Are abeciclib and palbociclib the same?

Palbociclib and Abemaciclib are two different drugs, although they are both targeted drugs used in the treatment of breast cancer and are CDK 4/6 inhibitors. Palbociclib is suitable for the first-line treatment of hormone receptor-positive HER-2-negative (HR+/HER-2-negative) advanced breast cancer and can be used in combination with letrozole or fulvestrant; abeciclib can be used together with endocrine therapy (tamoxifen) for the adjuvant treatment of adult patients with early-stage breast cancer who are hormone receptor (HR) positive, human epidermal growth factor receptor 2 (HER2) negative, lymph node positive, and have a high risk of recurrence. Both palbociclib and abeciclib may cause some adverse reactions, such as low blood cell counts, nausea, and hair loss.