Acalabrutinib

Classification of Acalabrutinib

• Acalabrutinib is a targeted anti-cancer medicine classified as a Bruton tyrosine kinase inhibitor (BTK inhibitor).
• It is also known by the development code ACP-196 in scientific literature.
• It is mainly used for certain B-cell blood cancers where the BTK pathway supports cancer cell growth and survival.

Information about Acalabrutinib

• BTK is a key signaling protein in the B-cell receptor pathway.
• Many B-cell cancers depend on this pathway to multiply, migrate, and avoid cell death.
• Acalabrutinib is a selective, covalent BTK inhibitor, meaning it binds strongly to BTK and blocks it for a sustained effect.
• Acalabrutinib has pH-dependent solubility, so stomach acid levels can affect how well it is absorbed.
• Chemical Structure of Acalabrutinib: insert image with attribution from DrugBank or an official label source.

Pharmacology of Acalabrutinib

• Pharmacokinetics (how the body handles it):

  • Taken orally.
  • Forms an active metabolite called ACP-5862, which also contributes to BTK inhibition.
  • Absolute bioavailability is about 25%.
  • Median time to peak concentration (Tmax): about 0.9 hours (acalabrutinib) and about 1.6 hours (ACP-5862).
  • A high-fat, high-calorie meal does not meaningfully change overall exposure, but can lower peak levels and delay onset by about 1–2 hours.
  • Highly protein-bound (about 97.5%).
  • Mainly metabolized by CYP3A enzymes.
  • Eliminated mostly as metabolites in feces (about 84%) and urine (about 12%), with less than 2% excreted unchanged.
  • Terminal half-life: about 1 hour (acalabrutinib) and about 3.5 hours (ACP-5862).

• Pharmacodynamics (what it does in the body):

  • Maintains high BTK occupancy with typical dosing (often 100 mg twice daily), supporting continuous pathway inhibition.

Uses of Acalabrutinib

• Used in adults for B-cell malignancies, including:
  • Chronic lymphocytic leukemia (CLL).
  • Small lymphocytic lymphoma (SLL).
  • Mantle cell lymphoma (MCL), including patients who have received at least one prior therapy.
• In some settings, it may be used in combination regimens based on diagnosis, treatment history, and oncology plan.

How Acalabrutinib works

• Blocks BTK, a signaling switch that malignant B cells often rely on for survival and growth.
• Reduces downstream signals that support:
  • Cell proliferation.
  • Cell trafficking and migration.
  • Chemotaxis (movement toward growth signals).
  • Adhesion (the ability of cancer cells to stick within supportive environments).
• Practical interaction considerations:
  • Proton pump inhibitors (PPIs) can reduce absorption because they reduce stomach acid.
  • Other acid reducers may require dose separation as advised by a clinician.
  • Strong CYP3A inhibitors or inducers can significantly change drug levels, so medication review is important.

Side effects of Acalabrutinib

• Common side effects:
  • Headache.
  • Diarrhea.
  • Fatigue.
  • Muscle or joint pain.
  • Bruising.
  • Nausea.
  • Upper respiratory infections.
• Important risks to monitor:
  • Serious infections (including opportunistic infections).
  • Bleeding events.
  • Low blood counts (neutropenia, anemia, thrombocytopenia).
  • Heart rhythm problems (atrial fibrillation or flutter).
  • Second primary cancers, including skin cancers.
• When to seek medical help urgently:
  • Fever with chills or signs of infection.
  • Unusual bleeding, black stools, or vomiting blood.
  • Chest pain, shortness of breath, fainting, or severe dizziness.
  • Fast or irregular heartbeat.

Available medicines of Acalabrutinib

• Brand name: Calquence.
• Oral formulations: capsules or tablets (varies by market).
• Dosing is commonly 100 mg about every 12 hours, but may be adjusted due to interactions or clinical factors.

Disclaimer for Acalabrutinib

• This content is for informational and educational purposes only and should not replace professional medical advice.
• Always consult a qualified healthcare provider before starting, stopping, or changing any medication.