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

Executive Summary: Anlotinib hydrochloride (CAS 1058157-76-8) is a novel small-molecule multi-target tyrosine kinase inhibitor (TKI) that potently inhibits VEGFR2, PDGFRβ, and FGFR1, with reported IC₅₀ values in the low nanomolar range under in vitro conditions (Lin et al., 2018). It demonstrates superior anti-angiogenic effects compared to sunitinib, sorafenib, and nintedanib in endothelial migration and tube formation assays. Anlotinib exhibits favorable pharmacokinetics, including high oral bioavailability, extensive tissue distribution, and strong plasma protein binding. Mechanistically, it blocks the ERK signaling pathway downstream of kinase inhibition, with effects validated in both cellular and in vivo models. APExBIO supplies Anlotinib (hydrochloride) (SKU C8688) for research use only, supporting advanced workflows in tumor angiogenesis and cell signaling studies.

Biological Rationale

Tumor growth and metastasis depend on angiogenesis, the formation of new blood vessels from pre-existing vasculature. Tumors secrete pro-angiogenic factors such as vascular endothelial growth factor (VEGF), platelet-derived growth factor-BB (PDGF-BB), and fibroblast growth factor 2 (FGF-2), which activate their respective receptors (VEGFR2, PDGFRβ, FGFR1) on endothelial cells (Lin et al., 2018). These signaling pathways promote endothelial cell proliferation, migration, and survival, underpinning neovascularization within the tumor microenvironment. Disrupting these pathways is an established strategy for inhibiting tumor progression and has led to the development of small-molecule tyrosine kinase inhibitors (TKIs) targeting these receptors (Lin et al., 2018).

Mechanism of Action of Anlotinib (hydrochloride)

Anlotinib hydrochloride is a multi-target TKI that exhibits high affinity for VEGFR2, PDGFRβ, and FGFR1. It inhibits ligand-induced autophosphorylation of these receptors, thereby blocking downstream signaling cascades including the ERK1/2 pathway (Lin et al., 2018). Quantitative in vitro studies demonstrate the following IC₅₀ values (mean ± SD): VEGFR2, 5.6 ± 1.2 nM; PDGFRβ, 8.7 ± 3.4 nM; FGFR1, 11.7 ± 4.1 nM, measured in kinase assays at 25°C, pH 7.4. This inhibition suppresses VEGF/PDGF-BB/FGF-2-induced migration and capillary-like tube formation in endothelial cells (EA.hy 926) in a concentration-dependent manner. Compared to sunitinib, sorafenib, and nintedanib, anlotinib delivers superior inhibition of endothelial cell migration and tube formation under equivalent experimental conditions (Lin et al., 2018).

Evidence & Benchmarks

• Anlotinib inhibits VEGFR2 kinase activity with an IC₅₀ of 5.6 ± 1.2 nM at 25°C (Lin et al., DOI).
• It suppresses PDGFRβ kinase activity with an IC₅₀ of 8.7 ± 3.4 nM under identical buffer and temperature conditions (Lin et al., DOI).
• Anlotinib demonstrates an IC₅₀ of 11.7 ± 4.1 nM for FGFR1 in recombinant kinase assays (Lin et al., DOI).
• In endothelial cell (EA.hy 926) migration and tube formation assays, anlotinib outperforms sunitinib, sorafenib, and nintedanib in reducing pro-angiogenic signal-induced effects at equimolar doses (Lin et al., DOI).
• Orally administered anlotinib shows bioavailability of 28–58% in rats and 41–77% in dogs; plasma protein binding in humans is 93% (manufacturer data, APExBIO).
• Median lethal dose (LD₅₀) in 14-day oral administration studies is 1735.9 mg/kg, with no significant organ or genetic toxicity observed (manufacturer data, APExBIO).

This article provides updated mechanistic clarity beyond the protocol-focused guide (Anlotinib Hydrochloride: Advancing Multi-Target Tyrosine ...), by presenting atomic, quantitative benchmarks and direct evidence from peer-reviewed sources.

Applications, Limits & Misconceptions

Anlotinib (hydrochloride) is used in cancer research to dissect the molecular mechanisms of angiogenesis inhibition, primarily in cellular assays with human vascular endothelial cells (EA.hy 926). Common applications include:

• Endothelial cell migration inhibition and wound healing assays
• Capillary-like tube formation assays under VEGF, PDGF-BB, or FGF-2 stimulation
• Analysis of downstream ERK signaling pathway inhibition
• Tumor xenograft models to assess anti-angiogenic and anti-tumor efficacy

For extended guidance on integrating Anlotinib into advanced angiogenesis assay workflows and troubleshooting, see Anlotinib Hydrochloride: Advanced Workflows for Tumor Ang.... This present article adds mechanistic context and direct comparative analysis to those protocol-focused resources.

Common Pitfalls or Misconceptions

• Not a diagnostic or therapeutic agent: Anlotinib (hydrochloride) is strictly for research use only and is not suitable for clinical or diagnostic applications (APExBIO).
• Limited kinase spectrum: While highly potent against VEGFR2, PDGFRβ, and FGFR1, it is less effective on unrelated kinases and cannot be used as a pan-kinase inhibitor (Lin et al., 2018).
• Requires specific storage: Must be stored at –20°C to maintain stability; improper storage may reduce potency (APExBIO).
• Not a substitute for in vivo selectivity profiling: In vitro potency does not guarantee identical selectivity or efficacy in complex in vivo settings.
• Not suitable for all tumor types: Efficacy is linked to angiogenesis dependency; tumors with low angiogenic signaling may not respond.

Workflow Integration & Parameters

Anlotinib (hydrochloride) is supplied by APExBIO as a research-grade reagent (SKU C8688), suitable for comprehensive in vitro and in vivo studies. For cell-based assays, prepare stock solutions in DMSO and dilute in culture medium to achieve final concentrations between 1–100 nM, as validated in endothelial migration and tube formation protocols. For in vivo studies, dosing regimens should be informed by preclinical pharmacokinetic data, with oral administration recommended due to high bioavailability. Store all reagents at –20°C and avoid repeated freeze-thaw cycles. For detailed workflow scenarios, troubleshooting, and comparative data with other TKIs, consult Anlotinib Hydrochloride: Multi-Target Tyrosine Kinase Inh..., which this article extends by emphasizing quantitative performance metrics and selectivity profiles.

For product specifications and ordering, visit the Anlotinib (hydrochloride) product page.

Conclusion & Outlook

Anlotinib hydrochloride is a best-in-class, multi-target tyrosine kinase inhibitor validated for robust, reproducible inhibition of angiogenesis in cancer research. Its superior potency against VEGFR2, PDGFRβ, and FGFR1, favorable pharmacokinetics, and high safety profile make it a preferred choice for advanced mechanistic and translational studies. Continued benchmarking and workflow optimization will further establish its role in tumor angiogenesis research. Researchers are encouraged to integrate Anlotinib (hydrochloride) into well-controlled workflow protocols and consult APExBIO’s technical resources for optimal performance. For scenario-driven assay guidance, see Optimizing Tumor Angiogenesis Assays with Anlotinib (hydr...), which this article updates with new mechanistic and pharmacokinetic insights.