BioCryst Pharmaceuticals (BCRX -0.68%) and privately held Presidio Pharmaceuticals today announced the termination of the companies' merger agreement, originally entered into Oct. 17. The merger was scheduled to close in the first quarter of 2013, and the all-stock transaction valued Presidio at approximately $101 million. Presidio focuses on hepatitis C treatments.

"Although the original rationale for the merger had merit, the parties determined that terminating the merger was in the best interest of both companies and their respective shareholders at this time," the companies said. Dissolution of the merger agreement has been approved by the boards of directors of each company.