Don’t Expect All-Out Biosimilar Competition for Herceptin—Just Yet

Five trastuzumab biosimilars have been approved for marketing in the US, and the composition-of-matter patent for the reference product, Herceptin®, expires June 30, 2019. That doesn’t mean we’ll see a jail break of competition, like that seen in the EU last October with adalimumab’s patent expiration. Yet there has been heavy interest in capturing a slice of Herceptin’s $2.9 billion US sales (in 2018).

Three manufacturers have signed licensing agreements with Genentech (subsidiary of Roche). In March 2017, Mylan signed the first agreement for its product Ogivri®. Its marketing partner is Biocon. In December 2018, Pfizer followed suit for its recently approved agent Trazimera®. None of the parties have indicated when a biosimilar agent will be launched. At the end of December, Celltrion and Teva came to a similar agreement on its Herzuma® biosimilar.

Herceptin patent litigation

According to Goodwin’s Big Molecule Watch, Roche’s infringement claims against Samsung Bioepis (Ontrusant®) and Amgen/Allergan (Kanjinti®) are still being litigated. For Genentech v. Samsung, the bench trial is slated to begin December 9, 2019. In addition, Samsung Bioepis is appealing the Patent Trial and Appeals Board ruling regarding the validity of Herceptin’s method of use patents. Separately, Genentech is challenging the PTAB’s decision that two other Herceptin patents were invalid. There’s a whole lot here that needs to be resolved (or settled).

In the case of Amgen and Allergan, Genentech originally brought suit claiming 38 patents were infringed (in June 2018). In July 2018, Genentech reduced this figure to less than half (17). A month later, Amgen responded to the suit. Little information is available on timing of next steps.

Based on this information, it is difficult to know just when the first trastuzumab biosimilars will be launched. If Genentech followed Abbvie’s example in its 2023 sequencing of adalimumab biosimilars, one might expect Mylan’s product to be available first, perhaps as early as this summer, with Pfizer’s and Celltrion to follow perhaps six months later.

Yet, unlike the Abbvie agreements, none of the Genentech licensing settlements were made public (other than the actual dates of the agreement). Keep in mind, Herceptin was first approved by the FDA in October 1998. In 2018, the drug’s sales in the US and EU combined was over $4.7 billion. Is 21 years of market exclusivity to anyone’s benefit, other than the manufacturer? Since 2006, US drug sales of Herceptin have been greater than $1 billion annually. If the biosimilar launches do not occur shortly, this may be a good test case of the Federal Trade Commission’s commitment to clearing patents in the name of competition.