What the label lists and what reports show
Iberdomide side effects
Iberdomide's FDA label: “Most common (≥20%) adverse reactions with ZENBEXUS in combination with daratumumab and hyaluronidase-fihj and dexamethasone are upper respiratory tract infection, fatigue, musculoskeletal pain, pneumonia, diarrhea, motor dysfunction, rash, sleep disorder …” FAERS holds 138 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 febrile neutropenia (22 reports).
- No generic listed
- Boxed warning
Check it at the source: the iberdomide FDA label on DailyMed (effective August 13, 2026, E.R. Squibb & Sons, L.L.C.); 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 ZENBEXUS?ZENBEXUS can cause serious side effects, including: • See "What is the most important information I should know about ZENBEXUS?" • Severe low white blood cell counts (neutropenia). Your healthcare provider will do blood tests during treatment with ZENBEXUS. Tell your healthcare provider if you have a fever. • Infections. ZENBEXUS can cause serious infections, including life-threatening infections or death. Tell your healthcare provider if you get signs and symptoms of an infection before or during treatment with ZENBEXUS, including fever, chills, or flu-like symptoms. • New cancers (secondary cancers). Your healthcare provider will monitor you for new cancers. […]
Source: FDA drug label, E.R. Squibb & Sons, L.L.C., effective August 13, 2026 (SPL set 3663d9cb-3f66-48ae-bf0a-6958bc0888de), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsMost common (≥20%) adverse reactions with ZENBEXUS in combination with daratumumab and hyaluronidase-fihj and dexamethasone are upper respiratory tract infection, fatigue, musculoskeletal pain, pneumonia, diarrhea, motor dysfunction, rash, sleep disorder, hypogammaglobulinemia, COVID-19, and constipation.
Table 3: Select Laboratory Abnormalities (≥30%) That Worsened from Baseline The denominator used to calculate the rate varied from 201 to 204 for both IberDd and DVd arms based on the number of patients with a baseline…
| Reaction | All Grades (%) | Grade 3 or 4 (%) | All Grades (%) | Grade 3 or 4 (%) |
|---|---|---|---|---|
| Neutrophil count decreased | 97 | 77 | 48 | 11 |
| White blood cell count decreased | 95 | 69 | 64 | 18 |
| Lymphocytes count decreased | 91 | 62 | 81 | 51 |
| Platelet count decreased | 62 | 9 | 92 | 46 |
| Hemoglobin decreased | 58 | 6 | 63 | 6 |
| Blood calcium decreased | 44 | 2 | 28 | 1 |
| Blood alkaline phosphatase increased | 33 | 0.5 | 26 | 0.5 |
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. • Serious Venous and Arterial Thromboembolism [see Warnings and Precautions (5.3) ] • Neutropenia [see Warnings and Precautions (5.4) ] • Infections [see Warnings and Precautions (5.5) ] • Second Primary Malignancies [see Warnings and Precautions (5.6) ] Most common (≥20%) adverse reactions with ZENBEXUS in combination with daratumumab and hyaluronidase-fihj and dexamethasone are upper respiratory tract infection, fatigue, musculoskeletal pain, pneumonia, diarrhea, motor dysfunction, rash, sleep disorder, hypogammaglobulinemia, COVID-19, and constipation. The most common Grade 3 or 4 (≥30%) laboratory abnormalities are neutrophil count decreased, white blood cell count decreased, and lymphocyte count decreased. (6) To report SUSPECTED ADVERSE REACTIONS, contact Bristol-Myers Squibb at 1-800-721-5072 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 to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. …
Source: FDA drug label, E.R. Squibb & Sons, L.L.C., effective August 13, 2026 (SPL set 3663d9cb-3f66-48ae-bf0a-6958bc0888de), via openFDA; the full label on DailyMed
What do FAERS reports show?
138 reports list iberdomide among the medicines taken, each a report of something that happened, not proof the medicine caused it; 12 are coded as a death and 88 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. Of the 23 reactions below, 13 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.
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?
- Iberdomide: 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