As part of its single technology appraisal process, the UK National Institute for Health and Care Excellence (NICE) invited the manufacturer of obinutuzumab (Roche) to submit evidence on its clinical and cost effectiveness when used in combination with bendamustine in patients with follicular lymphoma (FL) refractory to rituximab. The Evidence Review Group (ERG), the School of Health and Related Research Technology Appraisal Group at the University of Sheffield, produced a document summarising the key points from the company submission alongside a critical review. Efficacy for progression-free survival (PFS) and safety was positively demonstrated in the pivotal GADOLIN trial, which compared obinutuzumab in combination with bendamustine followed by obinutuzumab maintenance (O-Benda+O) against bendamustine monotherapy. Data on overall survival were immature. The company submitted a model-based economic analysis, including a patient access scheme. The ERG identified a number of limitations, in particular the absence of subgroup analysis and the approach used by the company to estimate overall survival (OS), which was more favourable to the intervention arm. The key uncertainty was the duration of the treatment effect on OS. This uncertainty is expected to be reduced when the final analysis of the GADOLIN trial is reported. Consequently, the NICE appraisal committee recommended O-Benda+O in the population covered by the marketing authorisation within the Cancer Drug Fund until NICE is able to review the guidance following publication of the final analysis of GADOLIN.