Safety information and possible side effects

Serious infections

LITFULO is a medicine that affects your immune system. LITFULO can lower the ability of your immune system to fight infections. Some people have had serious infections while taking LITFULO or other similar medicines, including tuberculosis (TB), and infections caused by bacteria, fungi, or viruses that can spread throughout the body and have been hospitalized. Some people taking similar medicines to LITFULO have died from these infections.

• Your healthcare provider should test you for TB before starting treatment with LITFULO.
• Your healthcare provider should watch you closely for signs and symptoms of TB during treatment with LITFULO.

You should not start taking LITFULO if you have any kind of infection unless your healthcare provider tells you it is okay.

You may be at a higher risk of developing shingles (herpes zoster).

Before starting LITFULO, tell your healthcare provider if you:

• are being treated for an infection.
• have an infection that has not gone away or that keeps coming back.
• have diabetes, chronic lung disease, HIV, or a weak immune system.
• have TB or have been in close contact with someone with TB.
• have had shingles (herpes zoster).
• have had hepatitis B or hepatitis C.
• live or have lived or have traveled to certain parts of the country (such as the Ohio and Mississippi River valleys and the Southwest) where there is an increased chance for getting certain kinds of fungal infections. These infections may happen or become more severe if you use LITFULO. Ask your healthcare provider if you do not know if you have lived in an area where these infections are common.
• think you have an infection or have symptoms of an infection such as:
  • fever, sweating, or chills
  • muscle aches
  • cough or shortness of breath
  • blood in your phlegm
  • weight loss
  • warm, red, or painful skin or sores on your body
  • diarrhea or stomach pain
  • burning when you urinate or urinating more often than usual
  • feeling very tired

After starting LITFULO, call your healthcare provider right away if you have any symptoms of an infection. LITFULO can make you more likely to get infections or make any infections that you have worse. If you get a serious infection, your healthcare provider may stop treatment with LITFULO until your infection is controlled.

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

Increased risk of death

Increased risk of death in people 50 years of age and older who have at least 1 heart disease (cardiovascular) risk factor and are taking a medicine in the class of medicines called Janus kinase (JAK) inhibitors. LITFULO is a kinase inhibitor medicine.

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

Cancer and immune system problems

LITFULO may increase your risk of certain cancers by changing the way your immune system works.

• Lymphoma and other cancers, including skin cancers, can happen in people taking LITFULO.
• People taking a medicine in the class of medicines called JAK inhibitors have a higher risk of certain cancers including lymphoma and lung cancer, especially if you are current or past smoker.
• Follow your healthcare provider's advice about having your skin checked for skin cancer during treatment with LITFULO.

Tell your healthcare provider if you have ever had any type of cancer.

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

Increased risk of major cardiovascular events

Increased risk of major cardiovascular events such as heart attack, stroke, or death in people 50 years of age and older who have at least 1 heart disease (cardiovascular) risk factor and taking a medicine in the class of medicines called JAK inhibitors, especially if you are a current or past smoker.

Get emergency help right away if you have any symptoms of a heart attack or stroke while using LITFULO, including:

• discomfort in the center of your chest that lasts for more than a few minutes, or that goes away and comes back
• severe tightness, pain, pressure, or heaviness in your chest, throat, neck, or jaw
• pain or discomfort in your arms, back, neck, jaw, or stomach
• shortness of breath with or without chest discomfort
• breaking out in a cold sweat
• nausea or vomiting
• feeling lightheaded
• weakness in one part or on one side of your body
• slurred speech

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

Blood clots

Blood clots in the veins of your legs (deep vein thrombosis, DVT), lungs (pulmonary embolism, PE), or eyes can happen in some people taking LITFULO. This may be life-threatening. Blood clots in the veins of the legs (deep vein thrombosis, DVT) and lungs (pulmonary embolism, PE) have happened more often in people who are 50 years of age and older with at least 1 heart disease (cardiovascular) risk factor taking a medicine in the class of medicines called JAK inhibitors.

• Tell your healthcare provider if you have had blood clots in the past.
• Stop taking LITFULO and get medical help right away if you have any signs and symptoms of blood clots during treatment with LITFULO, including:
  • swelling, pain or tenderness in one or both legs
  • sudden, unexplained chest or upper back pain
  • shortness of breath or difficulty breathing
  • changes in vision, especially in one eye only

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

Allergic reactions

Symptoms that may mean you are having an allergic reaction have been seen during treatment with LITFULO. Some of these reactions were serious. Stop taking LITFULO and get emergency medical help right away if you have symptoms of allergic reaction, including:

• hives
• rash
• trouble breathing
• feeling faint or dizzy
• swelling of your lips, tongue, or throat

Do not take LITFULO if you're allergic to ritlecitinib or any of its ingredients.

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

Changes in certain laboratory test results

Your healthcare provider should do blood tests before you start taking LITFULO and during treatment to check for the following:

• low lymphocyte count. Lymphocytes are white blood cells that help the body fight off infections.
• low platelet count. Platelets help form clots and stop or prevent bleeding.
• elevated liver enzymes. Liver enzymes help to tell if your liver is functioning normally. Elevated liver enzymes may indicate that your healthcare provider needs to do additional tests on your liver.
• increased creatine phosphokinase (CPK). Increased CPK levels in the blood are common with LITFULO and can also be severe.

You should not take LITFULO if your lymphocyte counts or platelet counts are too low or your liver tests are too high. Your healthcare provider may stop your LITFULO treatment for a period of time, if needed, because of changes in these blood test results.

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

What are the most common side effects of LITFULO?

The most common side effects of LITFULO include:

• headache
• diarrhea
• acne
• rash
• hives
• inflamed hair pores (folliculitis)
• fever
• eczema
• dizziness
• shingles
• decreased red blood cell counts
• mouth sores, redness and swelling of the lining of your mouth

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects to Pfizer at 1-800-438-1985.

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

What should I tell my healthcare provider before taking LITFULO?

Before taking LITFULO, tell your healthcare provider about all of your medical conditions, including if you:

• See the information in the sections above (under “What’s the most important information I should know about LITFULO?”) to learn more.
• have an infection
• are a current or past smoker
• have had a heart attack, other heart problems, or stroke
• have liver problems
• have low platelet counts or white blood cell counts
• have recently received or are scheduled to receive an immunization (vaccine). People who take LITFULO should not receive live vaccines during treatment or right before starting treatment with LITFULO.
• are pregnant or plan to become pregnant. It is not known if LITFULO will harm your unborn baby.

Females who are able to become pregnant:

• Tell your healthcare provider if you are pregnant or plan to become pregnant during treatment with LITFULO.
• There is a pregnancy registry for people who take LITFULO during pregnancy. Report pregnancies to Pfizer Inc. at 1-877-390-2940.

Females who are breastfeeding or plan to breastfeed:

• It is not known if LITFULO passes into your breast milk. Do not breastfeed during treatment with LITFULO and for 14 hours after your last dose of LITFULO. Talk to your healthcare provider about the best way to feed your baby during treatment with LITFULO.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. LITFULO and other medicines may affect each other causing side effects.

Know the medicines you take. Keep a list of them to show your healthcare provider and pharmacist whenever you get a new medicine.

Do not start LITFULO if you are under 12 years of age or intend to use it for a condition for which it was not prescribed.

These are not all of the possible side effects of LITFULO. Learn more and read the Medication Guide.

Is lab monitoring required before and while taking LITFULO?

Your dermatologist will do blood tests before you start LITFULO and during treatment. They may adjust your treatment plan based on changes in these blood test results.