These latest results show a durable and sustained OS benefit in patients with unresectable, Stage III NSCLC who had not progressed following concurrent chemoradiation therapy (CRT), a previous standard-of-care (SoC) treatment. The OS rate was 57% at three years for patients receiving Imfinzi vs. 43.5% for placebo following concurrent CRT. Median OS was not yet reached with the Imfinzi arm vs. 29.1 months for placebo.
Dave Fredrickson, Executive Vice President, Oncology Business Unit said: “These findings for Imfinzi are another example of our focus on bringing long-term survival benefits to patients who still have a chance of being cured. These three-year survival results further establish the PACIFIC regimen as the standard of care for these patients, and we are optimistic this survival trend will continue as we move towards the five-year landmark in this curative-intent setting.”
Results build on the primary two-year OS analysis that was published in The New England Journal of Medicine in September 2018 and demonstrated a significant OS benefit for treatment with Imfinzi vs. placebo after CRT, regardless of PD-L1 expression. The primary analysis showed Imfinzi reduced the risk of death by 32% (HR 0.68, [99.73% CI, 0.47-0.997], p=0.0025).
With the additional year of follow up, the latest results for Imfinzi showed consistent and durable efficacy, maintaining a 31% reduction in the risk of death vs. placebo after CRT (HR 0.69, [95% CI 0.55-0.86]).
Jhanelle Gray, MD, Director of Clinical Research in the Thoracic Oncology Department at Moffitt Cancer Center in Tampa, Florida, and an investigator in the PACIFIC trial, said: “In the past, patients with unresectable, Stage III non-small cell lung cancer faced five-year survival rates of only 15% to 30%. It is remarkable to see that more than half of patients treated with the PACIFIC regimen remain alive at three years, an important milestone that raises the bar for treatments in this curative-intent setting.”
The safety and tolerability profile for Imfinzi was consistent with the results reported at the time of the previous OS analysis. Among patients receiving Imfinzi, the most common adverse events (AE) (greater than or equal to 20% of patients) vs. placebo were cough (35.2% vs. 25.2%), fatigue (24.0% vs. 20.5%), dyspnoea (22.3% vs. 23.9%) and radiation pneumonitis (20.2% vs. 15.8%). 30.5% of patients experienced a grade 3 or 4 AE with Imfinzi vs. 26.1% with placebo, and 15.4% of patients discontinued treatment due to AEs with Imfinzi vs. 9.8% of patients on placebo.
AstraZeneca has several ongoing trials focused on testing Imfinzi in earlier stages of NSCLC (Stages I-III) in potentially-curative settings. The Phase III PACIFIC-2 trial design, presented today at the ASCO Annual Meeting, is evaluating Imfinzi given concurrently with CRT in patients with unresectable, Stage III NSCLC. In the Phase II PACIFIC-6 trial, Imfinzi is being tested in the same population following sequential chemotherapy and radiation therapy.
Additional trials assess Imfinzi in the neoadjuvant setting (prior to other treatments) in Stage II and III NSCLC patients (AEGEAN) and in the adjuvant setting (following the primary treatment) in Stage I to III (BR.31). The Phase III PACIFIC-4 trial is testing Imfinzi in unresected Stage I and II NSCLC patients following definitive stereotactic body radiation therapy (SBRT).
AstraZeneca is also testing novel combinations with Imfinzi in two Phase II platform trials in both unresectable, Stage III disease (COAST) and in resectable Stage I-III disease starting before surgery (NeoCOAST), to help find solutions for NSCLC patients not benefiting from currently-available therapies.
Imfinzi is approved for the treatment of unresectable, Stage III non-small cell lung cancer in more than 45 countries, including the US, EU and Japan, based on the Phase III PACIFIC trial. Since the first approval in February 2018, more than 20,000 patients in this setting have been treated with Imfinzi.
Source: Company Press Release