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

Executive Summary: Anlotinib hydrochloride is a small-molecule inhibitor targeting VEGFR2, PDGFRβ, and FGFR1, with nanomolar IC₅₀ values verified in cellular assays (DOI). It blocks pro-angiogenic factor-induced endothelial cell migration and tube formation, outperforming sunitinib, sorafenib, and nintedanib in preclinical benchmarks (DOI). The compound demonstrates favorable pharmacokinetics, including high plasma protein binding and tissue penetration (APExBIO). Safety studies show a high LD₅₀ and limited organ toxicity (APExBIO). Anlotinib is supplied by APExBIO for research use, optimized for mechanistic and translational cancer studies.

Biological Rationale

Angiogenesis, the formation of new blood vessels from pre-existing vasculature, is essential for tumor growth and metastasis (DOI). Tumor cells secrete pro-angiogenic cytokines such as VEGF, PDGF-BB, and FGF-2, which activate signaling pathways in endothelial cells, promoting migration and capillary tube formation (DOI). VEGFR2, PDGFRβ, and FGFR1 are critical receptor tyrosine kinases mediating these processes. Inhibiting these targets can suppress tumor angiogenesis, depriving tumors of nutrients and oxygen (Supporting article).

Mechanism of Action of Anlotinib (hydrochloride)

Anlotinib hydrochloride (CAS 1058157-76-8) is a small-molecule, multi-target tyrosine kinase inhibitor (TKI). It selectively inhibits the kinase activity of VEGFR2 (IC₅₀: 5.6 ± 1.2 nM), PDGFRβ (IC₅₀: 8.7 ± 3.4 nM), and FGFR1 (IC₅₀: 11.7 ± 4.1 nM) in concentration-dependent in vitro assays (DOI). Anlotinib blocks ligand-induced autophosphorylation events, thereby suppressing downstream ERK signaling pathways that regulate endothelial cell proliferation, migration, and survival. In cell-based systems, anlotinib inhibits VEGF/PDGF-BB/FGF-2-stimulated endothelial cell migration and tube formation (APExBIO). Preclinical models demonstrate that anlotinib reduces neovessel density and microvessel sprouting in rat aortic ring and chicken chorioallantoic membrane (CAM) assays (DOI).

Evidence & Benchmarks

• Anlotinib inhibits VEGFR2, PDGFRβ, and FGFR1 kinase activity with IC₅₀ values of 5.6 ± 1.2 nM, 8.7 ± 3.4 nM, and 11.7 ± 4.1 nM, respectively (Lin et al., 2018).
• It suppresses VEGF/PDGF-BB/FGF-2-induced endothelial cell migration and capillary-like tube formation in EA.hy 926 cells in vitro (Figure 2).
• In preclinical CAM and rat aortic ring models, anlotinib reduces neovessel formation and microvessel density more effectively than sunitinib, sorafenib, or nintedanib (Table 1).
• Pharmacokinetic studies show oral bioavailability of 28–58% (rats) and 41–77% (dogs); plasma protein binding in humans is 93% (APExBIO).
• The median lethal dose (LD₅₀) is 1735.9 mg/kg (14-day oral, rodent), with mild systemic toxicity and no significant organ/genetic toxicity (APExBIO).

In contrast to this product overview, which summarizes IC₅₀ values, this article provides a more granular breakdown of pharmacokinetics and comparative efficacy. For a translational perspective, see Translational Horizons in Tumor Angiogenesis; this current dossier updates those insights with the most recent safety and workflow integration data. For additional benchmarks, see this external summary.

Applications, Limits & Misconceptions

Anlotinib hydrochloride is used in research assays to dissect the molecular basis of tumor angiogenesis. Its low-nanomolar potency enables use in endothelial cell migration, capillary tube formation, and pathway analysis studies. The compound is suitable for both mechanistic and translational cancer research workflows (APExBIO). It is not approved for diagnostic or clinical use.

Common Pitfalls or Misconceptions

• Not for clinical or diagnostic use; restricted to research applications.
• May not inhibit non-angiogenic kinases; off-target effects are minimal but not zero.
• In vivo efficacy may vary by tumor type and microenvironment.
• Metabolism via CYP3A may result in drug–drug interactions not modeled in vitro.
• Does not substitute for direct genetic knockdown of target kinases; complementary controls are needed.

Workflow Integration & Parameters

The recommended storage temperature is -20°C (APExBIO). Reconstitution in DMSO is standard. Typical cell-based assay concentrations range from 1–100 nM, depending on endpoint and cell line. For endothelial cell migration assays, EA.hy 926 or HUVEC cells are stimulated with VEGF/PDGF-BB/FGF-2, followed by anlotinib treatment and quantification of migration or tube formation (DOI). For pathway analysis, Western blotting for phosphorylated ERK is recommended. For in vivo studies, refer to animal-specific guidelines and pharmacokinetic parameters.

The C8688 kit from APExBIO provides validated, research-grade anlotinib hydrochloride for these applications.

Conclusion & Outlook

Anlotinib hydrochloride is a next-generation multi-target tyrosine kinase inhibitor with robust, validated anti-angiogenic activity in preclinical models. Its low-nanomolar potency, favorable pharmacokinetics, and superior efficacy over clinically established TKIs make it an essential tool for cancer research. As additional translational studies emerge, anlotinib's unique target profile and safety data will inform the design of both mechanistic and therapeutic experiments. Researchers should consult APExBIO for detailed protocols and product support.