Pimicotinib API is a synthetic small-molecule pharmaceutical active ingredient developed as a selective colony-stimulating factor 1 receptor (CSF1R) inhibitor. Also known by the development code ABSK021, Pimicotinib is an orally active kinase inhibitor designed to block CSF1R-mediated signaling. It has been developed for diseases in which macrophage activity and CSF1R signaling contribute to disease progression, particularly tenosynovial giant cell tumor (TGCT). FDA substance-registration data identify Pimicotinib as a neutral molecular substance with the molecular formula C22H24N6O3 and molecular weight 420.47 g/mol.
Pimicotinib is identified by CAS Number 2253123-16-7 for the free-base anhydrous substance. PubChem lists Pimicotinib under CID 139549388 and confirms the molecular formula C22H24N6O3 and molecular weight approximately 420.5 g/mol. Its systematic chemical name is 3,3-dimethyl-N-[6-methyl-5-[[2-(1-methylpyrazol-4-yl)-4-pyridinyl]oxy]-2-pyridinyl]-2-oxopyrrolidine-1-carboxamide.
Pimicotinib belongs to the class of CSF1R inhibitors and has been investigated as an orally administered targeted therapy. CSF1R, also known as macrophage colony-stimulating factor receptor or CD115, plays an important role in macrophage development, differentiation and survival. By inhibiting CSF1R signaling, Pimicotinib can reduce pathological macrophage activity and associated signaling within affected tissues.
The compound is achiral and contains no defined stereocenters according to FDA Global Substance Registration System information. It has the molecular formula C22H24N6O3, a molecular weight of 420.47 g/mol, and the FDA UNII HV1XI8HST2.
Pimicotinib is also associated with hydrochloride forms. FDA substance records identify Pimicotinib hydrochloride monohydrate separately, with CAS 2759304-23-7 and molecular formula C22H27ClN6O4. This distinction is important for pharmaceutical API documentation because the free base and hydrochloride monohydrate are different chemical substances with different molecular weights and CAS numbers.
Pimicotinib has been extensively developed for tenosynovial giant cell tumor, a rare tumor-like disorder involving the synovial lining and associated tissues. Its mechanism is particularly relevant because CSF1-CSF1R signaling contributes to the recruitment and proliferation of macrophage-lineage cells involved in TGCT pathology. Pimicotinib's targeted inhibition of CSF1R provides a pharmacological approach for reducing this disease-associated cellular activity.
The compound has also advanced into clinical development in other disease areas. PubChem records its development in the MANEUVER clinical study for tenosynovial giant cell tumor, while the IUPHAR/BPS Guide to Pharmacology records Pimicotinib as an approved drug in China in 2025.
Pimicotinib is marketed in China as Betimai® and has also progressed into international regulatory development. Health Canada's Drug Product Database currently lists a marketed pimicotinib product, PIMJETMI, containing pimicotinib hydrochloride at a 25 mg capsule strength.
As a synthetic small-molecule API, Pimicotinib can be characterized using conventional pharmaceutical analytical techniques. However, a universal current pharmacopoeial API release specification was not identified in the authoritative sources reviewed, so unsupported numerical values should not be presented as official USP, Ph. Eur. or IP specifications.
Typical quality evaluation can include identity testing, assay by a validated chromatographic method, related substances, residual solvents, water or loss on drying, residue on ignition, elemental impurities, melting point and other process-specific quality attributes. The exact acceptance criteria should be based on the applicable regulatory specification and validated analytical methods.
The distinction between Pimicotinib free base and Pimicotinib hydrochloride monohydrate is particularly important during API procurement and quality documentation. The free base has CAS 2253123-16-7 and molecular weight 420.47 g/mol, whereas the hydrochloride monohydrate is identified by CAS 2759304-23-7 and has molecular formula C22H27ClN6O4.
Pimicotinib represents an important targeted small-molecule API within the CSF1R inhibitor class. Its development and commercialization demonstrate the growing pharmaceutical interest in selective kinase inhibitors that modulate macrophage-associated pathways. For pharmaceutical manufacturers and drug-development organizations, accurate chemical identification and form control are essential when evaluating Pimicotinib API.
For technical documentation, the CAS number, molecular formula, molecular weight and chemical form should always be stated clearly. Where Pimicotinib hydrochloride monohydrate is intended, its separate CAS number and molecular formula should be used rather than the free-base information.
Overall, Pimicotinib API is a targeted pharmaceutical ingredient with applications in oncology and immune-related disease research, particularly in CSF1R-dependent conditions such as tenosynovial giant cell tumor. Its established chemical identity and advancing regulatory status make it a relevant API for pharmaceutical research, development and manufacturing programs.
| 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 0.1% |
| Individual Impurity | NMT 0.5% |
| Total Impurities | NMT 1.0% |
| Water Content | NMT 0.5% |