Targeted Therapy / Oncology — Hematologic

Blenrep (belantamab mafodotin-blmf)

GSK (GlaxoSmithKline) · BCMA-Targeted Antibody-Drug Conjugate (ADC)

FDA Approved 2020 Intravenous (IV) infusion Specialty Medication
Blenrep belantamab mafodotin 100mg/vial, GSK, BCMA ADC for multiple myeloma

What is Blenrep? Blenrep (belantamab mafodotin-blmf) is a BCMA-targeted antibody-drug conjugate by GSK that delivers MMAF (a microtubule inhibitor) to BCMA-expressing multiple myeloma cells. It is approved for relapsed or refractory multiple myeloma after prior therapies.

About Blenrep

Brand NameBlenrep
Generic / INNbelantamab mafodotin-blmf
Drug ClassBCMA-Targeted Antibody-Drug Conjugate (ADC)
ManufacturerGSK (GlaxoSmithKline)
AdministrationIntravenous (IV) infusion
FDA Approval2020
📦 100 mg/vial lyophilized powder. Available ONLY through the Blenrep REMS Program (SIGHT).

FDA-Approved Uses

  • Relapsed or refractory multiple myeloma — adults who have received at least 4 prior lines of therapy including an anti-CD38 monoclonal antibody, a proteasome inhibitor, and an immunomodulatory agent
Biomarker Note: BCMA expression is universally high in multiple myeloma and does not require specific testing. Prior therapy requirements (4+ lines including anti-CD38, PI, and IMiD) must be confirmed.

How Does Blenrep Work?

Belantamab mafodotin uses an anti-BCMA antibody to deliver MMAF (monomethyl auristatin F) directly to BCMA-expressing myeloma cells. After internalization and linker cleavage, MMAF inhibits microtubule polymerization causing mitotic arrest and apoptosis. Unlike MMAE (used in brentuximab), MMAF is less membrane-permeable, limiting bystander effects.

Dosage & Administration

2.5 mg/kg IV over approximately 30 minutes every 3 weeks. Eye exam (including visual acuity) required before each dose. Dose modifications based on ocular toxicity severity.

⚠️ Important

Dosing is individualized by the treating oncologist. Do not adjust without medical guidance. This page is educational only.

Warnings & Side Effects

REMS PROGRAM REQUIRED: Ocular toxicity — keratopathy (corneal changes) occurs in the majority of patients and can cause vision changes or loss. Eye exam before each dose; risk mitigation strategies required. Thrombocytopenia. Infusion-related reactions. Embryo-fetal toxicity.

⛔ Serious Warnings
  • Ocular toxicity (keratopathy) — REMS required; eye exam before each dose
  • Severe thrombocytopenia
  • Infusion-related reactions
  • Embryo-fetal toxicity

Common Side Effects

  • Keratopathy/corneal changes (very common)
  • Blurred vision
  • Thrombocytopenia
  • Anemia
  • Fatigue
  • Nausea
  • Dry eye
  • Photophobia

Storage & Handling

Refrigerate at 2°C to 8°C (36°F to 46°F). Do not freeze. Protect from light.

💰 Medication Cost & Insurance Coverage

Approximate Wholesale Acquisition Cost (WAC / List Price)

~$16,000–$20,000/dose

2.5 mg/kg every 3 weeks

Coverage note: Medicare Part B; REMS program
⚠️ List Price vs. What You Pay

WAC is the manufacturer list price — not what most patients pay. Actual cost depends on insurance, deductible, copay tier, and patient assistance eligibility. Many patients pay $0–$100/month through manufacturer co-pay programs.

Patient Assistance Prior Authorization Insurance & Savings

Insurance & Prior Authorization

Blenrep requires prior authorization from all major insurance plans. BiologicHealthPlus handles the full PA process — clinical documentation, peer-to-peer reviews, and appeals — at no cost to patients or providers.

Prior Authorization Guide Patient Assistance Insurance & Savings

Frequently Asked Questions — Blenrep

Blenrep is a BCMA-targeted ADC by GSK that delivers MMAF chemotherapy directly into BCMA-expressing myeloma cells. Approved after 4+ prior lines of therapy.

Keratopathy (corneal epithelial changes) occurs in the majority of patients and can cause blurred vision, dry eyes, and light sensitivity. Eye exams are required before every dose through the REMS program.

The SIGHT REMS program restricts Blenrep to certified healthcare facilities with access to certified eye care providers. Patients must receive ophthalmology evaluation before each dose.

Blenrep is covered by Medicare Part B and commercial insurance for eligible myeloma patients with prior authorization and documentation of prior therapy lines.

Related Medications

Abecma (idecabtagene vicleucel — CAR-T BCMA)  ·  Carvykti  ·  Darzalex (daratumumab)  ·  Velcade (bortezomib)  ·  Revlimid

Related Conditions

Multiple myeloma  ·  Relapsed/refractory myeloma  ·  BCMA-expressing plasma cell malignancies

Medical Disclaimer: Educational purposes only. Not medical advice. Consult your oncologist for treatment decisions. Prices are approximate WAC list prices as of 2025-2026. Last reviewed: September 2026 — BiologicHealthPlus Clinical Team.