Brukinsa (Zanubrutinib) Is Not Indicated for Prostate Cancer
Brukinsa (zanubrutinib) is not used for prostate cancer and has no role in its treatment. Zanubrutinib is a Bruton tyrosine kinase (BTK) inhibitor specifically approved for B-cell lymphoid malignancies, not solid tumors like prostate cancer 1, 2, 3.
Current FDA-Approved Indications for Zanubrutinib
Zanubrutinib is approved exclusively for B-cell malignancies, including:
- Mantle cell lymphoma (MCL) in adults who have received at least one prior therapy 3, 4
- Waldenström macroglobulinemia (WM) 2, 5
- Relapsed or refractory marginal zone lymphoma after at least one anti-CD20-based therapy 2, 5
- Chronic lymphocytic leukemia (CLL) 1, 5
Mechanism of Action and Why It Doesn't Apply to Prostate Cancer
Zanubrutinib works by irreversibly inhibiting BTK, a critical signaling protein in B-cell receptor pathways that drives proliferation and survival of malignant B-cells 1, 5. Prostate cancer is an epithelial solid tumor that does not depend on BTK signaling for growth or survival, making this mechanism irrelevant for prostate cancer treatment 6.
Evidence-Based Treatments for Prostate Cancer
The 2023 ESMO guidelines provide comprehensive treatment recommendations for prostate cancer that do not include any BTK inhibitors 6:
For Metastatic Hormone-Sensitive Prostate Cancer (mHSPC):
- ADT + novel hormone agents (abiraterone, apalutamide, or enzalutamide) 6
- ADT + docetaxel + darolutamide (triplet therapy) 6
- ADT + docetaxel for fit patients 6
For Metastatic Castration-Resistant Prostate Cancer (mCRPC):
- Abiraterone or enzalutamide after progression on ADT 6
- Docetaxel chemotherapy for symptomatic patients with good performance status 6
- 177Lu-PSMA-617 for PSMA-expressing tumors after androgen receptor axis inhibitors and taxanes 6
- Cabazitaxel after docetaxel failure 6
- Olaparib for patients with BRCA1/2 alterations 6
Common Pitfall to Avoid
Do not confuse BTK inhibitors (used for B-cell malignancies) with androgen receptor pathway inhibitors (used for prostate cancer). While both are targeted therapies for cancer, they target completely different molecular pathways in entirely different cancer types 6, 1, 5. The "-ib" suffix in drug names (indicating kinase inhibitors) does not mean drugs are interchangeable across cancer types.