• Keep this leaflet. You may need to read it again.
• If you have any further questions, ask your doctor, pharmacist or nurse.
• This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.
• If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. See section 4.
• This leaflet has been written as though the person taking the medicine is reading it. If you are giving this medicine to your child, please replace “you” with “your child” throughout.

1. What Retsevmo is and what it is used for
2. What you need to know before you take Retsevmo
3. How to take Retsevmo
4. Possible side effects
5. How to store Retsevmo
6. Contents of the pack and other information

In patients whose cancer has an altered RET gene, the change in the gene causes the body to make an abnormal RET protein, which can lead to uncontrolled cell growth and cancer. Retsevmo blocks the action of the abnormal RET protein and so may slow or stop the growth of the cancer. It may also help to shrink the cancer.

If you have any questions about how Retsevmo works or why this medicine has been prescribed for you, ask your doctor.

• if you are allergic to selpercatinib or any of the other ingredients of this medicine (listed in section 6).

Talk to your doctor before taking Retsevmo:

• If you have lung or breathing problems other than lung cancer.
• If you have high blood pressure.
• If you have been told that you have an abnormality of your heart tracing after an electrocardiogram (ECG) known as prolonged QT interval.
• If you have problems with your thyroid or levels of thyroid hormone.
• Retsevmo may affect fertility in females and males, which may affect your ability to have children. Talk to your doctor if this is a concern for you.
• If you have a recent history of significant bleeding.

Retsevmo may cause hypersensitivity reactions such as fever, rash and pain. If you experience any of these reactions, talk to your doctor. After checking your symptoms, your doctor may ask you to take corticosteroids until your symptoms are better.

A fast breakdown of cancer cells (tumour lysis syndrome, TLS) can occur when you are taking Retsevmo. This can cause irregular heartbeat, kidney failure or abnormal blood test results. Talk to your doctor if you have a history of kidney problems or low blood pressure, because this may increase the risks associated with TLS.

Retsevmo may cause irregular hip joint growth or damage in paediatric patients (<18 years of age). If you experience pain in the hip or knee or have an unexplained limp, talk to your doctor.

See section 4, “Possible side effects”, and talk to your doctor if you have any symptoms.

• Retsevmo may cause severe, life-threatening, or fatal inflammation of the lungs. Your doctor will monitor you before and during treatment with Retsevmo for symptoms. Tell your doctor right away if you notice any symptoms of lung problems including breathlessness, cough and raised temperature.
• Retsevmo may affect your blood pressure. You will have your blood pressure measured before and during treatment with Retsevmo.
• Retsevmo may affect the way your liver works. Tell your doctor right away if you develop symptoms of liver problems including: jaundice (yellow discoloration of the skin and eyes), loss of appetite, nausea or vomiting, or pain on the upper right side of your stomach area.
• Retsevmo may result in abnormal ECGs. You will have an ECG taken before and during your treatment with Retsevmo. Tell your doctor if you experience fainting as it may be a symptom of abnormal ECG.
• Retsevmo may affect how your thyroid works. Your doctor will monitor your thyroid function before and during treatment with Retsevmo.
• You will have regular blood tests before and during treatment with Retsevmo, to check your liver function and electrolytes (such as sodium, potassium, magnesium and calcium) in your blood.
• If you are under 18 years of age, your doctor may monitor your growth during treatment. If you have hip, knee, or other leg pain let your doctor know.

Retsevmo is not intended for use in patients less than 18 years of age in lung or thyroid cancer other than medullary thyroid cancer.

The medullary thyroid cancer indication does not cover children younger than 12 years of age.

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.

In particular, tell your doctor or pharmacist before taking Retsevmo if you are taking the following:

• medicines that may increase the concentration of Retsevmo in the blood:
  • Clarithromycin (used to treat bacterial infections)
  • Itraconazole, ketoconazole, posaconazole, voriconazole (used to treat fungal infections)
  • Atazanavir, ritonavir, cobicistat (used to treat HIV infections/AIDS)
• medicines that may reduce the effectiveness of Retsevmo:
  • Carbamazepine (used to treat epilepsy, nerve pain, bipolar disorder)
  • Rifampicin (used to treat tuberculosis (TB) and some other infections)
  • St. John’s wort (a herbal product used to treat mild depression and anxiety)
  • Omeprazole, lansoprazole, or other proton pump inhibitors used to treat heartburn, ulcers, and acid reflux. If you are taking any of these medicines, then take Retsevmo with a full meal
  • Ranitidine, famotidine or other H2 blockers used to treat ulcers and acid reflux. If you are taking any of these medicines, then you need to take them 2 hours after taking Retsevmo
• medicines whose concentration in the blood might be increased by Retsevmo:
  • Repaglinide (used to treat type 2 diabetes and control blood sugar)
  • Dasabuvir (used to treat hepatitis C)
  • Selexipag (used to treat pulmonary arterial hypertension)
  • Digoxin (used to treat heart disorders)
  • Lovastatin and simvastatin (used to treat high cholesterol)
  • Dabigatran (used to prevent and treat blood clots)
• medicines that may be less effective when taken with Retsevmo:
  • Levothyroxine (used to treat hypothyroidism)

Pregnancy

If you are pregnant, think you may be pregnant or are planning to have a baby, ask your doctor before taking this medicine.

You should not use Retsevmo during pregnancy, since the effect of Retsevmo on the unborn is not known.

Breast-feeding

Do not breast-feed during treatment with Retsevmo as Retsevmo could harm a breast-fed baby. It is not known if Retsevmo passes into breast milk. You should not breast-feed for at least one week after your last dose of Retsevmo.

Contraception

It is recommended that women avoid becoming pregnant and that men do not father children during treatment with Retsevmo, because this medicine could harm the baby. If there is any possibility that the person taking this medicine may become pregnant or father a child, they must use adequate contraception during treatment and for at least one week after the last dose of Retsevmo.

Fertility

Retsevmo can affect your ability to have children. Talk to your doctor to seek advice about fertility preservation prior to treatment.

You should take special care when driving and using machines as you may feel tired or dizzy while taking Retsevmo.

Your doctor will prescribe the right dose for you. The maximum recommended dose is as follows:

• Less than 50 kg body weight: 120 mg twice daily.
• 50 kg body weight or greater: 160 mg twice daily.

Retsevmo is taken twice a day at about the same time every day, preferably in the morning and evening.

If you get certain side effects while you are taking Retsevmo your doctor may lower your dose or stop treatment temporarily or permanently.

You can take the capsules either with or without food. Swallow the capsule whole with a glass of water. Do not chew, crush or split the capsule before swallowing.

Retsevmo is available in blister packs and in bottles. The bottle is protected by a plastic screw cap:

To open the bottle, push down the plastic screw cap while turning it anticlockwise as shown in the picture.

To close the bottle, turn the cap clockwise tightly.

If you take too many capsules, or if someone else takes your medicine, contact a doctor or hospital for advice. Medical treatment may be necessary.

If you vomit after taking the dose or forget a dose, take your next dose at your usual time. Do not take a double dose to make up for the forgotten or vomited dose.

Do not stop taking Retsevmo unless your doctor tells you to.

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme, website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects, you can help provide more information on the safety of this medicine.

The active substance is selpercatinib. Each hard capsule contains 40 or 80 mg selpercatinib.

The other ingredients are:

• Capsule content: colloidal anhydrous silica, microcrystalline cellulose
• Capsule shell 40 mg: gelatin, titanium dioxide (E171), and iron oxide (E172).
• Capsule shell 80 mg: gelatin, titanium dioxide (E171), and brilliant blue FCF (E133).
• Black ink: Shellac, Ethanol (96 per cent), Isopropyl alcohol, Butanol, Propylene glycol, Water, purified, Ammonia solution (concentrated), Potassium hydroxide, Iron oxide black

Retsevmo 40 mg is supplied as grey opaque hard gelatin capsule, with black “Lilly”, “3977” and “40 mg” script.

Retsevmo 80 mg is supplied as blue opaque hard gelatin capsule, with black “Lilly”, “2980” and “80 mg” script.

Retsevmo is available in a white opaque bottle with a plastic screw cap, containing 60 hard capsules of 40 mg and either 60 or 120 hard capsules of 80 mg. Each carton contains one bottle.

Retsevmo is available in blister packs of 14, 42, 56 or 168 hard capsules of 40 mg and 14, 28, 56 or 112 hard capsules of 80 mg.

Not all the pack sizes may be marketed.