HONG KONG – Celltrion Inc. had a seven-year partnership with Pfizer Inc.'s new subsidiary, Hospira Inc., to develop two biosimilar assets, but those ties were severed last week when Pfizer cut loose the rights for the two assets, saying that it plans to focus on a pipeline of in-house developed biosimilars.

Celltrion is a different company than it was when it first partnered with Hospira and is much better positioned to take its products to the global market on its own.

"This is not devastating news for us, because we have at least 20 other distributional partners in America who would like to work with us," Benjamin Chang, assistant manager of Celltrion's IR team, told BioWorld Today. "Pfizer's Hospira had more advantage at that time, in 2007, because we hadn't even started clinical trials."

Chang also pointed out that Celltrion is the manufacturers of the biosimilars while Hospira is mainly responsible for sales.

Pfizer completed the acquisition of Hospira in September. To eliminate the redundancies in Pfizer's biosimilar pipeline caused by the acquisition, the company decided to return the rights of a biosimilar to Roche's Rituxan (rituximab) and Herceptin (trastuzumab) for the treatment of arthritis and HER-2 positive breast cancer. (See BioWorld Today, Feb. 6, 2015.)

Pfizer is not cutting the connection with Celltrion altogether. Hospira still distributes a Celltrion-made biosimilar of Remicade, Remsima, in Europe as well as early stage biosimilar versions of Amgen's Neupogen and Neulasta. Under an agreement with European antitrust regulators, Pfizer has promised to sell the EU rights to a Remicade biosimilar of its own, which is now in phase III development.

Remsima is Celltrion's lead biosimilar product. It has already picked up regulatory approvals in 62 markets, including most recently in Australia, and plans to add 22 more to its spectrum. (See BioWorld Today, Aug 28. 2015.)

The sale of the biosimilar has hit Remicade's sales outside of the U.S. hard. In its third quarter earnings report, Johnson & Johnson reported a decrease of 18.3 percent in the international sales of the drug and a 41.9 percent drop in U.S. export sales. The total drop was 9.5 percent in worldwide sales. Sales of Remicade in the first nine months of 2015 added up to $4.9 billion, 6.1 percent less than the $5.2 billion recorded during the same period in 2014.

For Pfizer, streamlining its drug pipeline makes sense.

"The biosimilars market is still in the process of forming in different regions of the world," said John Young, president of Pfizer's Global Established Pharma.

"We're very excited to be playing a leading role in the formation of that market with the portfolio that we now have, both of our own legacy Pfizer pipeline of biosimilars, but also the end market portfolio of products from Hospira."

The company said that the market opportunity for biosimilars is about $100 billion in revenues. Those revenues are likely to come from patented branded biologics that will lose patent protection over the next five years. The global market for biosimilars is expected to grow from $1 billion today to between $17 billion and $20 billion by 2020.

Pfizer already has an in-house Rituxan biosimilar that is currently undergoing phase III trials for lymphoma. It also has a Herceptin biosimilar in late-stage trials. Both drugs could prove redundant with Celltrion's products.

"Pfizer views biosimilars as playing a key role in the future of health care," Pfizer's APAC media relations manager Allyanna Anglim, told BioWorld Today. "Pfizer currently has 10 distinct biosimilar molecules in different stages of development. . . . We have three commercialized products in select markets: Retacrit (epoetin zeta), Nivestim (filgrastim) and Inflectra (infliximab)."

Inflectra, for example, has launched in more than 35 markets.

There are another seven drugs in its pipeline: bevacizumab, adalimumab, rituximab, trastuzumab, pegfilgrastim, denosumab and ustekinumab. In July, Pfizer began dosing patients in a multinational phase III trial of PF-06410293, a potential biosimilar to Abbvie Inc.'s Humira (adalimumab).

The phase III trial will evaluate the efficacy, safety and immunogenicity of the candidate plus methotrexate and adalimumab sourced from the EU plus methotrexate in subjects with moderately to severely active rheumatoid arthritis who have had an inadequate response to methotrexate monotherapy.

"We're the number two biosimilars company in the world," said Pfizer's chairman and CEO, Ian Read, in the company's third quarter earnings call on Oct. 27.

"Through the acquisition [of Hospira] we now have three marketed products and more than seven years of in-market experience with one of these products. . . . Our biosimilars pipeline is now one of the largest pipelines globally."

"Clearly there are a number of factors that will drive and influence the evolution of that marketplace, such as substitutions, such as the labels, that extrapolation of labels that products that come to market will have," said Young. "Overall we're really well placed to draw on the heritage as a really strong biologics company in R&D and in manufacturing."