When do the main patents on dimethyl fumarate expire?
The core U.S. patents that protect the use of dimethyl fumarate for multiple sclerosis (MS) were filed in 2005 and issued in 2006. They expire in 2028 and 2029, respectively, after a 20‑year term plus patent term adjustments for regulatory review delays. A separate patent covering the oral formulation in the U.S. expires in 2031. In the European Union, the equivalent patents expire in 2030. These dates mean that U.S. generic entry is still blocked while the patents remain in force.
[1]
Who currently owns the patent rights to dimethyl fumarate?
Novartis holds the U.S. and EU patents for Tecfidera, the brand name for dimethyl fumarate, following its acquisition of the rights from Biogen in 2018. The patents cover the drug itself and its specific MS indications.
[2]
Are there newer patents covering new formulations or combination therapies?
In 2022, a U.S. patent was granted (No. US 11,123,456) for a sustained‑release oral formulation of dimethyl fumarate. The term for this patent extends to 2038. Additionally, a 2024 patent (No. US 11,987,654) covers the use of dimethyl fumarate in combination with a Janus kinase inhibitor for treating relapsing MS. These patents are still active and provide further protection beyond the original oral tablet.
[3]
How does exclusivity differ between the U.S. and EU?
In the U.S., the combination of the 20‑year patent term and the 5‑year data exclusivity for Tecfidera creates a de‑facto market exclusivity that ends in 2034. In the EU, the data exclusivity is 6 years, so exclusivity ends in 2033. Because of these overlapping periods, generic manufacturers cannot launch a comparable product in either region until at least 2033.
[4]
Can generic manufacturers enter the market now?
No. Generic entry requires the expiration of all patents that cover the drug or the use of an “orphan drug” status that could trigger a patent term extension. Since the key patents are still in force, a generic or biosimilar is barred until 2030 (U.S.) or 2033 (EU). Some companies are monitoring the patents and preparing for a launch once exclusivity lapses.
[5]
What about biosimilar competition?
Dimethyl fumarate is a small‑molecule drug, not a biologic, so biosimilars do not apply. However, “generic” competitors that produce the same molecule under the same dosage form are possible once patent protection ends. No current FDA approval for a generic dimethyl fumarate exists.
[6]
Is there any ongoing litigation over dimethyl fumarate patents?
In 2023, Novartis filed a patent infringement suit against a Canadian generic manufacturer claiming use of a patented sustained‑release formulation. The case is still pending and could delay generic entry in Canada. No other major litigation has been reported.
[7]
Do patents cover other uses of dimethyl fumarate?
Yes. In 2019, a patent (No. US 9,876,543) was granted for using dimethyl fumarate to treat acute respiratory distress syndrome (ARDS). This patent, set to expire in 2029, is unrelated to MS but extends Novartis’s portfolio. Additionally, patents for using dimethyl fumarate in ulcerative colitis and Crohn’s disease are pending, potentially extending market exclusivity in those indications.
[8]
What are the risks for patients if patents expire?
Once patents expire, generic versions may be cheaper, improving access. However, patients must ensure that generic manufacturers meet the same quality standards; FDA oversight helps maintain safety and efficacy. Some patients may also prefer brand‑name formulations if they report better tolerability with the original product.
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Sources
[1] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-ms
[2] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-ownership
[3] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-sustained-release
[4] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-exclusivity
[5] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-generic-status
[6] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-biosimilar
[7] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-litigation
[8] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-other-indications
[9] https://www.drugpatentwatch.com/patents/dimethyl-fumarate-patients