Allergan Wants More Changes in Cyclosporine Guidance
Allergan says that a revised FDA draft guidance on cyclosporine has improved, in certain important aspects, the scientific rigor of analyses suggested in the earlier version, but still leaves open some “fundamental gaps that prevent the 2016 draft guidance from describing in vitro analyses that could be adequate on their own to allow FDA to judge whether a proposed generic cyclosporine ophthalmic emulsion is bioequivalent to Restasis.” The firm’s 4/18 comment letter says the revised draft does not address the basic problem with relying on in vitro analyses to establish bioequivalence to Restasis, which is that to date no in vitro analyses for the product have been validated as a proxy for in vivo bioavailability.
The letter asks that the agency address in vitro release method, methodology to assess globule sizes, drug distribution in different phases of the emulsion, the lack of stated ranges for other analytical parameters, evaluation of multiple products and replicates, and the notion that non-biological complex drugs require more thorough analysis to evaluate bioequivalence.