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

Executive Summary: Anlotinib hydrochloride (CAS 1058157-76-8) is a novel, orally available multi-target small-molecule tyrosine kinase inhibitor (TKI) that potently blocks VEGFR2, PDGFRβ, and FGFR1 with IC₅₀ values of 5.6 ± 1.2 nM, 8.7 ± 3.4 nM, and 11.7 ± 4.1 nM, respectively (APExBIO). It demonstrates superior anti-angiogenic activity in vitro and in vivo compared to sunitinib, sorafenib, and nintedanib (Chen & Feng 2019). Anlotinib inhibits endothelial cell migration and capillary tube formation, primarily by disrupting the ERK signaling pathway. Pharmacokinetic studies reveal high oral bioavailability, extensive tissue distribution, and low systemic toxicity. APExBIO provides rigorously characterized Anlotinib (hydrochloride) for research use only.

Biological Rationale

Tumor angiogenesis is a hallmark of cancer progression, enabling neoplastic growth and metastasis (Hanahan & Weinberg 2000). Multiple receptor tyrosine kinases, including VEGFR2, PDGFRβ, and FGFR1, orchestrate endothelial cell proliferation, migration, and tube formation. Inhibiting these kinases disrupts vascular supply to tumors, impeding their growth and survival. Traditional single-target agents often fail to address compensatory angiogenic pathways. Anlotinib hydrochloride, as a multi-target TKI, is rationally designed to simultaneously block VEGFR2, PDGFRβ, and FGFR1, providing a comprehensive anti-angiogenic strategy (APExBIO). This molecular profile is especially valuable for modeling resistance mechanisms and combinatorial strategies in preclinical cancer research (contrast: expands on target spectrum and resistance modeling).

Mechanism of Action of Anlotinib (hydrochloride)

Anlotinib (hydrochloride) acts by competitively binding the ATP sites of VEGFR2, PDGFRβ, and FGFR1 tyrosine kinases. This results in the inhibition of autophosphorylation and subsequent blockade of downstream signaling, notably the ERK/MAPK pathway. In cellular assays using human vascular endothelial cells (EA.hy 926), Anlotinib impedes VEGF/PDGF-BB/FGF-2-induced migration and capillary-like tube formation in a concentration-dependent manner. The compound also exhibits inhibitory activity against additional kinases, including c-Kit and Met, as demonstrated in kinase profiling studies (Chen & Feng 2019). Compared to sunitinib, sorafenib, and nintedanib, Anlotinib delivers greater inhibition of angiogenic processes at equivalent concentrations. Mechanistically, this broad-spectrum inhibition translates into robust suppression of neovascularization in tumor models (contrast: this article provides detailed mechanistic workflows).

Evidence & Benchmarks

• Anlotinib inhibits VEGFR2 kinase activity in vitro with an IC₅₀ of 5.6 ± 1.2 nM under standard kinase assay conditions (pH 7.5, 25°C, ATP 100 μM) (APExBIO).
• PDGFRβ inhibition by Anlotinib yields an IC₅₀ of 8.7 ± 3.4 nM, outperforming benchmark TKIs in comparative assays (Chen & Feng 2019, DOI).
• FGFR1 kinase activity is blocked with an IC₅₀ of 11.7 ± 4.1 nM, validated across multiple independent experiments (APExBIO).
• In endothelial cell migration assays (EA.hy 926, 37°C, 5% CO₂), Anlotinib reduces VEGF/PDGF-BB/FGF-2-induced migration by >80% at 20 nM (see: extends with troubleshooting and quantitative protocols).
• Capillary tube formation is significantly impaired in Matrigel assays, with dose-dependent inhibition observed at ≥10 nM (Chen & Feng 2019, DOI).
• Pharmacokinetic studies in rats show oral bioavailability ranging from 28% to 58%, and in dogs from 41% to 77%, with high plasma protein binding (93% in humans) (APExBIO).
• Tissue distribution analysis demonstrates high accumulation in lung, liver, kidney, heart, and tumor tissue, with blood-brain barrier penetration confirmed in preclinical models (Chen & Feng 2019, DOI).
• Median lethal dose (LD₅₀) is 1735.9 mg/kg (14-day oral administration in rodents) with minimal organ or genetic toxicity (Chen & Feng 2019, DOI).

Applications, Limits & Misconceptions

Anlotinib hydrochloride is widely used in cellular and animal models to investigate anti-angiogenic mechanisms, tumor microenvironment modulation, and combinatorial cancer therapies. It is particularly valued for dissecting cross-talk among tyrosine kinase signaling pathways and benchmarking novel anti-angiogenic agents. The compound is not approved for diagnostic or clinical use, and optimal results depend on precise titration and context-specific assay design (updates validated workflows for advanced studies).

Common Pitfalls or Misconceptions

• Anlotinib (hydrochloride) is not a selective inhibitor; it blocks multiple kinases and may affect off-target pathways in complex biological systems.
• It is not suitable for diagnostic or therapeutic use in humans; research-only restriction must be observed (APExBIO).
• Results from rodent or in vitro models may not directly translate to clinical settings due to interspecies pharmacokinetic differences.
• High protein binding may impact free drug concentrations in certain assay formats.
• Improper storage (above -20°C) can degrade compound potency and reproducibility.

Workflow Integration & Parameters

For optimal results, Anlotinib (hydrochloride) should be stored at -20°C and dissolved in DMSO prior to dilution in assay buffer. In vitro assays typically utilize concentrations ranging from 1 to 100 nM, with vehicle controls included. For endothelial cell assays, EA.hy 926 or HUVEC cells are seeded in serum-reduced medium and stimulated with VEGF, PDGF-BB, or FGF-2. Capillary tube formation is assessed on Matrigel matrices after 6–16 hours of exposure. For in vivo studies, dosing regimens are informed by preclinical pharmacokinetics: oral administration, 1–10 mg/kg/day, with careful monitoring of systemic exposure and toxicity. APExBIO's C8688 kit includes high-purity Anlotinib hydrochloride for reliable, reproducible research (product details).

Conclusion & Outlook

Anlotinib hydrochloride represents a next-generation, multi-target tyrosine kinase inhibitor, offering robust blockade of VEGFR2, PDGFRβ, and FGFR1 in preclinical angiogenesis models. Its superior potency, broad kinase spectrum, and favorable pharmacokinetics make it a preferred tool for cancer research. APExBIO's high-quality C8688 kit enables advanced mechanistic and translational studies. Future directions include integration into systems pharmacology workflows and exploration of resistance mechanisms (this article escalates to translational bottlenecks and future strategies).