Indication-Specific Generic Uptake of Imatinib Demonstrates the Impact of Skinny Labeling

Pathways for non-manufacturers to drive generic drug repurposing for cancer in the U.S

Repurposing generic drugs as new treatments for life-threatening diseases such as cancer is an exciting yet largely overlooked opportunity due to a lack of market-driven incentives. Nonprofit organizations and other non-manufacturers have been ramping up efforts to repurpose widely available generic drugs and rapidly expand affordable treatment options for patients. However, these non-manufacturers find it difficult to obtain regulatory approval in the U.S. Without a straightforward path for approval and updating drug labeling, non-manufacturers have relied on off-label use of repurposed drugs. This limits the broad clinical adoption of these drugs and patient access. In this paper, we explore the regulatory landscape for repurposing of small molecule generic drugs within the U.S. We describe case studies of repurposed drugs that have been successfully incorporated into clinical treatment guidelines for cancer without regulatory approval. To encourage greater adoption of generic drugs in clinical practice-that is, to encourage the repurposing of these drugs-we examine existing Food and Drug Administration (FDA) pathways for approval of new uses or indications for generic drugs. We show how non-manufacturers, who are generally more active in generic drug repurposing than manufacturers, could utilize existing regulatory authorities and pathways, and we describe the challenges they face. We propose an extension of the existing 505(b)(2) new drug application (NDA) approval pathway, called a "labeling-only" 505(b)(2) NDA, that would enable non-manufacturers to seek approval of new indications for well-established small molecule drugs when multiple generic products are already available. It would not require new chemistry, manufacturing, and controls (CMC) data or introducing new drug products into the marketplace. This pathway would unlock innovation broadly and enable patients to benefit from the enormous potential of low-cost generic drugs.

Partial Orphan Cancer Drugs: US Food and Drug Administration Approval, Clinical Benefit, Trials, Epidemiology, Price, Beneficiaries, and Spending

OBJECTIVES

The Orphan Drug Act (ODA) incentivizes drug development for rare diseases with limited sales potential. Partial orphans-drugs used to treat rare and common diseases-frequently turn into multi-billion dollar blockbusters. This study analyzes partial orphan cancer drugs' development, approval, and economics.

METHODS

170 drugs with US Food and Drug Administration approval for 455 cancer indications were identified (2000-2021). 110 full, 22 partial, and 38 non-orphan drugs were compared regarding their approval, benefits, trials, epidemiology, price, beneficiaries, and spending with data from regulatory documents, Global Burden of Disease study, and Medicare and Medicaid.

RESULTS

Full orphans, relative to partial and non-orphans, were more frequently monotherapies for hematologic cancers supported by smaller single-arm trials treating diseases with a lower incidence and higher severity. The time from first to second indication approval was 1 year shorter for partial than full orphans. Full orphans offered a greater overall survival (median: 4.0 vs 2.8 vs 2.8 months, P < .001) and progression-free survival benefit (median: 5.1 vs 2.5 vs 3.6 months, P < .001). Monthly prices were higher for full and partial than non-orphan drugs (median: $17 177 vs $13 284 vs $12 457, P < .001). Beneficiaries (8790 vs 4390 vs 1730) and spending ($570 vs $305 vs $156 million) per drug were greater for partial than non-and full orphans.

CONCLUSIONS

Although partial orphans' benefits, trials, and economics are more similar to non-than full orphans, they receive all of the ODA's benefits and are swiftly extended to new indications; resulting in greater spending. A maximum ODA revenue/patient threshold could limit expenditure on partial orphans.

Preserving Timely Generic Drug Competition with Legislation on "Skinny Labeling"

Patents prevent generic drug entry. Brand firms file new "method of use" patents for old drugs to prevent generic entry. Congress addressed this issue by creating the "skinny label" pathway, which allows generic firms to use the drug label to indicate that the old drug can only be used for non-patented uses. This pathway is now in jeopardy due to a recent court case. This paper outlines the issues and suggests possible legislative solutions.