It's a New Set of Rules for Insulin Products Under 351(k)

Based on an announcement last week, the longtime generics manufacturer Lannett would become among the first to file for insulin glargine product approval under the 351(k) Biologics License Application pathway.

Lannett’s progress through the 351(k) review process will be interesting to observe, said Ha Kung Wong, an intellectual property law attorney with Venable of New York.

Insulin products have previously tended to be approved under the 505(b)(2) pathway, under which applicants have had to do clinical studies to gain approval. Two phase 3 studies were done for Basalgar, Wong noted. So, it will be interesting to see whether the clinical testing requirements for Lannett’s insulin glargine candidate under 351(k) are as rigorous or less so, he said.

It will also be interesting to see whether or how easily Lannett’s insulin glargine obtains “interchangeable status,” which would mean pharmacists could decide on their own whether to fill prescriptions with this or Lantus. Much depends on the extent FDA’s interchangeability standards actually differ under the 351(k) pathway in practice for follow-on insulin products versus for other biosimilars, Wong said.

“Interchangeability status will give the follow-on insulin automatic substitution, depending on the state, at the pharmacy level, something that follow-on insulin via the 505(b)(2) pathway did not have access to. However, we know that interchangeability status typically requires additional testing,” he said.

He added that pursuant to the FDA’s guidance, if a biosimilar candidate under the 351(k) pathway passes a highly rigorous analytical assessment of biosimilarity to the reference product, an immunogenicity or “switching” study might not be required, assuming all other conditions are met. “Possibly, interchangeable status comes essentially automatically with biosimilar status for some follow-on insulins, which would make the 351(k) potentially more beneficial for those manufacturers,” Wong said, so this will be closely watched, too.

Besides a 505(b)(2) application, the other former route to approval for a follow-on insulin product was an Abbreviated New Drug Application, which unlike the 505(b)(2) pathway, offered the potential for 6 months of marketing exclusivity for the first filer approved as a generic.

The current guidelines on interchangeability indicate that, “depending on a number of factors,” a product approved as an interchangeable biosimilar may have as much as a year’s exclusivity, Wong said.

Also last week, the FDA approved an insulin glargine (Semglee) under the 505(b)(2) pathway. The drug automatically is deemed approved under section 351(a) of the Public Health Service Act of the Biologics Price Competition and Innovation Act. For the full story, click here.