FOLB1 Antibody

Introduction to FOLR1 and Its Antibodies

FOLR1 is a glycosylphosphatidylinositol (GPI)-anchored protein that facilitates unidirectional folate transport into cells, critical for DNA synthesis and methylation . Its overexpression in ovarian, lung, and breast cancers makes it a prime target for monoclonal antibody (mAb) development. FOLR1 antibodies are engineered to bind specifically to this receptor, enabling:

• Diagnostic detection of FOLR1-positive tumors .

• Therapeutic interventions via antibody-dependent cellular cytotoxicity (ADCC) or complement activation .

Development of FOLR1-Specific Antibodies

Key advancements in FOLR1 antibody development include:

• Immunogen Design: Full-length FOLR1 protein was used to generate mAbs targeting non-overlapping epitopes, ensuring robust detection across diagnostic platforms .

• Specificity Validation: Antibodies like MAB5646 (R&D Systems) show no cross-reactivity with FOLR2, FOLR3, or FOLR4 .

Table 1: Select FOLR1 Antibodies and Their Properties

Mechanism of Action

FOLR1 antibodies exert effects through:

• ADCC: Farletuzumab binds FOLR1 on cancer cells, recruiting natural killer (NK) cells via Fcγ receptors (e.g., CD16a) to induce tumor lysis .

• Diagnostic Binding: MAB5646 detects FOLR1 at ~40 kDa in Western blots and shows membrane localization in flow cytometry .

Diagnostic Applications

FOLR1 antibodies are critical for:

• Tissue Staining: Immunohistochemistry identifies FOLR1 overexpression in ovarian cancer biopsies .

• Flow Cytometry: MCF-7 breast cancer cells show strong FOLR1 surface expression when stained with MAB5646 .

Therapeutic Efficacy

• Preclinical Studies: Farletuzumab reduced tumor growth in xenograft models by 60–70% via ADCC .

• Clinical Trials: Phase II trials demonstrated safety and efficacy in platinum-sensitive ovarian cancer .

Challenges and Future Directions

• Structural Sensitivity: FOLR1’s post-translational modifications complicate antibody development .

• Therapeutic Resistance: Tumor heterogeneity in FOLR1 expression necessitates combination therapies .