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For appropriate patients,

WINREVAIR offers the convenience of at-home administration with 1 subcutaneous injection every 3 weeks

  • WINREVAIR is intended for use under the guidance of a healthcare professional (HCP). Patients and caregivers may administer WINREVAIR when deemed appropriate by their HCP with guidance, training, and follow-up on how to reconstitute, prepare, measure and inject WINREVAIR.
  • WINREVAIR dose is according to patient body weight. Consult the Prescribing Information for weight-based injection volumes per dose.

Scroll down to view additional dosage information and injection volume calculator.

The recommended STARTING DOSE is 0.3 mg/kg

  • Obtain hemoglobin (Hgb) and platelet count prior to the first dose of WINREVAIR.
  • Do not initiate treatment if platelet count is <50,000/mm3 (<50×109/L).

Injection volume for starting dose is calculated based on patient weight as follows:

For Starting Dose Injection Volume (mL) = Weight (kg) x 0.3 mg/kg Divided By 50 mg/mLFor Starting Dose Injection Volume (mL) = Weight (kg) x 0.3 mg/kg Divided By 50 mg/mL

Injection volume should be rounded to the nearest 0.1 mL.


For example: (70 kg x 0.3 mg/kg) ÷ 50 mg/mL = 0.42, rounds to 0.4 mL.

See the table below for selecting the appropriate kit based on calculated injection volume for starting dose.

Kit type based on injection volume for dose of 0.3 mg/kg

Injection volume (mL)Kit Type
0.2 to 0.945 mg kit (containing 1 x 45 mg vial)
1 to 1.160 mg kit (containing 1 x 60 mg vial)

The recommended TARGET DOSE is 0.7 mg/kg

  • After verifying acceptable Hgb and platelet count, increase to the target dose of 0.7 mg/kg.
  • Continue treatment at 0.7 mg/kg every 3 weeks unless dosage adjustments are required.

Injection volume for target dose is calculated based on patient weight as follows:

For Target Dose Injection Volume (mL) = Weight (kg) x 0.7 mg/kg Divided By 50 mg/mLFor Target Dose Injection Volume (mL) = Weight (kg) x 0.7 mg/kg Divided By 50 mg/mL

Injection volume should be rounded to the nearest 0.1 mL.


For example: (70 kg x 0.7 mg/kg) ÷ 50 mg/mL = 0.98, rounds to 1 mL.

See the table below for selecting the appropriate kit based on calculated injection volume for target dose.

Kit type based on injection volume for dose of 0.7 mg/kg

Injection volume (mL)Kit Type
0.4 to 0.945 mg kit (containing 1 x 45 mg vial)
1 to 1.260 mg kit (containing 1 x 60 mg vial)
1.3 to 1.890 mg kit (containing 2 x 45 mg vials)
1.9 to 2.4120 mg kit (containing 2 x 60 mg vials)

Missed dose, overdose, and underdose

  • If a dose of WINREVAIR is missed, administer as soon as possible.
  • If the missed dose of WINREVAIR is not administered within 3 days of the scheduled date, adjust the schedule to maintain 3-week dosing intervals.
  • In case of an overdose, monitor for erythrocytosis.

Dosage modifications due to Hgb increase or platelet count decrease

Check Hgb and platelet count before each dose for the first 5 doses, or longer if values are unstable. Thereafter, monitor Hgb and platelet count periodically.

Delay treatment for at least 3 weeks if any of the following occur:

  • Hgb increases >2.0 g/dL from the previous dose and is above upper limit of normal (ULN)
  • Hgb increases >4.0 g/dL from baseline
  • Hgb increases >2.0 g/dL above ULN
  • Platelet count decreases to <50,000/mm³ (<50.0 x 10⁹/L)

Recheck Hgb and platelet count before reinitiating treatment. For treatment delays lasting >9 weeks, restart treatment at 0.3 mg/kg and escalate to 0.7 mg/kg after verifying acceptable Hgb and platelet count.

Injection Volume Calculator

Calculates injection volume based on dose and patient weight

Access here
Report exposure during pregnancy or lactation to the Merck Sharp & Dohme, LLC Adverse Event reporting line at 1-877-888-4231

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The Injection Volume Calculator is intended for use only by qualified healthcare professionals.

All calculations should be confirmed before use. The information being provided is not a substitute for clinical judgment.

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INDICATION

WINREVAIR is an activin signaling inhibitor indicated for the treatment of adults with pulmonary arterial hypertension (PAH, World Health Organization [WHO] Group 1) to increase exercise capacity, improve WHO functional class (FC), and reduce the risk of clinical worsening events.

SELECTED SAFETY INFORMATION

Erythrocytosis: WINREVAIR may increase hemoglobin (Hgb). Severe erythrocytosis may increase the risk of thromboembolic events or hyperviscosity syndrome. Monitor Hgb before each dose for the first 5 doses, or longer if values are unstable, and periodically thereafter, to determine if dose adjustments are required.

 

Severe Thrombocytopenia: WINREVAIR may decrease platelet count. Severe thrombocytopenia may increase the risk of bleeding. Thrombocytopenia occurred more frequently in patients also receiving prostacyclin infusion. Do not initiate treatment if platelet count is <50,000/mm3. Monitor platelets before each dose for the first 5 doses, or longer if values are unstable, and periodically thereafter to determine whether dose adjustments are required.

 

Serious Bleeding: In clinical studies, serious bleeding (eg, gastrointestinal, intracranial hemorrhage) was reported in 4% of patients taking WINREVAIR and 1% of patients taking placebo. Patients with serious bleeding were more likely to be on prostacyclin background therapy and/or antithrombotic agents, or have low platelet counts. Advise patients about signs and symptoms of blood loss. Do not administer WINREVAIR if the patient is experiencing serious bleeding.

 

Embryo-Fetal Toxicity: WINREVAIR may cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use an effective method of contraception during treatment with WINREVAIR and for at least 4 months after the final dose. Pregnancy testing is recommended for females of reproductive potential before starting WINREVAIR treatment.

 

Impaired Fertility: Based on findings in animals, WINREVAIR may impair female and male fertility. Advise patients on the potential effects on fertility.

 

Adverse Reactions: The most common adverse reactions occurring in the phase 3 clinical trial (≥10% for WINREVAIR and at least 5% more than placebo) were headache (24.5% vs 17.5%), epistaxis (22.1% vs 1.9%), rash (20.2% vs 8.1%), telangiectasia (16.6% vs 4.4%), diarrhea (15.3% vs 10.0%), dizziness (14.7% vs 6.2%), and erythema (13.5% vs 3.1%).

 

Lactation: Because of the potential for serious adverse reactions in the breastfed child, advise patients that breastfeeding is not recommended during treatment with WINREVAIR, and for 4 months after the final dose.

 

Before prescribing WINREVAIR, please read the accompanying Prescribing Information. The Patient Information and Instructions for Use (1-vial kit, 2-vial kit) also are available.

INDICATION
SELECTED SAFETY INFORMATION

WINREVAIR is an activin signaling inhibitor indicated for the treatment of adults with pulmonary arterial hypertension (PAH, World Health Organization [WHO] Group 1) to increase exercise capacity, improve WHO functional class (FC), and reduce the risk of clinical worsening events.

SELECTED SAFETY INFORMATION

Erythrocytosis: WINREVAIR may increase hemoglobin (Hgb). Severe erythrocytosis may increase the risk of thromboembolic events or hyperviscosity syndrome. Monitor Hgb before each dose for the first 5 doses, or longer if values are unstable, and periodically thereafter, to determine if dose adjustments are required.

 

Severe Thrombocytopenia: WINREVAIR may decrease platelet count. Severe thrombocytopenia may increase the risk of bleeding. Thrombocytopenia occurred more frequently in patients also receiving prostacyclin infusion. Do not initiate treatment if platelet count is <50,000/mm3. Monitor platelets before each dose for the first 5 doses, or longer if values are unstable, and periodically thereafter to determine whether dose adjustments are required.

 

Serious Bleeding: In clinical studies, serious bleeding (eg, gastrointestinal, intracranial hemorrhage) was reported in 4% of patients taking WINREVAIR and 1% of patients taking placebo. Patients with serious bleeding were more likely to be on prostacyclin background therapy and/or antithrombotic agents, or have low platelet counts. Advise patients about signs and symptoms of blood loss. Do not administer WINREVAIR if the patient is experiencing serious bleeding.

 

Embryo-Fetal Toxicity: WINREVAIR may cause fetal harm when administered to a pregnant woman. Advise pregnant women of the potential risk to a fetus. Advise females of reproductive potential to use an effective method of contraception during treatment with WINREVAIR and for at least 4 months after the final dose. Pregnancy testing is recommended for females of reproductive potential before starting WINREVAIR treatment.

 

Impaired Fertility: Based on findings in animals, WINREVAIR may impair female and male fertility. Advise patients on the potential effects on fertility.

 

Adverse Reactions: The most common adverse reactions occurring in the phase 3 clinical trial (≥10% for WINREVAIR and at least 5% more than placebo) were headache (24.5% vs 17.5%), epistaxis (22.1% vs 1.9%), rash (20.2% vs 8.1%), telangiectasia (16.6% vs 4.4%), diarrhea (15.3% vs 10.0%), dizziness (14.7% vs 6.2%), and erythema (13.5% vs 3.1%).

 

Lactation: Because of the potential for serious adverse reactions in the breastfed child, advise patients that breastfeeding is not recommended during treatment with WINREVAIR, and for 4 months after the final dose.

 

Before prescribing WINREVAIR, please read the accompanying Prescribing Information. The Patient Information and Instructions for Use (1-vial kit, 2-vial kit) also are available.