BTK Degraders
- Mechanism: These agents degrade Bruton tyrosine kinase (BTK), a key protein in B-cell receptor signaling, which is essential for CLL cell survival.
- Examples: NX-2127, BGB-16673, and NX-5948 have shown efficacy in relapsed/refractory (R/R) CLL.
- Non-Covalent BTK Inhibitors
- Mechanism: These reversible inhibitors target BTK without relying on covalent binding, overcoming resistance caused by mutations like C481S.
- Examples:
- Pirtobrutinib: Demonstrates high selectivity and efficacy, even in heavily pretreated patients.
- Nemtabrutinib: Similar efficacy but less well-tolerated compared to pirtobrutinib.
- BH3 Mimetics
- Mechanism: Mimic pro-apoptotic proteins to inhibit anti-apoptotic BCL2 family proteins, promoting cell death.
- Examples: Venetoclax targets BCL2, while newer agents like sonrotoclax aim to overcome resistance caused by mutations like Gly101Val.
- Monoclonal Antibodies
- Mechanism: Target antigens on CLL cells (e.g., CD20, CD19, CD37) to induce apoptosis or recruit immune cells for cytotoxicity.
- Examples:
- Obinutuzumab: Anti-CD20 antibody with improved efficacy over rituximab.
- Otlertuzumab: Anti-CD37 antibody triggering apoptosis and antibody-dependent cell-mediated cytotoxicity.
- Bispecific Antibodies
- Mechanism: Bind both CLL cell antigens (e.g., CD19, CD20, BCMA) and CD3 on T cells, redirecting T cells to kill leukemia cells.
- Examples:
- Blinatumomab: Targets CD19 and CD3.
- Teclistamab: Targets BCMA and CD3.
- Chimeric Antigen Receptor (CAR) T Cell Therapies
- Mechanism: Genetically modified T cells express CARs targeting antigens like CD19, enabling direct killing of CLL cells.
- Examples: Lisocabtagene maraleucel (CD19 CAR T therapy).
- Siglec-6 Monoclonal Antibodies
- Mechanism: Target Siglec-6, a novel antigen absent on healthy cells, to activate T cells and eliminate CLL cells.
- Examples: RC-1 and RC-2 antibodies engineered for high specificity and potency.
- ROR1-Directed Therapies
- Mechanism: Target ROR1, a receptor tyrosine kinase expressed selectively on CLL cells.
- Examples: Cirmtuzumab and zilovertamab vedotin.
- Vg9Vd2-T Cell Engagers
- Mechanism: Activate Vg9Vd2-T cells to lyse CLL cells by targeting CD1d, a molecule expressed on leukemic cells.
- Example: Bispecific single-domain antibodies designed to boost T cell responses.
- Anti-BAFF Antibodies
- Mechanism: Target BAFF, a factor promoting CLL cell survival, to induce apoptosis.
- Examples: Belimumab and ianalumab.
- Precision Medicine Approaches
- Mechanism: Use predictive biomarkers (e.g., TP53, IGHV mutations) and machine learning algorithms to tailor treatments based on tumor heterogeneity and resistance profiles.
These novel agents address unmet clinical needs by targeting specific pathways, overcoming resistance mechanisms, and enhancing immune responses, offering hope for improved outcomes in CLL treatment.