Amgen faces patent infringement claims on big-selling osteoporosis drug Evenity

In developing its osteoporosis drug Evenity more than a decade ago, it is alleged in court documents that Amgen discussed forming a potential partnership with a small company from Kansas.

Those discussions never amounted to a deal. Now, 11 years later, the Kansas company is suing Amgen for patent infringement.

The suit, filed in U.S. District Court in Massachusetts, claims Amgen's Evenity infringes on three of patents owned by OssiFi-Mab, including one that was granted last month. The first patent was awarded in 2012, the same year that Amgen and the Kansas company talked of a potential collaboration, according to the suit.

The patents refer to the “discovery of methods of increasing bone density via administration of a sclerostin antagonist together with an antiresorptive,” the complaint says. Evenity works in part by decreasing bone resorption by inhibiting the action of sclerostin, which helps regulate bone metabolism.

Amgen declined to comment on the suit.

Evenity, which was approved in 2019, is on a blockbuster trajectory. It generated sales of $787 million last year, a 48% increase from 2021. The drug is for post-menopausal women at severe risk of bone fractures.

The patents in question were invented by Dera Ellies, Ph.D., who founded OssiFi subsidiary OsteoGeneX in 2006.

OssiFi is requesting a jury trial and an award of damages in addition to royalties on past and future sales.

Claims from small companies seeking royalties from large ones for successful drugs aren’t unusual. Two years ago, for example, Novartis was ordered to pay California company Plexxikon $178 million after a jury concluded the pharma giant infringed on patents with its skin cancer drug Tafinlar.

Plexxikon alleged that GSK acquired knowledge to develop the drug during partnership discussions. GSK later dealt the drug along with others to Novartis in a massive asset swap.  

Amgen and its partner on Evenity, UCB, had a rocky road to approval as trials turned up cardiovascular red flags in 2017. But the companies worked through those issues to notch an FDA advisory committee thumbs up by an 18-1 vote.

Evenity’s label includes a black box warning for myocardial infarction, stroke and cardiovascular death.