That "meaningless" four-letter suffix the FDA wants to add to the core drug substance to distinguish individual reference biologics and biosimilars? It's, well, meaningless. And confusing. And unnecessary. It also could stifle the biosimilars market in the U.S. before it has a chance to breathe.

That's the gist of the three posted comments to the FDA's proposed rule that would assign new nonproprietary names to six biologics, including the nation's first biosimilar and its reference biologic. Although they hadn't been posted as of Tuesday, the agency has received at least nine other comments on the rule. (See BioWorld Today, Aug. 28, 2015.)

"The 'meaningless' suffixes instantly create difficulty. . . . As physicians and pharmacists often make it a point to refer to drugs by generic name, we would encounter tremendous difficulty trying to 'remember' which random four-letter suffix belongs to each of the 'brand' names," Justin Nicholls, a pharmacy utilization manager, told the agency.

He noted that the FDA's naming proposal "fundamentally interferes with standard procedures by adding an unnecessary variable that adds uncertainty to perception." Nicholls said multiple products with a single nonproprietary, or "proper," name such as filgrastim likely would encounter less resistance from physicians and pharmacists than would three biologics named filgrastim-bflm (the proposed proper name for Sandoz Inc.'s Zarxio, a biosimilar), filgrastim-jcwp (Amgen Inc.'s Neupogen, the reference product) and filgrastim-vkzt (Teva Pharmaceutical Industries Ltd.'s Granix, developed as a "new" biologic).

The name changes also would have "tremendous financial implications," Nicholls said, as the manufacturers of the renamed drug products would have to change all their labeling. "Please ask yourself: 'Is this reasonable and necessary?'" he advised the FDA. His solution? Scrap the proposal and follow the model used in Europe – a model that makes no distinctions between the reference biologic and its biosimilars.

An unidentified biopharma worker pointed out the impact the distinct suffixes could have on the nascent biosimilar market. "This new regulation alone could set back years of biosimilars being used at their full potential by planting a seed of doubt and confusion into the minds of . . . users, both health care practitioners as well as patients. . . . Regulators need to show confidence that biosimilars have indeed shown bioequivalency and can be used just as the originators have been used for many years," the worker said.

A third comment on the proposed rule didn't object to the concept of unique names, but the random letter scheme the FDA suggested is "nonsense," the unidentified commenter said, adding, "just make it a simple system."

In addition to the dozen comments on the proposed rule, at least 90 companies, groups and individuals have chimed in on the agency's draft guidance that accompanied the rule. While the rule assigned new proper names to specific biologics, the guidance recommended the format for those names – the core drug substance and a random four-letter suffix.

The naming scheme is intended to help prevent inadvertent substitution of biologics that aren't deemed interchangeable, allow for biosimilar labeling carve-outs and support safety monitoring of all biologics on the market by making it easier to accurately track their usage in all settings.

When the FDA released the rule and guidance in August, it was on the fence about giving interchangeable biologics distinct names and asked those commenting on the guidance to weigh in on that issue.

The Immune Deficiency Foundation (IDF) did just that in the only comment the FDA had posted on the guidance as of Tuesday. The patient organization supported the agency's naming proposal and urged that it be extended to interchangeables. "We believe it is a safety issue that patients should know what biologic is being put in their bodies, including the manufacturer and whether a therapy is a biosimilar. The same can be said for prescribers as well," IDF said.

The group also urged the FDA to keep in mind the effect its decision would have on coverage and access. "When two products share the same suffix, it may be easier for an insurer to provide access to only one of the two, under the argument that these are two identical products and any formulary requirements are met by providing access to one of the two," IDF said. "This would create even more obstacles for our chronically ill, high-cost patients to access the treatments their physicians believe are necessary – a challenge that is already difficult in a world without interchangeable biosimilars."

Tuesday was the deadline for commenting on the draft guidance, but stakeholders have until Nov. 11 to respond to the proposed rule.

SECOND DRUG IPR GRANTED

Kyle Bass' Coalition for Affordable Drugs scored its second challenge to a drug patent, with the Patent Trial and Appeal Board (PTAB) accepting its inter partes review (IPR) petition against Celgene Corp.'s '501 patent.

The patent, which expires in August 2018, relates to a method of delivering a teratogenic drug to a patient while preventing delivery to a fetus, and it pertains to a risk evaluation and mitigation strategy related to Summit, N.J.-based Celgene's Revlimid (lenalidomide). PTAB noted that the patent also is being challenged in six U.S. district court cases.

The patent is "unimportant," RBC Capital Markets analyst Michael Yee said, especially since Revlimid is protected by numerous other patents that expire far later, including a polymorph patent that expires in 2027 or 2028.

Bass, a hedge fund manager with the Hayman Group, also filed an IPR petition against a Revlimid composition-of-matter patent. PTAB's decision to accept or reject that petition is due by Nov. 19. Composition-of-matter patents are generally thought "to be much stronger than other methods patents, so the chances of acceptance seem low" for that IPR, Yee said.

"Most of the Hayman IPRs have been rejected for review, and the group has filed numerous IPRs on the same patents and then re-files challenges again once rejected," Yee said. For instance, barely a week after PTAB rejected Bass' IPR petition challenging two patents for multiple sclerosis drug Ampyra (dalfampridine) in August, Bass filed a new petition against the drug's developer, Acorda Therapeutics Inc., of Ardsley, N.Y., requesting an IPR of four patents protecting the drug, including two patents that had been part of his original petition.

Through the Coalition for Affordable Drugs, Bass has filed dozens of IPR petitions challenging drug patents. Earlier this month, PTAB granted its first review of a Bass petition, which challenged the single patent listed in the FDA's Orange Book for Dublin-based Shire plc's ulcerative colitis drug Lialda (mesalamine). (See BioWorld Today, Oct. 16, 2015.)