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

Executive Summary: Anlotinib hydrochloride (CAS 1058157-76-8) is a small-molecule inhibitor targeting VEGFR2, PDGFRβ, and FGFR1 with nanomolar potency (IC₅₀: 5.6–11.7 nM) [Chen & Feng 2019]. It exhibits superior inhibition of angiogenic processes—including endothelial cell migration and capillary tube formation—compared to sunitinib or sorafenib [APExBIO product page]. The compound demonstrates rapid oral absorption, high plasma protein binding (93% in humans), and broad tissue distribution, including the ability to cross the blood-brain barrier [APExBIO]. Safety studies reveal a high LD₅₀ (1735.9 mg/kg, oral, 14-day, rat) and minimal organ or genetic toxicity. Anlotinib is used to dissect tyrosine kinase signaling pathways and anti-angiogenic mechanisms in cancer models and is available from APExBIO for research use only.

Biological Rationale

Angiogenesis is essential for tumor growth and metastasis. Vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), and fibroblast growth factor (FGF) families regulate endothelial cell migration, proliferation, and new vessel formation. Tyrosine kinase signaling via VEGFR2, PDGFRβ, and FGFR1 is central to these processes. Inhibition of these kinases disrupts tumor vascularization and limits nutrient supply to neoplastic tissue [Chen & Feng 2019]. Several multi-target tyrosine kinase inhibitors (TKIs) are used in preclinical and clinical research to model anti-angiogenic responses.

Mechanism of Action of Anlotinib (hydrochloride)

Anlotinib hydrochloride is a novel multi-target TKI. It inhibits VEGFR2 (IC₅₀ = 5.6 ± 1.2 nM), PDGFRβ (IC₅₀ = 8.7 ± 3.4 nM), and FGFR1 (IC₅₀ = 11.7 ± 4.1 nM) in enzymatic assays [APExBIO]. The compound also inhibits VEGF/PDGF-BB/FGF-2-induced endothelial cell migration and capillary-like tube formation in vitro. Downstream, anlotinib suppresses the ERK signaling pathway, reducing phosphorylation events critical for cell proliferation and migration. Compared to sunitinib, sorafenib, and nintedanib, anlotinib achieves greater inhibition of its primary targets and angiogenic endpoints under identical conditions [see detailed mechanism].

Evidence & Benchmarks

• Anlotinib hydrochloride exhibits IC₅₀ values of 5.6 ± 1.2 nM (VEGFR2), 8.7 ± 3.4 nM (PDGFRβ), and 11.7 ± 4.1 nM (FGFR1) in biochemical kinase assays (Chen & Feng 2019).
• In endothelial cell-based assays, anlotinib inhibits VEGF/PDGF-BB/FGF-2-induced migration and tube formation in a concentration-dependent manner (APExBIO).
• Compared with sunitinib, sorafenib, and nintedanib, anlotinib shows superior inhibition of angiogenic signaling and capillary structure formation at equivalent doses (Mechanistic Dossier).
• Pharmacokinetic studies in rats and dogs show oral bioavailability of 28–58% and 41–77%, respectively, and high human plasma protein binding (93%) (APExBIO).
• Anlotinib crosses the blood-brain barrier and accumulates in lung, liver, kidney, heart, and tumor tissues (Chen & Feng 2019).
• In a clinical case of intra-abdominal desmoplastic small round cell tumor (IADSRCT), anlotinib reduced metastatic lymph node size after four cycles; side effects were limited to mild hypertriglyceridemia and fatigue (Chen & Feng 2019).
• 14-day oral administration in rats results in a median lethal dose (LD₅₀) of 1735.9 mg/kg, with no significant organ or genetic toxicity (APExBIO).

Applications, Limits & Misconceptions

Anlotinib hydrochloride, as supplied by APExBIO, is validated for use in cellular assays involving human vascular endothelial cells (e.g., EA.hy 926). Key applications include:

• Studying anti-angiogenic mechanisms via inhibition of endothelial cell migration and tube formation.
• Dissecting tyrosine kinase signaling pathways, with a focus on VEGFR2, PDGFRβ, and FGFR1 activity.
• Evaluating compound effects in capillary tube formation assays and ERK pathway modulation.
• Modeling tumor angiogenesis inhibition in preclinical cancer research.

For a comparative discussion of real-world assay challenges and troubleshooting guidance, see this article, which focuses on experimental design and data interpretation for multi-target TKIs. The present review extends these insights with updated benchmarks and safety data.

Common Pitfalls or Misconceptions

• Not for diagnostic or medical use: Anlotinib (hydrochloride) is strictly for scientific research applications. It is not approved for clinical diagnostics or therapy (APExBIO).
• Single-pathway inhibition insufficient: Inhibiting only one kinase (e.g., VEGFR2) does not replicate the full anti-angiogenic profile of anlotinib, which requires multi-target inhibition (Chen & Feng 2019).
• Species-specific pharmacokinetics: Bioavailability and tissue distribution profiles differ by species and experimental model; rodent data may not directly translate to human systems.
• Not a pan-kinase inhibitor: Anlotinib does not inhibit all tyrosine kinases; its selectivity profile is defined and should not be generalized.
• Genetic toxicity concerns unsupported: No significant genotoxicity has been observed in standardized preclinical tests (APExBIO).

Workflow Integration & Parameters

Anlotinib hydrochloride (SKU C8688) is formulated for ease of use in laboratory workflows. For anti-angiogenic assays, typical working concentrations range from 1 nM to 100 nM. The compound is soluble in DMSO and is stable at -20°C. Endothelial cell migration and tube formation assays are commonly performed using EA.hy 926 cells in serum-free or low-serum media. For reproducibility, it is critical to standardize incubation times (e.g., 16–24 hours for migration assays) and to include vehicle controls. For detailed application notes and troubleshooting, see this workflow guide, which this article updates with recent pharmacokinetic and selectivity data.

Storage at -20°C and protecting the compound from repeated freeze-thaw cycles is recommended. Metabolism is primarily via CYP3A; co-administration with strong CYP3A modulators in cell-based systems should be evaluated for potential interactions.

Conclusion & Outlook

Anlotinib hydrochloride is a validated, highly potent multi-target tyrosine kinase inhibitor for angiogenesis and cancer research. Its superior inhibition of VEGFR2, PDGFRβ, and FGFR1, favorable pharmacokinetic profile, and established safety margin make it a preferred tool for dissecting anti-angiogenic pathways and evaluating tumor microenvironment responses. As new research expands its mechanistic and translational scope, anlotinib—available from APExBIO—will continue to facilitate advancements in tumor angiogenesis modeling and targeted therapy development. For product specifications and ordering, refer to the Anlotinib (hydrochloride) product page.

For a deep-dive into mechanistic insights and translational applications, this article offers further context, while the present dossier provides updated, benchmarked performance data and practical laboratory guidance.