Pharmacy Bulletin

Pharmacy Bulletin

We share important prescription drug information to help you stay informed about updates concerning particular prescription medicines.

VativoRx Bottle update

The U.S. Food and Drug Administration (FDA) approved Iwilfin(eflornithine) tablets on Dec. 13, 2023. It blocks the effects of the enzyme ornithine decarboxylase to lower the chances that patients who have responded at least partly to previous treatments for neuroblastoma will have a recurrence of the cancer. Dosing ranges from one tablet (192mg) twice a day to four tablets (768mg) twice a day based on the patient’s body surface area (BSA). For patients who cannot swallow tablets easily, Iwilfin can be chewed or crushed and mixed with soft food or a liquid. The manufacturer, US WorldMeds (USWM) plans a launch by mid-January, 2024. Cost information has not yet been released. For full prescribing information, look here.

At a Glance

  • Brand (Generic) Name: Iwilfin (eflornithine)
  • Manufacturer: US WorldMeds (USWM)
  • Date Approved: Dec. 13, 2023
  • Indication: to reduce the risk of relapse in adult and pediatric patients who have high-risk neuroblastoma and who have demonstrated at least a partial response to prior multiagent, multimodality therapy including anti-GD2 (ganglioside) immunotherapy
  • Dosage Forms Available: 192mg oral tablets
  • Launch Date: within about the next month
  • Estimated Annual Cost: Not yet announced
  • Neuroblastoma affects nerve cells that still are in development (neuroblasts), usually starting in the adrenal glands, along the spine, or in the chest, neck, or pelvis.
  • Fewer than 800 neuroblastoma cases are discovered in the U.S. per year – around 90% are in children younger than five years old.
  • Typically, neuroblastomas that affect older children, tumors that have specific genetic profiles, and those that have metastasized are considered to be high risk.
  • Only about one-half of patients at high risk live for five years after diagnosis.
  • Although topical and injectable forms of eflornithine are available, Iwilfin is the first oral formulation to be approved.
  • Iwilfin interferes with an enzyme critical for producing functioning cancer stem cells, so it stops or slows down tumor development.
  • In open-label clinical studies, 84% of those treated with Iwilfin had no relapses for four years or longer, as opposed to 73% of patients who received standard care. The overall survival (OS) rates were 96% and 84%, respectively.
  • Because Iwilfin may cause blood abnormalities, liver damage, or hearing loss, patients should have frequent blood counts, liver function tests, and hearing checks before and during therapy with it.
  • In the trials, other frequent side effects included coughing, fever, diarrhea, vomiting, and various infections – particularly in the upper respiratory and urinary tracts.
  • Unituxin (dinutuximab – United Therapeutics) injection was FDA approved in 2015 to be used along with a granulocyte-macrophage colony-stimulating factor (GM-CSF), an interleukin-2 (IL-2), and a 13-cis-retinoic acid, for treatment of children who have high-risk neuroblastoma that has improved completely or partially due to prior first-line multiagent, multimodality therapy. By attaching to GD2, which occurs on neuroblastoma cells, Unituxin causes cancer cells to die. It is given as intravenous (IV) infusions for four consecutive days in no more than five cycles that last 24 or 32 days.
  • Another GD2-binding antibody, Danyelza® (naxitamab-gqgk – Y-mAbs Therapeutics) injection received the FDA’s Accelerated Approval in 2020 for use along with a GM-CSF to treat high-risk neuroblastomas for patients at least one year old who have had some response to previous treatment, but who have relapsed or refractory (r/r) neuroblastoma in the bones or bone marrow. It is given as IV doses on the first, third, and fifth days of 28-day cycles, switching to 56-day cycles for maintenance.
  • Other treatments for relapsed high-risk neuroblastoma include intensive chemotherapy (chemo), radiation, surgery, and stem cell transplants.
  • Designated as an Orphan Drug and a Breakthrough Therapy, Iwilfin also underwent the FDA’s Priority Review and Real-Time Oncology Review (RTOR).