Mobius Therapeutics announced that it has received orphan drug status for Mitosol to prevent the recurrence of pterygium after surgical excision. The active ingredient, mitomycin has been used without FDA approval for eye surgeries since the mid 1960’s. Due to its long history of use, the FDA did not require that Mobius conduct clinical trials. According to Mobius, the key issue was developing a stable formulation. Thus, CMC is a chief component of the NDA filing.