FDA approves new treatment for blood cancer

Vonjo (pacritinib) is a prescription medication approved for treating myelofibrosis, a rare bone marrow disorder that causes scarring and disrupts blood cell formation. The drug functions by inhibiting proteins responsible for abnormal signaling in the bone marrow, which otherwise leads to fibrosis and related complications.

Mechanism and Patient Eligibility

The treatment is intended for adults with myelofibrosis who have low platelet counts, a condition that heightens bleeding risks due to impaired clotting. Low platelet levels can result in bruising, internal bleeding, or life-threatening hemorrhage.

Studies are still ongoing to confirm the full benefits of this medicine.

Dosage Guidelines

The recommended dose is 200 mg twice daily, administered as two 100 mg capsules at consistent times. Capsules must be swallowed whole, without crushing, breaking, or opening. Missed doses should not be doubled; instead, patients should skip the missed intake entirely.

Physicians often adjust dosages based on side effects, particularly low platelet counts or diarrhea, which are frequent reactions. The prescribing information advises discontinuing the drug seven days before surgery to minimize bleeding risks, with resumption permitted only after medical approval.

Before initiating Vonjo, patients must gradually reduce doses of other similar medications, such as ruxolitinib, to avoid overlapping risks.

Major Risks and Adverse Effects

Bleeding poses the most immediate danger. Among patients with very low platelet counts, 13% experienced severe bleeding events, including 2% who died from complications. Warning signs include unexpected bruising, blood in urine or stool, or coughing up blood. Immediate medical attention is required for any bleeding episode.

Cardiac risks also demand caution. A similar type of medicine increased the risk of heart attack, stroke, and heart-related death in patients with a different condition. Patients who smoke, or who have smoked in the past, are at higher risk. Talk to your doctor about your personal risk before starting Vonjo.

Additional serious risks include:

• Blood clots (indicated by leg swelling or sudden shortness of breath)
• Infections (marked by fever, chills, or painful urination)
• Severe diarrhea (posing dehydration risks and potentially requiring hospitalization)
• Cancer (with raised lymphoma risk in some cases)

Patients with liver or kidney disease must use Vonjo with heightened caution, as the drug may exacerbate these conditions. Those with active bleeding, low potassium levels, or a history of heart rhythm disorders may need dosage adjustments or alternative therapies.

For women of reproductive age, Vonjo can harm an unborn baby. Animal studies showed harm at doses lower than what people take. If you could become pregnant, talk to your doctor about birth control before starting this medicine. Tell your doctor right away if you become pregnant while taking Vonjo.

Drug Interactions and Handling

Certain medications can interact dangerously with Vonjo, including:

• Clarithromycin and rifampin (antibiotics that alter drug metabolism)
• Digoxin (heart medication requiring close monitoring)
• Rosuvastatin (cholesterol drug with a maximum daily dose of 20 mg)
• Hormonal birth control (potentially reduced effectiveness; non-hormonal methods like IUDs are recommended)
• Drugs affecting heart rhythm (such as certain antidepressants or antipsychotics)

Patients must inform their healthcare providers about all supplements, over-the-counter drugs, and vitamins, as some may intensify side effects. Fluconazole, an antifungal medication, also requires careful monitoring due to interaction risks.

Storage instructions are simple: capsules should remain in their original, tightly sealed container at room temperature, protected from light. The drug is unsafe for children, and accidental ingestion necessitates immediate medical attention.

Patient Preparation and Monitoring

Physicians will typically order regular blood tests to track platelet counts, liver function, and other health markers. Diarrhea, a common side effect in the first eight weeks, can often be managed with fluids and over-the-counter remedies like loperamide. Severe cases may require prescription treatment.

Patients should carry a medical alert card or wear a bracelet identifying their condition and treatment, as Vonjo increases bleeding risks. Emergency personnel must be informed of its use, particularly before medical procedures.

Men concerned about fertility may need to preserve sperm before starting treatment, as the drug’s effects on sperm remain unclear. Women should use non-hormonal birth control during treatment and for 30 days after the final dose.

Vonjo is only available through special pharmacies. Your doctor or care team can help you get it. You can also visit www.ctiaccess.com for more information.

Vonjo does not cure myelofibrosis. Its primary role is symptom management, particularly reducing spleen enlargement. Ongoing research will clarify whether the drug improves survival rates or enhances quality of life for patients with low platelet counts.