Percanib 80 Capsule

Indications

Selpercatinib is a targeted cancer medicine used for cancers that carry a specific change in the RET gene. These include non-small cell lung cancer with a RET gene fusion, medullary thyroid cancer with a RET mutation, other thyroid cancers with a RET fusion that need further treatment, and some other advanced solid tumours with a RET fusion. A laboratory test on the tumour or blood must confirm the RET change before treatment. It is prescribed by a cancer specialist.

How It Works

The RET gene makes a protein called a tyrosine kinase, which sends growth signals inside cells. When the gene is fused with another gene or mutated, this protein becomes stuck in the on position and drives the cancer to grow. Selpercatinib selectively blocks the faulty RET kinase, switching off these growth signals and slowing or shrinking the tumour.

Dosage and Administration

The dose is set by the oncologist, mainly according to body weight, and is taken twice a day, about 12 hours apart, exactly as prescribed. The doctor may pause, lower or stop the dose if side effects occur.

• Swallow the capsules or tablets whole with water; do not chew or crush them.
• It can be taken with or without food, but see Interactions for advice about acid-reducing medicines.
• If you vomit or miss a dose, do not take an extra dose; take the next dose at the usual time.

Interactions

• Strong CYP3A blockers such as Itraconazole, Clarithromycin and Ritonavir raise Selpercatinib levels; the dose may need to be reduced.
• Rifampicin, Carbamazepine, Phenytoin and St John's wort lower its levels and should be avoided.
• Acid-reducing medicines affect absorption: with a proton pump inhibitor such as Omeprazole, take Selpercatinib with a meal; take it 2 hours before or 10 hours after an H2 blocker such as Famotidine; separate it from antacids by about 2 hours.
• Medicines that prolong the QT interval on the heart tracing, such as some antiarrhythmics, can add to heart rhythm risks.
• It can raise the levels of medicines broken down by CYP2C8, such as Repaglinide.
• Avoid grapefruit and grapefruit juice.

Contraindications

Do not take Selpercatinib if you are allergic to it or to any ingredient of the product.

Side Effects

Common side effects include dry mouth, diarrhoea, constipation, high blood pressure, tiredness, swelling of the legs or face, rash, headache, nausea, stomach pain and raised liver enzymes on blood tests. It can also cause changes in heart rhythm (QT prolongation), bleeding, slow wound healing, low thyroid hormone levels, low blood counts, and in children, changes in bone growth. Serious allergic reactions and lung inflammation are uncommon.

Get urgent medical help if you have yellowing of the skin or eyes, dark urine or pain on the right side of the tummy, a very severe headache or chest pain, a fast or irregular heartbeat or fainting, any unusual or heavy bleeding, fever with rash, or new trouble breathing.

Pregnancy and Lactation

Selpercatinib can harm an unborn baby. Women who could become pregnant should use effective contraception during treatment and for at least 1 week after the last dose; men with such partners should use contraception for the same period. It may reduce fertility. Do not breastfeed during treatment and for 1 week after the last dose.

Precautions and Warnings

• Liver blood tests are checked every 2 weeks for the first 3 months, then monthly or as directed.
• Blood pressure must be controlled before starting and checked regularly.
• An ECG and blood salts (potassium, magnesium, calcium) are checked to monitor heart rhythm.
• Stop the medicine at least 7 days before planned surgery and restart only when the wound has healed, as advised.
• Thyroid function is checked during treatment.

Overdose

If too much has been taken, contact a doctor or go to hospital straight away and take the pack with you. There is no specific antidote; treatment is supportive with heart rhythm monitoring.

Therapeutic Class

Antineoplastic agent, selective RET kinase inhibitor.

Storage

Store below 30°C in a dry place, in the original pack, away from light and out of the reach of children.