Erythropoietin (EPO) is a glycoprotein hormone that plays a key role in the formation of red blood cells (RBCs). EPO is primarily synthesized in the peritubular cells of the kidney and released into the systemic circulation in adult individuals. Circulating EPO binds to the EPO receptor on bone marrow erythroid progenitors, triggering multiple signaling pathways that support differentiation into mature RBCs. A reduction in EPO production is the primary cause of anemia in people with chronic renal failure \[4\]. Human recombinant epoetin (rHuEPO) or erythropoiesis stimulating agents (ESA) have been demonstrated to stimulate erythropoiesis in anemic patients with chronic renal failure, including those who need and don't need dialysis. ESAs are used to treat chemotherapy-induced anemia in cancer patients and to reduce the requirement for allogenic blood transfusions in patients with mild anemia who are undergoing surgery. Furthermore, human recombinant epoetin is recommended for patients who are at high risk for perioperative transfusions due to considerable blood loss.

Recombinant rHuEPO was manufactured using recombinant DNA techniques. Alpha epoetins are the most commonly used type of rHuEPO among the other forms. Eprex®, the pioneer product of alpha epoetins, is a regular medicine with proven efficacy and tolerability. Globe Biotech Limited, a Bangladeshi biopharmaceutical company has developed GBPD002, a biosimilar of Eprex® which is synthesized in genetically engineered Chinese hamster ovary (CHO) cells. Upstream and downstream process development and validation was done for large scale production. Step by step identical analytical results confirmed the biosimilarity of GBP002 with Eprex®. Single and repeat dose toxicity was performed in Wister rat to analyze the toxicity of GBPD002 with Eprex®.

The aim of this study is to analyze the bioequivalence of GBPD002 and Eprex®. The purpose of this study is to compare the pharmacokinetic (PK), pharmacodynamics (PD) and safety of human recombinant erythropoietin, GBPD002, developed by Globe Biotech Limited and the reference product Eprex® manufactured by Janssen Cilag Ltd., UK in healthy volunteers. An independent ethics committee gave ethical clearance for this study and the protocol for this study was approved by the Directorate General of Drug Administration (DGDA) of Bangladesh.

A randomized, double-blind, single-dose, and two-sequence crossover trial was conducted in 42 healthy volunteers in 2 groups/cohorts/arms. The Clinical Research Organization (CRO Ltd.) conducted this investigation at Farabi General Hospital, Dhanmondi R/A, Dhaka 1209, in compliance with the principles of the Declaration of Helsinki and the International Conference on Harmonization's Guideline for Good Clinical Practice. Bangladesh's Directorate General of Drug Administration (DGDA) approved the study methodology and informed consent form. Volunteers were given thorough information about the study and they have signed an informed consent form to affirm their willingness to participate.

The study was open to healthy male participants aged 19-45 years old who weighed 55.0-90.0 kg and had a body mass index of 18.0-27.0 kg/m2. Subjects were eliminated if they had at least one of the following clinical laboratory test results: Hemoglobin level \<12 g/dL or \>17 g/dL, vitamin B12 level \<200 pg/mL, ferritin level \<21.8 ng/mL, transferrin level \<190 mg/dL and any anomalous range for the reticulocyte (RET) count, erythrocytes, platelets or serum potassium levels. The number of subjects was determined based on the results of a previous clinical study on a single subcutaneous injection of epoetin alfa in healthy subjects. The total number of subjects was 42, assuming a 20% dropout rate. COVID-19, HIV, HBsAg, and HCV (Hepatitis C Virus) positive individuals were excluded from the study.The recruited volunteers were randomly assigned to one of the two sequences and received a single subcutaneous injection of 4,000 IU of either the comparator drug (Eprex®) or the test drug (GBPD002) in the abdomen from a prefilled syringe (PFS), based on the allocated sequences with a 28-day washout period: sequence A, administered the comparator drug in period 1 followed by the test drug in period 2; sequence B, given the test drug in period 1 followed by the comparator drug in period 2.Blood samples were taken for the PK evaluation at predose and at 1, 3, 6, 8, 10, 14, 24, 48, 72, 96, 120 and 144 h postdose. For the PD evaluation, the reticulocyte count (RET; %), hematocrit (HCT; %), haemoglobin (HB) (g/L) and red blood cell (RBC) count (106/mm3) were calculated at predose and at 72, 144, 216, and 312 h postdose.