Pamiparib API is a small-molecule, orally active poly(ADP-ribose) polymerase (PARP) inhibitor developed under the code BGB-290. Pamiparib is primarily associated with oncology research and pharmaceutical development as a selective inhibitor of PARP enzymes involved in DNA damage repair.
Pamiparib has the molecular formula C₁₆H₁₅FN₄O and a molecular weight of 298.31 g/mol. The CAS Number is 1446261-44-4, and the FDA Global Substance Registration System identifies the substance with UNII 8375F9S90C. FDA GSRS also identifies BGB-290 as a synonym for Pamiparib.
Pamiparib contains a defined stereogenic center and is identified as the (10aR) stereoisomer in FDA GSRS and PubChem records. Therefore, stereochemical or enantiomeric purity is an important quality consideration for pharmaceutical-grade Pamiparib API.
Pamiparib belongs to the PARP inhibitor class of targeted oncology compounds. PARP1 and PARP2 are enzymes involved in cellular responses to DNA damage. Inhibition of PARP-mediated repair can increase DNA damage accumulation and may lead to genomic instability and cancer-cell death, particularly in tumors with deficiencies in homologous recombination repair.
Pamiparib selectively inhibits PARP activity and interferes with PARP-mediated repair of single-strand DNA breaks. Research has demonstrated strong inhibitory activity against PARP1 and PARP2, with reported biochemical IC₅₀ values of 1.3 nM and 0.9 nM, respectively. A cellular PARylation assay reported an IC₅₀ of 0.2 nM.
Pamiparib has been investigated in clinical development for multiple solid tumors, including ovarian and gastric cancers. ClinicalTrials.gov records include studies evaluating Pamiparib as monotherapy and in maintenance-treatment settings.
Its development has particularly focused on cancers involving BRCA1/2 mutations and DNA-repair deficiencies, where PARP inhibition can exploit synthetic-lethal mechanisms. Pamiparib has also attracted research interest because of its pharmacological properties and ability to penetrate the central nervous system in preclinical studies.
Pamiparib API quality control can include chromatographic assay, related-substance determination, identity testing, stereochemical purity, residual-solvent analysis and elemental impurity assessment. Orthogonal analytical techniques such as IR, HPLC/UHPLC, LC-MS and other validated methods may be used to establish chemical identity and purity.
Because publicly available sources do not establish a universal USP/IP/Ph. Eur. numerical monograph specification for Pamiparib, numerical release limits should not be presented as official pharmacopoeial limits unless supported by the applicable controlled API specification.
Pamiparib is a stereochemically defined compound. FDA GSRS identifies absolute stereochemistry, while PubChem provides the corresponding stereochemically defined structure. This makes control of the correct stereoisomer particularly important during pharmaceutical manufacturing and quality testing.
Typical Pamiparib API documentation may include:
| Parameter | Specification |
|---|---|
| Appearance | white to off-white crystalline powder |
| Identification | IR & HPLC compliant |
| Assay (HPLC) | 98.0% – 102.0% |
| Loss on Drying | NMT 1.0% |
| Residue on Ignition | NMT 0.50% |
| Heavy Metals | NMT 20 ppm |
| Individual Impurity | NMT 0.50% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 1.0% |