TARGETED THERAPY Targeted therapy treats cancer at its most basic biological level. Researchers study tumor cells to find molec- ular changes that may lead to cancer growth. They then develop “targeted” drugs to correct these changes. These changes or signs of changes are called biomarkers. Certain biomarkers have been associated with breast cancer. More may be discovered in the coming years. There are different types of targeted therapy. You may get targeted therapy alone or in combination with other treatments, like chemotherapy or hormonal therapy. The table (below and on the next page) lists targeted therapies by type and their possible side effects. Keep in mind that you may not get any or even most of the possible side effects of a drug. New treatments become available all the time so this may not be a complete list. These are the latest targeted therapies that are available as of August 2020. TYPE OF COMMON IMPORTANT TARGETED THERAPY SIDE EFFECTS THINGS TO KNOW ANTI-HER 2 MONOCLONAL • Diarrhea (more common with Perjeta) • For HER2+ cancer. ANTIBODY • Fatigue • Can work well to control ‹ pertuzumab (Perjeta®) • Rash MBC with few side effects. ® • Hair thinning/loss ‹ trastuzumab (Herceptin ) • Side effects often lessen and its biosimilars • Flu-like symptoms such as fever, chills, after the first treatment. including: and muscle aches (with Herceptin and - trastuzumab-anns its biosimilars, such as Ogivri) • Your doctor will test (Kanjinti™) • Rare infusion reactions your heart function - trastuzumab-dttb before, during, and after ® • Lung problems are a rare but serious (Ontruzant ) treatment. - trastuzumab-dkst (Ogivri™) side effect. - trastuzumab-pkrb • Heart damage is a rare but serious • Herceptin is available as ® (Herzuma ) possible side effect especially in older an IV or an injection under - trastuzumab-qyyp people or those who have had prior the skin. (Trazimera™) anthracycline treatment. ‹ pertuzumab, trastuzumab, • Phesgo is a combination and hyaluronidase-zzxf of Perjeta and Herceptin (PhesgoTM) available as an injection. TYROSINE KINASE • Rash • For HER2+ cancer. INHIBITOR • Diarrhea • Used with Xeloda and ® Herceptin when HER2+ ‹ lapatinib (Tykerb ) • Fatigue cancer no longer responds ® ‹ neratinib (Nerlynx ) • Nausea and vomiting (very mild for to Herceptin alone. ‹ tucatinib (TukysaTM) Tykerb) • Take Tykerb 1 hour before • Liver problems are a rare but serious eating or 2 hours after side effect. eating. • Heart damage is a rare but serious side • Take Nerlynx with food to effect of Tykerb. decrease nausea. • Avoid grapefruit juice and grapefruit while taking. ANTIBODY-DRUG • Low blood counts • Kadcyla and Enhertu are CONJUGATES • Diarrhea (Trodelvy) used for HER2+ cancer. ‹ ado-trastuzumab • Risk for bleeding • Trodelvy is used for triple emtansine (Kadcyla®) • Abnormal liver function tests negative breast cancer. ‹ fam-trastuzumab deruxtecan-nxki • Mild nausea • Kadcyla and Enhertu are a (Enhertu®) • Fatigue combination of Herceptin ‹ sacituzumab govitecan- • Lung problems and heart damage are and a chemotherapy drug. 8 hziy (Trodelvy™) rare but serious side effects. TARGETED THERAPY (Continued)

TYPE OF COMMON IMPORTANT TARGETED THERAPY SIDE EFFECTS THINGS TO KNOW MTOR INHIBITORS • Mouth sores • For HR+/HER2- cancer ‹ everolimus (Afinitor®) • Rash • Light can affect this • Irritation of the lining around the lungs medicine. • Diarrhea • Do not take with grapefruit, grapefruit juice, or St. John’s • Fatigue wort. • Very mild nausea and vomiting • Antifungal drugs, like • Weakness fluconazole, may make this • Abnormal blood tests (such as medicine stronger or worsen cholesterol or glucose) its side effects. • Tell all your doctors you are taking this drug. • Afinitor must be kept in the packaging it comes in. PARP INHIBITORS • Low blood cell counts • For HER2-/BRCA+ cancer ‹ olaparib (Lynparza®) • Mild to moderate nausea & vomiting • May interact with other ® • Fatigue ‹ talazoparib (Talzenna ) drugs. Tell your doctor about • Diarrhea everything else you are • Hair thinning/loss taking. • Loss of Appetite • Avoid grapefruit and Lynparza grapefruit juice while taking. • Bone marrow problems are a rare but serious possible side effect. Talzenna • Liver problems are a rare but serious possible side effect. CDK 4, 6 INHIBITORS • Low blood cell counts • For HR+/HER2- cancer. Being studied for HR+/ ‹ abemaciclib (Verzenio®) • Diarrhea (ask your doctor about HER2+ cancer. ® taking an anti-diarrheal medicine ‹ palbociclib (Ibrance ) before treatment), most common with • Ibrance and Kisqali are given ‹ ribociclib (Kisqali®) Verzenio in four-week cycles with 3 • Mild nausea & vomiting weeks of drug then 1 week off. Verzenio is continuous. • Fatigue • Hair thinning/loss (common for Kisqali • Avoid grapefruit and & Ibrance) grapefruit juice while taking.

PI3K INHIBITOR • Diarrhea • For HR+/HER2-/PI3K+ breast cancer in men and post- ‹ alpelisib (Piqray®) • High blood sugar menopausal women • Change in kidney or liver function • Skin rash/itching • Given with Faslodex • Fatigue • May interact with other • Nausea & vomiting drugs. Tell your doctor about everything else you are taking. • Low blood counts • Do not take with grapefruit, Mouth sores • grapefruit juice, or St. John’s 9 • Loss of appetite wort.