TYLIDYS 250 mg contains lapatinib, an oral targeted therapy used in the treatment of certain types of breast cancer. It belongs to a class of medications known as tyrosine kinase inhibitors. Lapatinib is particularly effective in cancers that overexpress the HER2 protein, which is commonly associated with aggressive tumor growth. It is often used in combination with other treatments for enhanced effectiveness.

Mechanism of Action
Lapatinib works by inhibiting the activity of two proteins involved in cancer cell growth, specifically HER2 and EGFR. These proteins send signals that promote cell division and survival. By blocking these signals, lapatinib slows down or stops the growth of cancer cells and may help shrink tumors. Its dual inhibitory action helps overcome resistance that might develop with other HER2-targeted treatments.

Uses
TYLIDYS is primarily used in the treatment of HER2-positive breast cancer, especially in cases where the cancer has spread or is no longer responding to first-line therapies. It is usually prescribed in combination with capecitabine or letrozole, depending on the patient’s condition and hormone receptor status. It may be used in patients who have already received other HER2-directed therapies like trastuzumab.

Adverse Effects
Common side effects of lapatinib include diarrhea, nausea, vomiting, and fatigue. Some patients may experience hand-foot syndrome, rash, or mouth sores. It can also affect liver function, so regular monitoring through blood tests is important. Less commonly, lapatinib may cause heart-related effects such as a decrease in heart pumping strength, which requires careful observation in patients with pre-existing cardiac conditions.