Samsung Bioepis Scores FDA Approval of Ontruzant, the Third Biosimilar Trastuzumab

The US Food and Drug Administration (FDA) announced on January 18, 2019 the approval of a new biosimilar version of trastuzumab. Produced by Samsung Bioepis, this agent was dubbed Ontruzant (trastuzumab-dttb).

This is the third trastuzumab biosimilar approved by the FDA, following those by Mylan and Biocon in December 2017 (Ogivri®) and Teva and Celltrion last month (Herzuma®). As with biosimilars other than Herzuma and the reference biologic Herceptin®, this agent is approved for use in the treatment of HER2-overexpressing breast cancer and the treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma. Herzuma is not approved for the latter indication.

As with Renflexis®, Samsung Bioepis’ first FDA-approved biosimilar, Merck will market the product in the US when launched. No launch date has yet been revealed.

Mylan and Biocon had signed a licensing agreement with Roche, the manufacturer of Herceptin, which ended their patent fight, but which delayed launch. Teva and Celltrion have not yet disclosed whether a similar deal has been reached with Roche. Pfizer has an investigational trastuzumab biosimilar, and they too have signed a licensing agreement with Roche.

FDA Approves Celltrion and Teva’s Herceptin® Biosimilar

On December 14, the US Food and Drug Administration gave its approval for a new trastuzumab biosimilar (Herzuma™). Manufactured by Celltrion and marketed in the US by Teva, this agent has been designated trastuzumab-pkrb.

The decision marks the second trastuzumab biosimilar approval, and the 16th biosimilar agentthat has made it through the 351(k) regulatory pathway.

Herzuma was approved for a single indication: the treatment of HER2-overexpressing breast cancer. Unlike the other trastuzumab biosimilar, Ogivri®, and Herceptin, Herzuma does not carry the extrapolated indication for the treatment of HER2-overexpressing metastatic gastric or gastroesophageal junction adenocarcinoma.

Originally submitted for approval by Celltrion in July 2017, the FDA issued a complete response letter because of plant manufacturing issues. A year later, after addressing these problems, Celltrion refiled its 351(k) application (June 2018).

Celltrion has launched Herzuma in Europe and elsewhere with marketing partners other than Teva. Neither Celltrion or Teva have announced at this time when the US launch may occur or how it will be priced. Partners Mylan and Biocon, makers of Ogivri, and Pfizer, the manufacturer of a potential competitor, have signed licensing agreements with Roche, makers of the reference product to delay launch.

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.