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

Executive Summary: Anlotinib hydrochloride is a novel small-molecule inhibitor that targets VEGFR2, PDGFRβ, and FGFR1, key receptors in tumor angiogenesis (Lin et al., 2018). It exhibits low nanomolar IC₅₀ values for these kinases in standardized cell-based assays. Compared to sunitinib, sorafenib, and nintedanib, Anlotinib demonstrates superior inhibition of endothelial cell migration and capillary tube formation. The compound is orally bioavailable, rapidly absorbed, and achieves high plasma protein binding in preclinical models. APExBIO supplies Anlotinib (hydrochloride) (SKU C8688), validated for reproducible results in anti-angiogenic research (APExBIO).

Biological Rationale

Angiogenesis is essential for tumor growth and metastasis, as new blood vessels supply nutrients and oxygen to proliferating tumor cells (Lin et al., 2018). Key pro-angiogenic factors include vascular endothelial growth factor (VEGF), platelet-derived growth factor-BB (PDGF-BB), and fibroblast growth factor-2 (FGF-2). Their respective receptors—VEGFR2, PDGFRβ, and FGFR1—are receptor tyrosine kinases (RTKs) expressed on endothelial and tumor-associated cells. Activation of these kinases induces downstream ERK signaling, promoting endothelial cell proliferation, survival, and migration. Inhibition of these pathways is a validated strategy for suppressing tumor-driven angiogenesis and halting cancer progression. Small-molecule multi-target tyrosine kinase inhibitors (TKIs) are now central to advanced cancer research and therapy optimization.

Mechanism of Action of Anlotinib (hydrochloride)

Anlotinib hydrochloride is a synthetic multi-target TKI with potent inhibitory activity against VEGFR2 (IC₅₀: 5.6 ± 1.2 nM), PDGFRβ (IC₅₀: 8.7 ± 3.4 nM), and FGFR1 (IC₅₀: 11.7 ± 4.1 nM), determined using recombinant kinase assays at 25°C and pH 7.4 (Lin et al., 2018). Anlotinib binds the ATP-binding site of these RTKs, blocking autophosphorylation and subsequent activation of downstream signals, including the ERK pathway. This blockade results in concentration-dependent inhibition of VEGF/PDGF-BB/FGF-2-induced endothelial cell migration and tube formation. In cellular models (EA.hy 926), treatment with Anlotinib reduces microvessel density and impairs angiogenic outgrowth in rat aortic ring and chicken chorioallantoic membrane assays. The compound modulates multiple angiogenic pathways, offering mechanistic redundancy and reducing resistance observed with single-target TKIs.

Evidence & Benchmarks

• Anlotinib inhibits VEGFR2 kinase activity with an IC₅₀ of 5.6 ± 1.2 nM in vitro (Lin et al., 2018).
• PDGFRβ and FGFR1 inhibition are observed at IC₅₀ values of 8.7 ± 3.4 nM and 11.7 ± 4.1 nM, respectively (Lin et al., 2018).
• In endothelial cell migration and capillary tube formation assays, Anlotinib is more potent than sunitinib, sorafenib, and nintedanib (Lin et al., 2018).
• Oral bioavailability in preclinical models: 28–58% in rats, 41–77% in dogs (standardized PK studies, 24°C, fed state) (APExBIO).
• High plasma protein binding (93% in human plasma at 37°C) and large volume of distribution are confirmed (APExBIO).
• Tissue distribution studies show high accumulation in lung, liver, kidney, heart, and tumor tissues; blood-brain barrier penetration is observed in rodent models (Lin et al., 2018).
• Genotoxicity and organ toxicity are minimal in 14-day oral LD₅₀ studies (LD₅₀: 1735.9 mg/kg, rat, oral gavage) (APExBIO).

For an in-depth comparison of Anlotinib's selectivity and reproducibility in tumor angiogenesis assays, see Applied Cancer Research with Anlotinib Hydrochloride, which this article extends by providing updated quantitative IC₅₀ and pharmacokinetic data.

For practical workflows and troubleshooting in angiogenesis assays, Anlotinib Hydrochloride: Multi-Target Tyrosine Kinase Inhibitor offers complementary stepwise protocols, while the present review clarifies comparative efficacy among TKIs using peer-reviewed benchmarks.

Applications, Limits & Misconceptions

Anlotinib (hydrochloride) is validated for use in cellular angiogenesis assays, including human EA.hy 926 endothelial cell migration and capillary tube formation studies. It is recommended for mechanistic dissection of VEGFR2, PDGFRβ, and FGFR1 signaling in preclinical cancer models. The compound is stored at –20°C and is suitable for in vitro and ex vivo research, not for clinical or diagnostic use.

Common Pitfalls or Misconceptions

• Anlotinib is not approved for therapeutic use outside controlled clinical trials; research use only.
• The compound's efficacy in non-angiogenic disease models is unproven and not supported by current evidence.
• Use in non-mammalian systems may yield variable pharmacokinetics and distribution profiles.
• Effects on off-target kinases at supra-pharmacological concentrations are possible; use validated concentrations.
• Do not use for human or veterinary diagnostic applications.

See also Optimizing Tumor Angiogenesis Assays with Anlotinib (hydrochloride), which addresses laboratory implementation challenges, whereas the present article emphasizes molecular mechanism and quantitative benchmarks.

Workflow Integration & Parameters

Anlotinib (hydrochloride) (SKU C8688) from APExBIO integrates into standard endothelial cell-based angiogenesis assays. For migration or tube formation assays, recommended working concentrations range from 1 nM to 100 nM, depending on endpoint and cell type. Dissolve in DMSO to prepare a 10 mM stock; dilute into serum-free medium for assay use. Store aliquots at –20°C and avoid repeated freeze-thaw cycles. The compound is compatible with automated imaging and quantitative capillary tube analysis workflows. For ERK signaling studies, pre-treat cells for 30–60 minutes before growth factor stimulation. Confirm all experimental parameters per referenced protocols (Lin et al., 2018).

Conclusion & Outlook

Anlotinib hydrochloride is a rigorously characterized multi-target tyrosine kinase inhibitor with superior potency for VEGFR2, PDGFRβ, and FGFR1, validated in angiogenesis inhibition assays. Its favorable pharmacokinetic and safety profile, along with reliable supply by APExBIO, make it a cornerstone compound for cancer research targeting angiogenic mechanisms. Ongoing studies will further define its translational potential and inform next-generation TKI design.

For detailed product specifications and ordering information, refer to the Anlotinib (hydrochloride) product page.