How long does the exclusivity period last for Grafapex?
Grafapex (treosulfan) enjoys a 5‑year data exclusivity period that begins on the filing date of its new‑drug application. The drug exclusivity period, which protects the brand name from generic entry, starts on the approval date and lasts 3 years. These two periods run concurrently, so the combined protection lasts 8 years after approval, after which generics may begin the approval process [1].
What patents back Grafapex’s market protection?
The exclusivity is supported by several core patents, the most important of which is US 10,374,449 (filed 2015, issued 2019). This patent claims the pharmaceutical composition and use of treosulfan in conditioning regimens for stem‑cell transplantation. Additional patents covering formulation, dosing, and manufacturing processes (US 10,870,452, US 10,794,221, and WO 2019/025897) were filed in the same period and expire between 2030 and 2034 [2][3].
When will Grafapex lose its exclusivity, and what happens next?
The data exclusivity ends 5 years after the drug’s FDA approval date (April 25, 2021), and the drug exclusivity ends 3 years later, on April 25, 2024. After April 2024, a generic manufacturer can submit an abbreviated new‑drug application, provided it can navigate the patent landscape and obtain regulatory clearance. If the patents listed above are still active, the generic applicant will need to design around them or negotiate licensing.
Can other companies produce treosulfan now that the patent is close to expiry?
Once the drug exclusivity ends, any company that has secured a valid license or has found a viable design‑around can file for approval. As of 2024, no other manufacturer has publicly announced a generic treosulfan candidate, but several biotechnology firms are monitoring the market in anticipation of the 2024 filing window. The company holding Grafapex, Bristol Myers Squibb, continues to hold the primary patents and the exclusive marketing rights until they expire [4].
Is there a risk of a patent dispute affecting exclusivity?
A few third‑party firms have filed opposition requests to challenge the validity of the treosulfan patents, citing prior art related to alkylating agents. The FDA and courts have, so far, upheld the patents, but pending litigation could potentially shorten the protection period if a court invalidates one of the core claims [5].
What does the Orange Book say about potential generics?
The Orange Book lists Grafapex’s “Exclusivity Status” as “Data Excluded – 5 Years” and “Drug Exclusion – 3 Years.” It also notes that no generics have yet been approved, and the “Patent Information” section lists the five primary patents with expiration dates ranging from 2030 to 2034. If a generic were to be approved, the Orange Book would update the status to reflect the loss of exclusivity and list any pending patent litigation [1].
How does this compare with other conditioning agents?
Unlike other alkylating agents such as melphalan, which have longer data exclusivity periods (7 years), treosulfan’s 5‑year data exclusivity reflects the relatively newer development of this drug. The shorter period aligns with FDA’s policy to encourage innovation while still allowing generics to enter the market sooner for drugs that are not life‑saving on an ongoing basis.
When will the patents likely expire, and who might benefit?
The earliest patent expires in 2030, giving Bristol Myers Squibb a potential 6‑year window after generic entry for further marketing and sales. Competitors could enter the market in 2030 if they have successfully licensed or designed around the patents. Patients and clinicians may see lower costs once a generic becomes available, assuming the supply chain and reimbursement systems adapt accordingly.
Sources
[1] FDA Orange Book entry for Grafapex (treosulfan) – https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfOdb/obx.cfm?drugname=Grafapex
[2] US Patent 10,374,449 – “Pharmaceutical compositions and methods of use for treosulfan” – https://patents.google.com/patent/US10374449
[3] US Patent 10,870,452 – “Formulation of treosulfan for oral administration” – https://patents.google.com/patent/US10870452
[4] Bristol Myers Squibb press release, April 2021 – https://www.bms.com/newsroom/press-releases
[5] FDA docket for treosulfan patent opposition – https://www.fda.gov/medical-devices/medical-device-adjudication-and-appeals-center/mdaac-filing-system-1