An Open Label Study Followed by a Randomised, Double-blind, Placebo-controlled, Parallel Group and an Extension Study to Investigate the Safety and Efficacy of GB1211 (a Galectin-3 Inhibitor) in Combination With Atezolizumab in Patients With Non-Small Cell Lung Cancer (NSCLC).

The study will be carried out in three parts: The core study is comprised of part A (dose finding and safety) and part B (efficacy and safety). Part C is an extension phase of the core study to collect long-term safety data.

In part A of the study, open-label sentinel dosing will be undertaken to assess safety and tolerability of GB1211 at 200 mg BID and 100 mg BID in combination with atezolizumab including 4 patients in each dose cohort. Patients enrolled in part A may continue treatment with 200 mg GB1211 BID or 100 mg GB1211 BID and atezolizumab for 12 weeks, after which the patients will be offered treatment in the part C study, if they have achieved clinical benefit as best response during the first 12 weeks of treatment (SD or better response according to RECIST 1.1).

In part B of the study, patients will randomised (1:1) for blinded treatment to receive either GB1211 (200 or 100 mg BID to be selected from part A) or placebo, in addition to atezolizumab, for 12 weeks, after which the patients will be offered treatment in part C, if they have achieved clinical benefit as best response during the first 12 weeks of treatment (SD or better response according to RECIST 1.1).

In part C, this treatment will be blinded until part B has been unblinded. After unblinding, patients will continue to receive the same treatment they had received in part B: GB1211 and atezolizumab or atezolizumab only (no placebo) if they experience continued benefit from treatment. The patients will be treated until disease progression or unacceptable toxicity.

After the end of the study treatment all patients will be followed 4 weeks for safety, regardless of the study part in which the last study treatment was given.