Aphexda is used in the treatment of multiple myeloma, a cancer that forms in plasma cells. Aphexda (motixafortide) is a medication used to increase the number of circulating stem cells before they are collected for a stem cell transplant. Aphexda is called a hematopoietic stem cell mobilizer and is used together with filgrastim, which is a G-CSF (granulocyte colony-stimulating factor).

Aphexda (motixafortide) works by blocking the receptor CXCR4, which increases stem cells in the circulation, available for collection. Aphexda is from the class of medicines called CXCR4 antagonist.

Aphexda became an FDA-approved medicine on September 11, 2023, to be used in conjunction with filgrastim (G-CSF) to mobilize hematopoietic stem cells into the peripheral blood for collection and subsequent autologous transplantation in patients with multiple myeloma. FDA approval was based on positive results from the 2-part, Phase 3 GENESIS trial (NCT 03246529), which was a randomized, double-blind, placebo-controlled study comparing how effective Aphexda plus filgrastim was compared to placebo plus filgrastim.

Multiple myeloma and stem cell transplants

One treatment choice for certain multiple myeloma patients involves high-dose chemotherapy (HDT) to eradicate cancer cells, followed by the re-implantation of healthy stem cells into the patient's body. This procedure, known as an autologous stem cell transplant (ASCT), uses the patient's previously collected and stored stem cells harvested before chemotherapy.

An issue for patients is having enough stem cells to harvest, so Aphexda is used to increase the number of stem cells in the circulation. In clinical trials, 67.5% of patients using Aphexda with filgrastim were able to collect enough stem cells in two collections compared to 9.5% of patients who only used filgrastim.

Anaphylactic Shock and Hypersensitivity Reactions: Aphexda may cause serious allergic reactions. You will be given medication before treatment to help prevent allergic reactions. You will have treatment in a setting where personnel and therapies are available for immediate treatment if you have an anaphylactic reaction or a hypersensitivity reaction

Injection Site Reactions: You may have a reaction at the injection site therefore, pain premedication (e.g., acetaminophen) is recommended.

Tumor Cell Mobilization in Patients with Leukemia: This medicine may mobilize leukemic cells and should not be used in leukemia patients.

Leukocytosis: Increased circulating leukocytes have been observed. Your white blood cell counts will be monitored during treatment.

Potential for Tumor Cell Mobilization: Tumor cells may be released from marrow during hematopoietic stem cell mobilization with Aphexda and filgrastim. The effect of reinfusion of tumor cells is unknown.

Embryo-fetal Toxicity: Aphexda can cause fetal harm. Women of reproductive potential should use effective contraception.

Aphexda is given as a slow subcutaneous injection 10 to 14 hours before starting harvesting the stem cells.

If required, A second dose of Aphexda can be administered 10 to 14 hours before the third apheresis (stem cell collection).

The slow subcutaneous injection can be given in the abdomen, thigh, or back or side of the upper arm. Avoid any skin area that is reddened, inflamed, swollen or scarred. Avoid a 5 cm diameter circle around the navel if injecting into the abdomen.

Aphexda is used in combination with filgrastim

Each injection volume should not exceed 2 mL. Divide doses requiring greater than 2 mL into multiple syringes to allow different injection sites.

If more than one injection is needed for a single dose of this medicine, the injection sites should be at least 2 cm apart from previous injection locations.

You will be monitored for one hour after administration.

Filgrastim should be given once daily for 4 days before the first dose of Aphexda and then on each day before apheresis (stem cell collection).

Aphexda vial should be reconstituted with 2 mL of 0.45% sodium chloride for injection (or 1 mL water for injection + 1 mL 0.9% sodium chloride for injection). This yields a clear solution of 36.5 mg/mL motixafortide, pH 5.8 to 7.5.

The recommended Aphexda dosage is 1.25 mg/kg administered via slow (approximately 2 minutes) subcutaneous injection.

Dosing is based on actual body weight.

Aphexda dose should be given 10 to 14 hours prior to the initiation of the first apheresis.

A second dose can be administered 10 to 14 hours before a third apheresis, if necessary.

You should not take this medicine if you are allergic to the active ingredient motixafortide or any of the inactive ingredients

Pregnancy

Aphexda can cause fetal harm when administered to pregnant women. Women of reproductive potential should use effective contraception during treatment with this medicine and for 8 days after the final dose. Women of reproductive potential should have a negative pregnancy test before starting treatment.

Breastfeeding

Breastfeeding is not recommended during the treatment with Aphexda and for 8 days after the final dose.