The U.S. Food and Drug Administration has approved a new oral medication for advanced breast cancer that takes a novel approach to destroying estrogen receptors, offering a new option for patients whose disease has stopped responding to standard hormone therapies. The drug, vepdegestrant (brand name Veppanu), was approved on May 1, 2026, for adults with estrogen receptor-positive, HER2-negative advanced or metastatic breast cancer that carries an ESR1 mutation and has progressed after hormonal therapy.
The approval is based on results from the VERITAC-2 trial, which compared vepdegestrant to the existing drug fulvestrant. In patients whose cancer had grown while on hormonal therapy and a CDK4/6 inhibitor, those taking vepdegestrant lived three months longer without their cancer progressing. The response rate was also starkly different: 19% of tumors shrank with vepdegestrant, compared to just 4% with fulvestrant.
Vepdegestrant belongs to a new class of drugs called PROTACs (proteolysis-targeting chimeras). While it works like other selective estrogen receptor degraders (SERDs) by blocking estrogen from attaching to cancer cells, it goes further. It actively breaks down the estrogen receptors on cancer cells and changes their shape so they stop functioning. This mechanism is especially important because up to 40% of advanced ER-positive, HER2-negative breast cancers develop an ESR1 mutation during hormone therapy, making them resistant to common first-line treatments like aromatase inhibitors and tamoxifen. The drug is taken as a 200 mg pill once daily with food.
As with any cancer treatment, vepdegestrant carries side effects. A key concern is QT interval prolongation, a heart rhythm abnormality that can lead to dangerous irregular heartbeats. Patients will need an EKG every two weeks during treatment. The drug can also harm a developing fetus, so women who can become pregnant must use effective non-hormonal birth control while taking it and for at least two weeks after the last dose. Men with partners who can become pregnant should also ensure their partner uses birth control during treatment and for two weeks afterward. Certain medications and supplements, including St. John's wort and grapefruit, can interfere with vepdegestrant and should be avoided.
The approval marks a meaningful step forward for patients with resistant breast cancer, a group that has had limited options after initial hormone therapies fail. While cost and insurance coverage will vary, Pfizer, one of the drug's developers, offers a financial assistance program called PfizerForAll. For patients facing an ESR1-mutated cancer that no longer responds to standard treatments, vepdegestrant provides a new, targeted tool that attacks the disease from a different angle. Researchers continue to study whether it may help even earlier in the treatment journey, offering hope for longer disease control in the years ahead.