Amgen Settles With Alexion on Soliris Biosimilar, Dropping Litigation and Getting a Release Date

As reported by several sources, Amgen and eculizumab maker Alexion Pharmaceuticals have come to an agreement on patent disputes that will allow Amgen to begin marketing a biosimilar version of Soliris^® in 2025.

Amgen has been developing ABP 959 for some time, and a phase 3 clinical trial in patients with paroxysmal nocturnal hemoglobinuria (PNH) is underway. The estimated completion date of this 18-month study is March 2022.

On May 29, Alexion Pharmaceuticals notified the US Securities and Exchange Commission that it settled with Amgen. Amgen filed a motion on June 1 that terminated the inter partes review (IPR) process, which disputed three Alexion patents. Big Molecule Watch reported that the initial hearing on the three IPRs was scheduled for June 1, which may have prompted the settlement. The three patents at issue were to expire in 2027.

The settlement itself is confidential, but it is nonexclusive and provides for royalty-free use of the patents. It clears the way for Amgen to produce and market its eculizumab biosimilar in the United States (pending Food and Drug Administration approval of ABP 959) on March 1, 2025.

Eculizumab is an interesting target for biosimilar development, in that it treats rare diseases. One of its primary indications, PNH, is a very rare disorder, affecting only up to five people per million population. Its other indications include atypical hemolytic uremic syndrome, myasthenia gravis, and neuromyelitis optica spectrum disorder. In 2018, Alexion introduced a follow-on drug, Ultomiris^®, which is a meant to be given every eight weeks, as opposed to every two weeks in patients with PNH. The company reported that the majority of patients who were taking Soliris for PNH have been converted to the newer agent.

For the first quarter of 2020, Alexion stated that Soliris sales were slightly more than $1 billion (6% higher than Q1 2019). In comparison, Ultomiris, which does not have the full set of indications that Solirisdoes, earned $223 million for the same quarter and was growing rapidly since its introduction. Without a biosimilar appearing until 2025, the question remains as to whether payers will get on board with the conversion to the follow-on agent.