The Inflation Reduction Act's Impact Upon Late-Stage R&D

This study analyzes clinical trial data to demonstrate that the Inflation Reduction Act has significantly reduced late-stage small molecule research and approvals in oncology, thereby refuting claims that the legislation has minimal negative impact on patient access to new treatments for serious conditions.

The Gist

The Big Picture: A "Price Cap" That Changed the Game

Imagine the pharmaceutical industry as a massive garden where scientists grow different types of plants (drugs) to help people who are sick.

For a long time, there was a belief that once a plant was successfully grown and sold (approved by the FDA), the gardener would keep planting more seeds of that same plant to see if it could help with other problems (secondary indications). Many people thought a new law called the Inflation Reduction Act (IRA), passed in late 2021, wouldn't change this behavior much. They assumed that because the money was already spent to get the first plant approved, the gardeners would keep working on the rest of the garden regardless of the new rules.

This paper argues that assumption is wrong. The authors found that the new law acted like a sudden change in the weather, causing gardeners to stop planting specific types of seeds almost immediately.

The Main Discovery: The "Small Molecule" Chill

The study looked at over 1,100 research projects (trials) for drugs that had already been approved. They compared the years before the law (2018–2021) with the years after (2022–2025).

They found a major shift, but it wasn't equal for all plants. The law affected two main types of "seeds" differently:

1. Small Molecules: Think of these as simple, hardy seeds (often chemical pills).
2. Large Molecules (Biologics): Think of these as complex, delicate plants (often made from living cells).

The Result:

• The "Small Molecule" Garden: After the law passed, the number of new research projects for these simple seeds dropped by 35%. It's as if the gardeners suddenly decided, "It's not worth planting these anymore."
• The "Large Molecule" Garden: The number of projects for these complex plants stayed exactly the same. The gardeners kept planting them just as before.

Why Did This Happen? The "9-Year vs. 13-Year" Rule

The paper explains that the new law has different rules for when the government can negotiate lower prices for these drugs.

• Small Molecules can be negotiated on prices after just 9 years.
• Large Molecules get a longer grace period of 13 years.

Because the government can come in and lower the price of the "small molecule" drugs sooner, the potential profit for the companies drops faster. The authors suggest that companies are acting like investors who see a business opportunity shrinking; they are pulling their money out of the "small molecule" projects to avoid the risk of lower profits later.

The Impact on Cancer Research (Oncology)

The most dramatic effect was seen in the cancer (oncology) section of the garden.

• Cancer research makes up more than half of all the follow-up studies the authors looked at.
• After the law, research into new uses for small molecule cancer drugs plummeted.
• Specifically, research into rare cancers (called "orphan" diseases) dropped by 14%.

The authors argue this is dangerous because these "follow-on" studies are often how patients get new treatments for advanced or hard-to-cure cancers. If the gardeners stop planting these seeds, patients might not get the new cures they need.

A Counter-Example: The "Hematology" Surprise

Interestingly, the study found a spike in research for hematology (blood diseases), but this was a small area to begin with. The authors note this increase is likely just a side effect: because so many cancer projects stopped, the proportion of blood disease projects went up, even if the total number of blood projects didn't change much.

The "Sunk Cost" Myth

The paper challenges a common idea called the "Sunk Cost Fallacy."

• The Myth: "We already spent millions to get the first drug approved, so we must finish the follow-up studies to make that money back."
• The Reality: The data shows companies are not sticking to this plan. Even though they spent the money, the new law made the future return on investment look too risky, so they stopped the work anyway.

The Bottom Line

The authors conclude that the belief that the Inflation Reduction Act would have "minimal impact" on late-stage drug development is incorrect.

Instead, the law has created a "disincentive" (a reason not to do something) that has caused a significant drop in research for small-molecule cancer drugs. The authors warn that this could mean fewer new treatments for patients with serious, late-stage cancers in the future. They hope this study sparks a debate to fix these unintended consequences so that patients don't lose access to life-saving medicines.

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Important Note from the Paper:
The authors explicitly state that this research has not been peer-reviewed yet (it is a preprint). They also disclose that the study was funded by Sanofi, a major pharmaceutical company, and the authors were paid consultants for them.

Technical Summary

Technical Summary: The Inflation Reduction Act's Impact Upon Late-Stage R&D

Problem Statement
While previous research has established that the Inflation Reduction Act (IRA), enacted on September 27, 2021, reduced early-stage venture capital and angel investments in small molecules targeting Medicare-aged populations, the impact on late-stage and post-approval research has been largely assumed to be limited or ignored. Critics and some academic analyses suggest that capital already committed to late-stage projects will be deployed regardless of shifted return expectations, and that the Congressional Budget Office (CBO) excluded post-approval innovation from its IRA impact analysis. This study addresses the gap in literature regarding whether the IRA has created measurable disincentives for late-stage development, specifically for secondary indications (follow-on studies) and lead indications in areas of high unmet medical need, such as oncology.

Methodology
The authors conducted a multi-year, multi-indication analysis of post-approval Research and Development (R&D) using a dataset of 1,148 secondary trials derived from 364 FDA-approved lead indications of new molecular entities and biological products. The data, spanning 2018 to 2025, was sourced from Biomedtracker and clinicaltrials.gov, covering 175 firms.

The study employed two primary statistical approaches:

1. Multiple Linear Regression: Used to predict the annual number of follow-on studies per year, segmented by disease group, modality (small molecule vs. large molecule/biologic), and orphan status. The IRA's introduction was indexed as January 1, 2022.
2. Fractional Multinomial Logit (FMLogit) Regression: Used to model the share distribution of secondary indication studies across 19 disease groups. This model estimated the probability that a study targets a specific disease group based on variables including the IRA (pre- vs. post-introduction), modality, orphan status, and the prevalence of the disease in the U.S. population aged 65 and older.

Key Contributions
This paper provides empirical evidence refuting the assumption that the IRA has minimal negative effects on late-stage biopharmaceutical R&D. It specifically isolates the impact of the IRA's price negotiation provisions, which differ by modality (9 years for small molecules vs. 13 years for large molecules), on the pipeline of secondary indications. The study contributes a granular view of how regulatory changes alter the "portfolio mix" of drug development, shifting focus away from small molecule oncology research.

Results
The analysis reveals a statistically significant decline in post-approval research activity following the IRA's introduction, driven primarily by the oncology sector:

• Overall Decline: The total number of post-approval studies declined by 12% (from 610 to 535) after the IRA's introduction.
• Oncology Impact: Oncology studies, which comprised over 50% of the cohort, saw a 20% decline (from 325 to 260 studies).
• Modality-Specific Effects:
  • Small Molecules: Follow-on small molecule oncology studies exhibited a statistically significant 35% decline (from 53 to 34 per year; $R^2 = .48, p < 0.014$).
  • Large Molecules: Follow-on large molecule (biologic) oncology studies showed no statistically significant change, remaining steady at approximately 30 per year.
• Lead Indication Approvals: Lead indication small molecule oncology approvals declined by 27% (from 11.3 to 8.3 per year; $R^2 = .70, p < 0.002$), while large molecule approvals increased by 32%.
• Orphan Status: There was a statistically significant 14% decline in the proportion of orphan oncology studies post-IRA ($p < 0.001$).
• Hematology: In contrast to oncology, the study observed a statistically significant increase in secondary hematology studies (over 200% increase), though this rose from a low pre-IRA base of 1.5 studies per year. No other disease groups showed statistically significant changes.

Significance and Claims
The authors claim that these findings demonstrate the IRA has created substantial disincentives for late-stage drug development, particularly for small molecule therapies in oncology and for orphan indications. The study argues that the belief in the resilience of late-stage R&D may be an example of the "sunk-cost fallacy," where continued investment is assumed despite altered return probabilities.

The paper concludes that the IRA manifestly negatively impacts patient access to new medicines, especially for those requiring cures for metastatic late-stage cancers. The authors assert that the observed shifts in the R&D pipeline should prompt regulators to reconsider the law's unintended consequences. They note that while the "Orphan Cures Act" (passed in 2025) attempts to exempt certain orphan drugs from price negotiations, its potential repeal could further exacerbate the decline in late-stage orphan cancer research. The study calls for thoughtful policy solutions to address these economic risks to drug developers and the resulting declines in treatment availability.

Note: The study acknowledges limitations, including the potential for downward bias in counting secondary studies due to the time lag between lead approval and secondary study initiation, and the possibility that the 2022 index date may underestimate the full impact of the legislation introduced in late 2021.