This is a multi-centre retrospective analysis of clinical outcomes in patients who were on teprotumumab for thyroid eye disease but had the usual regime of eight infusions, three weeks apart, interrupted due to COVID-19. Manufacturing was suspended between Dec 2020 and April 2021 to allow for production of the COVID-19 vaccines. The records of 74 incompletely treated patients were analysed to assess clinical findings before treatment, around the time of cessation and before reinitiating therapy. This included 62 active patients, defined as having a clinical activity score of four or more from seven parameters, and 12 minimally-active or inactive patients. Patients were included if they had started, but not completed, a full course of treatment and then had treatment suspended. On average, patients had received 4.2 infusions before interruption. The results showed that 73% of patients had experienced a reduction of proptosis of 2mm or more in the worse eye by the time of cessation, including nine patients in the minimally- or inactive group, with the amount of reduction correlating with the number of infusions. During cessation none of this improvement was lost, and three further patients also experienced proptosis reduction. Amongst the 62 active patients there was a mean reduction in clinical activity score (CAS) of 3.4 points, which was also maintained during cessation of therapy. Of the 62 patients who had pre-treatment diplopia in primary gaze, 11 resolved on treatment, but two relapsed during cessation. There was a significant decrease in extraocular muscle restriction on therapy in active patients, which was not lost during interruption. Interestingly, there were no changes in lid retraction. Side-effects were common, and included muscle cramps, hair loss, hyperglycaemia and hearing changes. This is an interesting study especially as the existing treatment regimen for teprotumumab is based on empiric extrapolation from oncology, rather than formal randomised controlled trials in patients with thyroid eye disease. Long-term data was unavailable, but the study suggests that the temporary interruption was not detrimental.