This site requires JavaScript to be enabled to work properly. Please modify your settings or use a different browser to continue


Leaving GSK Pro

You are leaving GSK Pro to visit a separate website not associated with GSK Pro, a portal for US Healthcare Professionals.There are website links to third-party sites on GSK Pro. GSK is not responsible for content on third-party websites.




Use the Vial Calculator for BENLYSTA IV to determine a vial combination for each patient that helps minimize waste

BENLYSTA IV comes in two vial sizes and is administered as a 10 mg/kg dose. For more information about ordering BENLYSTA, call BENLYSTA Gateway at 1-877-4-BENLYSTA.

Enter the weight or dose for each patient and click the “Calculate” button below.

VIAL CALCULATOR: Content will be injected here for the vial calculator functionality.

BENLYSTA IV is available as 120 mg in a 5-mL single-dose vial and 400 mg in a 20-mL single-dose vial for injection, for intravenous use only. The vials contain a rubber stopper not made with natural rubber latex. BENLYSTA is administered as an intravenous infusion and must be reconstituted and diluted prior to administration. It is administered over 1 hour as a weight-based dose of 10 mg/kg. The recommended dosage regimen is 10 mg/kg at 2-week intervals for the first 3 doses and at 4-week intervals thereafter. Do not administer BENLYSTA as an intravenous push or bolus. Discontinue immediately in the event of a serious hypersensitivity reaction and administer appropriate medical therapy.

Reconstitute BENLYSTA IV

  • Reconstitute BENLYSTA IV using aseptic technique
  • Remove BENLYSTA IV from the refrigerator and allow to stand 10 to 15 minutes for the vial(s) to reach room temperature
  • Reconstitute BENLYSTA IV powder with Sterile Water for Injection, USP, as follows. The reconstituted solution will contain a concentration of 80 mg/mL belimumab. Use of a 21- to 25-gauge needle is recommended
    • Reconstitute the 120-mg vial with 1.5 mL Sterile Water for Injection, USP
    • Reconstitute the 400-mg vial with 4.8 mL Sterile Water for Injection, USP
  • The stream of sterile water should be directed toward the side of the vial to minimize foaming
  • Reconstitution is typically complete within 10 to 15 minutes after the sterile water has been added, but it may take up to 30 minutes
  • Protect the reconstituted solution from direct sunlight
  • Once reconstitution is complete, the solution should be opalescent and colorless to pale yellow and without particles. Small air bubbles, however, are expected and acceptable
  • If a mechanical reconstitution device (swirler) is used, it should not exceed 500 rpm and the vial swirled for no longer than 30 minutes
  • The reconstituted solution of BENLYSTA IV, if not used immediately, should be stored protected from direct sunlight and refrigerated at 36° to 46°F (2° to 8°C)
  • The total time from reconstitution of BENLYSTA IV to completion of infusion should not exceed 8 hours


Remember that when reconstituting BENLYSTA IV, you must swirl—not shake—the vial.

  • Allow the vial to sit at room temperature during reconstitution
  • Gently swirl the vial for 60 seconds every 5 minutes until the powder is dissolved

Prepare the infusion

The reconstituted BENLYSTA IV must be diluted.
Calculate the volume required to be added to the infusion bag using this formula:

__-mg dose ÷ 80 mg/mL = __ mL to be added to infusion bag

Example of a 180-lb (81.8-kg) patient
818-mg dose ÷ 80 mg/mL = 10.2 mL to be added to infusion bag

  • Dextrose intravenous solutions are incompatible with BENLYSTA IV. BENLYSTA IV should only be diluted in 0.9% Sodium Chloride Injection, USP (normal saline) or 0.45% Sodium Chloride Injection, USP (half normal saline) or Lactated Ringer's Injection, USP to a volume of 250 mL for intravenous infusion.
    • For patients whose body weight is ≤ 40kg, 100 mL may be used such that the resulting belimumab concentration in the infusion bag does not exceed 4 mg/mL.
  • From the 250-mL infusion bag or bottle, withdraw and discard a volume of fluid equal to the volume of reconstituted solution of BENLYSTA required for the patient's dose
  • Add the required volume of the reconstituted solution of BENLYSTA IV to the bag or bottle, and then gently invert to mix
  • Inspect solution for particulate matter and discoloration prior to administration and discard if either is observed
  • Any unused solution in the vials must be discarded
  • Diluted solutions of BENLYSTA IV may be stored at 36° to 46°F (2° to 8°C) or room temperature
  • Remember, the total time from reconstitution of BENLYSTA IV to completion of infusion should not exceed 8 hours.

Administer BENLYSTA IV

The diluted solution should be administered as an intravenous infusion and given over a 1-hour period.

  • Do not administer as an intravenous push or bolus
  • Consider administering premedication for prophylaxis against infusion reactions and hypersensitivity reactions. However, there is insufficient evidence to determine whether premedication diminishes the frequency or severity of hypersensitivity reactions
  • BENLYSTA IV should be administered by healthcare providers prepared to manage anaphylaxis or other infusion reactions
  • BENLYSTA should not be infused concomitantly in the same intravenous line with other agents 
  • Use of a filter was not required in the clinical trials.


BENLYSTA is indicated for patients aged ≥5 years with active, autoantibody-positive systemic lupus erythematosus (SLE) who receive standard therapy. The subcutaneous (SC) formulation is approved for patients aged ≥18 years. BENLYSTA is not indicated or recommended in patients with severe active lupus nephritis, or severe active central nervous system lupus, or in combination with other biologics or intravenous cyclophosphamide.



Previous anaphylaxis with BENLYSTA.



Serious Infections: Serious and sometimes fatal infections have been reported in patients receiving immunosuppressive agents, including BENLYSTA. The incidence of serious infections was similar in patients receiving BENLYSTA versus placebo, whereas fatal infections occurred more frequently with BENLYSTA. The most frequent serious infections in adults treated with BENLYSTA IV included pneumonia, urinary tract infection, cellulitis, and bronchitis. Use caution in patients with severe or chronic infections, and consider interrupting therapy in patients with a new infection.

Progressive Multifocal Leukoencephalopathy (PML): Cases of JC virus-associated PML resulting in neurological deficits, including fatal cases, have been reported in patients with SLE receiving immunosuppressants, including BENLYSTA. If PML is confirmed, consider stopping immunosuppressant therapy, including BENLYSTA.

Hypersensitivity Reactions (including Anaphylaxis): Acute hypersensitivity reactions, including anaphylaxis (eg, hypotension, angioedema, urticaria or other rash, pruritus, and dyspnea) and death, have been reported, including in patients who have previously tolerated BENLYSTA. Generally, reactions occurred within hours of the infusion but may occur later. Non-acute hypersensitivity reactions (eg, rash, nausea, fatigue, myalgia, headache, and facial edema) typically occurred up to a week after infusion. Patients with a history of multiple drug allergies or significant hypersensitivity may be at increased risk. With BENLYSTA SC, systemic hypersensitivity reactions were similar to those in IV trials.

Healthcare providers (HCPs) should monitor patients during and after IV administration and be prepared to manage anaphylaxis; discontinue immediately in the event of a serious reaction. Premedication may mitigate or mask a hypersensitivity response. Advise patients about hypersensitivity symptoms and instruct them to seek immediate medical care if a reaction occurs.

Infusion Reactions: Serious infusion reactions (eg, bradycardia, myalgia, headache, rash, urticaria, and hypotension) were reported in adults. HCPs should monitor patients and manage reactions if they occur. Premedication may mitigate or mask a reaction. If an infusion reaction develops, slow or interrupt the infusion.

Depression and Suicidality: In adult trials, psychiatric events reported more frequently with BENLYSTA IV related primarily to depression-related events, insomnia, and anxiety; serious psychiatric events included serious depression and suicidality, including 2 completed suicides. No serious depression-related events or suicides were reported in the BENLYSTA SC trial. Before adding BENLYSTA, assess patients’ risk of depression and suicide and monitor them during treatment. Instruct patients/caregivers to contact their HCP if they experience new/worsening depression, suicidal thoughts, or other mood changes.

Malignancy: The impact of BENLYSTA on the development of malignancies is unknown; its mechanism of action could increase the risk for malignancies.

Immunization: Live vaccines should not be given for 30 days before or concurrently with BENLYSTA as clinical safety has not been established.

Use With Biologic Therapies or IV Cyclophosphamide: BENLYSTA has not been studied and is not recommended in combination with other biologic therapies, including B-cell targeted therapies, or IV cyclophosphamide.


The most common serious adverse reactions in adults were serious infections: BENLYSTA IV 6.0% (placebo 5.2%). Fatal infections occurred in 0.3% of patients receiving BENLYSTA and in 0.1% of patients receiving placebo. Adverse reactions occurring in ≥3% of adults and ≥1% more than placebo: nausea 15% (12%); diarrhea 12% (9%); pyrexia 10% (8%); nasopharyngitis 9% (7%); bronchitis 9% (5%); insomnia 7% (5%); pain in extremity 6% (4%); depression 5% (4%); migraine 5% (4%); pharyngitis 5% (3%); cystitis 4% (3%); leukopenia 4% (2%); viral gastroenteritis 3% (1%).

Adverse reactions in pediatric patients aged ≥5 years receiving BENLYSTA IV were consistent with those observed in adults.

The safety profile observed for BENLYSTA SC in adults was consistent with the known safety profile of BENLYSTA IV with the exception of local injection site reactions.


Pregnancy: There are insufficient data in pregnant women to establish whether there is drug-associated risk for major birth defects or miscarriage. After a risk/benefit assessment, if prevention is warranted, women of childbearing potential should use contraception during treatment and for ≥4 months after the final treatment.

Pregnancy Registry: HCPs are encouraged to register patients and pregnant women are encouraged to enroll themselves by calling 1-877-681-6296.

Lactation: No information is available on the presence of belimumab in human milk, the effects on the breastfed infant, or the effects on milk production. Consider developmental and health benefits of breastfeeding with the mother’s clinical need for BENLYSTA and any potential adverse effects on the breastfed child or from the underlying maternal condition.

Pediatric Use: The safety and effectiveness have not been established for BENLYSTA IV in patients <5 years of age and for BENLYSTA SC in patients <18 years of age.

Please see full Prescribing Information and Medication Guide for BENLYSTA.