FDA Approval Eludes Amgen for Biosimilar Trastuzumab

Amgen will have to wait a bit longer to market its biosimilar version of trastuzumab . On Friday, June 1, the Food and Drug Administration (FDA) rejected Amgen’s 351(k) application for its Herceptin® biosimilar. biosimilar trastuzumab approvalIn a brief press release, Amgen announced receiving the complete response letter for ABP 980. In the announcement, it also said that the delay in its biosimilar trastuzumab approval should not “impact our US launch plan.” This may signal that even if it received approval, it would not market the biosimilar trastuzumab immediately.

The timing of the FDA announcement on the biosimilar trastuzumab approval contrasted with the near-simultaneous marketing authorization of this same trastuzumab biosimilar by the European Medicines Agency. The biologic will be marketed in Europe under the trade name Kanjinti™.

Mylan/Biocon’s Ogivri™ remains the only biosimilar trastuzumab approved by the FDA. It is not yet marketed, however. Separate trastuzumab biosimilars by Teva/Celltrion and Pfizer have been stalled by the FDA. Samsung Bioepis’s entry is due for an FDA approval decision in the fourth quarter of 2018.

In related biosimilar news… in September 2017, Mylan filed a 505(b)2 application for its insulin glargine agent. The manufacturing duo of Mylan and Biocon received a rejection from the FDA on June 1. The complete response letter specified issues raised by a change in manufacturing site (from one in India to a new facility in Malaysia). As reported by the Economic Times, the complete response letter was expected by Mylan and Biocon. They told the Economic Times, “Together, Mylan and Biocon are already executing on all required activities we had agreed upon with the FDA, and they are progressing according to plan,” the statement said.

Although insulins are not currently approved through the 351(k) biosimilar pathway, they are among the “transitional agents,” which by 2020 will be considered biosimilars by the FDA.

Two New Trastuzumab Biosimilars Submitted for FDA Approval

The team of Mylan and Biocon may have some company in the biosimilar competition for Herceptin® (trastuzumab). Two additional partnerships announced the filing of their 351(k) applications for trastuzumab biosimilars.

Amgen and Allergan are hoping ABP 980 will have smooth sailing through the approval system. The phase 3 study in patients with early-stage HER2-positive breast cancer was completed in January 2017, with study results reported in July 2016. This study enrolled 725 patients, and yielded positive results in terms of safety, efficacy, and similarity to the originator product.

Celltrion submitted their product application for CT-P6 (Herzuma™) to the FDA on July 30 as well. Its partner Teva will distribute and market the product in the US, upon approval. The phase 3 study for this product is ongoing, but the results of the primary outcome data from 549 patients were published in June 2017. The outcomes were found to be similar to those of Herceptin.

Mylan and Biocon had submitted their biosimilar version on November 1, 2016. The FDA Advisory Committee reviewing their product gave it their unanimous support on July 13, and the final FDA decision is expected by September 3, 2017. If approved, Mylan will have at least a 9-month time advantage to get their foot in the door of a $2.6 billion trastuzumab marketplace.

This sets up a very interesting pricing dynamic. I had originally thought that this scenario might occur first with adalimumab after the patent litigation was resolved, but it is very possible that multiple biosimilars for trastuzumab may be launched first and in a very short timeframe.

Assuming Mylan gets the nod from FDA first, they have a couple of obvious paths they can travel: (1) launch with a substantial discount in an attempt to capture as much marketshare as possible before the other market entrants arrive or (2) launch with a modest (but attractive) discount in an effort to maximize their revenue while their product remains the sole biosimilar available. It will then be a guessing game as to how Amgen/Allergan and Celltrion/Teva play their turns in this poker game. With sudden market competition, such as their launches could potentially pose, payers may play a bit of a waiting game themselves, to see where the chips fall.