Zanubrutinib is a BTK (Bruton’s tyrosine kinase) inhibitor that is approved for use in several types of B-cell malignancies. It is an oral targeted cancer therapy that may reduce the need for treatment-related visits to the clinic for patients and their families. The effect of the oral cancer therapy is, however, highly dependent on the patient’s adherence to the prescribed drug(s) and the duration for which the patient remains on therapy.
To make informed and practical recommendations about the use of Zanubrutinib for health care providers, the other key factors that determine adherence and persistence to oral anticancer drugs need to be reviewed. Those factors include the treatment regimen, toxicity of the treatment, potential drug interactions with concomitant medications, patient understanding of treatment, presence of comorbidities, other medications that the patient is taking, accessing the cancer treatment, and monitoring of the patient during treatment.
Understanding Adherence and Persistence
The terms ‘adherence’ and ‘persistence’ are in wide use within health care. Adherence describes the degree to which patients adhere to the treatment given by their doctors and follow the prescribed treatment plan correctly. Persistence describes the duration of time for which a patient takes the treatment.
Since most oral anti-cancer drugs are given over extended time periods, one missed dose can be as detrimental as permanent cessation of treatment; yet they are perceived to be very different by patients and doctors alike.
Due to the nature of hematologic malignancies and their treatment, patients may be on long term therapy. Taking into account the indication for which a patient is treated and their specific clinical situation, healthcare professionals must also consider the length of time for which a treatment is prescribed and the patient’s ability to adhere to it.
Dosing and Treatment Routines
Oral anticancer therapies may reduce the need for treatment in hospital or cancer care settings and can often be taken at home by patients or caregivers. However, patients and caregivers must understand and follow the prescribed dosing instructions.
Patients can miss doses due to work or travel commitments, or simply because of changes to their daily routine. Older patients may have problems with their memory, or with managing their medication because of difficulty with dexterity, vision, or a number of other age related problems.
These issues should be addressed by the health care team to ensure appropriate management. Written instructions on how to take oral anticancer therapy and strategies for patients to manage their medication can help. Incorporating their cancer treatment into their daily routine can also help.
Adverse Events and Treatment Persistence
Side effects influence the degree to which patients continue to take their targeted cancer therapy. Adverse reactions that occur with BTK inhibitors (such as Zanubrutinib) have to be monitored and, in some cases, managed with specific treatment modifications. Appropriate Zanubrutinib use also requires careful consideration of these adverse reactions to support safe and effective treatment.
Whether certain adverse events (AEs) require monitoring will depend on the clinical setting and patient specific factors (e.g. a patient with a history of bleeding may require close monitoring of bleeding events).
Detection of adverse events early on and proper management is crucial to continuing treatment. Healthcare professionals and patients may discuss which symptoms require treatment.
Temporary or permanent treatment interruption or modification in dose may be necessary due to occurrence of certain adverse events. The healthcare provider should evaluate the severity of the adverse event(s), the patient’s clinical situation, treatment outcomes, and management options.
Comorbidities and Polypharmacy
Many patients with B-cell malignancies are older and have comorbidities. Long-term management of cancer treatment in patients with comorbidities such as cardiovascular disease, chronic infection, hypertension and renal impairment presents practical challenges for cancer treatment.
Polypharmacy is a large problem that can increase the complexity of oral treatment of cancer patients even more. Different health care providers can prescribe medications for the patient, which are to be taken in addition to cancer treatment. Medication reconciliation is a challenge for these patients.
A complete medication review is performed before and during treatment. Some medicines may have significant drug-drug interactions which require modification to treatment, increase the adverse event profile or require increased monitoring.
Patient Education
Education of patients and their families is also crucial to support adherence of patients. Patients need to have detailed information on the treatment purpose, treatment dosing schedule, potential side effects, and actions to take in case of a missed dose.
It is also important that patients are informed of the need for them to inform their treating team of any changes to their health status. Patients who have been told the reasons for continued treatment and monitoring of their side effects might take an active role in their treatment.
Use appropriate language when discussing treatment with patients to ensure they have understanding of its aims and potential side effects. Reviewing treatment issues with patients at subsequent clinic appointments provides an opportunity for exploration of emerging problems with treatment.
Monitoring and Follow-Up
Monitoring both the treatment’s effect and the practical side of treatment is necessary during follow-up appointments. The healthcare provider can monitor whether the patient is taking the correct dose of his or her medications, track any side effects, review test results, review other medications that the patient is currently taking and monitor any changes to the patient’s circumstances.
Monitoring why medication is not given, including persistent side effects and other possible reasons for discontinuation and missing doses and reviewing the treatment on a regular basis is also important.
Access and Financial Considerations
Additional considerations for oral anticancer drugs are access to the prescribed medication and persistence. Problems with prescription processing, with respect to required approvals by health insurance companies, problems with the availability of prescribed medication, and with respect to travel to pick up the medication can lead to a lack of persistence. Out-of-pocket costs for anticancer drugs can pose a problem for some patients.
Of note, there are many unseen challenges to patients’ access to anticancer oral medications including challenges related to prescription processing, lack of adequate insurance coverage, lack of stock of prescribed oral medications, patients’ inability to afford to travel to access pharmacy for picking up prescribed medications, patients’ inability to read and write medication names, patients’ inability to afford copayments for oral anticancer medications, and many other challenges.
Healthcare providers from a variety of clinical and pharmacy settings (e.g., specialty pharmacies) can work together to address a variety of barriers to treatment that may arise.
Supporting Long-Term Treatment
As with any chronic treatment given for long periods, the management of patients on zanubrutinib requires an organized approach and consideration of both medical and practical issues influencing the long-term treatment of individual patients.
Rather than regarding the patients’ responsibility for taking their long-term prescribed medication, the contribution of both clinicians and patients to adherence should be regarded as a clinical issue that can be influenced when identified early.
Key Takeaways
Adherence and persistence to Zanubrutinib treatment are important in the long-term management of patients with B-cell malignancies. While the fact that Zanubrutinib is administered orally is an advantage over some other treatments, the patients have to manage their treatment on an ongoing basis outside the setting of medical care.
The use of Zanubrutinib therefore must extend beyond choosing a treatment and consider the patient’s dosage schedule, side effects, co-morbidities, other medications, and other individual factors, as well as ensure access to the treatment and regular follow-up of the patient.
Medical Disclaimer: The information provided in this article is intended for educational purposes only and should not be interpreted as medical advice, clinical guidelines, or a recommendation for any specific treatment.


