Biosimilars – Current Treatment – Biosimilar Target Product Profiles (Immunology)

The figure titled “Rheumatology biosimilars Target Product Profile: attribute importance” shows the relative importance of each of the seven attributes included in the study, derived from the responses of surveyed rheumatologists, 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 “Rheumatology 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 rheumatologists, 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).

Unsurprisingly, list price is the most important attribute influencing the attractiveness of a biosimilar TPP among surveyed U.S. and European rheumatologists, indicating that list price is a key driver of physicians’ choice of a biosimilar. List price relative to the brand is inversely correlated with the attractiveness of a biosimilar, as evidenced by the relatively large decline in part-worth utility scores associated with incremental increases in price points. This result underscores the high price sensitivity of surveyed physicians in adopting a biosimilar. The availability of clinical data in the indication of interest is the second most important attribute in our conjoint analysis in both regions. This result suggests that an emerging biosimilar boasting Phase 3 clinical data in the relevant indication will likely be preferred to biosimilars for which regulatory approval is extrapolated.

The duration of postmarketing data is the third most important attribute influencing the attractiveness of a biosimilar TPP to surveyed rheumatologists across Europe (score = 17) and United States (score = 14); with a greater preference for biosimilars with a higher duration of postmarketing data indicated by higher part-worth utility values for 24 months of postmarketing data compared to biosimilars having no data. The analysis of part-worth utility scores 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. Therefore, a biosimilar manufactured by a biotech outside the United States and Europe or by an emerging market biopharma company may face obstacles in gaining uptake, even if pricing and clinical profiles are comparable to other biosimilars.

Further, the importance of inclusion in treatment guidelines in Europe suggests that a biosimilar included in national, institutional, or clinical guidelines might be more positively differentiated from its competing biosimilars in Europe (score = 9) than in the United States (score = 7), especially when pricing and clinical profiles are similar.

Reimbursement restrictions received the same importance score in both regions (score = 5). The analysis of responses from surveyed rheumatologists in both regions reveals that it is a more important determinant of a biosimilar TPP‘s attractiveness than drug delivery. Drug delivery is the least important attribute influencing physicians’ likelihood to prescribe a biosimilar TPP, although the part-worth utility trend indicates that an improved formulation compared with that of the brand renders a biosimilar TPP more attractive than delivery with an improved device or the same delivery as the brand.