Medicare's Final Negotiation Rule Counts Subcutaneous Versions of Infused Biologics as the Same Drug
From the 2029 cycle, CMS will group hyaluronidase-based subcutaneous products with their intravenous originals, sharing one price and one licensure clock. The first list under the rule is due Feb. 1, 2027.
A subcutaneous antibody made by adding hyaluronidase to an infused one will count as the same drug as the infused version when Medicare chooses drugs for price negotiation. That is the most consequential new policy for infusion practices in the Medicare Drug Price Negotiation Program final rule the Centers for Medicare and Medicaid Services published on Nov. 9, 2026.
The rule, CMS-4215-F, takes effect Dec. 5 and applies from initial price applicability year 2029, the cycle for which CMS must publish up to 20 selected drugs by Feb. 1, 2027. CMS says it received about 11,330 comment letters on the proposal.
What the new policy does
Under the finalized section 429.125(b)(4)(ii), when one manufacturer's products differ only because a new formulation adds an ingredient that "enables an alternative route of administration" for the original active ingredient, CMS will treat all dosage forms of the shared ingredient as one potential qualifying single source drug. CMS says commenters generally read the scope as products containing hyaluronidase or a hyaluronidase variant, which it says "aligns with our general expectation."
Three things follow. Spending on the intravenous and subcutaneous versions is added together when CMS ranks drugs. The 11-year licensure clock for biologics runs from the earliest-approved application containing the shared ingredient, which is the intravenous original. And if the drug is selected and a maximum fair price is agreed, that price applies across all of its dosage forms and strengths.
Under CMS's earlier guidance, a fixed combination product was generally its own drug. CMS wrote that this let a manufacturer "avoid selection" or avoid the negotiated price by marketing a reformulation, and called the gap a program integrity risk. Many commenters argued that subcutaneous products are distinct medicines that FDA approves on separate applications and that they shorten chair time and widen access. CMS answered that clinical differences between formulations are weighed during negotiation, against therapeutic alternatives, rather than at selection.
Which products fit the description?
The rule does not name products. To see what the policy could reach, we searched FDA's Drugs@FDA database through openFDA for licensed products combining an antibody or fusion protein with hyaluronidase, and matched each to its intravenous original from the same company.
| Ingredient | IV original | Subcutaneous version | Gap, years | IV turns 11 |
|---|---|---|---|---|
| Rituximab | Rituxan, Nov. 26, 1997 | Rituxan Hycela, June 22, 2017 | 19.6 | Nov. 2008 |
| Trastuzumab | Herceptin, Sept. 25, 1998 | Herceptin Hylecta, Feb. 28, 2019 | 20.4 | Sept. 2009 |
| Pembrolizumab | Keytruda, Sept. 4, 2014 | Keytruda Qlex, Sept. 19, 2025 | 11.0 | Sept. 2025 |
| Nivolumab | Opdivo, Dec. 22, 2014 | Opdivo Qvantig, Dec. 27, 2024 | 10.0 | Dec. 2025 |
| Daratumumab | Darzalex, Nov. 16, 2015 | Darzalex Faspro, May 1, 2020 | 4.5 | Nov. 2026 |
| Atezolizumab | Tecentriq, May 18, 2016 | Tecentriq Hybreza, Sept. 12, 2024 | 8.3 | May 2027 |
| Ocrelizumab | Ocrevus, Mar. 28, 2017 | Ocrevus Zunovo, Sept. 13, 2024 | 7.5 | Mar. 2028 |
| Amivantamab | Rybrevant, May 21, 2021 | Rybrevant Faspro, Dec. 17, 2025 | 4.6 | May 2032 |
| Efgartigimod alfa | Vyvgart, Dec. 17, 2021 | Vyvgart Hytrulo, June 20, 2023 | 1.5 | Dec. 2032 |
The gap column is the point. Treated as separate drugs, a subcutaneous version would start its own 11-year clock on its own licensure date, 1.5 to 20 years after the original. Under the final rule, it inherits the original's date. By our arithmetic, the intravenous originals of pembrolizumab, nivolumab and daratumumab all pass 11 years before the Feb. 1, 2027, list date; atezolizumab passes in May 2027. Keytruda Qlex uses berahyaluronidase alfa, a hyaluronidase variant, which the rule's description covers.
Passing 11 years is necessary, not sufficient. Whether any of these is selected depends on Medicare spending rankings, biosimilar competition (rituximab and trastuzumab already have biosimilars), orphan-drug exclusions and the other tests CMS applies when it builds the list. We left out pertuzumab, trastuzumab and hyaluronidase (Phesgo), because it combines two antibodies sold separately and the passages we reviewed do not say how CMS would group it.
The policy changes what Medicare counts, not what a patient receives. Both formulations stay on the shelf, but they may end up sharing one negotiated price.
What it means at the infusion chair
Most of these drugs are physician-administered and paid under Part B, the same territory as Medicare's GLOBE international pricing model, which drugmakers have sued to stop. CMS says the policy is not meant to steer patients between formulations and that physicians and patients "retain the ability to choose among available formulations." What it does change is the economics a practice sees: if an aggregated drug is selected, the negotiated price would apply to both versions, so the purchasing gap between them could narrow.
How that price reaches a practice that buys and bills is not settled here. CMS says it will issue program guidance on how manufacturers effectuate negotiated prices in 2028, including for Part B drugs, and intends to codify the rules for 2029 and later in future rulemaking. The next fixed date is Feb. 1, 2027, when CMS publishes the 2029 list. Practices that infuse oncology or neurology biologics should review their payer mix for these products now, before the list arrives.
Reported, fact-checked and edited by The Script Pad's editorial staff. See How we use AI.
This article is for professional education and does not replace clinical judgment. Treatment decisions should be based on the individual patient and current guidelines.
