Is Palbociclib effective against bone metastasis?

When breast cancer (BC) spreads to the bones, it is no longer curable and new treatments are needed. When administered daily, the CDK4/6 inhibitor palbociclib significantly inhibited tumor growth in murine models of estrogen receptor-positive and triple-negative bone metastatic breast cancer. In combination therapy with the bisphosphonate zoledronic acid or a CDK7 inhibitor, palbociclib was insufficient to prevent tumor growth.

CDK 4/6 inhibitors have demonstrated significant improvements in survival in patients with estrogen receptor (ER)-positive breast cancer (BC). Primary tumor growth and the number of hindlimb bone tumors were significantly reduced in palbociclib-treated animals compared with vehicle controls. In the TNBC MDA-MB-231 model of metastatic growth in bone (intracardiac route), continued palbociclib treatment significantly inhibited tumor growth in bone compared with vehicle. When a seven-day break was introduced after 28 days, tumor growth resumed and was not inhibited by a second cycle of palbociclib alone or in combination with the bone-targeting drug zoledronic acid (Zol) or a CDK7 inhibitor.

The original drug of palbociclib has been launched in China and has entered the scope of Class B medical insurance, but reimbursement is limited to patients who meet the indications. The price of each box may be more than more than 4,000 yuan. The price of palbociclib's original drug, 125mg*21 capsules, per box sold overseas may be more than RMB 10,000 (the price may fluctuate due to exchange rates). There are also generic palbociclib drugs produced in other countries. The price of 125mg*21 tablets produced by a Bangladeshi pharmaceutical factory may be around a few hundred yuan per box (the price may fluctuate due to the exchange rate). The price is cheaper. The pharmaceutical ingredients of generic drugs are basically the same as those of domestic and foreign original drugs.