Webace 100mg Capsule contains Palbociclib, a selective cyclin-dependent kinase (CDK) 4/6 inhibitor indicated for the treatment of hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced or metastatic breast cancer. Palbociclib works by inhibiting CDK4 and CDK6, enzymes critical for cell cycle progression from the G1 to S phase, thereby preventing cancer cell proliferation. Webace is typically administered in combination with endocrine therapies such as letrozole or fulvestrant to enhance therapeutic efficacy. The recommended dosage is one 100mg capsule daily for 21 consecutive days followed by 7 days off treatment, constituting a 28-day cycle. Dose adjustments may be necessary based on hematologic toxicities, particularly neutropenia, which is the most common adverse effect. Other potential side effects include fatigue, nausea, alopecia, and infections. Regular monitoring of complete blood counts is essential to manage and mitigate adverse events. Webace should be used under strict medical supervision, with consideration of patient-specific factors including hepatic function and concomitant medications. It is contraindicated in patients with hypersensitivity to Palbociclib or any capsule components. This medication contributes significantly to the management of advanced breast cancer by targeting cell cycle dysregulation, thereby improving progression-free survival.