European Patent Office Delivers Setback to Alexion on Soliris Patents

Last week, Alexion disclosed in a filing to the US Securities and Exchange Commission that the European Patent Office (EPO) did not grant Alexion its request for 2 patents on its brand-name eculizumab product, Soliris, a C5 complement inhibitor that treats rare and ultrarare diseases.

The Form 8-K, dated September 5, indicates that the office declined to grant patent application 3124029, which covers a pharmaceutical composition comprising an antibody or antibody fragment binding to C5 for use in treating a patient with paroxysmal nocturnal hemoglobinuria (PNH), and patent application 3167888, which relates to the composition of matter of eculizumab.

Alexion says that it is evaluating its options with respect to appealing the decision on these patents once it receives the office’s written decision.

The setback comes after the EPO revoked another patent for the drug, 2359834, following a multiparty opposition proceeding earlier this year. That patent had covered a pharmaceutical composition comprising a single-unit dosage form of an anti-C5 antibody or antibody fragment. Alexion signaled that it would appeal in that matter as well, and noted that, while an appeal is pending, the claims in the patent remain enforceable.

On the US front, Alexion faces challenges from Amgen, which recently saw the Patent Trial and Appeal Board institute 3 inter partes review proceedings for patents on eculizumab. The first is related to a method of treatment related to paroxysmal nocturnal hemoglobinuria by complement inhibition, the second concerns formulation, and the third is related to composition of matter.

Meanwhile, Amgen forges ahead with its development of its proposed biosimilar, ABP 959. The biosimilar developer is recruiting patients for a randomized, double-blind, phase 3 study of the proposed biosimilar in patients with PNH. Amgen expects to enroll 40 participants in this crossover assignment study that is expected to be completed in 2021.

Alexion also faces challenges from Samsung Bioepis, which has also begun enrolling patients in a phase 3 clinical trial of its proposed biosimilar—SB12—in PNH. Samsung Bioepis also expects its trial to be completed in 2021.