The Rare Disease Company Coalition met recently with the White House Office of Management and Budget to seek the exclusion of orphan drugs from two pilot programs implementing most-favored-nation pricing, the policy of tying US prices to those charged in other wealthy countries.
The request is unremarkable in isolation. Read alongside everything else that has happened to orphan drug policy in the past eighteen months, it describes a pattern worth examining.
The carve-outs have accumulated
Under the Inflation Reduction Act, only single-indication orphan drugs were exempt from Medicare price negotiation. Amendments enacted last year extended those exemptions to multi-indication drugs, meaning a drug approved for a rare disease keeps its exemption even after gaining approval for additional conditions.
Separately, the Rare Pediatric Disease Priority Review Voucher program was reauthorized through September 2029. Those vouchers cut FDA review time on a subsequent application from roughly ten months to six, and have historically sold for over $100 million, which is a transferable asset of substantial value awarded on top of the pricing protections.
Add the underlying Orphan Drug Act framework of market exclusivity and tax credits, and now a requested exemption from international reference pricing, and orphan designation has become the most commercially valuable regulatory status a drug can hold in the United States.
Why the exemptions exist, and why the argument is sound
The rationale deserves a fair hearing, because it is not a lobbying invention.
A therapy for 5,000 patients cannot recover development costs at mass-market prices. The arithmetic is unforgiving: clinical development costs roughly the same whether the eventual population is five thousand or five million, and dividing fixed costs by a tiny denominator produces a high per-patient price or no drug at all.
The Orphan Drug Act of 1983 exists because before it, the market produced almost nothing for rare diseases. Exclusivity and tax credits changed that, and thousands of designations and hundreds of approvals followed. It is one of the more clearly successful pieces of US health legislation, and the case that squeezing orphan pricing would reduce rare disease development is not merely industry rhetoric. The same funding-durability logic runs through a separate story about rare disease treatment, where a new nonprofit is trying to industrialize gene therapy development on ARPA-H funding because no commercial model can recover costs for a mutation carried by a handful of patients.
The consequence nobody chose
Here is what the accumulation produces, and it is the part of this that deserves more attention than the individual policy fights.
Capital allocates toward protected categories. Analysts tracking the effect of most-favored-nation policy describe investment flowing toward rare disease and oncology with reduced pricing pressure and away from chronic conditions, such as heart disease and obesity, where price comparisons will likely lead to lower prices. Orphan drugs are projected to reach roughly 20% of prescription drug sales, growing at about twice the rate of non-orphan drugs, with rare disease candidates approaching a third of total pharma pipelines.
Sit with that. A third of the industry's research pipeline is aimed at conditions affecting fewer than 200,000 Americans each, while pricing pressure concentrates on the drugs for heart disease, diabetes, and obesity, which affect tens of millions.
This is not an argument that rare disease research is undeserving. Those patients have historically been abandoned by markets, and the treatments now emerging are genuinely transformative for people who had nothing.
It is an argument that the aggregate incentive structure was not designed by anyone. Each policy was written to solve a specific problem: protect small-population drugs, lower prices for expensive widely-used drugs, encourage pediatric rare disease work. The combined effect is a systematic tilt in research investment away from the diseases that kill the most people, arrived at by accumulation rather than decision.
The boundary is where the money is
The sharper technical problem is that the orphan category is defined at a moment in time, and drugs move.
Analysis of high-revenue orphan-first drugs found that the interval between original approval for a rare disease and subsequent approval for a non-rare disease ranged from a few months to 15 years, with a median of two years.
A median of two years. Which means a substantial number of drugs enter through the rare disease door, secure the protections attached to it, and then expand into large populations while the protections travel with them. Extending exemptions to multi-indication drugs makes that pathway considerably more attractive.
The concrete example is ibrutinib, approved for rare blood cancers and among the top-selling drugs in Medicare, costing the program nearly $2.4 billion in 2023 while being used by roughly 17,000 Medicare Part D patients. Negotiation secured a 38% reduction from list price starting in 2026. Under the expanded carve-out, that negotiation would not have occurred.
Note the per-patient arithmetic: $2.4 billion across 17,000 people is roughly $140,000 per patient per year, from a public program. The rare disease rationale is that small populations require high prices to make development viable. It is a different proposition when the small population is generating billions and the price was set without meaningful competitive constraint. A congressional investigation found rebates on that drug ran below 11% before negotiation.
What international pricing would actually test
The most-favored-nation request raises a distinct question from the Medicare negotiation exemption, and it is worth separating.
MFN ties US prices to prices in other wealthy countries. Orphan drugs frequently carry much larger US-to-foreign price gaps than ordinary drugs, because other countries' health technology assessment bodies refuse to pay American prices for small-population therapies. So MFN would bite orphan drugs unusually hard, which is precisely why the exemption is being sought.
Two honest readings compete. One is that if a manufacturer sells a therapy in Germany at a fraction of its US price and continues doing so voluntarily, the German price presumably exceeds marginal cost, which tells you something about how much of the US price reflects development recovery versus what the market will bear.
The other is that the US market genuinely funds a disproportionate share of global development, and that if every country paid German prices, fewer drugs would be developed. That is also true, and it is the strongest argument against reference pricing generally.
Where those meet is an empirical question about how much US pricing exceeds what development recovery requires. Nobody outside the companies has the cost data to answer it, which is why this debate keeps being conducted through anecdote and assertion.
Seventeen manufacturers have now signed MFN agreements, representing roughly 86% of the branded drug market. The policy is arriving regardless of the exemption fight; the question is what it applies to.
A better-designed rule
The defensible version of an orphan exemption would track the thing it is meant to protect rather than a designation obtained at approval.
Tie protection to actual patient population and revenue, not to initial designation. A drug treating 5,000 people and earning $200 million needs the exemption. A drug earning $2.4 billion from one public program does not, whatever door it entered through, because at that revenue the development costs have been recovered many times over.
Sunset the exemption when a drug gains a non-rare indication or crosses a revenue threshold, rather than extending it indefinitely, which is the change that was made in the opposite direction.
And apply it prospectively so companies can plan, since predictability is a substantial part of what makes rare disease investment possible in the first place. None of that reduces support for genuinely rare disease development. It targets the boundary, which is where the money is and where the policy currently fails. The alternative is the present trajectory, in which the most reliable route to pricing protection is to enter through a rare indication, and research capital keeps flowing accordingly.