Pirtobrutinib is a small-molecule active pharmaceutical ingredient and a highly selective, non-covalent inhibitor of Bruton’s tyrosine kinase (BTK). It is identified by CAS Number 2101700-15-4, with the molecular formula C₂₂H₂₁F₄N₅O₃ and molecular weight 479.44 g/mol. Pirtobrutinib is the active pharmaceutical ingredient in Jaypirca and is used in the treatment of certain B-cell malignancies.
Pirtobrutinib API, also known by the development code LOXO-305, is an orally active BTK inhibitor. Unlike covalent BTK inhibitors, pirtobrutinib binds non-covalently to BTK, and its inhibitory activity can be maintained against BTK containing the Cys481 mutation. PubChem identifies pirtobrutinib as a kinase inhibitor and antineoplastic agent.
Pirtobrutinib is supplied as the active pharmaceutical ingredient in pharmaceutical formulations and is chemically distinct from related BTK inhibitors such as ibrutinib, zanubrutinib and acalabrutinib.
Pirtobrutinib has the molecular formula C₂₂H₂₁F₄N₅O₃ and molecular weight 479.44 g/mol. Its CAS Number is 2101700-15-4 and its FDA GSRS UNII is JNA39I7ZVB. PubChem reports an exact mass of 479.15805220 Da, XLogP3-AA of 3.3, hydrogen-bond donor count of 3, hydrogen-bond acceptor count of 9, rotatable bond count of 7, and topological polar surface area of 125 Ų.
The FDA describes pirtobrutinib as a white to practically white to yellow to brown solid. Its aqueous solubility is considered practically insoluble or insoluble across the pH 1 to pH 7 range.
Pirtobrutinib is a targeted anticancer API used as a Bruton’s tyrosine kinase inhibitor.
Its established pharmaceutical applications include:
The FDA label identifies pirtobrutinib as a kinase inhibitor and provides its approved indications.
Pirtobrutinib API can be characterized using chromatographic, spectroscopic and solid-state analytical techniques, including HPLC, chiral HPLC, LC-MS, NMR, elemental analysis, XRPD, DSC and TGA, depending on the applicable specification and solid-state form.
A commercial technical source reports >99% purity by achiral and chiral HPLC and elemental-analysis verification for anhydrous material. A recent pharmaceutical process patent reports pirtobrutinib purity of >98%, preferably >99%, and more preferably >99.5% by HPLC for material produced by the disclosed process. These are process/commercial specifications rather than a universal pharmacopoeial API acceptance limit.
Pirtobrutinib has multiple reported crystalline and solid-state forms. Therefore, solid-state characterization can be important when defining API quality, since polymorphic form can affect physical and pharmaceutical properties.
Pirtobrutinib API is identified by CAS 2101700-15-4, molecular formula C₂₂H₂₁F₄N₅O₃, and molecular weight 479.44 g/mol. The API is relevant to targeted oncology drug development and pharmaceutical manufacturing involving BTK inhibition.
Quality evaluation may include identity, assay, chromatographic purity, chiral purity, residual solvents, water content, elemental impurities and solid-state characterization according to the applicable approved product specification.
Pirtobrutinib should be packed in suitable, tightly closed pharmaceutical-grade packaging that protects the material from moisture, contamination and unsuitable environmental exposure.
Because pirtobrutinib exists in different solid-state forms, packaging and storage conditions should be established according to the applicable API specification, stability data and solid-state form.
For research-grade material, commercial technical sources may specify controlled-temperature storage, with conditions varying by supplier and batch. The applicable Certificate of Analysis and product specification should therefore be followed for commercial API material.
Applicable documentation may include:
Pirtobrutinib is a well-characterized next-generation BTK inhibitor with an established pharmaceutical application in targeted oncology. Its CAS Number 2101700-15-4, molecular formula C₂₂H₂₁F₄N₅O₃, and molecular weight 479.44 g/mol provide clear chemical identification.
The availability of analytical data involving achiral and chiral HPLC, NMR, elemental analysis and solid-state characterization supports comprehensive quality evaluation. Because pirtobrutinib has multiple crystalline forms, the applicable solid-state form and batch-specific quality requirements should be clearly defined for pharmaceutical development and manufacturing.
| 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% |
| Heavy Metals | NMT 20 ppm |
| Individual Impurity | NMT 0.20% |