US-based biopharmaceutical firm Portola Pharmaceuticals (PTLA) has started patient enrolment in a Phase I/II proof-of-concept clinical study of its novel, oral, dual spleen tyrosine kinase (Syk) and janus kinase (JAK) inhibitor PRT2070 to treat haematologic cancers.
Syk is an important modulator of immune signalling, while the Janus kinase family is one of ten recognised groups of non-receptor tyrosine kinases that regulate cellular processes involved in cell growth, differentiation and transformation through their association with cytokine receptors.
The Phase I/II trial is designed to evaluate the safety, pharmacokinetics, pharmacodynamics and clinical activity of oral PRT2070.
In the multi-dose, dose-escalation Phase I part of the study, PRT2070 is being administered to sequential dose cohorts at increasing dose levels until the maximum tolerated dose is identified.
In this stage of the trial patients with relapsed or refractory chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma and non-Hodgkin's lymphoma (NHL) (including DLBCL, follicular lymphoma and mantle cell lymphoma) will be included.
Phase II of the trial is a cohort expansion that will assess measures of safety and efficacy in cancer types identified based on the responses seen in the dose-escalation phase.
Portola has engaged SCRI, a strategic research organisation, to conduct the Phase I/II study.
Sarah Cannon Research Institute (SCRI) director of the hematologic malignancies research programme Ian Flinn said: "It is clear that new treatment options are needed for patients with relapsed and refractory lymphoma, chronic lymphocytic leukemia and other lymphoproliferative disorders."
The company is currently developing PRT2070 for the treatment for haematologic cancers, including for those patients who have progressive or relapsed disease, genetically-defined subtypes or acquired mutations.
PRT2070 is an oral, potent inhibitor of both the B-cell receptor (BCR) pathways that promote survival and proliferation of haematologic cancers, like NHL and CLL.
The company said PRT2070 has a dual mechanism of action that targets two pathways for acquired and pre-existing mutations or resistance, simultaneously targeting these two validated pathways in a single pill.
Portola has worldwide rights to develop and commercialise PRT2070 for haematologic cancers and other systemic indications, while rights for certain nonsystemic indications are shared 50/50 with Aciex Therapeutics.
Image: Micrograph of mantle cell lymphoma, a type of non-Hodgkin lymphoma. Photo: courtesy of Nephron.