What the label lists and what reports show
Acalabrutinib side effects
Acalabrutinib's FDA label: “The most common adverse reactions (≥ 30%), excluding laboratory abnormalities, are upper respiratory tract infection, diarrhea, headache, and musculoskeletal pain.” FAERS holds 12,049 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 fatigue (677 reports).
- No generic listed
Check it at the source: the acalabrutinib FDA label on DailyMed (effective February 19, 2026, AstraZeneca Pharmaceuticals LP); 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 CALQUENCE?CALQUENCE can cause serious side effects, including: • Serious infections have happened in people treated with CALQUENCE and may lead to death. Your healthcare provider may prescribe certain medicines if you have an increased risk of getting infections. Tell your healthcare provider right away if you have any signs or symptoms of an infection, including fever, chills, or flu-like symptoms. • Bleeding problems (hemorrhage) have happened in people treated with CALQUENCE and can be serious and may lead to death. Your risk of bleeding may increase if you are also taking a blood thinner medicine. […]
Source: FDA drug label, AstraZeneca Pharmaceuticals LP, effective February 19, 2026 (SPL set b1409184-3267-4d8c-8f17-4e01f69828b1), via openFDA; the full label on DailyMed
What does the label list?
From the label: adverse reactionsThe most common adverse reactions (≥ 30%), excluding laboratory abnormalities, are upper respiratory tract infection, diarrhea, headache, and musculoskeletal pain.
Table 9: Common Adverse Reactions (≥ 15% Any Grade) with CALQUENCE in Patients with CLL (ELEVATE-TN)
| Reaction | All Grades (%) | Grade ≥ 3 (%) | All Grades (%) | Grade ≥ 3 (%) | All Grades (%) | Grade ≥ 3 (%) |
|---|---|---|---|---|---|---|
| Infection | 69 | 22 ‡ | 65 | 14 ‡ | 46 | 13 ‡ |
| Upper respiratory tract infection | 39 | 2.8 | 35 | 0 | 17 | 1.2 |
| Lower respiratory tract infection a | 24 | 8 | 18 | 4.5 | 7 | 1.8 |
| Urinary tract infection | 15 | 1.7 | 15 | 2.8 | 5 | 0.6 |
| Neutropenia c | 53 | 37 | 23 | 13 | 78 | 50 |
| Anemia d | 52 | 12 | 53 | 10 | 54 | 14 |
| Thrombocytopenia e | 51 | 12 | 32 | 3.4 | 61 | 16 |
| Lymphocytosis f | 12 | 11 | 16 | 15 | 0.6 | 0.6 |
| Headache | 40 | 1.1 | 39 | 1.1 | 12 | 0 |
| Dizziness | 20 | 0 | 12 | 0 | 7 | 0 |
| Diarrhea | 39 | 4.5 | 35 | 0.6 | 21 | 1.8 |
| Nausea | 20 | 0 | 22 | 0 | 31 | 0 |
| Musculoskeletal pain g | 37 | 2.2 | 32 | 1.1 | 16 | 2.4 |
| Arthralgia | 22 | 1.1 | 16 | 0.6 | 4.7 | 1.2 |
| Fatigue h | 34 | 2.2 | 23 | 1.1 | 24 | 1.2 |
| Bruising i | 31 | 0 | 21 | 0 | 5 | 0 |
| Rash j | 26 | 2.2 | 25 | 0.6 | 9 | 0.6 |
| Hemorrhagek | 20 | 1.7 | 20 | 1.7 | 6 | 0 |
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 discussed in greater detail in other sections of the labeling: • Serious and Opportunistic Infections [see Warnings and Precautions (5.1) ] • Hemorrhage [see Warnings and Precautions (5.2) ] • Cytopenias [see Warnings and Precautions (5.3) ] • Second Primary Malignancies [see Warnings and Precautions (5.4) ] • Cardiac Arrhythmias [see Warnings and Precautions (5.5) ] • Hepatotoxicity, including DILI [see Warnings and Precautions (5.6) ] The most common adverse reactions (≥ 30%), excluding laboratory abnormalities, are upper respiratory tract infection, diarrhea, headache, and musculoskeletal pain. The most common Grade 3 or 4 laboratory abnormalities (≥ 10%) are absolute neutrophil count decreased, uric acid increased, absolute lymphocyte count decreased, and platelets decreased. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact AstraZeneca at 1-800-236-9933 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 practice. …
Source: FDA drug label, AstraZeneca Pharmaceuticals LP, effective February 19, 2026 (SPL set b1409184-3267-4d8c-8f17-4e01f69828b1), via openFDA; the full label on DailyMed
What do FAERS reports show?
12,049 reports list acalabrutinib among the medicines taken, each a report of something that happened, not proof the medicine caused it; 2,592 are coded as a death and 3,233 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 2024 (2,719, against a median of 588 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, 16 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?
- Acalabrutinib: 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