Anamorelin

Anamorelin is a pivotal pharmaceutical active pharmaceutical ingredient (API) and analytical reference standard developed by Ono Pharmaceutical Co., Ltd. for the treatment of cancer-related cachexia—a debilitating wasting syndrome characterized by involuntary weight loss, muscle atrophy, and reduced appetite in patients with advanced cancer. As a first-in-class ghrelin receptor agonist, Anamorelin promotes appetite stimulation, increases body weight, and improves lean body mass in cachectic cancer patients through its selective activation of the GHS-R1a receptor. Anamorelin is supplied as a crystalline solid with limited water solubility but good solubility in organic solvents including ethanol (≥20.52 mg/mL) and DMSO (≥91.4 mg/mL). In quality control contexts, Anamorelin serves as a primary reference standard for analytical method development, method validation, and impurity profiling of anamorelin-containing drug products. The compound's related substances—including Anamorelin Impurity 5 (the key synthetic intermediate) and other process-related impurities—are officially recognized as critical quality attributes requiring strict control during commercial manufacturing. Anamorelin is classified as photolabile and hygroscopic, necessitating careful handling and storage under controlled conditions to maintain product integrity. The therapeutic versatility and structural complexity of Anamorelin make it not only a valuable API but also an essential reference material for generic manufacturers and analytical laboratories developing ANDA filings for anamorelin-based therapeutics.

 

Product Parameters

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Parameter	Specification
Product Name	Anamorelin
CAS Number	249921-19-5
Molecular Formula	C₃₁H₄₂N₆O₃
Molecular Weight	546.7 g/mol
Appearance	White solid
Melting Point	132–134 °C
Density	1.214 g/cm³
pKa	16.22±0.46
Storage Condition	Refrigerator

Bioactivity

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Anamorelin (ONO-7643, RC-1291, ST-1291) is an orally active, high-affinity selective agonist of the chemical book ghrelin receptor, with an EC50 of 0.74 nM in HEK293/GRLNFLIPR cells.

 

In Vitro S tudy

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Anamorelin exhibits significant agonistic effects and binding activity toward the growth hormone receptor, stimulating growth hormone release in vitro. Due to these properties, anamorelin promotes appetite and enhances anabolic effects. In screening studies of its activity, 10 μM anamorelin demonstrated weak binding affinity for L-type calcium ion channels, serotonin transporters, and sodium ion channels, indicating high selectivity for the growth hormone receptor. By inhibiting NF-κB, anamorelin reduces the production of pro-inflammatory cytokines and prevents muscle breakdown (by suppressing proteolysis).

 

 

In Vivo Studies

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In rats, anamorelin significantly and concentration-dependently increased food intake and body weight, and at doses of 10 mg/kg or 30 mg/kg, it markedly elevated growth hormone levels. In pigs, administration of anamorelin resulted in increased levels of growth hormone and IGF-1. Anamorelin exhibits oral activity and has a longer half-life in vivo than ghrelin, approximately 7 hours. It stimulates neuroendocrine responses, induces significant appetite stimulation, and promotes rapid metabolism. Plasma clearance studies using radiolabeled anamorelin demonstrated that the majority of the drug is excreted and secreted (92%). Food intake reduces the area under the curve (AUC) of anamorelin, indicating decreased absorption and utilization in vivo. Anamorelin is metabolized via CYP3A4. In murine tumor models, such as Lewis lung cancer and human bronchioloalveolar carcinoma models, anamorelin did not promote tumor growth.

 

Contact Us

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Whether you are developing analytical methods for anamorelin quality control, preparing an ANDA filing, or scaling up anamorelin API manufacturing, Cosperpharm is your trusted partner for high-quality reference standards and research chemicals. Our team is ready to support your project with technical expertise, responsive service, and supply solutions tailored to your specific needs. Reach out today to discuss your requirements for Anamorelin—we look forward to working with you.