Sandoz' filgrastim biosimilar is blocked from US distribution by a federal court

First US biosimilar is hung up in litigation with Amgen; meanwhile, Amgen and others form a Biosimilars Forum and FDA issues some final biosimilar guidance

There was a buzz when FDA approved Sandoz’ application for a biosimilar form of Amgen’s Neuprogen; it would be the first biosimilar to enter the US market under the 2010 Biologics Price Competition Act. (Sandoz already markets the product, provisionally called Zarxio, widely outside the US.) Now, according to a report from The Reporter, a California legal publisher (registration required), the US District Court in San Francisco has issued a preliminary injunction barring further Sandoz action, and arguments will be heard in June on the litigation. The legal issue turns on the level of disclosure of manufacturing methods that needs to be disclosed to FDA as part of the original Sandoz application, which is also being litigated in other US courts.

This decision appeared just as CMS is setting a “Healthcare Common Procedure Coding System” HCPCS) public meeting to be held on May 7 for identifying Zarxio and other products (which is not the same as, but serves similar functions to, FDA’s rules on names and labels of drugs). And that is preceded by a letter that several Republican senators on the Health, Education, Labor and Pensions Committee sent to FDA, questioning the decision to approve Zarxio with a “placeholder” name (filgrastim-sndz), and “urging [FDA] to immediately finalize all guidance regarding the approval of biosimilar drugs.” Which FDA proceeded to do in late April, for five of eight categories of guidances that it plans to provide.

The guidances that have been issued provide some clarity around the degree of biosimilarity question, and recommends the use of human pharmacokinetics and pharmacodynamics (PK and PD) studies as part of the approval process. “Residual uncertainty” (as FDA calls it) should be addressed by a comparative study of the biosimilar and the original (reference) product. FDA is sticking with its “totality of evidence” approach to authorizing interchangeability (and by implication, a naming convention), which is likely to be fought out in courts for every new biosimilar on the horizon.

Meanwhile, 11 of the leading biopharma companies pushing for biosimilarity commercialization have formed a new trade group, the Biosimilars Forum, “solely dedicated to expanding patient access to biosimilars in the United States.” The 11 are Actavis, Amgen, Boehringer Ingelheim, Coherus BioSciences, EMD Serono, Hospira, Merck, Pfizer, Samsung, Sandoz and Teva. (Hospira is the process of being acquired by Pfizer.) That group lines up approximately in conflict with the Alliance for Safe Biologic Medicines, formed several years ago to push for maintaining distinct names for biosimilar products in the belief that that ensures patient safety. (ASB also maintains the questionable stance that substitability of one biologic for a biosimilar is a matter of state and not federal rules, and has been pushing state legislatures to adopt rules to that effect.) Genentech and, paradoxically, Amgen are the sole biopharma members of the Alliance, although the Biotechnology Industry Organization, the trade group of biotech manufacturers generally, is also a member.

A strange-bedfellows environment hovers around all this that is keeping a lot of law firms busy. Amgen is tangling with Sandoz over the Neuprogen/Zarxio litigation, while Sandoz appears to have crossed the legal finish line in litigation with Teva over generic Copaxone (which was approved by FDA in mid-April; note that Copaxone—glatimer acetate—is not a biologic).