by Dr. C.H. Weaver M.D. updated 9/2019
The US Food and Drug Administration (FDA) approved Imfinzi (durvalumab) for the treatment of patients with stage III non-small cell lung cancer (NSCLC) whose cancer is unresectable and has not progressed after chemoradiation based on results from the "Pacific" clinical trial because the addition of Imfinizi to chemoradiation further delayed cancer progression and prolonged survival. (2,3)
About Stage III NSCLC
Stage III NSCLC represents approximately one third of NSCLC’s and was estimated to affect around 100,000 individuals worldwide.(1) About half of these patients have cancers that cannot be removed by surgery. For patients with stage III lung cancer that cannot be removed surgically, the current standard treatment is chemoradiation. Although a small number of patients may be cured with the chemoradiation, the cancer will typically progress. New treatment approaches are needed in order to improved the outcome of these individuals.
Imfinzi is an investigational human monoclonal antibody directed against programmed death ligand-1 (PD-L1). PD-L1 can be expressed by tumors to evade detection by the immune system through binding to PD-1 on cytotoxic T lymphocytes. Imfinzi blocks the PD-L1 interaction with PD-1, countering the tumor’s immune-evading tactics. Imfinzi is being developed, alongside other immunotherapies, to empower the patient’s immune system and attack the cancer. Imfinzi is already FDA approved for certain patients with locally advanced or metastatic bladder cancer.
About PACIFIC Clinical Trial
The PACIFIC clinical evaluated the use of Imfinzi as sequential treatment in patients with locally-advanced, unresectable, stage III NSCLC following treatment with chemotherapy and radiation. All patients were treated with 2 cycles of platinum based chemotherapy and radiation with the goal of making the cancer more sensitive to treatment with immunotherapy.
Patients then received treatment with either a placebo or sequential Imfinzi for up to 12 months if they had not progressed following standard platinum-based chemotherapy concurrent with radiation.(2,3)
The new approval in NSCLC was based on these results from the multicentre PACIFIC trial, in which all of the patients with stage IIIA NSCLC that had non progressive cancer after chemoradiation were treated with either with Imfinzi or a placebo and directly compared. Imfinzi was initially reported to significantly delay the time to cancer progression compared with placebo. Imfinzi treated patients survived on average 16.8 months without cancer progression compared to only 5.6 months for those treated with placebo. Trial results were updated in May 2019; overall 57% of Imfinzi treated patients survived 3 years from treatment compared to 44% of those treated with chemoradiation without Imfinzi. Imfinai reduced the risk of dying from stage IIIA NSCLC by 32%. (3)
- Kantar, other market research based on 2016 patient numbers; Globocan 2012. G7 countries include the US, Japan, Germany, the UK, France, Italy and Canada.
- AstraZeneca news release. (2016.) Retrieved from: https://www.astrazeneca.com/our-company/media-centre/press-releases/2016/Durvalumab-granted-Breakthrough-Therapy-designation-by-US-FDA-for-treatment-of-patients-with-PD-L1-positive-urothelial-bladder-cancer-17022016.html
- Antonia. N Engl J Med. 2018;379:2342