Lonsurf

(Trifluridine/Tipiracil Hydrochloride)

Lonsurf works by stopping cancer cells from making new DNA, so they can’t grow and divide. It contains two drugs: trifluridine (a nucleoside analog that gets incorporated into cancer cell DNA, disrupting its function and inhibiting tumor growth), which gets built into cancer-cell DNA and disrupts it, and tipiracil (a thymidine phosphorylase inhibitor), which prevents trifluridine from breaking down too quickly so it stays active in the body longer. Together, they slow or stop the growth of cancer cells, while also affecting some healthy fast-growing cells, which is why side effects like low blood counts can occur.

Follow all directions given to you by your doctor and read all documents provided, including the full Prescribing Information, FDA-Approved Product Labeling, Instructions for Use, and Medication Guide before using Lonsurf. However, the following is a synopsis of the general guidelines for the use of Lonsurf:

• Lonsurf is taken by mouth as tablets.
• It is usually taken twice daily after meals.
• Treatment is given in cycles, commonly on days 1 through 5 and days 8 through 12 of a 28-day cycle.
• Tablets should be swallowed whole with water and should not be crushed or chewed.
• Your dose is based on body surface area and may be adjusted based on blood cell counts and side effects.
• If you miss a dose, do not take an extra dose to make up for it. Take the next dose at the scheduled time.
• Blood tests are required before starting treatment and during each cycle to monitor white blood cells, red blood cells, and platelets. Your healthcare provider may delay treatment or reduce the dose if blood counts are too low.

Some mild or most common side effects of Lonsurf seen in clinical trials as compared to placebo include:

• Tiredness or weakness.
• Nausea or vomiting.
• Decreased appetite.
• Diarrhea.
• Abdominal pain.

Some individuals may experience serious side effects while using Lonsurf. These side effects may require immediate medical attention. If you experience any of the following, contact your healthcare provider or seek emergency medical help:

• Neutropenia is a low white blood cell count that increases infection risk.
• Anemia, which may cause shortness of breath, dizziness, or fatigue.
• Thrombocytopenia may increase the risk of bleeding or bruising.
• Fever or signs of infection, such as chills or sore throat.
• Severe weakness or unusual bleeding.
• Fever or infection risk due to low neutrophil levels.

These are not all of the possible side effects of Lonsurf. You should always seek medical advice from your healthcare provider for any questions or concerns about your medical condition or treatment. Read all patient information, medication guides, or drug information sheets that come with this medication. You can also report adverse effects to the U.S. Food and Drug Administration at www.fda.gov/medwatch or 1-800-FDA-1088.

Before starting Lonsurf, it is crucial to discuss any existing health conditions with your healthcare provider. You should be sure that your healthcare provider is aware of all your medical conditions, including if you have:

• A history of low blood cell counts.
• Liver disease or abnormal liver function tests.
• Kidney disease.
• Active infections or frequent infections.
• Poor performance status or significant weight loss.
• Your healthcare provider will closely monitor blood cell counts and overall health throughout treatment. Dose delays or reductions may be necessary to reduce the risk of life-threatening complications.

Boxed Warning

Lonsurf has a boxed warning for severe and life-threatening bone marrow suppression. Treatment with Lonsurf can cause neutropenia, anemia, and thrombocytopenia. Blood cell counts must be monitored before and during treatment, and therapy should not be started unless blood counts are adequate.

There are no absolute contraindications listed for Lonsurf. However, it should not be used in patients with severe bone marrow suppression at the start of treatment. Your healthcare provider will determine if Lonsurf is appropriate based on blood test results and overall health.

Lonsurf does not work immediately. In clinical trials, benefits such as progression-free survival and overall survival were measured over months of treatment. The goal is to slow cancer growth and spread rather than produce rapid symptom relief. Your healthcare provider will assess treatment response through scans, blood tests, and clinical evaluation.

When Lonsurf is taken with other prescription drugs, over-the-counter medications, vitamins, and supplements, it may change how they work or increase the frequency or severity of side effects. Make sure that you tell your healthcare professional about anything that you are taking to avoid any negative drug interactions, including:

• Other chemotherapy agents may increase bone marrow suppression.
• Medications that affect blood cell production may raise the risk of infection or bleeding.
• Supplements that may interfere with blood counts or immune function.
• Bevacizumab.

Drug interactions mainly increase the risk of hematologic toxicity and should be managed by your oncology healthcare provider.

Lonsurf tablets are available in fixed-dose combinations containing trifluridine and tipiracil. Dosing is individualized based on body surface area and adjusted as needed according to blood test results and tolerability.

It should be stored at room temperature, away from the reach of children or pets.

Lonsurf is manufactured by Taiho Oncology.

No. There is currently no generic version of Lonsurf available.

Do not stop taking Lonsurf without speaking to your healthcare provider. Treatment may be stopped or adjusted if severe side effects occur or if the cancer no longer responds to therapy. Your oncology team will guide any changes to treatment.

Lonsurf can cause harm to an unborn baby. Effective contraception is recommended during treatment and for at least 6 months after the final dose.

Breastfeeding is not recommended during treatment with Lonsurf and for 1 day following the final dose due to the potential for serious adverse reactions in a breastfed child.