William B. Feldman, MD, DPhil, MPH

William B. Feldman, MD, DPhil, MPH

Associate Professor of Medicine, UCLA Geffen School of Medicine

William Feldman is a research collaborator with PORTAL and Associate Professor of Medicine at UCLA, where he is an attending physician in the Division of Pulmonary, Critical Care, Sleep Medicine, Clinical Immunology & Allergy, and Director of the Pharmaceutical Policy & Outcomes Lab. His research focuses on FDA regulation, pharmaceutical pricing and policy, intellectual property, and pharmacoepidemiology.

Feldman’s work has been funded by the National Institutes of Health, the Food and Drug Administration, the Commonwealth Fund, and Arnold Ventures, and has appeared in the New England Journal of Medicine, JAMA, BMJ, and other top medical and health policy journals. He has advised policymakers and testified before Congress, and has mentored trainees at all levels, from undergraduate and medical students to residents, postdoctoral fellows, and junior faculty. He is an Associate Editor at Health Affairs Scholar and serves on the Editorial Board of the Journal of Law, Medicine, and Ethics.

Feldman received his undergraduate degree in philosophy from Duke University, his medical degree from UCSF, his doctorate in politics from the University of Oxford, and his MPH from the Harvard T.H. Chan School of Public Health. He was a Fulbright Scholar at the University of Haifa and a Zuckerman Fellow at the Center for Public Leadership at the Harvard Kennedy School. He completed his residency in internal medicine and fellowship in pulmonary and critical care medicine at Brigham and Women’s Hospital and Harvard Medical School. Prior to joining the faculty at UCLA, he was an Assistant Professor of Medicine at Harvard Medical School and co-chair of the Ethics Committee at Brigham and Women’s Hospital.

Featured Work

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List Price Reductions Among Brand-Name ICS-LABA Inhalers in 2024 Were Associated With Increased Generic Uptake

Han J, Wang SV, Kesselheim AS, Avorn J, Feldman WB - Health Affairs

  • Price, Value, and Access
Following the American Rescue Plan Act’s removal of the Medicaid rebate cap in January 2024, brand-name ICS-LABA manufacturers reduced list prices by 21-50%, and generic ICS-LABA use immediately increased by 23%, driven by gains in commercial plans and Medicare. The authors conclude that list these price reductions likely limited brand-name manufacturers’ ability to offer large rebates to PBMs, disrupting financial incentives that had previously suppressed generic uptake.
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Comparative Effectiveness and Safety of Single Inhaler Triple Therapies for Chronic Obstructive Pulmonary Disease: New User Cohort Study

Feldman WB, Suissa S, Kesselheim AS, Avorn J, Russo M, Schneeweiss SG, Wang SV - BMJ

  • Regulation and Clinical Evidence
Two single-inhaler triple therapies for chronic obstructive pulmonary disease (COPD) are available in the US: Breztri Aerosphere, a twice daily metered-dose inhaler, and Trelegy Ellipta, a once daily dry powder inhaler. Breztri Aerosphere was associated with a 9% higher risk of moderate or severe COPD exacerbations and an identical risk of pneumonia hospitalizations compared to Trelegy Ellipta among patients with COPD treated in routine clinical practice.
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Patents and Regulatory Exclusivities on Inhalers for Asthma and COPD, 1986-2020

Feldman WB, Bloomfield D, Beall RF, Kesselheim AS - Health Affairs

  • Innovation Incentives and Competition
An analysis of patents and exclusivities for 62 FDA-approved inhalers (1986–2020) found that brand-name products enjoyed a median of 16 years of protection from generic competition, with over 50% of all patents covering the device rather than the active ingredient. Manufacturers extended exclusivity through “device hops” that yielded a median of 28 years of protection across product lines, despite only 1 inhaler containing a genuinely novel mechanism of action. These findings suggest that current patent and regulatory frameworks disproportionately reward device modifications over true therapeutic innovation, underscoring the need for reform to improve generic inhaler competition and reduce costs.
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