Palbociclib, Isethionate Salt (Ibrance, PD-0332991, PD 332991, CAS 827022-33-3), >99%

LC Laboratories' Product Number P-7766 - Palbociclib, Isethionate Salt (Ibrance, PD-0332991, PD 332991, CAS 827022-33-3), >99% - for research use only. Palbociclib, also known as PD 0332991, is an inhibitor of cyclin-dependent kinases (CDK)4 and CDK6. It inhibited CDK4 and CDK6 with IC50 values of 11 nM and 16 nM, respectively. It inhibited the proliferation of retinoblastoma (Rb)-positive tumor cells in vitro with IC50 values ranging from 40 to 400 nM and induced a G1 arrest with a concomitant reduction of phospho-Ser780/Ser795 on the Rb protein. It also had antitumor activity against a panel of advanced stage human tumor xenografts in vivo. This research compound is the isethionate salt form of palbociclib. We also offer the free base, hydrochloride salt, and dihydrochloride salt forms; please see Palbociclib, Free Base, Cat. No. P-7744, Palbociclib Hydrochloride Salt, Cat. No. P-7788, and Palbociclib, Dihydrochloride Salt, Cat. No. P-7722. Palbociclib potently inhibited the phosphorylation of the Rb protein and cell cycle progression through G1 in primary 5T33MM cells in vivo and ex vivo. It induced tumor suppression and a significant improvement in survival of 5T33MM diseased mice. Palbociclib sensitized 5T33MM tumor cells to killing by bortezomib in vitro and prolonged survival in vivo. CDK4/6 inhibition by palbociclib induced a cooperative cytostatic effect in combination with doxorubicin in triple-negative breast cancer (TNBC) cells but ultimately antagonized cytotoxicity. However, palbociclib did not modify the sensitivity of Rb-deficient TNBC cells to doxorubicin-mediated cytotoxic chemotherapy. Palbociclib antagonized doxorubicin-mediated cytotoxicity in vivo in an Rb-dependent manner and allowed tumor cell outgrowth following doxorubicin treatment. This palbociclib product is the isethionate salt, whose CAS number is given above. The CAS number of the free base form is 571190-30-2, the CAS number of the monohydrochloride salt form is 827022-32-2, the CAS number of the hydrochloride (1:1.85) salt form is 571189-11-2 and the CAS number of the dihydrochloride salt form has not been reported as of October 30, 2014. Palbociclib is the active ingredient in the drug product with the trade name Ibrance®. As of December 2014, this drug is currently is not approved for any indication in any market. However, Ibrance® is in development for the treatment of breast cancer. NOTE: THE PALBOCICLIB, DIHYDROCHLORIDE SALT RESEARCH COMPOUND SOLD BY LC LABORATORIES IS NOT IBRANCE®, AND IS NOT FOR HUMAN USE.

• Supplier: LC Laboratories
• Product #: P-7766
• Sku #: P-7766_50mg