteria. Most drugs (65%) demonstrated an inflation-adjusted decline by 12/31/2023 (mean decline=19.0%). In 2019, 2021, and 2023 there were 2.8%, 5.6%, and 12.5% of NDCs in shortage, respectively. ASP decline from baseline was greater for drugs ever in shortage (-32.7%) vs. others (-13.6%). The base case adjusted analysis showed a non-significant trend toward association between price decline and shortage (HR=4.23, 95% CI=0.54-33.04, p=0.17), whereas the sensitivity analysis demonstrated a significant association (HR=7.23, 95% CI=4.39-11.92, p<0.0001).
CONCLUSIONS: In the U.S. from 2018-2023, drugs with ASP decline had several-fold increased risk of shortage vs. drugs without decline. Future research should generate additional evidence about price decline as cause of drug shortages, and should extend to oncology biosimilars given similar ASP decline and shortage risk.
Conference/Value in Health Info
2025-11, ISPOR Europe 2025, Glasgow, Scotland
Value in Health, Volume 28, Issue S2
Code
PT7
Topic
Economic Evaluation, Health Policy & Regulatory, Real World Data & Information Systems
Topic Subcategory
Pricing Policy & Schemes
Disease
Biologics & Biosimilars, Musculoskeletal Disorders (Arthritis, Bone Disorders, Osteoporosis, Other Musculoskeletal), Oncology