AstraZeneca Canada is having a good week. They have received two Health Canada approvals this week. Earlier this week, we reported on the first approval – an indication extension for Lynparza (olaparib) to treat all forms of platinum-sensitive relapsed ovarian cancer. The most recent approval is for Imfinzi (durvalumab) to treat locally advanced, unresectable non-small cell lung cancer (NSCLC) following platinum-based chemoradiation therapy.
The approval of Imfinzi was fast-tracked under Health Canada’s accelerated approval framework and largely based on the impressive data from the phase 3 PACIFIC trial showing the addition of Imfinzi following chemoradiotherapy added 11.2 months of progressive free survival (PFS) when compared to those receiving placebo.
More specifically, 709 patients with stage 3 NSCLC received chemoradiotherapy. Following that therapy, the patients were randomized to receive Imfinzi (10 mg/Kg intravenously every 2 weeks for up to 12 months; n=473) or placebo (n=236). At the end of the trial, the study found that the median PFS was 16.8 months in the Imfinzi group compared to 5.6 months for the placebo group. Furthermore, the 12-month PFS rates was 55.9% vs 35.3%, and the 18-month PFS rate was 44.2% versus 27.0% (for the Imfinzi group vs placebo group, respectively). The median time to death or distant metastasis was also prolonged in the Imfinzi group compared to the placebo group – 23.2 months vs. 14.6 months.
The most common adverse events in the Imfinzi-treated patients were cough (40%), pneumonitis or radiation pneumonitis (34%), upper respiratory tract infections (26%), and rash (22%).
News of the approval was heralded by many in the oncology field throughout Canada.
Rosalyn Juergens, M.D., Medical Oncologist, Juravinski Cancer Centre in Hamilton, Ontario said, “Health Canada’s approval of Imfinzi heralds a new era in the treatment of stage III, unresectable lung cancer. Despite its often deadly prognosis, we attempt to treat these patients with the intent to cure their disease. We have been long awaiting a new therapeutic option that can offer some hope post-chemoradiation therapy. With Imfinzi, we now have a proven, approved treatment that may significantly improve outcomes for patients within this disease setting.”
Rob El-Maraghi, Medical Oncologist at the Simcoe Muskoka Regional Cancer Centre added, “This approval marks a significant milestone for a great proportion of lung cancer patients who now have an effective treatment option following curative-intent chemoradiation. The progression-free survival rates seen with Imfinzi are unprecedented in their impact in this disease setting where there have been no other beneficial treatments to offer patients in the last two decades.”
Following the approval by Health Canada, the next step will be to get the drug recommended by the pan-Canadian Oncology Drug Review (pCODR) Expert Review Committee to get it into the public formularies. Shem Singh, Executive Director, Lung Cancer Canada said, “Health Canada’s approval of Imfinzi is welcome news for patients living with stage III, unresectable non-small cell lung cancer and gives them a better chance at survival. Health Canada approval is a first step. We call on all stakeholders to work together so that it is publicly funded for all that need it.”
Approximately 28,600 Canadians were diagnosed with lung cancer in 2017 and Stage III, NSCLC accounts for about 35% of all new NSCLC diagnoses. Only a small portion of patients (15%) live more than 5 years.