Pazopanib Hydrochloride

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Cat Number

API635702646

CAS Number

635702-64-6

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Product Detail Description Scientific Support Customer Q&A

CAS Number

635702-64-6

EINECS

619-728-0

Storage

Store at room temperature

Synonyms

pazopanib HCl; UNII-33Y9ANM545; pazopanib monohydrochloride; 33Y9ANM545

Molecular Formula

C21H24ClN7O2S

Molecular Weight

474

Smiles

CC1=C(C=C(C=C1)NC2=NC=CC(=N2)N(C)C3=CC4=NN(C(=C4C=C3)C)C)S(=O)(=O)N.Cl

Appearance

Off-white to light yellow powder

Melting Point

>290°C (dec.)

Boiling Point

728.8°C at 760 mmHg

General Description

Pazopanib hydrochloride is an oral, small-molecule multi-tyrosine kinase inhibitor (TKI) with a 2-indazolyl pyrimidine core. It targets multiple angiogenic and oncogenic receptors. The hydrochloride salt improves water solubility. The molecule contains a sulfonamide group and a dimethylamine side chain, which contribute to its binding selectivity.

Mechanism of Action

Pazopanib potently inhibits the kinase activity of vascular endothelial growth factor receptors (VEGFR-1, -2, -3), platelet-derived growth factor receptors (PDGFR-α, -β), and stem cell factor receptor (c-KIT). By blocking these targets, it suppresses tumor angiogenesis, reduces microvessel density, and inhibits tumor cell proliferation. The drug also shows activity against fibroblast growth factor receptors (FGFR) at higher concentrations.

Application

Pazopanib is indicated for the treatment of advanced renal cell carcinoma (RCC) as first-line therapy and for advanced soft tissue sarcoma (STS) in patients who have received prior chemotherapy. In RCC, it demonstrates progression-free survival comparable to sunitinib but with a different side effect profile. It is also investigated in ovarian cancer and other solid tumors.

This phase I/II trial evaluated pazopanib (400 mg daily MTD) plus weekly topotecan (4 mg/m²) in platinum‑resistant recurrent ovarian cancer (n=61). Objective response rate was 16%, clinical benefit rate 68%, but median progression‑free survival was only 3.5 months. Only 20% of patients could start maintenance pazopanib due to early progression. Hematologic and liver toxicities (grade 3/4 leucopenia 25%, neutropenia 22%, thrombocytopenia 19%, cholestatic damage 20%) were manageable. The combination was feasible and showed activity, but no significant survival benefit was observed.

Fig. 1 Patient recruitment and treatment within the TOPAZ phase I/II trial. (Chekerov R, et al., 2023)

References

Chekerov R, et al. Pazopanib with Topotecan weekly for patients with platinum-resistant or intermediate-sensitive recurrent ovarian cancer: results of a multicentre, open label phase I/II study (TOPAZ). J Cancer Res Clin Oncol. 2023;149(10):7637-7649.

Does Pazopanib Hydrochloride require protection from light during storage?

Yes, it is photosensitive. Light exposure can cause photodegradation and discoloration. Store in light-resistant containers, preferably amber glass.

What is the recommended storage temperature for Pazopanib Hydrochloride?

Store at controlled room temperature (15-25°C). Avoid temperatures above 30°C, which can accelerate hydrolysis of the sulfonamide group.

Is Pazopanib Hydrochloride hygroscopic, and how is this managed?

It is slightly hygroscopic. Under high humidity (>70% RH), it may absorb moisture and clump. Storage in tightly sealed containers with desiccant is recommended.

How is the impurity pazopanib N-oxide (an oxidative degradation product) monitored?

This degradation product is quantified using a stability-indicating HPLC method, ensuring it remains within ICH qualification thresholds.