The FDA has given its final word on how sponsors of implantable minimally invasive glaucoma surgical devices should conduct clinical and nonclinical studies to support a premarket approval.
Sponsors should follow patients during clinical studies for at least 12 months prior to submitting a premarket application for MIGS devices, according to the final guidance. If follow-up will be less than 24 months, sponsors should provide justification based on a benefit-risk analysis.
The endpoint for primary effectiveness should be the percentage of subjects with a reduction of at least 20 percent in mean diurnal intraocular pressure from baseline. The secondary endpoint should be the mean diurnal IOP change from baseline.
Also, the FDA recommends nonclinical testing, saying it should be performed on the finished sterilized product that is intended to be marketed. Biocompatibility testing should consider factors such as cytotoxicity, sensitization, ocular irritation, genotoxicity and carcinogenicity.
Bioabsorbable materials should be tested for toxicity, with assessments continuing until the polymer is no longer present in the tissue, or until the biological tissue response is demonstrated to be stable, the guidance says.
Twelve comments were submitted, including some addressing the inclusion of pre-perimetric glaucoma — optical coherence tomography changes and optic nerve changes without any field abnormalities. But, the FDA does not believe pre-perimetric glaucoma should be included in interventional studies because there are differing expert opinions about whether the condition warrants surgical treatment.