Clinical-stage pharmaceutical firm Karyopharm Therapeutics has started the selinexor treatment of refractory myeloma (STORM study) to assess patients with multiple myeloma.

The trial is a multi-centre, single-arm and Phase II study of selinexor (KPT-330) in heavily-pretreated patients with quad-refractory multiple myeloma.

Selinexor, an oral selective inhibitor of Nuclear Export/SINE compound, will be assessed in combination with low-dose dexamethasone in multiple myeloma patients whose disease was refractory to treatment with bortezomib, (Velcade), lenalidomide (Revlimid), carfilzomib (Kyprolis) and pomalidomide (Pomalyst).

Selinexor obtained orphan drug designation from the US Food and Drug Adminsitration (FDA) and the European Medicines Agency (EMA) for multiple myeloma.

Karyopharm Therapeutics president and CEO Dr Sharon Shacham said: "We are very encouraged by the responses and durability demonstrated to-date with selinexor in combination with low-dose dexamethasone in patients with relapsed and refractory multiple myeloma and look forward to continuing to evaluate selinexor in this patient population."

The company will enrol around 80 patients at about 30 sites in the US in first cohort, with around 25% of the patients also having received treatment with an anti-CD38 monoclonal antibody such as daratumumab.

The Phase II trial will assess the safety and efficacy of a fixed dose of selinexor (80mg) plus low dose dexamethasone (20mg) and is designed based on data from firm’s Phase I study of selinexor in combination with low dose dexamethasone in relapsed/refractory multiple myeloma.

It will be expanded to include additional patients, depending on the results from the initial cohort and data from an expanded trial is expected to support an accelerated approval of selinexor in refractory multiple myeloma.

According to the firm, overall response rate (ORR) is the primary endpoint of the study, which served as the basis for accelerated approvals in multiple myeloma for other agents.

Image: Bone marrow aspirate showing the histologic correlate of multiple myeloma under the microscope. Photo: courtesy of KGH.