Merck (NYSE:MRK)is returning all of the rights of an antifungal compound to Scynexis after the drug giant decided it did not want to pursue that compound anymore.

The compound, MK-3118, was the product of a 2002 license and research agreement between Merck and Research Triangle Park-based Scynexis. The collaboration focused on discovering and developing treatments for invasive fungal infections such as Candida and Aspergillus. MK-3118 was the first compound from the collaboration to complete phase I and be ready for phase IIb studies.

MK-3118 is a semi-synthetic derivative of the natural product enfumafungin. It’s in a class of antifungal agents called glucan synthase inhibitors that work by blocking an enzyme in fungi. While glucan synthase inhibitors have been effective in hospitals, they are currently available only in intravenous dosage form. MK-3118 us being developed as a pill.

Scynexis said Merck decided to return MK-3118 after reviewing and prioritizing its infectious disease portfolio. Scynexis will receive all of the rights to the compound, including the preclinical and clinical data to date. Scynexis said it plans to advance the compound, now called SCY-078, while also evaluating other opportunities to partner the drug. But Merck will still be eligible to receive milestones and royalties on the compound, depending on its progress. No financial details were disclosed.