NEW YORK – AstraZeneca on Wednesday said the European Commission has approved its PD-1 inhibitor Imfinzi (durvalumab) with the PARP inhibitor Lynparza (olaparib) as a maintenance treatment for patients with primary advanced or recurrent mismatch repair proficient (pMMR) endometrial cancer following first-line treatment with Imfinzi and chemotherapy.
The commission also approved Imfinzi plus chemotherapy followed by Imfinzi alone for patients with mismatch repair deficient (dMMR) disease. The commission's decision in these indications follows a positive opinion issued by the Committee for Medicinal Products for Human Use based on a prespecified exploratory subgroup analysis from the DUO-E Phase III trial.
In that trial, researchers compared first-line treatment with Imfinzi plus platinum-based chemotherapy followed by Imfinzi monotherapy or Imfinzi plus Lynparza to chemotherapy alone followed by placebo in patients with newly diagnosed advanced or recurrent endometrial cancer.
Patients in the Imfinzi maintenance arm and the Imfinzi plus Lynparza arm had statistically significant improvements in progression-free survival, compared to the control arm. In the exploratory analysis, patients with dMMR disease had comparable benefits in progression-free survival when treated with Imfinzi alone or Lynparza plus Imfinzi as maintenance therapy. However, those with pMMR disease in the Imfinzi plus Lynparza group lived longer without recurrence or death, at a hazard ratio of 0.57, compared to 0.77 for those who received only Imfinzi as maintenance therapy.
Patients with advanced endometrial cancer have a poor prognosis with five-year survival rates around 20 percent. Patients with pMMR disease represent around 70 percent to 80 percent of patients with endometrial cancer and have thus far had few available treatment options.
"This approval of Imfinzi and Lynparza regimens marks the first-ever approval for a combination of an immunotherapy and PARP inhibitor in endometrial cancer and a major step forward for patients," Dave Fredrickson, executive VP of AstraZeneca's oncology business unit, said in a statement.
The US Food and Drug Administration approved Imfinzi plus chemo followed by single-agent Imfinzi as a treatment for patients with dMMR advanced or recurrent endometrial cancer in June.