In one main study of 713 patients with locally advanced NSCLC, patients given Imfinzi lived on average for around 17 months without their disease getting worse, compared with 6 months for those given placebo (a dummy treatment). Preliminary results also indicated that patients given Imfinzi lived longer overall compared with patients on placebo.

In another main study of patients with metastatic NSCLC, 338 patients given Imfinzi in combination with tremelimumab and chemotherapy lived on average for 14 months, compared with 12 months for 337 patients given only chemotherapy. They also lived longer without their disease getting worse: around 6 months on average, compared with 5 months for patients who only received chemotherapy.

In a main study of 805 patients with extensive-stage SCLC, patients given Imfinzi together with chemotherapy lived on average for 13 months compared with 10 months for those given chemotherapy alone.

In another main study, Imfinzi was compared with placebo in 730 patients with limited-stage SCLC whose disease had not progressed following platinum-based chemoradiation therapy. Patients given Imfinzi lived for 55.9 months on average, compared with 33.4 months on average for those given placebo. They also lived longer without their disease getting worse: around 16.6 months on average, compared with 9.2 months on average for patients given placebo.

In a study with 685 patients with advanced biliary tract cancer, patients who received Imfinzi plus gemcitabine and cisplatin lived on average for 12.8 months, compared with 11.5 for those who received placebo plus gemcitabine and cisplatin.

In a main study involving patients with advanced hepatocellular cancer who had not been treated before, Imfinzi given on its own and in combination with tremelimumab increased the time patients lived overall compared with standard treatment (sorafenib). Patients who received either Imfinzi on its own (389 patients) or together with tremelimumab (393 patients) lived for an average of 16.6 months and 16.4 months, respectively, compared with an average of 13.8 months for those who received sorafenib (389 patients).

In about 17% of patients who received Imfinzi on its own, the tumour shrank or disappeared; this response lasted for about 17 months on average. While in about 20% of patients who received Imfinzi with tremelimumab, the tumour shrank or disappeared, with the response lasting about 22 months on average. About 5% of patients who received sorafenib had a response to treatment and their response lasted on average 18 months.

A main study consisting of two parts involved 718 patients with advanced or recurrent endometrial cancer who had not been treated before.

In the first part of the study, lasting 6 treatment cycles (18 weeks), two groups of patients were given standard treatment (carboplatin and paclitaxel) plus Imfinzi, and a third group was given standard treatment and placebo. In the second part of the study, patients whose disease had not worsened since starting treatment were included for maintenance treatment. The two groups of patients who received standard treatment plus Imfinzi in the first part of the study were given either Imfinzi in combination with olaparib or Imfinzi with a placebo; the group of patients given standard treatment and placebo continued on placebo only.

Patients given standard treatment plus Imfinzi in the first part and Imfinzi and placebo during maintenance treatment lived, on average, for 10.2 months before their disease got worse. In patients starting on standard treatment plus Imfinzi and continuing on Imfinzi and olaparib maintenance therapy this was 15.1 months. Patients given standard treatment with placebo in the first part of the study and placebo during maintenance lived, on average, for 9.6 months before they their disease got worse. Supportive analyses showed a benefit of maintenance therapy with Imfinzi and placebo or Imfinzi with olaparib in patients whose cancer was MMR deficient (dMMR). In patients whose cancer was MMR proficient (pMMR), a benefit was seen with Imfinzi plus olaparib but not with Imfinzi and placebo.

For the full list of side effects and restrictions with Imfinzi, see the package leaflet.

When Imfinzi is given alone, the most common side effects (which may affect more than 1 in 10 people) include cough, diarrhoea, rash, joint pain, fever, abdominal (belly) pain, nose and throat infections, itching and hypothyroidism (an underactive thyroid gland).

When Imfinzi is given together with chemotherapy, the most common side effects (which may affect more than 1 in 10 people) include neutropenia (low levels of neutrophils, which fight infections), anaemia (low levels of red blood cells), tiredness, nausea (feeling sick), thrombocytopenia (low levels of platelets in the blood), hair loss, constipation, decreased appetite, peripheral neuropathy (nerve damage in arms and legs), abdominal pain, diarrhoea, rash, vomiting, leucopenia (low levels of white blood cells),fever, joint pain, cough, itching, hypothyroidism, increased level of liver enzymes and peripheral oedema (swelling, especially of the ankles and feet).

When Imfinzi is given with tremelimumab and chemotherapy for non-small cell lung cancer, the most common side effects (which may affect more than 1 in 5 people) include anaemia, nausea, neutropenia (low levels of neutrophils, a type of white blood cell that fights infection), tiredness, rash, thrombocytopenia and diarrhoea.

When Imfinzi is given with tremelimumab for hepatocellular cancer, the most common side effects (which may affect more than 1 in 10 people) include rash, itching, diarrhoea, abdominal pain, increased levels of liver enzymes, fever, hypothyroidism, cough, and peripheral oedema (swelling especially of the ankles and feet); increased levels of lipase may affect up to 1 in 10 people.

When Imfinzi is given together with chemotherapy and followed by Imfinzi with olaparib, the most common side effects (which may affect more than 1 in 5 people) include anaemia, nausea, tiredness, peripheral neuropathy, hair loss, neutropenia, constipation, thrombocytopenia, diarrhoea, vomiting, joint pain, rash, abdominal pain, decreased appetite and leucopenia.