Elacestrant HCl

China [CN]

Elacestrant HCl (Elacestrant Hydrochloride) Core Information

Generic Name: Elacestrant Hydrochloride (Elacestrant HCl)  Chinese Name: Elacestrant Hydrochloride  Development Code: RAD1901  Trade Name: Orserdu (FDA Approved)  CAS Number: 1349723-93-8  Molecular Formula: C₃₀H₄₀Cl₂N₂O₂ (dihydrochloride)  Molecular Weight: 531.56 g/mol  Chemical Name: (6R)-6-[2-[ethyl[[4-[2-(ethylamino)ethyl]phenyl]methyl]amino]-4-methoxyphenyl]-5,6,7,8-tetrahydro-2-naphthol dihydrochloride

Drug Type and Mechanism of Action

Drug Type: Oral Selective Estrogen Receptor Degrader (SERD)

Mechanism of Action:

Potently binds to ERα (IC₅₀=48 nM), competitively blocking estrogen signaling

Induces ERα conformational change and is completely degraded by the proteasome, directly reducing intracellular ER levels

Maintains strong degradation activity against **ESR1 mutations (Y537S/D538G)** resistant receptors

Oral administration, no injection or refrigeration required

Core Clinical Value (Latest as of 2026)

Approved Indication (FDA, 2023-01):

For ER-positive, HER2-negative, ESR1-mutated advanced/metastatic breast cancer;

Suitable for postmenopausal women/adult men who have previously failed at least one line of endocrine therapy

Key Clinical Data (EMERALD Study):

ESR1 mutation subgroup: Median PFS 3.78 months vs 1.87 months in the control group, 45% reduction in risk of progression

Previous 1st-line endocrine therapy + ESR1 mutation: Median PFS reached 8.6 months

Dosing Regimen: 345 mg, once daily Once daily, taken orally with food.

Safety: Primarily mild to moderate nausea (35%), fatigue (19%), and musculoskeletal pain (14%); grade 3–4 adverse reactions occurred in only 6.3%.

Physicochemical Properties (API)

Appearance: White to off-white crystalline powder

Solubility: Easily soluble in 0.01N hydrochloric acid; soluble in DMSO (100 mg/mL), water (25 mg/mL), and ethanol (6 mg/mL)

Storage: Stable for 3 years at -20℃ (powder); store at room temperature (20–25℃) in a sealed container, protected from light and moisture.

Chirality: (6R)- configuration, single isomer