HONG KONG – Japan could welcome nine biosimilar drugs to the market in the coming years, thanks to a commercialization deal between Amgen Inc. and local company Daiichi Sankyo Co. Ltd. The Thousand Oaks, Calif.-based pharma major said it inked a deal with Daiichi Sankyo to bring nine of its biosimilar drugs, some now undergoing late-stage clinical studies, to the Japanese market.

Among the drugs are biosimilars of adalimumab (Humira, Abbvie Inc.), bevacizumab (Avastin, Roche Holding AG) and trastuzumab (Herceptin, Roche Holding AG).

"Other biosimilars than adalimumab, bevacizumab and trastuzumab are not disclosed," said Ogiwara Koji, manager at the communication department of Daiichi Sankyo. "We don't disclose information on the detailed indications we plan to apply for in Japan; however they would be basically the same as the originator drugs in Japan."

The Japanese company also declined to comment on the timeline for regulatory approval application of those drugs.

Under the terms of the agreement, Amgen will develop and manufacture the biosimilars. Daiichi Sankyo will pursue marketing approval in Japan as well as take up the distribution and commercialization responsibilities in Japan. Amgen will help promote the product in Japan but will retain the rights to distribute and commercialize the drugs outside of the country.

Amgen has a comprehensive biosimilar pipeline, which also includes biosimilars to rituximab (Rituxan, Roche Holding AG), infliximab (Remicade, Johnson & Johnson) and cetuximab (Erbitux, Bristol-Myers Squibb Co.) for the treatment of autoimmune diseases and cancers. There are three additional biosimilar programs in development that Amgen has yet to reveal.

This is not the first time the two companies have worked together. Their collaboration tracks back to 2007 when Amgen granted Daiichi Sankyo exclusive rights to develop and commercialize denosumab in Japan. Denosumab is a human monoclonal antibody for the treatment of bone loss conditions, including osteoporosis and bone metastases. The drug was approved in 2013 in Japan, where it is branded Pralia.

But Daiichi Sankyo also is working on a separate deal to develop a biosimilar of an Amgen drug. In 2012, it partnered with San Francisco-based Coherus Biosciences Inc. to co-develop the biosimilar version of Enbrel (etanercept) for rheumatoid arthritis in Japan. In January, the company said it achieved major objectives in the joint phase III trial of that drug, CH-0214, and expects to file the application for CHS-0214 before March 2017, the end of the current fiscal year.

If approved, it would become the first domestically approved biosimilar etanercept.

"At the current time, the only [Daiichi Sankyo] biosimilar for the Japan market in clinical trial phase is CHS-0214. However, we are evaluating both proprietary and collaborative options for other biosimilars," William Hennings, from the communication department of Daiichi Sankyo, told BioWorld Asia in an interview following the CHS-0214 release. And the company has explored more possibilities – the Amgen biosimilar agreement came only six months later.

Seizing opportunity in Japan

Just like other Asian countries, Japan is an exciting market for biosimilar makers.

"Now is certainly a good time for pharmaceutical firms to consider their position in the [Japanese] biosimilar market," said Ang Wei Zheng, pharmaceutical and health care analyst at BMI Research. "The Japanese government continues to follow through with its promise and objective of rationalizing pharmaceutical expenditure, which will be a plus for biosimilars."

Japan's competitive landscape will also be a reason for firms to make a move now. Attracted by the market potential, many companies have already started to move into that field, from South Korean drugmakers such as Celltrion Inc., which received approval in 2014 for its biosimilar of infliximab, to Indian firms like Biocon Ltd. and to multinational pharmaceutical partners like Eli Lilly and Co. and Boehringer Ingelheim GmbH, which received approval for their biosimilar insulin glargine in 2015 and 2016.

However, seizing opportunities in the Japanese biosimilar market comes with challenges.

Since biosimilars are not identical to their reference drugs, many physicians are reluctant to prescribe them to patients, especially without notifying them of the differences and risks of biosimilars. Japan is known for its strict requirement for drug quality, so products have to be of high quality to earn places in the market.

"We believe that Amgen will supply the biosimilars with high quality because they have been already supplying denosumab with high quality to us," Ogiwara told BioWorld Asia.

"Under the existing regulations, automatic substitution of biosimilars by a pharmacist is not allowed in Japan, and biosimilar products will have distinguishable names from their reference products," said BMI's Ang. "Sandoz's biosimilar of filgrastim in Japan, for example, is named Filgrastim BS Injection. As such, extensive stakeholder engagement will be integral to win doctors, pharmacists and patients acceptance with regards to biosimilars."