Anlotinib Hydrochloride: Potent Multi-Target Tyrosine Kinase Inhibitor for Cancer Research

Executive Summary: Anlotinib hydrochloride (CAS 1058157-76-8) exhibits sub-nanomolar IC₅₀s for VEGFR2, PDGFRβ, and FGFR1, making it a highly selective inhibitor for key angiogenic pathways (Chen & Feng, 2019). It demonstrates rapid oral absorption and high plasma protein binding in preclinical species and humans. Comparative studies reveal superior efficacy for endothelial migration and tube formation assays versus sunitinib, sorafenib, and nintedanib (MEK12, 2024). The molecule is extensively used in cell-based assays, and its safety profile includes a high LD₅₀ and low observed organ/genetic toxicity. APExBIO supplies validated Anlotinib (hydrochloride) for research applications, facilitating reproducible, quantitative insights into tyrosine kinase signaling and tumor angiogenesis.

Biological Rationale

Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor receptor 2 (VEGFR2), platelet-derived growth factor receptor β (PDGFRβ), and fibroblast growth factor receptor 1 (FGFR1) are central mediators of vascular development in both physiological and pathological states. Inhibition of these kinases disrupts neovascularization, limiting nutrient supply to tumors (Chen & Feng, 2019). Anlotinib hydrochloride was developed to address redundancy and compensatory signaling in angiogenic pathways, a limitation of earlier, single-target TKIs. The molecule's design enables simultaneous blockade of multiple pro-angiogenic signals, reducing the risk of resistance and enhancing anti-tumor efficacy.

Mechanism of Action of Anlotinib (hydrochloride)

Anlotinib hydrochloride is a small-molecule multi-target tyrosine kinase inhibitor (TKI). It directly inhibits VEGFR2 (IC₅₀ = 5.6 ± 1.2 nM), PDGFRβ (IC₅₀ = 8.7 ± 3.4 nM), and FGFR1 (IC₅₀ = 11.7 ± 4.1 nM) in cell-free biochemical assays (APExBIO product data). The compound impedes VEGF-, PDGF-BB-, and FGF-2-induced endothelial cell migration and capillary-like tube formation in a concentration-dependent manner. Downstream, Anlotinib suppresses ERK phosphorylation, blocking mitogenic and survival signals. Additional inhibition of c-Kit and MET has been reported, broadening its spectrum (Chen & Feng, 2019). The multi-target profile is essential for overcoming adaptive resistance in tumor vasculature.

Evidence & Benchmarks

• Anlotinib hydrochloride demonstrates IC₅₀ values of 5.6 ± 1.2 nM for VEGFR2, 8.7 ± 3.4 nM for PDGFRβ, and 11.7 ± 4.1 nM for FGFR1 in in vitro kinase assays, outperforming sunitinib and sorafenib under matched conditions (DOI:10.2147/OTT.S190333).
• In EA.hy 926 endothelial cell migration assays, Anlotinib inhibits VEGF-, PDGF-BB-, and FGF-2-induced migration at low nanomolar concentrations; this effect is dose-dependent and reproducible (MEK12, 2024).
• Capillary-like tube formation assays show significant inhibition with Anlotinib at concentrations as low as 10 nM, exceeding activity levels of nintedanib in side-by-side studies (TKI-258.com, 2024).
• Pharmacokinetic studies reveal oral bioavailability of 28–58% in rats and 41–77% in dogs; high plasma protein binding (93%) observed in humans (APExBIO).
• Preclinical safety assessment indicates a median lethal dose (LD₅₀) of 1735.9 mg/kg (14-day oral, mouse), with minimal off-target or genotoxic effects (DOI:10.2147/OTT.S190333).
• Clinical case reports confirm efficacy in highly angiogenic tumors, including intra-abdominal desmoplastic small round cell tumor (IADSRCT) refractory to chemotherapy (DOI:10.2147/OTT.S190333).

This article expands upon "Applied Cancer Research with Anlotinib Hydrochloride" by providing new clinical benchmarks and pharmacokinetic parameters not covered in the referenced piece. For a discussion on assay pitfalls and protocol optimization, see "Solving Lab Challenges with Anlotinib (hydrochloride)". For readers interested in translational and strategic applications, "Redefining Tumor Angiogenesis Research" offers a roadmap to integrating Anlotinib into broader research pipelines.

Applications, Limits & Misconceptions

Anlotinib hydrochloride is widely used in cancer biology research for:

• Cellular migration and invasion assays in human endothelial cells, especially EA.hy 926 lines.
• Capillary tube formation assays to quantify anti-angiogenic effects.
• Signaling pathway studies involving ERK, VEGFR, PDGFR, and FGFR cascades.
• Pharmacokinetic profiling and tissue distribution studies in rodent and canine models.
• Preclinical efficacy testing in xenograft or orthotopic tumor models.

Common Pitfalls or Misconceptions

• Anlotinib is not suitable for diagnostic or clinical use: It is strictly for research applications and not approved for human administration outside of clinical trials (APExBIO).
• Single-target settings underestimate efficacy: The compound's strength lies in multi-pathway inhibition; single-pathway assays may not reflect its full anti-angiogenic potential.
• Not all tumor types are equally sensitive: Tumors lacking VEGFR2/PDGFRβ/FGFR1 dependency may show limited response (DOI:10.2147/OTT.S190333).
• Metabolic context matters: CYP3A-mediated metabolism can alter exposure and efficacy; co-administration with CYP3A modulators requires caution.
• Storage and handling: The reagent must be stored at -20°C; repeated freeze-thaw cycles can compromise activity (APExBIO).

Workflow Integration & Parameters

Anlotinib (hydrochloride) from APExBIO (SKU: C8688) is supplied as a lyophilized solid for reconstitution in DMSO or appropriate aqueous buffer. Standard working concentrations for cell-based assays range from 1 nM to 1 μM, with typical exposure times of 24–72 hours. For migration and tube formation assays, concentrations of 10–100 nM are recommended. Pharmacokinetic studies should account for species-specific bioavailability (28–58% in rats, 41–77% in dogs), high protein binding (93% in humans), and extensive tissue distribution (lung, liver, kidney, heart, tumor) (product data). The compound demonstrates stability for >12 months at -20°C. For further assay guidance, see the comparative protocol recommendations in "Solving Lab Challenges with Anlotinib (hydrochloride)".

Conclusion & Outlook

Anlotinib hydrochloride is a validated multi-target tyrosine kinase inhibitor with robust anti-angiogenic activity and favorable pharmacokinetic and safety profiles. It is a benchmark research reagent for dissecting tumor angiogenesis, cell migration, and kinase signaling. Ongoing studies continue to map its utility across cancer types and combinatorial regimens. For the latest product specifications and ordering information, visit the APExBIO Anlotinib (hydrochloride) page.