The figure titled “Oncology biosimilars Target Product Profile: attribute importance” shows the relative importance of each of the attributes included in the study, derived from the responses of surveyed medical oncologists in the ACBC module of the survey, regarding their likelihood to prescribe and preference for the various TPPs presented to them. The importance scores for each attribute are based on a scale where the sum of all scores totals 100. Thus, an attribute with a score of 20 is twice as important as an attribute with a score of 10 in determining physician preference for a biosimilar.
The figure titled “Oncology biosimilars Target Product Profile: attribute-level part-worth utilities” shows the individual part-worth utilities for each attribute level across the seven attributes, derived from the responses of surveyed medical oncologists in the ACBC module of the survey, regarding their likelihood to prescribe and preference for the various TPPs presented to them. Each level for each attribute was assigned a value indicating how attractive that particular level is to surveyed physicians, relative to other levels of that attribute. Values are scaled to a sum of 0 within each attribute (the summation of all level values within each attribute equals 0). Values can be negative or positive, with the highest positive value viewed as the best/most attractive option. A negative value, however, does not imply that a level is unacceptable; it implies that the level is less attractive when compared with the other levels for that attribute. The more positive the value, the more attractive the performance level is to surveyed physicians. Conjoint part-worth utilities are measured using interval data and are uniquely scaled for each attribute; therefore, utilities cannot be compared across attributes and utilities within each attribute are not relative (a utility of 50 is not twice as preferred as a utility of 25).
In our conjoint analysis of U.S. and European medical oncologists’ responses, list price is the most important attribute in determining the attractiveness of a biosimilar TPP. Given that reducing cost of treatment is foundational to the value proposition of biosimilars and key for both prescribers and patients (e.g., when considering OOP costs) as well as payers, this finding is not surprising. In Europe, biosimilars’ lower cost to payers, institutions, and clinics is a major factor driving uptake, whereas surveyed U.S. clinicians recognize the opportunity to reduce costs and improve access for their patients.
The availability of clinical data in a given indication is the second most important factor influencing the attractiveness of a biosimilar TPP, and part-worth utilities indicate that Phase 3 data in a given indication render a biosimilar TPP more attractive than a biosimilar approved in a given indication through extrapolation. Positive postmarketing data and time on the market that support the longer-term clinical efficacy and safety of a biosimilar is also considered as a meaningful attribute, emerging as the third most important in our ACBC analysis, i.e., the part-worth utility data indicates that the attractiveness of a biosimilar TPP correlates with the duration of available postmarketing data.
Inclusion of a biosimilar in treatment guidelines and type of manufacturer were deemed equally important and are the fourth most important attributes. Inclusion in national or institutional guidelines render a biosimilar TPP more attractive than one that is lacking the inclusion in these recommendations. Guideline inclusion likely increases prescriber comfort with biosimilars because such recommendations are typically evidence-based and also improve/ease access to the biosimilar. The analysis suggests that a biosimilar from a well-known large biopharmaceutical company or a well-known small-molecule generics company is more attractive to physicians than a product from a nonpharma company partnered with a pharma company, a product from a biotech outside the United States or Europe, or a biosimilar from a biopharma company in an emerging market. These findings suggest that a biosimilar manufactured by a biotech outside the United States and Europe or by an emerging market biopharma company would face more obstacles in gaining uptake compared with biosimilars manufactured by a well-known biopharma / generics company even if pricing and clinical profiles are comparable with each other.
Reimbursement restrictions are least important in determining a biosimilar TPP’s attractiveness.