Zynlonta

Zynlonta can only be obtained with a prescription and treatment should be started and supervised by a doctor with experience in using cancer medicines.

Zynlonta is given as an infusion (drip) into a vein over 30 minutes every 3 weeks. Treatment can continue for as long as the patient benefits from it and does not have intolerable side effects. The dose depends on the patient’s body weight. If certain side effects develop, the doctor may decide to reduce the dose or to interrupt or stop treatment with Zynlonta.

Before starting treatment, patients should be given dexamethasone (an anti-inflammatory medicine) to help reduce possible side effects of treatment.

For more information about using Zynlonta, see the package leaflet or contact your doctor or pharmacist.

In patients with B-cell lymphoma, B-cells (a type of white blood cell) have become cancerous. The active substance of Zynlonta, loncastuximab tesirine, is made up of a monoclonal antibody (a type of protein) combined with a cytotoxin (a substance that kills cells) called SG3199. The monoclonal antibody attaches to a protein called CD19 on the B-cells, including cancerous B-cells, and the medicine enters these cells. When Zynlonta is inside the B-cells, SG3199 is released and kills them.

The effect of Zynlonta was investigated in a main study with 145 patients with relapsed or refractory B-cell lymphoma. In this study, Zynlonta was not compared with any other treatment for B-cell lymphoma. The study showed that 48.3% (70 out of 145) of the patients responded to treatment with Zynlonta, with about 25% (36 out of 145) of them showing no sign of cancer (complete response).

The most common side effects with Zynlonta (which may affect more than 1 in 5 people) are increased levels of gamma glutamyltransferase (GGT, a liver enzyme), neutropenia (low levels of neutrophils, a type of white blood cell), tiredness, anaemia (low levels of red blood cells), thrombocytopenia (low levels of blood platelets), nausea (feeling sick), peripheral oedema (swelling due to fluid retention, especially of the ankles and feet) and rash.

The most common serious adverse reaction (which may affect up to 1 in 20 people) are febrile neutropenia (low levels of white blood cells with fever), abdominal pain, dyspnoea (difficulty breathing), pleural effusion (fluid around the lungs) and lung infection.

For the full list of side effects of Zynlonta, see the package leaflet.

The prognosis for patients with relapsed or refractory B-cell lymphoma is extremely poor. At the time of approval of Zynlonta, the available treatment options for these patients were limited and not satisfactory.

Although more data are needed to confirm the results of the main study, the European Medicines Agency considered that Zynlonta showed a clinically meaningful favourable effect and met an unmet medical need. Overall, the safety of Zynlonta is similar to other B-cell lymphoma medicines of the same type and seems generally manageable.

Zynlonta has therefore been given ‘conditional authorisation’. This means that that the European Medicines Agency decided that the benefits of Zynlonta are greater than its risks, but the company will have to provide additional evidence after authorisation.

Conditional authorisation is granted on the basis of less comprehensive data than are normally required. It is granted for medicines that fulfil an unmet medical need to treat serious diseases and when the benefits of having them available earlier outweigh any risks associated with using the medicines while waiting for further evidence. Every year, the Agency will review any new information that becomes available until data become comprehensive and this overview will be updated as necessary.

Since Zynlonta has been given conditional authorisation, the company that markets Zynlonta will provide further data on its long-term safety and on its safety and effectiveness in patients with B-cell lymphoma when used in combination with another cancer medicine.

The company that markets Zynlonta will ensure that healthcare professionals receive patient alert cards to give to patients. The patient alert card contains important safety information on the increased risk of photosensitivity reactions, signs and symptoms of such reactions, and instructions on how to avoid exposure to direct and indirect sunlight when using Zynlonta. Patients are advised to contact a healthcare professional if they have photosensitivity reactions.

Recommendations and precautions to be followed by healthcare professionals and patients for the safe and effective use of Zynlonta have also been included in the summary of product characteristics and the package leaflet.

As for all medicines, data on the use of Zynlonta are continuously monitored. Suspected side effects reported with Zynlonta are carefully evaluated and any necessary action taken to protect patients.

Zynlonta received a conditional marketing authorisation valid throughout the EU on 20 December 2022.