Over the past few years, many of my medical affairs field leadership clients across all therapeutic areas have considered expanding their field-based medical teams. What struck me recently was that easily half of these clients were the oncology field medical leadership. Being ZSers, our internal medical affairs team decided to run some quick analyses to see if we could figure out what was going on. What we discovered was startling.

The rule of thumb most often cited is that for every 10 sales reps, you should have 1 medical science liaison (MSL) in field. Based on data from a few years ago, this was absolutely the case, though, of course, individual companies and teams had wide variations based on business need and their historical presence with MSLs, among other factors. But, when we analyzed PharmaForce’s 2014 data on U.S. MSL and sales rep staffing levels, we saw that the general rule of 10 to 1 didn’t hold true for oncology (see Figure 1).

Figure 1



  • In therapy areas outside of oncology, the general rule of 10 to 1 holds true for the median ratio of sales reps to MSLs. Among leading pharma and biotech companies, the ratio ranges from 8 to 1 to 25 to 1.
  • But within oncology, the median is closer to 8 sales reps for every 1 MSL. What’s even more interesting is that the range is much smaller, from 6 to 1 to 18 to 1.

And I’ve even had a number of conversations recently with clients considering significantly lower ratios! One client mentioned 2 to 1 and others have even raised the idea of disrupting the sales model altogether and not having sales reps in their current role at all.

For pharma companies seeking greater access to oncologists, it’s important to understand what’s behind the disproportionate shift in the field force’s resources to medical affairs. In recent years, as the number of available cancer treatments has proliferated and outcomes for patients continue to improve, the nature of interactions between the pharma field force and oncologists has increasingly shifted from commercial to clinical. Additionally, the topics discussed and needs of the key opinion leaders (KOLs) have elevated the importance of MSLs, who, along with medical information call-center specialists, engage with healthcare providers in scientific, information-based and nonpromotional dialogs. These medical affairs representatives are a trusted resource for unbiased, nonpromotional information about a company’s products.

We believe that at least some of this shift has occurred because off-label use is commonplace in oncology, making the need for this information even greater than in other specialties. What’s more, investigator-initiated trials (IITs) and other nonregistration trials are more common in oncology, given that many KOLs experiment with how to use a particular drug in combination or in different tumors and indications. MSLs are the key contacts for establishing a scientific-based relationship with investigators and maintaining it throughout a trial. MSLs are well suited to sustaining a relationship that emphasizes clinical communications, because they provide a continuous voice for the pharma company in a therapeutic area regardless of a particular product’s life cycle.

At the same time that oncologists’ engagement with MSLs has increased, these providers have become much less accessible for commercial discussions with sales reps. The percentage of accessible oncologists (reached by more than 70% of reps) declined from 83% in 2008 to 27% in 2015, according to ZS’s AccessMonitor™ survey (see Figure 2). In tracking similar access levels for MSLs, we see significantly lower declines across the board, and for many company’s MSL teams, we see no decline at all over similar time periods.

Figure 2



Although MSLs will never replace the sales force in promoting products, pharma companies need to recognize that MSLs are playing an increasingly important role in conveying nonpromotional information. What’s more, oncologist KOLs definitely want access to MSLs. I spend a good deal of time interviewing oncologist KOLs each year; they’re very clear on this point.

I often talk with company leaders who are struggling to figure out where to start. I see good decisions made when we begin by discussing these questions:

  • What is your current ratio of sales reps to MSLs in oncology and overall? How have these ratios changed over time? How do they compare with the ratios at other pharma companies and the industry average?
  • What needs are oncologists seeking to address in their interactions with your field force? How well does your current resource allocation enable you to meet these needs?
  • Beyond shifting the balance of resources between the commercial and medical a ffairs organizations, how can you improve the appropriate collaboration between these departments to better meet your customers’ needs?

If you are struggling with decisions related to your MSL team, let us know. If you post comments here, we’ll respond.

Topics: oncology, MSL, Sarah Jarvis, Field Sales