WINREVAIR Solution for injection Ref.[109322] Active ingredients: Sotatercept

2.1 Recommended Starting Dosage

WINREVAIR is administered once every 3 weeks by subcutaneous injection according to patient body weight. The starting dose of WINREVAIR 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) [see Dosage and Administration (2.3)].

Inhjection Volume (mL) = Weight (kg) x 0.3 mg/kg / 50 mg/mL

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

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 mL, rounds to 0.4 mL

See Table 1 for selecting the appropriate kit based on calculated injection volume for starting dose.

Table 1. Kit Type Based on Injection Volume for Dose of 0.3 mg/kg:

2.2 Recommended Target Dosage

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 [see Dosage and Administration (2.3)].

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

Inhjection Volume (mL) = Weight (kg) x 0.7 mg/kg / 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 mL, rounds to 1 mL

See Table 2 for selecting the appropriate kit based on calculated injection volume for target dose.

Table 2. Kit Type Based on Injection Volume for Dose of 0.7 mg/kg:

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 [see Overdosage (10)].

2.3 Dosage Modifications Due to Hemoglobin 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 [see Warnings and Precautions (5.1, 5.2)].

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 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 × 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.

2.4 Preparation and Administration

Administration is subject to monitoring of hemoglobin and platelet count [see Dosage and Administration (2.3), Warnings and Precautions (5.1, 5.2)].

WINREVAIR is intended for use under the guidance of a healthcare professional. Patients and caregivers may administer WINREVAIR when considered appropriate and when they receive training and follow-up from the healthcare provider (HCP) on how to reconstitute, prepare, measure, and inject WINREVAIR [see Patient Counseling Information (17)].

Confirm at subsequent visits that the patient and/or caregiver can correctly prepare and administer WINREVAIR, particularly if the dose changes or the patient requires a different kit [see Warnings and Precautions (5.1)].

Refer to the Instructions for Use (IFU) for detailed instructions on the proper preparation and administration of WINREVAIR.

Selecting the Appropriate Product Kit

If a patient’s body weight requires the use of two 45 mg vials or two 60 mg vials of lyophilized product, use a 2-vial kit instead of two individual 1-vial kits. A 2-vial kit includes instructions to combine the contents of two vials, which aids in measuring the proper dosage and eliminates the need for multiple injections [see How Supplied/Storage and Handling (16.1)].

Reconstitution Instructions:

• Remove the injection kit from the refrigerator and wait 15 minutes to allow the prefilled syringe(s) and drug product to come to room temperature prior to preparation.
• Attach the vial adapter to the vial.
• Visually inspect the pre-filled syringe for any damage or leaks and the Sterile Water for Injection inside to ensure there are no visible particles.
• Snap off the cap of the pre-filled syringe and attach the syringe to the vial adapter.
• Inject all of the Sterile Water for Injection from the attached syringe into the vial containing the lyophilized powder. This will provide a final concentration of 50 mg/mL.
• Gently swirl the vial to reconstitute the drug product. DO NOT shake or vigorously agitate.
• Allow the vial to stand for up to 3 minutes to allow bubbles to disappear.
• Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
• When properly mixed, WINREVAIR should be clear to opalescent and colorless to slightly brownishyellow and does not have clumps or powder.
• If prescribed a 2-vial presentation, repeat the steps within this section to prepare the second vial.
• Use the reconstituted solution as soon as possible, but no later than 4 hours after reconstitution. Discard unused reconstituted solution.

Syringe Preparation:

• Turn the syringe and vial upside-down and withdraw the appropriate volume for injection, based on the patient’s weight.
  • If the dose amount requires the use of two vials, withdraw the entire contents of the first vial and slowly transfer full contents into the second vial.
  • Turn the syringe and vial upside-down and withdraw the required amount of drug product.
  • If necessary, remove excess drug product.
• If necessary, remove excess air from the syringe.

Administration Instructions:

WINREVAIR is for subcutaneous injection.

• Select the injection site on the abdomen (at least 2 inches away from navel), upper thigh, or upper arm, and swab with an alcohol wipe. Select a new site for each injection that is not scarred, tender, or bruised.
  • For administration by the patient or caregiver, use only the abdomen and upper thigh (see IFU).
• Perform subcutaneous injection.

In healthy volunteers, WINREVAIR dosed at 1 mg/kg resulted in increases in Hgb associated with hypertension; both improved with phlebotomy. In the event of overdose, monitor closely for increases in Hgb and blood pressure, and provide supportive care as appropriate. WINREVAIR is not dialyzable.

Store vials refrigerated at 2°C to 8°C (36°F to 46°F) in original carton to protect from light. Do not freeze.

The kit should remain in the refrigerator until ready for use. The unused kit can be out of the refrigerator for (up to 25°C/77°F) up to 24 hours. For additional information on temperature excursions, call Merck Sharp & Dohme LLC at 1-800-672-6372.