MC-21

MC-21 was a Puerto Rico-based pharmacy benefit management company focused on designing, implementing, and administering prescription benefit programs for commercial plans, employer groups, and government healthcare programs. The company operated in managed care rather than drug R&D, offering services such as pharmacy claims administration, formulary and utilization management, pharmacy network services, and related clinical and cost-containment programs. In 2018, MC-21 was acquired by ProCare Pharmacy Benefit Manager, and the combined PBM operations were subsequently rebranded under the MC-Rx name. As a result, MC-21 appears to survive primarily as a legacy corporate and brand identity rather than as a standalone biotech or pharmaceutical developer.