Biosimilar Candidate GP40141 Found Similar to Romiplostim for Idiopathic Thrombocytopenic Purpura

The aim of developing GP40141 as a biosimilar is to help reduce the cost of the drug and make treatment more affordable for those with idiopathic thrombocytopenic purpura, according to investigators.

The pharmacodynamic between GP40141 (Geropharma), a proposed biosimilar, compared to romiplostim (Nplate; Amgen) was similar, including a comparable safety profile, for the treatment of idiopathic thrombocytopenic purpura (ITP), according to results of a study published in Pharmacology Research and Perspectives.

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According to the investigators, romiplostim is a second generation thrombopoietin receptor agonist used as a second-line therapy for persistent ITP, including chronic, relapsing, and refractory disease. The drug “stimulates growth and platelet production of megakaryocytes in blood marrow,” the study authors said.

For GP40141, investigators said that preclinical in vivo studies have been conducted in rats as well as studies in primates, including single and double administrations. The study authors stated that the aim of developing GP40141 as a biosimilar is to help reduce the cost of the drug and make treatment more affordable. In this study, investigators assessed the pharmacodynamic comparability, pharmacokinetics, and safety of GP40141 compared with romiplostim in males aged 18 to 45 years old.

Individuals were in good health, as determined by data regarding their medical history, physical examination, and clinical laboratory evaluations. The platelet counts of individuals included needed to range from 150.0 to 306.0 x 10⁹/L, according to the authors. GP40141 is a lyophilized powder for injection at the 250-mcg strength, which was evaluated with romiplostim in the same strength. Investigators randomly administered one of the study drugs to each individual.

About The Trial

Trial Name: Double-blind, Randomized Comparative Cross-sectional Study of Pharmacodynamics and Pharmacokinetics of Drugs GP40141

ClinicalTrial.gov ID: NCT05652595

Sponsor: Geropharm

Estimated Completion Date: September 2024

The study was a phase 1 randomized and double-blinded trial that included 1 research location in Yaroslavl, Russia, from July 2022 and December 2022, according to the study authors. It included a screening period of 14 days and 2 treatment periods of 33 days each. In the first treatment period, the first group received GP40141 and the second received the reference drug, switching drugs in the second treatment period. There was also a 33-day period where no treatment was given before the first day of each treatment period.

The primary endpoints were the area under the platelet curve from baseline until the last sample and the maximum platelet count observed. The secondary endpoints included the maximum number of platelets to the basal level and time to the maximum number of platelets. Further, all pharmacokinetic endpoints included were also secondary, and the safety profile of GP40141 and the reference product were also evaluated.

A total of 56 healthy male volunteers were included in the study, with 38 individuals assigned to each arm. The mean age was 29.5 years old with a mean platelet count of 217.91, according to the study investigators. The results showed that the mean area under the curve was 253,366.65 for GP40141 compared to 252,053.01 for the reference product. The mean maximum platelet counts were 559.78 and 546.27, respectively, according to the study authors.

The safety data showed that there were no adverse events in relation to either drug, with urinalysis, assessment of vital signs, physical examination, and evaluation of injection site. The investigators concluded that GP40141 and romiplostim were similar, making GP40141 a favorable biosimilar candidate as of current data. However, investigators noted that the trial was the first of its kind to determine the pharmacokinetic profile of romiplostim in healthy male individuals at a clinically relevant and safe subcutaneous dosage.

Reference

Makarenko I, Dorotenko A, Noskov S, et al. A randomized, double-blind, comparative study of the pharmacodynamics and pharmacokinetics of GP40141 (romiplostim biosimilar) and reference romiplostim in healthy male volunteers. Pharmacol Res Perspect. 2023;11(5):e01125. doi:10.1002/prp2.1125