Medical/clinical science liaisons (M/CSLs) play an important role in disseminating complex clinical and product information that assists players in making critical decisions that impact market access. HIRC's report, Best in Class Medical/Clinical Science Liaison Customer Insights, provides nominations of the best medical/clinical science liaisons, as well as the descriptive factors that define industry excellence. The report addresses the following questions:

• Which very large, large and mid-size firms' medical/clinical science liaisons receive the most best-in-class nominations?
• Which firms lead in best medical/clinical science liaison nominations across health plan pharmacy directors, health plan medical directors, and pharmacy benefit manager executives?
• Which M/CSL attributes operationally define the best-in-class?
• Which manufacturers receive the most nominations for providing the best "medical value story" in the last 12-18 months? What do the best value stories most often include or communicate?

Key Finding: The best M/CSLs excel in their role as an information provider of clinical insights, demonstrate deep therapeutic area and product knowledge, and are responsive to customer needs.

Medical/Clinical Science Liaisons from Sanofi are Most Frequently Nominated as Best-in-Class. HIRC queried 68 commercial health plan and pharmacy benefit manager key decision-makers to learn which firms' medical/clinical science liaisons are best-in-class. Sanofi leads with the most best-in-class nominations from managed markets customers, followed by AbbVie, Boehringer Ingelheim, Lilly, and Novo Nordisk.

The full report provides a complete listing of best MCSL nominations as well as the rationale behind the nominations.

Defining Best-in-Class Medical/Clinical Science Liaisons. Managed markets customers were asked to explain their rationale for best-in-class medical/clinical science liaison nominations. Analyses reveal that their evaluations fall within five key descriptive factor categories: (1) M/CSL Knowledge, (2) M/CSL Role Expectation, (3) Relationship Management, (4) General Impressions, and (5) M/CSL Skills.

When it comes to knowledge, managed markets customers value M/CSLs who are true experts in the areas & products they represent, demonstrate deep disease state and therapeutic area knowledge, and have knowledge of their customer and needs. M/CSLs can further differentiate themselves by demonstrating a strong knowledge of managed care and how a product fits into the current competitive/treatment landscape.

Research Methodology and Report Availability. In May 2025, HIRC surveyed 68 key decision-makers from commercial health plans and pharmacy benefit managers. Online surveys and follow-up telephone interviews were used to gather information. The complete report, Best in Class Medical/Clinical Science Liaison Customer Insights, is available now to HIRC’s Best Programs and Best People subscribers at www.hirc.com.