Acalabrutinib is an oral targeted medicine that blocks a protein needed for the growth and survival of certain blood cancer cells. It belongs to a class of medicines called BTK (Bruton tyrosine kinase) inhibitors, used to treat chronic lymphocytic leukaemia, small lymphocytic lymphoma, and mantle cell lymphoma. It is a prescription-only medicine.

• Therapeutic Class: Anti-cancer (oncology) targeted therapy for B-cell malignancies.

• Pharmacological Class: Bruton tyrosine kinase (BTK) inhibitor, second-generation.

• Drug Family: Small-molecule BTK inhibitors.

• ATC Classification: L01EL02 (Acalabrutinib).

Approved: Chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma (SLL) in adults, both as monotherapy and in combination regimens; mantle cell lymphoma (MCL) in adults who have received at least one prior therapy (accelerated approval indication).

Commonly used for: Adults with CLL/SLL as first-line or later-line treatment, and adults with relapsed or refractory mantle cell lymphoma.

Off-label use (only under medical guidance): Being studied in other B-cell malignancies in clinical trials; use outside its approved indications is a specialist decision.

● Oral capsules: 100 mg.

● Oral tablets: 100 mg.

BTK is a protein that certain B-cells (a type of white blood cell) rely on for growth, survival, and movement. In CLL, SLL, and mantle cell lymphoma, malignant B-cells depend heavily on this signalling. Acalabrutinib binds to and blocks BTK, interrupting this survival signal and helping slow or stop the growth of these cancer cells.

• Standard dose: 100 mg taken orally approximately every 12 hours (twice daily), continued until disease progression or unacceptable toxicity.

• Condition-wise dose: In certain first-line CLL/SLL combination regimens (e.g., with venetoclax and obinutuzumab), acalabrutinib is started in Cycle 1, with the combination partners introduced in later cycles per a defined treatment schedule, for a total of 14 cycles (each cycle 28 days) in some regimens.

• Route: Oral, swallowed whole with water; capsules/tablets should not be broken, crushed, or chewed. Can be taken with or without food.

• Missed dose: If a dose is missed by up to 3 hours, it can still be taken; if missed by more than 3 hours, it should be skipped and the next dose taken at its regular scheduled time — extra doses are not taken to make up for a missed one.

• Overdose: May increase the risk of known side effects such as bleeding or infection; requires medical attention.

• Common: Headache, diarrhoea, fatigue, muscle/joint pain, and bruising.

• Serious: Bleeding events (including major haemorrhage), serious infections, low blood counts (neutropenia, anaemia, thrombocytopenia), second primary cancers, and heart rhythm changes (atrial fibrillation).

• Emergency symptoms: Unusual or severe bleeding/bruising, signs of serious infection (fever, chills), a rapid or irregular heartbeat, or symptoms of a stroke (sudden weakness, slurred speech).

• Recovery advice: Because acalabrutinib increases bleeding risk, patients are usually advised to inform their doctor before any surgery or dental procedure, and to report unusual bruising or bleeding promptly rather than waiting for a scheduled visit.

• Pregnancy: Not recommended; may cause fetal harm.

• Breastfeeding: Not recommended during treatment and for a period after the last dose.

• Liver disease: No dose adjustment needed in mild to moderate impairment; avoided in severe hepatic impairment.

• Kidney disease: No specific dose adjustment generally required in mild to moderate impairment.

• Elderly: Commonly used in this age group, as CLL is more common with age; monitored for bleeding and cardiac risk.

• Children: Not established for use in children; a medicine for adult B-cell malignancies.

● Strong CYP3A inhibitors (e.g., ketoconazole): significantly increase acalabrutinib levels; avoided or requires dose adjustment.

● Strong CYP3A inducers (e.g., rifampin): can significantly reduce acalabrutinib levels and effectiveness; avoided.

● Proton pump inhibitors: reduce acalabrutinib absorption due to its need for stomach acid; combined use is avoided.

● H2-receptor antagonists and antacids: also reduce absorption; specific timing separation (H2 blockers taken 2 hours before acalabrutinib; antacids separated by at least 2 hours) is required if these must be used together.

● Antiplatelet or anticoagulant medicines: may further increase bleeding risk when combined with acalabrutinib.

● Complete blood counts monthly during treatment.

● Monitoring for signs of bleeding or bruising, particularly around any planned surgery or dental procedure.

● Cardiac monitoring for signs of atrial fibrillation or flutter (palpitations, irregular heartbeat).

● Monitoring for signs of infection throughout treatment.

Ibrutinib, Zanubrutinib (other BTK inhibitors); Venetoclax (a BCL-2 inhibitor, different mechanism, sometimes used in combination or as an alternative).

Used as monotherapy in many settings; also approved in combination with obinutuzumab for CLL/SLL, and studied in triplet regimens with venetoclax and obinutuzumab for first-line CLL treatment, following defined cycle-based schedules.

● Chronic Lymphocytic Leukaemia (CLL) Medicines

● Mantle Cell Lymphoma Treatments

● BTK Inhibitors

1. Understand Blood Cancer Stages & 3 Main Types of Blood Cancer

2. Bone Marrow Cancer: Causes And Treatment

1. https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/210259s010lbl.pdf

2. https://www.drugs.com/acalabrutinib.html

The information on this page is for educational purposes only and is not a substitute for medical advice. Please consult your oncologist to know if this treatment is appropriate for your condition.