PTAB Will Review Key Patents on Brand-Name Eculizumab, Soliris

Last week, the Patent Trial and Appeal Board (PTAB) instituted 3 inter partes review (IPR) proceedings concerning patents on Alexion’s brand-name eculizumab, Soliris, a complement inhibitor that treats rare diseases. Amgen is the petitioner in all 3 cases, which were filed in February of this year.

IPR proceedings are trials conducted by the PTAB that allow the board to review the patentability of 1 or more claims of a patent, and IPRs are instituted if there is a reasonable likelihood that the petitioner will prevail on at least 1 claim challenged. Decisions in instituted IPRs are typically issued within 1 year.

The first case, IPR2019-00739, is related to US Patent Number 9,725,504, which concerns a method of treatment related to paroxysmal nocturnal hemoglobinuria by complement inhibition. The second case, IPR2019-00740, concerns US Patent Number 9,718,880, which relates to formulation. Finally, case IPR2019-00741, is related to US Patent Number 9,732,149, which concerns composition of matter.

News of the IPR institutions comes just months after Amgen announced that its proposed eculizumab biosimilar, ABP 959, showed pharmacokinetic and pharmacodynamic equivalence to Soliris in a phase 1 study. The biosimilar also demonstrated similar safety and immunogenicity to its reference in the study.

Alexion has been attempting to “convert” patients currently receiving Soliris to its follow-up C5 complement inhibitor, Ultomiris, as Alexion’s chief executive officer Ludwig Hanston said earlier this year. Ultomiris offers less frequent administration than Soliris, but to date, Ultomiris carries 1 FDA-approved indication (PNH) to Soliris’ 4 (PNH, atypical hemolytic uremic syndrome, myasthenia gravis, and neuromyelitis optica spectrum disorder).

Alexion has also been highly reliant on Soliris for its revenue; last quarter, the drug brought in $980.8 million for the company, versus just $54.2 million for Ultomiris.