FDA to Pfizer: To win OK for Herceptin biosimilar, fork over more 'technical' info

The FDA issued a Complete Response Letter for Pfizer's Herceptin biosim. (Roche)

Pfizer is no stranger to biosimilar setbacks, and the company suffered another on Monday with the FDA's decision to turn away its application for a knockoff of Roche's Herceptin. 

The FDA issued a Complete Response Letter seeking "additional technical information," Pfizer reported Monday. The company didn't offer more details or disclose a timeline for resubmitting its application. The FDA didn't ask for additional safety or clinical data, the drugmaker pointed out. 

A Pfizer spokesperson told FiercePharma that the agency's request for info isn't related to manufacturing, which has tripped up Pfizer's biosim development in the past. 

Last June, regulators turned away the company's biosimilar version of Amgen's anemia drug Epogen because of problems with a fill-finish facility in McPherson, Kansas. The decision followed a 2015 rejection that sought more clinical data. 

RELATED: FDA rejects Pfizer's Epogen biosimilar for the second time 

And even after that second Epogen biosimilar rejection, FDA reviewers again found issues at the plant during an October 2017 inspection.

Aside from regulatory and manufacturing stumbles, Pfizer faces a legal challenge from Roche, which is seeking to protect billions in U.S. sales for Herceptin. In November, Roche sued Pfizer for infringement on 40 patents, asking a court to block a potential biosim launch. Pfizer said it will defend its "position vigorously and in the appropriate venue."

Increasingly over the next few years, Roche cancer blockbusters Rituxan, Herceptin and Avastin are forecast to come under biosim attack. 

Aside from Pfizer, Samsung Bioepis and Celltrion are working on their own biosim programs. Celltrion recently received a CRL for its application, and Samsung's app is under review at the agency, according to the company's online pipeline. Mylan and its partner, Biocon, won FDA approval in December, but timing for their launch is confidential under a licensing agreement with Roche. Samsung's copycat is approved in Europe.

RELATED: With $2.5B in Herceptin sales on the line, Roche sues Pfizer for biosim patent infringement 

But even if Pfizer makes it to market with the Herceptin biosim, additional hurdles remain. As the company has experienced with Inflectra—the first biosimilar to Johnson & Johnson's Remicade—it's not easy to steal share from an entrenched blockbuster in the U.S. 

Pfizer recently sued pharma rival Johnson & Johnson for what it calls "anticompetitive" contracting that's prohibiting Inflectra from poaching market share. The company said J&J has tied rebates for existing Remicade patients to the stipulation that payers don't use biosims, blocking competition. J&J responded that Pfizer isn't offering enough value to win business.