Chronic lymphocytic leukaemia (CLL) is a type of cancer that affects blood and bone marrow. Chronic lymphocytic leukemia (CLL) is the most common type of leukemia among adults in the Western world. Over the past decade, its treatment landscape has changed dramatically with the rise of targeted therapies—medications designed to block specific pathways that help cancer cells grow and survive. Among the most impactful of these are Bruton’s tyrosine kinase (BTK) inhibitors, which have quickly become central to CLL management.
In this article, we take a closer look at two key BTK inhibitors: Brukinsa (zanubrutinib) and Jaypirca (pirtobrutinib). By exploring how they work and what sets them apart, we aim to give a clearer understanding of the evolving treatment options available to patients and clinicians across Europe.
An Overview of Brukinsa (Zanubrutinib)
Brukinsa, with the active substance Zanubrutinib, is a second-generation, covalent BTK inhibitor. It has been designed to maximise BTK inhibition while minimising off-target effects on other kinases, which can often lead to unwanted side effects.
Mechanism and Efficacy
Brukinsa works by irreversibly binding to the BTK protein. This protein plays a key role in the B‑cell receptor signalling pathway—a pathway that cancers like CLL depend on to grow and survive. By shutting down BTK, Brukinsa disrupts this communication line, slowing down the cancergrowth and helping eliminate the malignant cells.
Clinical trials have demonstrated Brukinsa’s high level of efficacy. For instance, the ALPINE study compared Zanubrutinib to ibrutinib, a first-generation BTK inhibitor, in patients with relapsed or refractory (R/R) CLL.
The results showed that Brukinsa was better at preventing the disease from getting worse. Its design aims for a complete and more sustained BTK occupancy, which is thought to contribute to its strong clinical performance. It is approved for treating CLL as well as other B-cell malignancies like Waldenström’s macroglobulinaemia.
An Overview of Jaypirca (Pirtobrutinib)
Jaypirca, which contains the active ingredient Pirtobrutinib, represents a different type of BTK inhibitor. Unlike covalent BTK inhibitors, it is a non-covalent (reversible) BTK inhibitor, which gives it a unique profile and way of working. Mechanism and Effectiveness In contrast to covalent inhibitors, which form a permanent bond, Jaypirca binds to the BTK protein in a reversible way. This unique method allows it to work well even when cancer cells have become resistant to covalent BTK inhibitors.
Mechanism and Efficacy
Unlike covalent inhibitors that form a permanent bond, Jaypirca binds the BTK protein reversibly. This unique mechanism allows it to work effectively even in cases where cancer cells have developed resistance to covalent BTK inhibitors. A common resistance mechanism involves a mutation at the C481 site of the BTK protein, which prevents covalent inhibitors from binding. Since Jaypirca does not rely on this binding site, it remains effective in the presence of this mutation.
The BRUIN Phase 1/2 trial highlighted Jaypirca’s effectiveness, particularly in heavily pre-treated CLL patients, including those who had previously been treated with a covalent BTK inhibitor. The study showed promising response rates in this difficult-to-treat population, establishing Jaypirca as a valuable option for patients who have exhausted other therapies. Its approval provides a much-needed treatment for patients with R/R CLL who have received at least two prior lines of therapy, including a BTK inhibitor.
Comparing Brukinsa and Jaypirca
When evaluating targeted therapies, clinicians and patients consider several factors, including how the drugs work, their effectiveness, and how they are administered. A comparison of jaypirca vs brukinsa reveals key distinctions that influence treatment decisions.
Effectiveness and Place in Therapy
Brukinsa is a potent inhibitor often used as a primary or secondary treatment for CLL. Its head-to-head trial success against a first-generation inhibitor has positioned it as a preferred option for many patients, both newly diagnosed and those with relapsed disease.
Jaypirca, on the other hand, carves out a critical niche for patients who have already been treated with a covalent BTK inhibitor (like Brukinsa or acalabrutinib) and have seen their disease progress. Its ability to overcome common resistance mutations makes it an essential sequential therapy. It is not typically used as a first-line treatment but rather as a later-line option to extend the benefits of BTK inhibition.
Dosage and Administration
Both medications are oral therapies, which offer convenience to patients.
- Brukinsa: The recommended dose is typically 160 mg twice daily or 320 mg once daily, taken with or without food.
- Jaypirca: The standard dosage is 200 mg taken orally once daily, also with or without food.
The once-daily dosing of Jaypirca may be seen as slightly more convenient for some patients, but both regimens are generally manageable.
Safety and Side Effects
The safety profile is a paramount consideration in CLL treatment, as therapies are often taken for an extended period. The unique designs of Brukinsa and Jaypirca influence their respective side effect profiles.
Brukinsa’s Safety Profile
As a highly selective BTK inhibitor, Brukinsa was developed to reduce off-target effects. Clinical studies have suggested it may have a more favourable cardiovascular safety profile compared to first-generation BTK inhibitors, with lower rates of atrial fibrillation (an irregular and often rapid heart rate). Common side effects associated with Brukinsa include upper respiratory tract infections, decreased neutrophil counts (neutropenia), bruising, and rash. While generally well-tolerated, serious side effects like major hemorrhage and infections can occur.
Jaypirca’s Safety Profile
Jaypirca has also shown a manageable safety profile in clinical trials. The most common side effects include fatigue, bruising, and diarrhea. Other reported adverse events include neutropenia and infections. Because it is a non-covalent inhibitor, its interactions with other cellular proteins differ from those of covalent inhibitors, which may contribute to its distinct tolerability. As with any cancer therapy, monitoring a healthcare team is essential to manage any side effects that arise.
Conclusion: Navigating Treatment Choices in CLL
The development of Brukinsa and Jaypirca marks significant progress in the management of chronic lymphocytic leukaemia. Both drugs are powerful BTK inhibitors, yet they serve distinct and complementary roles in the treatment pathway. Brukinsa offers a highly effective and relatively well-tolerated option for front-line and relapsed settings. Jaypirca provides a vital solution for patients whose disease has become resistant to covalent BTK inhibitors, allowing them to continue benefiting from this therapeutic class.
The discussion of Jaypirca vs Brukinsa is less about determining a single “better” drug and more about understanding their specific places in a personalised treatment strategy. The choice depends on a patient’s treatment history, genetic markers, co-existing health conditions, and overall treatment goals. As the field of oncology continues to advance, having these sophisticated and differentiated options empowers clinicians to tailor therapy more precisely. Patients should always consult with their healthcare provider to discuss their individual circumstances and determine the most appropriate treatment plan for them.