Alpelisib (Piqray): What it is and who it helps

If you or someone you care for has hormone receptor–positive (HR+), HER2‑negative advanced breast cancer with a PIK3CA mutation, alpelisib can be a helpful option. Sold as Piqray, alpelisib blocks the PI3K alpha enzyme that helps some cancer cells grow. In a major trial (SOLAR‑1), patients with that specific PIK3CA mutation lived longer without disease progression when alpelisib was added to endocrine therapy.

Who should consider alpelisib?

Doctors usually offer alpelisib when a patient has progressed on previous endocrine therapy and testing shows a PIK3CA mutation. The mutation can be found by testing tumor tissue or a blood sample (circulating tumor DNA). If the test is positive and your doctor thinks the benefits outweigh the risks, alpelisib plus fulvestrant is a common next step.

This drug isn’t for everyone. People with uncontrolled diabetes, certain lung problems, or who are pregnant should avoid it or use it only under careful supervision. Always talk to your oncologist about whether it fits your situation.

How to take alpelisib and what to watch for

Typical dose: 300 mg once daily with food. Take the tablets at about the same time every day. If side effects occur, doctors may pause the drug or reduce the dose. Don’t stop suddenly without checking with your care team.

Before you start, expect baseline tests: fasting blood glucose or A1c, liver tests (LFTs), and sometimes lung imaging or breathing checks. During treatment, blood sugar and LFTs are checked frequently—at least every 2 weeks at first, then periodically. High blood sugar (hyperglycemia) is the most common and significant side effect; it often needs medicines like metformin and close monitoring. Bring up any new cough, shortness of breath, severe rash, or mouth sores right away—some reactions can be serious.

Other common side effects include diarrhea, nausea, decreased appetite, fatigue, and rash. Most are manageable with supportive care, dose changes, or temporary breaks. Your oncology nurse or pharmacist can help plan symptom control so you can stay on treatment if possible.

Drug interactions matter. Ask your pharmacist about other medicines, especially strong enzyme inducers (which can lower alpelisib levels) or strong inhibitors (which may raise levels). Use reliable contraception during treatment and for a period after—alpelisib can harm a developing baby.

Bottom line: alpelisib can offer meaningful benefit for patients with a PIK3CA mutation, but it needs careful monitoring—especially for blood sugar and skin or lung problems. Keep close contact with your care team, get the recommended tests, and report side effects early so dosing can be adjusted and side effects managed.