Alpelisib: What It Is, Who It Helps, and What You Need to Know

When standard breast cancer treatments stop working, alpelisib, a targeted drug that blocks a specific protein called PI3K-alpha that fuels cancer growth. Also known as Vijoice, it’s not for everyone—but for those with a certain genetic change, it can make a real difference. Alpelisib is designed for postmenopausal women and men with advanced, hormone receptor-positive, HER2-negative breast cancer that has a PIK3CA mutation, a genetic alteration found in about 40% of these cancers that causes cells to grow uncontrollably. This isn’t a chemo drug. It doesn’t attack all fast-growing cells. It zeroes in on one broken switch inside the cancer cell, which is why it’s called a PI3K inhibitor, a class of drugs that shut down a key signaling pathway cancer cells rely on to survive. The FDA approved it in 2019 after trials showed it slowed tumor growth when paired with fulvestrant, especially when other drugs failed.

What makes alpelisib different isn’t just how it works, but who it’s for. Before starting, doctors test tumor tissue or blood for the PIK3CA mutation, a specific DNA change that tells them whether this drug will even have a chance to work. If you don’t have it, alpelisib won’t help—and it comes with side effects like high blood sugar, diarrhea, and rash. That’s why it’s not a first-line option. It’s a precision tool, used after hormone therapy and sometimes CDK4/6 inhibitors have run their course. It’s also not a cure. But for many, it buys time—sometimes months, sometimes more—while keeping quality of life in mind. It connects directly to other targeted therapies like everolimus and the newer drugs in development that target the same pathway. And because it affects blood sugar, it often requires close monitoring with diabetes meds like metformin, making it one of the few cancer drugs that overlaps heavily with endocrine management.

What you’ll find in the posts below isn’t just information about alpelisib itself. You’ll see how it fits into the bigger picture of personalized cancer care, what alternatives exist when it stops working, how side effects are managed in real life, and why genetic testing matters more than ever in treatment decisions. You’ll also find connections to other targeted therapies, how drug resistance develops, and what patients are actually experiencing when they take it. This isn’t a list of drug facts—it’s a guide to understanding where alpelisib sits in the modern treatment landscape, and what it means for someone facing advanced breast cancer today.