A study on the use of acalabrutinib and direct-acting oral anticoagulants (DOACs) in patients with chronic lymphocytic leukemia

CLL is a cancer of the white blood cells that progresses slowly and continuously weakens the immune system. As a result, those affected are more susceptible to infections, experience fatigue, and are more prone to bleeding. Treatment varies greatly from person to person and may include chemotherapy, immunotherapy, and, increasingly these days, targeted therapies. Targeted therapies intervene at a specific point in the tumor-forming mechanism and therefore have fewer side effects than many chemotherapy drugs. Acalabrutinib is one such targeted Bruton’s tyrosine kinase inhibitor (BTK-I) that blocks a protein essential for the survival of cancer cells, thereby inhibiting their growth. This BTK inhibitor is used alone or in combination as one of the first-line treatments for CLL. Since CLL occurs primarily in older adults, it is often necessary to treat other conditions concurrently.

Anticoagulants (DOACs: e.g., edoxaban, dabigatran, rivaroxaban) are used in patients suffering from conditions such as atrial fibrillation, deep vein thrombosis, or pulmonary embolism to reduce the risk of blood clots. However, anticoagulation also leads to an increased risk of bleeding. The CICERO study is investigating the safety of this drug combination in people with CLL who are receiving concurrent therapy with acalabrutinib and a DOAC. It is a non-interventional, prospective, and open-label observational study.

The primary objective of the study is to investigate the frequency of bleeding events using a specialized questionnaire. Patients will be asked about any bleeding episodes during each doctor’s visit; serious events, such as bleeding requiring a transfusion, are of particular importance.

All adult patients diagnosed with chronic lymphocytic leukemia (CLL) who choose to be treated with acalabrutinib are eligible to participate. Combination therapy with obinutuzumab is permitted; all other CLL treatments are excluded from the study. In addition, the participant should be receiving or require treatment with a DOAC. Patients will be monitored regularly for up to 36 months after the start of the study.