By Franco Pissani, Ph.D.
After a couple of losses at Circuit Courts, Sandoz’s battle to invalidate both of Amgen’s patents on Enbrel has seemingly come to a dead-end after SCOPUS declined their petition to review the case. This 9-1 decision gives Amgen another decade of exclusivity for their blockbuster drug Enbrel.
In a previous blog, How Pharma Can Prepare for the Patent Cliff, we discussed strategies that pharma companies can employ to prepare for an impending loss of exclusivity. In that blog, we stipulated that innovative ligation methodologies will be an additional strategy employed by pharma companies. The legal teams at Roche and Immunex/Amgen expertly demonstrated a successful contract and litigation strategy.
Amgen and Sandoz have been in a legal battle over the anti-TNF receptor – IgG fusion protein for several years. Amgen acquired patent rights to their blockbuster autoimmune therapy, Enbrel (etanercept) through the acquisition of Immunex, who licensed it from Roche. Two patents protected this biologic through 2018. Considering this impending LOE, Sandoz developed and sought regulatory approval for their biosimilar Elrizi in 2018.
Expecting Amgen/Immunex – Roche’s patent on Enbrel to expire, Sandoz sought – and secured – FDA approval for the TNFR-IgG fusion protein biosimilar, Erelzi. While Sandoz admitted to infringing on both of Amgen’s patents, they claimed that these should be invalidated based on a legal doctrine (Obviousness-type Double Patenting, or ODP) that prohibits the issuance to a single inventor of claims in a second patent which is not “patentably distinct” from the claims of a first patent”. In other words, patent owners cannot extend patent protection beyond the statutorily afforded term. However, creative licensing agreements between Roche, Immunex, and Amgen successfully thwarted the challenge by Sandoz by circumventing a key criterion of the ODP doctrine. Indeed, ODP restrictions only apply when the patents are owned by the same entity and the agreements between Amgen/Immunex and Roche went right up to the line of ownership without crossing it. The successful strategy awards Amgen another decade of exclusivity for their blockbuster drug.
The ruling in this case has significant repercussions on the commercialization of biosimilars. In addition to the grueling process of developing biosimilars – selection of appropriate targets, designing suitable manufacturing processes, rigorous evaluation for similarity in lieu of preclinical and clinical studies, etc. – biosimilar manufacturers now must maintain a keen awareness of the patent landscape of their reference biologics. Despite thorough evaluation of patent issues, including infringement and validity in establishing a risk profile for the biosimilar, certain aspects of agreements that can derail a commercialization strategy are only revealed once litigation has been initiated, during discovery. This additional risk may ultimately impact the pricing landscape of biosimilar products. Thus, the commercialization strategy for biosimilar assets will have to be adjusted to account for additional risks that may be uncovered in the due diligence process.