WARNING

Enhertu (trastuzumab deruxtecan) is a medication used to treat certain types of breast cancer or stomach/esophageal cancer. While it can be effective in treating these cancers, like any medication, it carries potential risks. Here are some of the risks associated with taking Enhertu:

• Cardiotoxicity: Enhertu can lead to heart problems, including heart failure or weakening of the heart muscle. Patients may experience symptoms such as shortness of breath, swelling, or fatigue.
• Interstitial lung disease (ILD) or pneumonitis: Some patients may develop ILD or pneumonitis, which are conditions affecting the lungs and causing symptoms such as cough, difficulty breathing, or fever.
• Infusion-related reactions: Patients may experience reactions such as fever, chills, nausea, or headache during or after receiving Enhertu infusions.
• Hematological toxicities: Enhertu can cause a decrease in blood cell counts, including red blood cells (anemia), white blood cells (neutropenia), and platelets (thrombocytopenia), increasing the risk of infection, bleeding, or fatigue.
• Embryo-fetal toxicity: Enhertu can harm an unborn baby, so it should not be used during pregnancy. Women of childbearing age should use effective contraception during treatment and for some time afterward.
• Potential for secondary malignancies: There is a risk of developing secondary cancers with Enhertu treatment, although this risk must be weighed against the potential benefits of the medication.
• Other common side effects: These may include nausea, vomiting, diarrhea, fatigue, decreased appetite, hair loss, muscle and joint pain, or changes in taste.

It’s important for patients to discuss these risks with their healthcare provider and to report any concerning symptoms promptly during treatment. Additionally, patients should undergo regular monitoring as recommended by their healthcare team to detect and manage any potential side effects early.

Why is this medication prescribed?

Enhertu (trastuzumab deruxtecan) is prescribed primarily for the treatment of certain types of cancer, including:

• Breast Cancer: Enhertu is used in patients with HER2-positive breast cancer who have received prior treatment with other anti-HER2 therapies, such as trastuzumab and pertuzumab, and have either metastatic breast cancer (cancer that has spread to other parts of the body) or locally advanced breast cancer (cancer that has grown into nearby tissue or lymph nodes).
• Stomach (Gastric) Cancer or Gastroesophageal Junction Adenocarcinoma: Enhertu is prescribed for patients with HER2-positive gastric or gastroesophageal junction adenocarcinoma who have received prior treatment with a trastuzumab-containing regimen.

How should this medicine be used?

Enhertu works by targeting and blocking the HER2 protein, which is overexpressed in certain types of cancer cells, thereby inhibiting the growth and spread of these cancer cells.

Enhertu is typically administered as an intravenous infusion, meaning it is injected directly into a vein. The dosage and schedule for Enhertu can vary depending on factors such as the type and stage of cancer being treated, as well as the patient’s overall health and response to treatment. It’s essential to follow the specific instructions provided by your healthcare provider.

Generally, Enhertu is administered once every three weeks (21-day cycle), but the exact dosage and frequency will be determined by your healthcare provider. The infusion process is typically done in a hospital or clinic setting under the supervision of a healthcare professional.

It’s crucial to attend all scheduled appointments and follow your healthcare provider’s instructions closely while taking Enhertu to maximize its effectiveness and minimize the risk of side effects. If you have any questions or concerns about your treatment with Enhertu, be sure to discuss them with your healthcare provider.

Other uses for this medicine

Enhertu (trastuzumab deruxtecan) is primarily indicated for the treatment of HER2-positive breast cancer and HER2-positive gastric or gastroesophageal junction (GEJ) adenocarcinoma. However, it’s important to note that healthcare providers may sometimes prescribe medications off-label for conditions not specifically approved by regulatory agencies.

What special precautions should I follow?

Regarding special precautions for Enhertu, here are some important considerations:

• Monitoring: Your healthcare provider will monitor you closely during treatment with Enhertu for any signs of adverse reactions or side effects. This may include regular blood tests and imaging scans to assess the response to treatment and detect any potential complications.
• Cardiotoxicity: Enhertu can cause cardiotoxicity, which may manifest as heart failure, decreased heart function, or other cardiovascular complications. Patients with a history of heart disease or risk factors for heart disease may require closer monitoring during treatment. Your healthcare provider may perform cardiac assessments before and during treatment with Enhertu.
• Interstitial Lung Disease (ILD) or Pneumonitis: Enhertu can cause ILD or pneumonitis, which may be severe or fatal. Patients experiencing new or worsening respiratory symptoms such as cough, dyspnea (difficulty breathing), or fever should promptly seek medical attention. Treatment with Enhertu may need to be interrupted or discontinued if ILD or pneumonitis occurs.
• Hematologic Toxicity: Enhertu can lead to decreases in blood cell counts, including white blood cells, red blood cells, and platelets. Your healthcare provider will monitor your blood cell counts regularly and may adjust the dosage or temporarily halt treatment if necessary.
• Pregnancy and Breastfeeding: Enhertu can harm an unborn baby if used during pregnancy. Therefore, it’s essential to inform your healthcare provider if you are pregnant or planning to become pregnant. Additionally, breastfeeding while receiving Enhertu is not recommended due to the potential for harm to the infant.
• Liver Impairment: Patients with pre-existing liver impairment may require dose adjustments or closer monitoring while receiving Enhertu.
• Infusion Reactions: Enhertu infusion can cause infusion-related reactions, such as fever, chills, flushing, or shortness of breath. These reactions typically occur during or shortly after the infusion and may require medical intervention.
• Other Precautions: Inform your healthcare provider about all medications, supplements, and herbal products you are taking, as they may interact with Enhertu.

As always, it’s crucial to discuss any questions or concerns with your healthcare provider before starting treatment with Enhertu. They can provide personalized guidance based on your individual medical history and treatment needs.

What special dietary instructions should I follow?

Regarding special dietary instructions for Enhertu, there are no specific dietary restrictions associated with this medication. However, maintaining a healthy and balanced diet is generally recommended to support overall health and well-being during cancer treatment.

What should I do if I forget a dose?

If you forget a dose of Enhertu, it’s important to contact your healthcare provider or treatment team as soon as possible for guidance. They can advise you on the best course of action, which may include rescheduling the missed dose or adjusting your treatment plan as appropriate. It’s essential not to double up on doses unless instructed to do so by your healthcare provider.

What side effects can this medication cause?

Enhertu (trastuzumab deruxtecan) can cause a range of side effects, some of which may be serious. It’s important to be aware of these potential side effects and to promptly report any symptoms to your healthcare provider for evaluation. Common side effects of Enhertu may include:

• Nausea and vomiting: Feeling sick to your stomach and vomiting are common side effects of Enhertu treatment.
• Fatigue: Feeling tired or lacking energy is a common side effect of many cancer treatments, including Enhertu.
• Hair loss: Enhertu treatment may cause hair thinning or hair loss, although this is usually temporary and hair typically grows back after treatment ends.
• Decreased appetite: Some people may experience a decreased appetite while receiving Enhertu.
• Diarrhea: Enhertu treatment can cause diarrhea, which may be mild or severe.
• Anemia: Enhertu may lead to a decrease in red blood cells, resulting in anemia. Symptoms of anemia may include fatigue, weakness, and shortness of breath.
• Neutropenia: Neutropenia is a decrease in the number of white blood cells called neutrophils, which can increase the risk of infections.
• Thrombocytopenia: Enhertu treatment may cause a decrease in platelets, which are important for blood clotting. Thrombocytopenia can increase the risk of bleeding or bruising.
• Nail changes: Enhertu may cause changes to the nails, such as discoloration or brittleness.
• Interstitial lung disease (ILD) or pneumonitis: Enhertu can cause inflammation of the lungs, leading to symptoms such as cough, difficulty breathing, and chest pain.
• Cardiotoxicity: Enhertu treatment may cause heart problems, including decreased heart function or heart failure.
• Infusion reactions: Some people may experience infusion-related reactions during or shortly after receiving Enhertu, such as fever, chills, or flushing.

These are not all the possible side effects of Enhertu. Side effects may vary depending on individual factors such as the dose, frequency, and duration of treatment, as well as the specific characteristics of each person’s health condition. It’s important to discuss any concerns or symptoms with your healthcare provider for proper evaluation and management.

What should I know about storage and disposal of this medication?

Storage and disposal:

• Storage: Enhertu (trastuzumab deruxtecan) should be stored in the refrigerator at a temperature between 2°C to 8°C (36°F to 46°F). It should be kept in its original carton to protect it from light. Do not freeze or shake the medication. Keep Enhertu out of reach of children and pets.
• Disposal: Any unused Enhertu should be disposed of properly according to local regulations for hazardous waste disposal. Do not dispose of Enhertu in household trash. Ask your healthcare provider or pharmacist for guidance on the proper disposal of Enhertu.

In case of emergency/overdose

In case of emergency or overdose:

• Seek medical attention: If you suspect an overdose or experience severe side effects after receiving Enhertu, seek immediate medical attention. Contact your healthcare provider, local emergency services, or go to the nearest emergency room for evaluation and treatment.
• Symptom management: If you experience mild to moderate side effects or infusion reactions after receiving Enhertu, inform your healthcare provider promptly. They can provide appropriate management and support to alleviate symptoms.

What other information should I know?

• Regular follow-up: It’s important to attend all scheduled appointments with your healthcare provider for monitoring and follow-up during Enhertu treatment. Your healthcare provider will assess your response to treatment, monitor for any side effects or complications, and make adjustments to your treatment plan as needed.
• Supportive care: Enhertu treatment may cause various side effects that can impact your quality of life. Your healthcare provider may recommend supportive care measures to manage these side effects, such as medications to control nausea or supportive therapies for fatigue.
• Patient education: Make sure to understand how to properly prepare for Enhertu infusions, recognize potential side effects, and follow any instructions provided by your healthcare provider. It’s important to communicate openly with your healthcare team about any concerns or questions you may have throughout the treatment process.
• Medication interactions: Inform your healthcare provider about all medications, supplements, and herbal products you are taking, as they may interact with Enhertu and affect its effectiveness or increase the risk of side effects.
• Pregnancy and breastfeeding: Discuss with your healthcare provider the risks and benefits of Enhertu treatment if you are pregnant, planning to become pregnant, or breastfeeding. Enhertu may harm a developing fetus or nursing infant, so appropriate precautions should be taken.

Always follow your healthcare provider’s instructions and recommendations regarding Enhertu treatment to ensure safe and effective use of the medication.