Clinical Drug Experience Knowledgebase

A Single-center, Uncontrolled, Open, Phase 1 Study of Recombinant(Expressed by Pichia Pastoris) Human Serum Albumin/Human Granulocyte-Colony Stimulating Factor(I)Fusion Protein For Injection(GW003)to Metastatic Tumors

So far, granulocyte colony stimulating factor (G-CSF) is still currently the only effective and security therapy drug for neutropenia caused by cancer chemotherapy. At present, the widely used G-CSF products are of such short-acting G-CSF product in China. However, there existed some shortcoming about short-acting G-CSF, such as shorter half-life, continuous monitoring of the patient's blood neutrophil count and so on.

Nowadays,long-acting G-CSF product,such as Neulasta®, has become the mainstream of the foreign G-CSF market for its superiority of long half-life and absence of monitoring of the patient's blood neutrophil count. The new drug Recombinant(Expressed by Pichia pastoris) Human Serum Albumin/Human Granulocyte-Colony Stimulating Factor(I)Fusion Protein(GW003) is a long-acting G-CSF.Preclinical studies have shown that GW003 has accelerated neutrophil recovery and can shorten the duration of neutropenia symptoms, also reduce its extent, therefore minimize the likelihood of serious infections, reflecting a better efficacy and more long half-life.

Phase I was performed as two parts, Ia and Ib. Ia was a sequential dose escalation to observe the dose-limiting toxicity(DLT) and Maximum Tolerated Dose of GW003 given subcutaneously to patients without receiving chemotherapy,6 dose cohorts(50、150、300、400、500 and 600μg/kg) with 2-3 subjects in the 50、150μg/kg cohorts and 3-6 subjects（depend on the Dose-limiting toxicity） in the 300、400、500 and 600μg/kg cohorts, to evaluate safety and pharmacokinetics prior to the Ⅰb.

Ib proposed two arms (150 and 300μg/kg；n=6-8/arm), and to determine whether to continue to increase other dose arm based on the safety and efficacy assessment. Subjects need to receive two cycles treatment of AT chemotherapy. In cycle 1, subjects received AT chemotherapy only; in cycle 2, subjects were administered subcutaneously GW003 24 hours after chemotherapy drugs.