BioLineRx Ltd. announced that the U.S. Food and Drug Administration (FDA) has approved APHEXDA? (motixafortide) in combination with filgrastim (G-CSF) to mobilize hematopoietic stem cells to the peripheral blood for collection and subsequent autologous transplantation in patients with multiple myeloma. APHEXDA is administered by injection, for subcutaneous use.

Multiple myeloma is the second most-common hematologic malignancy. Autologous stem cell transplantation (ASCT) is part of the standard of care treatment paradigm for multiple myeloma and delivers prolonged survival for patients with this cancer type.1 The success of ASCT depends on adequate mobilization of stem cells during the treatment process. The American Society for Transplantation and Cellular Therapy (ASTCT) guidelines recommend a collection target of 3-5 x 106 CD34+ cells/kg.2 Additionally, collection of a sufficient number of stem cells to perform two transplantations is recommended.2-5 Historically, depending on induction regimens and mobilization strategies, up to 47% of patients have had challenges collecting target numbers of hematopoietic stem cells for ASCT after one apheresis session.

The FDA approval of APHEXDA is based on results from the 2-part, Phase 3 GENESIS trial, a randomized, double-blind, placebo-controlled study evaluating the safety and efficacy of APHEXDA (motixafortide) plus filgrastim, compared to placebo plus filgrastim, for the mobilization of hematopoietic stem cells for autologous transplantation in multiple myeloma patients. Part 1 was a single center, lead-in, open-label study involving 12 patients treated with motixafortide plus filgrastim designed to ascertain the dose. Part 2 involved 122 patients who were randomized 2:1 in a double-blind, placebo-controlled, multicenter study.8 The assessment of CD34+ cells was performed by central and local laboratories.

Central laboratory assessments were used for the efficacy results. Local laboratory results were used for clinical treatment decisions. APHEXDA plus filgrastim enabled 67.5% of patients to achieve the stem cell collection goal of = 6 × 106 CD34+ cells/kg within two apheresis sessions, versus 9.5% for the placebo plus filgrastim regimen, as measured by central laboratory.9 Additionally, 92.5% of patients reached the stem cell collection goal in up to two apheresis sessions in the APHEXDA arm and 21.4% in the placebo arm, as measured by local laboratories.9 Local laboratory data were used for a sensitivity analysis.

The data are descriptive and were not statistically powered nor prespecified. The information should be cautiously interpreted. In GENESIS, the safety was evaluated in 92 patients with multiple myeloma who received APHEXDA 1.25 mg/kg subcutaneously plus filgrastim, and 42 patients who received placebo plus filgrastim.

Serious adverse reactions occurred in 5.4% of patients receiving APHEXDA plus filgrastim. These reactions included vomiting, injection site reaction, hypersensitivity reaction, injection site cellulitis, hypokalemia and hypoxia. The most common adverse reactions occurring in GENESIS (incidence >20%) were injection site reactions (pain, erythema and pruritus), pruritus, flushing, and back pain.

Increased age, as well as exposure to lenalidomide-containing induction regimens, including 3-4 drug combination regimens, have been associated with impaired stem cell mobilization.2-3 The GENESIS study included patients considered representative of the typical multiple myeloma population undergoing ASCT, with a median age of 63 years and with ~70% of patients in both arms of the trial receiving lenalidomide-containing induction therapy.8 In this contemporary population, patients in the APHEXDA plus filgrastim arm were able to mobilize more than four times the amount of stem cells with a single dose over a 24-hour period compared with placebo plus filgrastim.