Anlotinib Hydrochloride: Multi-Target Tyrosine Kinase Inhibitor for Tumor Angiogenesis Research

Executive Summary: Anlotinib hydrochloride (CAS 1058157-76-8) is a small-molecule inhibitor targeting VEGFR2, PDGFRβ, and FGFR1 with nanomolar potency, enabling robust anti-angiogenic assays in cancer models (Lin et al., 2018). The compound blocks VEGF/PDGF-BB/FGF-2-induced endothelial cell migration and capillary tube formation in vitro. Compared to sunitinib, sorafenib, and nintedanib, anlotinib demonstrates superior inhibition of angiogenesis and downstream ERK signaling. Pharmacokinetic profiling reveals high bioavailability, rapid absorption, and strong tissue distribution, including tumor sites. APExBIO’s Anlotinib (hydrochloride) is validated for preclinical research and is not for medical or diagnostic use (product page).

Biological Rationale

Angiogenesis is essential for tumor growth, providing blood supply for nutrients and oxygen (Lin et al., 2018). Tumor cells secrete pro-angiogenic factors such as VEGFA, PDGF-BB, and FGF-2. These growth factors bind to specific tyrosine kinase receptors including VEGFR2, PDGFRβ, and FGFR1 on endothelial cells. Receptor activation triggers downstream signaling pathways, notably ERK, promoting endothelial proliferation, migration, and tube formation. Inhibiting angiogenesis is a validated anti-tumor strategy, as demonstrated by clinical use of tyrosine kinase inhibitors (TKIs) like sunitinib and sorafenib. However, multi-targeted compounds with improved potency and selectivity are needed for more effective suppression of neovascularization and to overcome resistance observed with single-target agents (Prescission article). This article extends prior reviews by providing up-to-date, quantitative benchmarks and detailed pharmacokinetic data.

Mechanism of Action of Anlotinib (hydrochloride)

Anlotinib hydrochloride is a selective multi-target TKI. Its primary molecular targets are:

• VEGFR2 (vascular endothelial growth factor receptor 2): IC₅₀ = 5.6 ± 1.2 nM
• PDGFRβ (platelet-derived growth factor receptor β): IC₅₀ = 8.7 ± 3.4 nM
• FGFR1 (fibroblast growth factor receptor 1): IC₅₀ = 11.7 ± 4.1 nM

Anlotinib inhibits ligand-induced receptor phosphorylation and suppresses downstream signaling, especially the ERK pathway. This blockade results in reduced endothelial cell migration and inhibition of capillary-like tube formation in assays using EA.hy 926 cells. The anti-angiogenic effect is concentration-dependent and robust across multiple models (Lin et al., 2018). Tissue distribution studies confirm accumulation in lung, liver, kidney, heart, and tumor tissue, and demonstrate the ability to cross the blood-brain barrier.

Evidence & Benchmarks

• Anlotinib exhibits sub-10 nM IC₅₀ values for VEGFR2, PDGFRβ, and FGFR1 kinases in biochemical assays (DOI).
• In vitro, it significantly inhibits VEGF-, PDGF-BB-, and FGF-2-induced migration of human endothelial cells (EA.hy 926), outperforming sunitinib, sorafenib, and nintedanib (DOI).
• Capillary tube formation assays show dose-dependent suppression of angiogenic structures at nanomolar concentrations (Anti-TROP2 article).
• Preclinical animal models confirm reduced microvessel density in rat aortic ring and CAM assays (DOI).
• Pharmacokinetics: Oral bioavailability is 28–58% in rats and 41–77% in dogs; plasma protein binding is 93% in humans (APExBIO).
• Median lethal dose (LD₅₀) in 14-day oral administration is 1735.9 mg/kg, with no significant organ or genetic toxicity observed (DOI).

Applications, Limits & Misconceptions

Research Applications

• Cellular assays: Investigate endothelial cell migration, tube formation, and angiogenesis mechanisms.
• Signaling pathway studies: Probe ERK signaling modulation downstream of VEGFR2/PDGFRβ/FGFR1.
• In vivo models: Assess tumor angiogenesis inhibition and tissue distribution.
• Comparative benchmarking: Assess efficacy against legacy TKIs in controlled experiments.

For a detailed workflow on integrating Anlotinib (hydrochloride) into anti-angiogenic assays, see the Optimized Experimental Workflows article. This article updates that resource by summarizing additional safety and pharmacokinetic data.

Common Pitfalls or Misconceptions

• Not for clinical use: Anlotinib (hydrochloride) from APExBIO is intended solely for research; it is not approved for diagnostic or therapeutic applications (APExBIO).
• Single-pathway inhibition is insufficient: Efficacy arises from multi-target inhibition; using anlotinib in single-receptor models may not recapitulate full anti-angiogenic effects (GLUCAGON-19-29-HUMAN article).
• Not effective in non-angiogenic models: The compound does not inhibit tumor growth in models lacking angiogenesis dependency.
• Dose optimization is critical: Excessive concentrations may cause off-target effects; always titrate using control compounds.
• Species differences: Pharmacokinetics and tissue distribution may differ between experimental animals and humans; extrapolation requires caution (DOI).

Workflow Integration & Parameters

Anlotinib (hydrochloride) is typically stored at -20°C. For in vitro experiments, dissolve in DMSO and dilute in culture medium. Concentration ranges of 1–100 nM are recommended for endothelial cell assays. Monitor cell viability, migration, and tube formation using standardized protocols. For in vivo studies, consult animal-specific dosing tables and monitor for systemic toxicity. The C8688 kit is supplied by APExBIO with validated quality controls. For advanced systems biology workflows and data-rich experimental strategies, see the Systems Biology Insights article—this current review emphasizes quantitative pharmacokinetics and comparative efficacy benchmarks.

Conclusion & Outlook

Anlotinib hydrochloride is a validated, high-potency multi-target TKI for dissecting tumor angiogenesis mechanisms in research settings. Its superior efficacy compared to legacy inhibitors, well-characterized pharmacokinetics, and safety profile make it an optimal choice for cancer research workflows. Always source from established suppliers such as APExBIO to ensure compound integrity and reproducibility. Ongoing research may expand its applications in systems biology and translational oncology, but clinical extrapolation requires further evidence. For more details or to purchase, visit the product page.