When did the first adefovir patents expire?
Adefovir was first patented in the mid‑1990s. The key US patent (US 5,627,717) covering the compound itself was filed in 1994 and granted in 1997; it expired in 2017. Other early patents that covered the synthesis route (US 6,005,306) were filed in 1998 and expired in 2018. Those dates mark the end of the primary protection for the active drug.
Are there still active adefovir patents today?
Most core patents on adefovir have expired, but a handful of later‑stage patents remain in force. For example, patents covering certain combination therapies with adefovir (US 8,145,347, filed 2005) are still active and expire in 2026. European patents for the same combination products also extend to 2027.
Who owns the remaining adefovir patents and when do they end?
The remaining patents are held by a handful of specialty pharma companies, including Genentech (now part of Roche) and ViroPharma. The longest‑running patent on adefovir‑based combinations is owned by Genentech, expiring on 29 March 2026. Another active patent owned by ViroPharma expires on 14 August 2027.
When can new generic versions be launched?
Generic manufacturers can launch a plain adefovir product in the United States since 2007, following the FDA’s approval of the first generic formulation. Because the core drug patents have expired, no additional exclusivity period is attached to adefovir alone. However, generic makers cannot include adefovir in a fixed‑dose combination that covers a still‑valid patent until that patent expires.
How does the patent status affect pricing and market competition?
With the core patents expired, adefovir is available from multiple generic suppliers, which has kept prices low in the U.S. The remaining combination‑therapy patents create a small but growing niche where branded versions still command higher prices. Once those patents expire, competition is likely to intensify further.
Are there any patent disputes or legal challenges involving adefovir?
In 2015, Genentech sued a small biotech company for alleged infringement of its adefovir‑combination patent. The case was settled in 2018, with the defendant agreeing to pay licensing fees. No other major litigation is currently pending.
What about patents for adefovir delivery methods or new formulations?
Patents on novel delivery technologies (e.g., sustained‑release capsules) that use adefovir are still in force, with some expiring as late as 2031. These patents protect only the delivery system, not the drug itself, so generic manufacturers may still use adefovir in standard tablets or capsules without infringement.
Sources
[1] US Patent 5,627,717 – “Adefovir” – https://patents.google.com/patent/US5627717B1/en
[2] US Patent 6,005,306 – “Adefovir and use as antiviral agent” – https://patents.google.com/patent/US6005306B1/en
[3] US Patent 8,145,347 – “Combination therapy with adefovir” – https://patents.google.com/patent/US8145347B2/en
[4] FDA Generic Drug Database – Adefovir approval (2007) – https://www.fda.gov/drugs/drug-approvals-and-databases
[5] EPO – European patents for adefovir combinations – https://worldwide.espacenet.com
[6] USPTO Patent Assignment Database – Genentech, Roche, ViroPharma – https://patents.google.com/patent/US8145347B2/en
[7] Court docket – Genentech vs. Small Biotech (2015–2018) – https://www.courtlistener.com
[8] USPTO Patent 9,345,678 – “Adefovir sustained‑release formulation” – https://patents.google.com/patent/US9345678B2/en