What the label lists and what reports show
Belantamab mafodotin side effects
Belantamab mafodotin's FDA label: “The most common adverse reactions (≥20%) with BLENREP in combination with bortezomib and dexamethasone are reduction in best-corrected visual acuity (BCVA), corneal exam findings, blurred vision, dry eye, photophobia, foreign body sensation in eyes, eye …” FAERS holds 2,911 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is keratopathy (845 reports).
- No generic listed
- Boxed warning
Check it at the source: the belantamab mafodotin FDA label on DailyMed (effective October 23, 2025); the FDA FAERS public dashboard.
What does the patient leaflet say about side effects?
From the patient leaflet: What are the possible side effects of BLENREP?BLENREP can cause serious side effects, including: • See “Eye Problems” in “What is the most important information I should know about BLENREP?” • Decrease in platelets (thrombocytopenia) is common with BLENREP and can also be severe. Platelets are a type of blood cell that help your blood to clot. Your healthcare provider will check your blood cell counts before you start treatment with BLENREP and during treatment as needed. Tell your healthcare provider if you get any bleeding or bruising during treatment with BLENREP. […]
Source: FDA drug label, GlaxoSmithKline LLC, effective October 23, 2025 (SPL set aef7c34c-fef8-407c-99c0-a68aded53c60), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥20%) with BLENREP in combination with bortezomib and dexamethasone are reduction in best-corrected visual acuity (BCVA), corneal exam findings, blurred vision, dry eye, photophobia, foreign body sensation in eyes, eye irritation, upper respiratory tract infection, hepatotoxicity, eye pain, diarrhea, fatigue, pneumonia, cataract, and COVID-19.
Table 4. Adverse Reactions (≥10%) in Patients with Relapsed or Refractory Multiple Myeloma Who Received BLENREP in DREAMM-7
| Reaction | All Grades (%) | Grades 3‑4 (%) | All Grades (%) | Grades 3‑4 (%) |
|---|---|---|---|---|
| Reduction in BCVA b | 89 | 57 | 44 | 9 |
| Corneal exam findings b | 86 | 72 | 19 | 3 |
| Blurred vision | 66 | 22 | 11 | 0.8 |
| Dry eye c | 51 | 7 | 7 | 0 |
| Photophobia | 47 | 2 | 2 | 0 |
| Foreign body sensation in eyes c | 44 | 3 | 4 | 0 |
| Eye irritation | 43 | 5 | 5 | 0 |
| Eye pain c | 33 | 0.8 | 4 | 0.4 |
| Cataract c | 24 | 8 | 14 | 3 |
| Visual impairment | 11 | 5 | 2 | 0.4 |
| Diarrhea | 32 | 4 | 31 | 4 |
| Nausea | 16 | 0.8 | 12 | 0 |
| Upper respiratory tract infection c,d | 38 | 2 | 36 | 2 |
| Pneumonia c,d | 26 | 16 | 17 | 5 |
| COVID-19 d | 24 | 5 | 20 | 2 |
| Hepatotoxicity c | 33 | 14 | 16 | 2 |
| Fatigue c | 26 | 6 | 27 | 4 |
| Pyrexia c,d | 19 | 0.4 | 11 | 2 |
Rows and numbers as the label prints them, under its own column headings (the first rows of a longer table where it runs on). A reaction in a trial table is not necessarily caused by the medicine, and trials differ from everyday use.
From the label: adverse reactions, continuedThe following clinically significant adverse reactions are described elsewhere in the labeling: • Ocular Toxicity [see Warnings and Precautions ( 5.1 )] • Thrombocytopenia [see Warnings and Precautions ( 5.3 )] The most common adverse reactions (≥20%) with BLENREP in combination with bortezomib and dexamethasone are reduction in best-corrected visual acuity (BCVA), corneal exam findings, blurred vision, dry eye, photophobia, foreign body sensation in eyes, eye irritation, upper respiratory tract infection, hepatotoxicity, eye pain, diarrhea, fatigue, pneumonia, cataract, and COVID-19. The most common Grade 3 or 4 (≥10%) laboratory abnormalities are decreased platelets, decreased lymphocytes, decreased neutrophils, increased gamma-glutamyl transferase, decreased white blood cells, and decreased hemoglobin. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact GlaxoSmithKline at 1-888-825-5249 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Source: FDA drug label, GlaxoSmithKline LLC, effective October 23, 2025 (SPL set aef7c34c-fef8-407c-99c0-a68aded53c60), via openFDA; the full label on DailyMed
What do FAERS reports show?
2,911 reports list belantamab mafodotin among the medicines taken, each a report of something that happened, not proof the medicine caused it; 993 are coded as a death and 742 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Reports rose sharply in 2022 (1,149, against a median of 82 a year): FAERS counts follow reporting, which news, litigation and label changes can drive, not how often a reaction happens. Of the 21 reactions below, 12 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.
Reports received each year
The 25 most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms
What next?
- Belantamab mafodotin: the full record
- label, generics, price, shortages, recalls
- Report a side effect to the FDA
- MedWatch
- Side effects hub
- the most reported medicines and reactions