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  • Writer's pictureLighthouse

MSLs: The Value of Local Knowledge

Updated: Jul 28, 2023

Summary in Thirty Seconds

  • Medical Science Liaisons perform many roles, with the primary duty being to foster relationships with HCPs, especially Key Opinion Leaders, to educate and improve awareness of new insights and treatments, manage relationships, deliver scientific presentations, and exchange objective scientific information.

  • Over 50% of MSLS coordinate company-sponsored research and clinical trials, communicating with Principal Investigators, study sites, and referral centers to ensure trials are meeting timelines and goals.

  • MSLs focused on cancer clinical trials may be called “Precision Medical Liaisons” (PMLs), and they fill an unmet need in the clinical trial world, particularly internationally, where languages, disease management protocols, and complex regulations vary by country can complicate clinical trial success.

  • PMLs face challenges in communicating with overworked PIs, navigating trial site hierarchies, balancing multiple work demands, and dealing with oncopolitics.

  • PMLs bridge the gap between sponsors and sites, offering a “boots on the ground” approach, helping to personalize the set-up, roll-out, and follow-through of clinical trials in a variety of sites, both nationally and internationally.

Local Knowledge

One of the charming quirks of baseball is that all 30 Major League Baseball (MLB) stadiums have different dimensions within limits set by the MLB. For example, Boston has its left field 37-foot tall “Green Monster” only 310 feet from home plate, whereas the left field wall at Coors Field in Denver is 347 feet away. In San Francisco and Chicago, at least part of the outfield wall has a brick façade producing crazy caroms from line drives. Home team outfielders have an advantage over visitors, knowing how to play the “short porch” at Fenway Park or the ivy-covered bricks at Wrigley Field. When a player gets traded to a new team, his new teammates give him “local knowledge” about the peculiarities of his new outfield home so he can play his position better. Medical Science Liaisons are local knowledge experts as well, bridging knowledge and awareness gaps by communicating the specifics of a new medical product, an emerging treatment, or a newly introduced clinical trial to healthcare providers.


Medical Science Liaisons

The first Medical Science Liaison (MSL) team was created by the Upjohn Company in 1967. This team of sales representatives with technical/scientific backgrounds had as its main objective to enhance the company’s image amongst researchers and KOLs by engaging them in peer-to-peer interactions, collecting insights on their needs, and leveraging Upjohn products into research activities.[1] Over the years, MSLs have shifted from the sales department to more diversified roles typically within Med Affairs[2] (by 2010, only 2% of MSLs worked in a sales department).[3]


The role of an MSL is now defined by the many roles an MSL holds, although their primary and overarching function is to foster relationships—building trust with physicians/healthcare providers (HCPs), especially key opinion leaders (KOLs).[4] Additional MSL roles expanding on this primary function include educating clinicians (49% of KOLs report that receiving updates on new/existing drugs and discoveries is the most valuable data they receive from MSLs[5]), ensuring the appropriate use of drugs and devices by HCPs and their patients, and providing objective insight into the scientific and clinical trial data regarding therapeutics manufactured by their employers.[6]According to the Medical Science Liaison Society, the most typical activities for an MSL include the following: attending medical conferences (95%), managing KOL relationships (95%), educating KOLs and HCPs (93%), and delivering scientific presentations (92%).[7]A study by the MSL Society found that compared to the two minutes a sales representative spends with a physician, an MSL spends over an hour communicating with a physician.[8]


Although the role of PMLs has expanded greatly over the years, there is limited published literature on the value and efficacy of MSLs.[9] This paucity is primarily due to core PML roles tending to be more qualitative than quantitative—relationship building, collaborative activities, and adding value to ideas and insights.[10]


MSLs and Clinical Trials

Theron et al. highlight three key roles for MSLs:

  1. exchanging objective scientific/medical information;

  2. generating evidence through research studies, clinical trials, and clinical audits;

  3. gathering and communicating insights with clinical trial participants.[11]

Over 50% of MSLs coordinate company-sponsored research and clinical trials.[12] Providing such clinical trial support means communicating with Principal Investigators (PIs), study sites, and referral centers to ensure sites are meeting study deadlines, rules, and regulations while efficiently enrolling patients in clinical trials.[13] This specific role might be better referred to as a “Clinical Trial Liaison” (CTL) or specifically for cancer clinical trials, “Precision Medicine Liaison” (PML).[14] Such PMLs develop and build relationships between the companies, clinical sites, and HCPs who drive research and clinical trials.[15],[16]


Precision Medicine Liaisons

Meeting enrollment goals is a major challenge for cancer clinical trials. A means to improve enrollment is to expand trials outside of the United States, but such expansion comes with challenges related to specific rules and regulations in different countries. PMLs fill an unmet need in the clinical trial world, particularly internationally, where languages, disease management protocols, and complex regulations vary by country and can hinder clinical trial success. PMLS need to have extensive experience in clinical trial work, including expertise in local regulations and clinical trial operations customs. It is also important that they understand the local disease landscape, testing practices, and treatment paradigms, thus providing an inside perspective to help sponsors successfully run trials in a diverse global setting. For example, while the EU has a standard of Clinical Trials Regulation and the Clinical Trial Information System, each member state has specific policies, fees, and timelines that necessitate “local knowledge” for efficient clinical trial implementation in that country.[17]

Strong PMLs have previously worked with a broad range of oncologists, pathologists, and other personnel at hospitals and cancer centers across their region, so they already know many Principal Investigators and sub-Investigators. This familiarity facilitates strong working relationships in which the PMLs communicate regularly with PIs to discuss testing, enrollment, and data, face-to-face, in the local language. This relationship exists separately from the CRO. As noted, PMLs not only work to build relationships with main study sites but also with satellite sites while staying engaged with the effectiveness and challenges of the new molecule being tested. PMLs can also use their communication and relationship-building skills to get pathologists and oncologists to collaborate in patient identification to improve clinical trial enrollment.


CROs are a staple in the clinical trial world and handle many essential logistics and paperwork duties. However, communication, attention to detail, and urgency are often missing, and important issues get lost or passed around, causing damaging delays in testing or enrollment. This is where the PMLs come in. PMLs provide accurate, timely feedback between the sponsor and PI. PIs trust and depend on PMLs to relay their questions and needs to the sponsor, thus bridging a common gap between sites and sponsors. PMLs can evaluate the patient testing situation at trial sites and determine the scope of pre-screening financial support that the sites need and then create proposals with options for the sponsor to consider. They also help PIs find outside testing options if they don't have in-house assays that meet the trial requirements. PMLs can also help enrich the patient pool by networking and negotiating referrals with commercial testing labs and oncologists/hospitals outside of the clinical trial sites, thereby boosting enrollment.[18]

Challenges for PMLs

PMLs face challenges in performing their work effectively. Such challenges include:

Communication—Unresponsive/overworked Principal Investigators (e.g., PIs who are either too busy or unwilling to receive help from PMLs). Such problems with PIs lead to significant challenges in site engagement in a clinical trial.

Navigation—Navigating hierarchies at trial sites (e.g., while some PIs find it acceptable that PMLs discuss the trial with other oncologists to increase trial enrollment, other PIs want all communication to go through them, leading to delays).

Balancing Multiple Demands—Funding/Patient Finding (e.g., when facilitating negotiations between the sponsor and PI regarding financial support for pre-screening patients, PMLs must sometimes reconcile hospital policies on/funding for mutation testing versus what PIs need to find patients, which can be a very complex balancing act).

“Oncopolitics”[19]—Oncologists and/or hospitals that are external to trial sites may be unwilling to refer patients to the trial sites due to the potential loss of income from treating the patient.


International MSLs/PMLs

One 2021 Canadian survey found that almost 70% of respondents agreed that using outcome metrics is vital to assessing MSL value, and 98% had used metrics in the past year. This survey also revealed that scientific engagement was regarded as the most important role of an MSL.[20] Koot et al., argue that MSLs will be vital for growing the number and quality of clinical trials in Africa; however, given that the role of an MSL is poorly defined in Africa, these professionals will not be requested or utilized as often as they have been in Europe and North America, where their role is better known.[21] However, even in these regions, the impact of MSLs can be under-appreciated.[22] In India, many MSLs are physicians, resulting in more illness/disease and treatment knowledge but less research training and pharmaceutical expertise, which can complicate clinical trial work.[23] In Japan, while MSLs are needed and valued, the lack of a standardized training curriculum, assessment of MSL capabilities, and key performance indicators (KPIs) has made it challenging for MSLs to carry out the core MSL tasks described above.[24]


For both American and international MSLs/PMLs, the role of building trusting relationships with HCPs (including KOLs and PIs) is a core and vital component of their work, leading to more effective and efficient clinical trial activation, enrollment, and oversight. MSL/PML country-specific expertise is invaluable to navigating complex regulations and timelines of specific countries.[25]


The Bottom Line

The role of MSLs has expanded greatly since the role was first envisioned, evolving from supporting sales departments to building trust and relationships with HCPs, KOLs, Principal Investigators, and others for a variety of purposes. There is no reason to believe this evolution will stop as companies adapt to market demands, more formalized regulations, and greater medical and pharmaceutical specialization.[26] Support and assistance in all aspects of clinical trials is a common and important role for MSLs, and for those working in oncology, the more accurate term may be “Precision Medicine Liaisons.” PMLs bridge the gap between sponsors and sites, particularly when local knowledge is needed at sites in various countries that each have specific regulations and rules. PMLs offer a “boots on the ground” approach, helping to personalize the set-up, roll-out, and follow-through of clinical trials in a variety of sites, both nationally and internationally. Spreading clinical trials beyond American borders can not only vastly increase clinical trial enrollment but also trial diversity.

[1] Drug Info. J. 2000; 34:1049-1052 [2] Maximizing value as a medical science liaison | Pharmaspectra [3] “The Medical Science Liaison Career Guide.” 2014, Med. Sci. Liaison Inc., Highland Beach, FL, USA [4] J of Comm Biotech. 2021; 26(3):39-45 [5] MSL Society. 2021 [6] AORN Journal. 2010; 91(3):394-398 [7] MSL Society. 2018 [8] The Influence of MSLs | PharmaVoice [9] Ther Innov & Reg. Sci. 2022; 56:96-103 [10] J of Comm. Biotech. 2007; 13(3):177-182 [11] Ther. Innov. Regul. Sci. 2021; 55(6):1139-1144 [12] MSL Society. 2018 [13] BMJ Evidence-Based Med. 2022; 27(Suppl_1):A38 [14] www.bestmsls.com/ctls [15] J of Comm. Biotech. 2004; 10(4):312-318 [16] www.bestmsls.com/hire/enhance-clinical-trial-enrollment [17] Ther. Innov. & Regul. Sci. 2023; 1-10 [18] themsls.org/msl-guidelines [19] Surg. Oncol. Clinics of North Am. 2000; 9(2):279-294 [20] Ther. Innov. & Reg. Sci. 2021; 55:954-965 [21] Pan African Med. J. 2019; 33:313 [22] Maximizing value as a medical science liaison | Pharmaspectra [23] The MSL Journal. 2020; 2(1):36-37 [24] Pharmaceut Med. 2020 Oct;34(5):315-326 [25] Ther. Innov. & Regul. Sci. 2023; 1-10 [26] The Emerging Role of Medical Science Liaison in Pharmaceutical Industry. 2014

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