AstraZeneca and MedImmune, its global biologics research and development arm, announced high-level results from the phase III ARCTIC trial in patients with locally-advanced or metastatic non-small cell lung cancer (NSCLC) who have received at least two prior treatments. This randomised, open-label, multi-centre trial assessed the efficacy and safety of the combination of Imfinzi (durvalumab) plus tremelimumab, as well as Imfinzi and tremelimumab monotherapies, versus standard-of-care chemotherapy (SoC) in patients with PDL1-low/negative NSCLC (sub-study B), and Imfinzi monotherapy versus SoC in patients with PDL1-high NSCLC (sub-study A).
In sub-study B, the combination of Imfinzi plus tremelimumab in patients with PD-L1 low/negative NSCLC did not meet the primary endpoints of a statistically-significant and clinically-meaningful improvement in progression-free survival (PFS) and overall survival (OS) compared to SoC. Activity and safety of monotherapy arms of sub-study B were consistent with prior published data.
Sub-study A was not powered for statistical significance; however, Imfinzi monotherapy showed a clinically-meaningful reduction in the risk of death compared to chemotherapy.
Full data from the ARCTIC trial will be presented at a forthcoming medical meeting.
Sean Bohen, executive vice president, global medicines development and chief medical officer, said: “While we are disappointed that the combination of Imfinzi plus tremelimumab did not result in a statistically-significant survival benefit in this heavily pre-treated patient population, we are encouraged by the activity of Imfinzi monotherapy observed in this trial and look forward to presenting the full data from the ARCTIC trial at an upcoming medical meeting.”
AstraZeneca recently received approval from the US FDA for Imfinzi for the treatment of patients with unresectable, Stage III NSCLC whose disease has not progressed following concurrent platinum-based chemotherapy and radiation therapy.
The ARCTIC trial was a randomised, open-label, multi-centre, global Phase III trial containing two sub-studies: sub-study A (1:1 randomisation of patients with PDL1-high tumours to Imfinzi (durvalumab) vs. SoC) and sub-study B (2:3:1:2 randomisation of patients with PDL1-low/negative tumours to Imfinzi monotherapy, Imfinzi plus tremelimumab or tremelimumab vs SoC). Tumour PD-L1 expression was assessed with the Ventana PD-L1 (SP263) assay with PD-L1 high defined as =25% of tumour cells with membrane staining.
Imfinzi is a human monoclonal antibody that binds to PD-L1 and blocks the interaction of PD-L1 with PD-1 and CD80, countering the tumour's immune-evading tactics and releasing the inhibition of immune responses.
In February 2018, Imfinzi received US FDA approval for the treatment of patients with unresectable, Stage III NSCLC whose disease has not progressed following concurrent platinum-based chemotherapy and radiation therapy. Imfinzi also received accelerated approval in the US for the treatment of patients with locally-advanced or metastatic urothelial carcinoma, who have disease progression during or following platinum-containing chemotherapy, or whose disease has progressed within 12 months of receiving platinum-containing chemotherapy before (neoadjuvant) or after (adjuvant) surgery.
As part of a broad development programme, Imfinzi is also being tested as a monotherapy and in combination with tremelimumab, an anti-CTLA-4 monoclonal antibody and potential new medicine, as a first-line treatment for patients with NSCLC, small cell lung cancer, locally-advanced or metastatic urothelial carcinoma, head and neck cancer and other solid tumours.
Tremelimumab is a human monoclonal antibody and potential new medicines that targets the activity of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Tremelimumab blocks the activity of CTLA-4, contributing to T cell activation and boosting the immune response to cancer. Tremelimumab is being tested in an extensive clinical-trial programme in combination with Imfinzi in NSCLC, locally-advanced or metastatic urothelial carcinoma, head and neck cancer, liver cancer and blood cancers.
Lung cancer is the leading cause of cancer death among both men and women, accounting for about one-third of all cancer deaths and more than breast, prostate and colorectal cancers combined.