Winrevair

Pulmonary Arterial Hypertension (PAH)

Winrevair is used to treat pulmonary arterial hypertension (PAH) in adults. PAH is a condition characterized by high blood pressure in the arteries that carry blood from the heart to the lungs. This medication is specifically indicated for patients classified as World Health Organization (WHO) Group 1.

Treatment Goals

The primary objectives of treatment with Winrevair include:

• Improving exercise capacity: Helping patients increase their ability to perform physical activities.
• Improving functional class: Enhancing the patient's ability to carry out daily tasks and reducing physical limitations caused by the disease.
• Reducing clinical worsening: Lowering the risk of disease progression, hospitalization, or the need for additional medical interventions.

Winrevair is typically used in combination with other standard therapies for PAH. It is intended to help manage the symptoms and progression of the disease rather than serve as a cure.

Restoring Signaling Balance

In people with pulmonary arterial hypertension (PAH), the blood vessels in the lungs become thick and narrow. This happens because of an imbalance in the signals that control how cells in the blood vessel walls grow and multiply. Specifically, there is often too much signaling that promotes cell growth and not enough signaling that limits it.

Winrevair works by targeting this imbalance. It is a fusion protein that binds to certain proteins, such as activins, that contribute to the overgrowth of cells in the lung's blood vessels.

Improving Blood Flow

By binding to these proteins, Winrevair helps to:

• Reduce vessel wall thickening: It limits the excessive growth of cells that cause the pulmonary arteries to narrow.
• Improve vascular health: It helps restore a more normal environment within the blood vessels.
• Lower blood pressure in the lungs: As the vessels become less constricted, blood can flow more easily from the heart to the lungs.

This mechanism is different from many other PAH treatments, which primarily focus on widening the blood vessels. Winrevair aims to address the underlying structural changes in the vessels themselves.

Common Side Effects

The most common side effects reported by people taking Winrevair include:

• Headache
• Nosebleeds
• Small red or purple spots on the skin, often called spider veins (telangiectasia)
• Rash
• Dizziness
• Diarrhea
• Redness, itching, or pain at the injection site

Serious Side Effects

Winrevair can cause serious changes in your blood. Contact your doctor immediately if you experience signs of a serious reaction.

• Increased hemoglobin: This medication can cause an increase in red blood cells (erythrocytosis), which may raise the risk of blood clots.
• Low platelet count: A decrease in platelets (thrombocytopenia) can increase the risk of bleeding. Symptoms may include unusual bruising or bleeding that does not stop.
• Severe allergic reactions: Seek emergency medical help if you experience hives, difficulty breathing, or swelling of the face, lips, or throat.

Because of these risks, your healthcare provider will perform blood tests to check your hemoglobin and platelet levels before each dose for at least the first five doses, and periodically thereafter. Your dose may be delayed or adjusted based on these results.

Increased Hemoglobin (Erythrocytosis)

Winrevair may cause an increase in hemoglobin levels. Excessive increases in red blood cells can lead to serious complications, such as blood clots or hyperviscosity syndrome. Healthcare providers typically check hemoglobin levels before starting treatment, before each of the first five doses, and periodically afterward to determine if the dose needs to be adjusted or paused.

Decreased Platelets (Thrombocytopenia)

This medication can lower the number of platelets in the blood, which are necessary for clotting. Low platelet levels can increase the risk of bleeding. Platelet counts are monitored before starting treatment, before each of the first five doses, and periodically during therapy.

Severe Bleeding

Serious bleeding events, including bleeding in the brain or digestive tract, have been reported in patients using this medication. The risk may be higher for individuals who are also taking blood thinners or antiplatelet medications. It is important to watch for signs of bleeding, such as unusual bruising, nosebleeds, or dark stools.

Blood Pressure Changes

Increases in blood pressure have occurred in some patients. Blood pressure should be monitored regularly while using this medication.

Pregnancy and Fertility

Winrevair may cause harm to an unborn baby. Individuals who can become pregnant should use effective contraception during treatment and for at least four months after the final dose. This medication may also affect fertility in both men and women based on findings in animal studies.

Pregnancy

There is limited information regarding the use of Winrevair in pregnant women. Based on animal studies, this medication may cause harm to a developing fetus. Healthcare providers typically recommend that the drug only be used during pregnancy if the potential benefit outweighs the potential risk.

Females of reproductive potential are advised to use effective contraception during treatment and for at least 4 months after the final dose. If you become pregnant or suspect you are pregnant while using this medication, notify your healthcare provider immediately.

Breastfeeding

It is currently unknown whether Winrevair passes into human breast milk or if it affects a nursing infant or milk production. Due to the potential for serious side effects in a breastfed child, it is generally recommended to avoid breastfeeding during treatment and for 4 months following the last dose.

Fertility

Animal studies suggest that Winrevair may impair both female and male fertility. It is not yet known how this medication affects human fertility. Individuals planning to have children should discuss these risks with their doctor before beginning treatment.

Dosage Forms

Winrevair is supplied as a sterile powder in a single-dose vial. It does not contain preservatives. Before administration, the powder must be dissolved using a specific liquid provided in the medication kit.

Administration Route

This medication is given by subcutaneous injection. This involves injecting the liquid into the layer of fat directly under the skin.

Packaging

Winrevair is distributed in kits designed for single-use. These kits generally include vials containing the medication powder and prefilled syringes containing sterile water for injection, which is used to dissolve the powder. The kits also include components for mixing and administration, such as vial adapters and needles.

The medication is available in kits that contain a single vial or kits that contain multiple vials.

FDA Approval and Indications

The U.S. Food and Drug Administration (FDA) approved Winrevair in March 2024. It is indicated for the treatment of adults with pulmonary arterial hypertension (PAH), specifically those in World Health Organization (WHO) Group 1. The medication is used to increase exercise capacity, improve WHO functional class, and reduce the risk of clinical worsening events.

Regulatory Designations

The FDA granted Winrevair Breakthrough Therapy and Orphan Drug designations during its development. These designations are intended to expedite the review of drugs for serious conditions and encourage the development of treatments for rare diseases.

Safety Monitoring

There are no boxed warnings or Risk Evaluation and Mitigation Strategy (REMS) requirements for this medication. However, the FDA requires healthcare providers to monitor hemoglobin and platelet levels before each of the first five doses and periodically thereafter to manage potential side effects like erythrocytosis (increased red blood cells) or thrombocytopenia (decreased platelets).

Estimated List Price

The manufacturer's list price for Winrevair is approximately $14,000 per vial. Most patients require one vial every three weeks, though the total cost can vary depending on the specific dose prescribed by a healthcare provider.

Insurance and Coverage

The amount a patient pays out-of-pocket is largely determined by their insurance plan. Coverage details may include:

• Commercial Insurance: Many private plans cover Winrevair, but patients may be responsible for deductibles, co-pays, or coinsurance.
• Medicare and Medicaid: Coverage is generally available through government programs, though the specific costs depend on the individual's plan and phase of coverage.
• Specialty Pharmacy: Winrevair is a specialty medication and is typically distributed through specialty pharmacies rather than standard retail locations.

Financial Assistance Programs

Because of the high cost of treatment, financial support options may be available to help eligible patients:

• Co-pay Assistance: Patients with commercial insurance may be eligible for co-pay cards or coupons provided by the manufacturer to lower their out-of-pocket expenses.
• Patient Assistance Programs: For individuals who are uninsured or have limited insurance coverage, the manufacturer may offer programs that provide the medication at no cost or a significantly reduced rate based on financial need.

Patients should consult with their insurance provider or a specialty pharmacy coordinator to understand their specific coverage and potential costs.