A phase III, randomized, non-inferiority study comparing the efficacy and safety of biosimilar filgrastim versus originator filgrastim for chemotherapy-induced neutropenia in breast cancer patients

OBJECTIVES: To compare the efficacy and safety of two filgrastim formulations for controlling chemotherapy-induced neutropenia and to evaluate the non-inferiority of the test drug relative to the originator. METHODS: This phase III non-inferiority study had a randomized, multicenter, and open-label design. The patients were randomized at a ratio of 1:1 with a follow-up period of 6 weeks for each patient. In both study arms, filgrastim was administered subcutaneously at a daily dose of 5 mg/kg body weight. The primary endpoint was the rate of grade 4 neutropenia in the first treatment cycle. The secondary endpoints were the duration of grade 4 neutropenia, the generation of anti-filgrastim antibodies, and the rates of adverse events, laboratory abnormalities, febrile neutropenia, and neutropenia of any grade. RESULTS: The primary efficacy analysis demonstrated the non-inferiority of the test drug compared with the originator drug; the upper limit of the 90% confidence interval (CI) for the rate of neutropenia between the two groups (12.61%) was lower than the established margin of non-inferiority. The two treatments were similar with respect to the secondary endpoints and safety. CONCLUSION: The efficacy and safety profile of the test drug were similar to those of the originator product based on the rate of grade 4 neutropenia in the first treatment cycle. This study supports Anvisa’s approval of the first biosimilar drug manufactured by the Brazilian industry (Fiprima¯).

Biosimilars / Biossimilares

Although common themes permeate the environment across continents and particular divergences as to how to proceed exist between different regulatory agencies, it seems that policies are still in flux. Not all polices will suffice to fit all dissimilar biologics, and these in place or being developed may, in turn, change to accommodate new or unexpected developments. Consideration for accelerated approval for those compounds that do not present complex questions should be considered.The regulatory agencies should be more forthcoming, the industry sector exercise social responsibility, and the public should have realistic expectations.

Embora haja temas comuns no ambiente dos diferentes continentes e divergências particulares sobre como proceder entre diferentes agências regulatórias, parece que as decisões políticas ainda caminham. Nem todas as políticas serão suficientes para acomodar todos os diferentes produtos biológicos, e as políticas atuais ou em desenvolvimento podem, por sua vez, mudar para acomodar novos e inesperados desenvolvimentos. Deve-se considerar a aprovação mais rápida para aqueles compostos que não apresentem questões complexas. As agências regulatórias deveriam ser mais acessíveis, as indústrias deveriam exercitar sua responsabilidade social e o público deveria ter expectativas realísticas.