Two Reminders in Biosimilar Discussions

Sometimes I can be excused for taking important details for granted. Scientists, medical professionals, and health systems, however, do not have that luxury. Two recent studies reminded me of classic gaps, in not only broader biosimilar discussions, but in pharmaceutical testing and use overall. For the purposes of this discussion, the actual study results are less the point than the objectives of the investigators.

With biosimilars, as with any conventional agent, a good deal of research is done using commercial or working-age populations, and unless the target indication is for pediatric use, testing on younger patients is rarely done. On the other hand, testing on older populations is extremely important, especially for diseases that are more likely in the older population (and in some cases, patients over 75 years of age). For example, older patients may have renal impairments that could interfere with drug clearance, they may exhibit differences in drug metabolism, and the possibility exists that drug interactions in the elderly may more likely result in clinical manifestations.

French investigators sought to better understand how the biosimilar agent epoetin zeta (available only in Europe) worked in patients younger and older than 70 years for the treatment of chemotherapy-induced anemia. The result of this observational study was that the tolerability and effectiveness of an epoetin biosimilar for treating chemotherapy-induced anemia was equivalent in patients at least 70 years old compared with younger patients.

Another key component of some biosimilar products (self-administered injectables) that is often glossed over is the injector itself. These devices attempt to make the patient as comfortable as possible and dosing simple, and in general, the pharmaceutical manufacturers do an excellent job of engineering these devices.

In a market research study sponsored by Biogen (maker of a biosimilar etanercept brand in Europe called Benepali), German and Swiss investigators sought opinions from patients with rheumatoid arthritis about their preference for the Benepali autoinjector or Enbrel’s autoinjector. Needless to say, Biogen’s injector came out on top. The most important attributes of either injector, they said, were (in ranked order), ease of operation, ease of grip, and intuitive use.

These basic issues often get lost in the broader discussion of biosimilar uptake and utilization. For example, what is the benefit to payers, patients, or physicians of an interchangeable biosimilar that must be injected, if no one is comfortable with the injector device?

It can also be argued that accurate characterization and analysis of a biosimilar prior to clinical trials should predict its equivalent effect to the originator product in older and younger patients alike. In any case, this subgroup analysis is very important in comparative clinical trials and should not be glossed over.