Age drives retreatment in patients treated with teprotumumab

Repeat treatment is not uncommon among patients who received a full course of teprotumumab therapy for thyroid eye disease (TED), and the sole predictor of retreatment is age. 

A multicentre retrospective study included 119 patients from three centres across the US to determine the rate of retreatment in this population following a full course of teprotumumab therapy. Charts were evaluated for information regarding age, sex, months since diagnosis of TED, smoking status, and prior treatments. 

In addition, the researchers reviewed the clinical activity score (CAS), proptosis, and the Gorman diplopia score at baseline, at the end of the first course, and at baseline for the second course in those who received it. They also identified the drivers of repeat treatment using a logistic regression model. 

Overall, the rate of retreatment was 24 percent or 29 out of 119 patients, with no difference noted among the three sites (p=0.6). 

Univariable analyses revealed no difference in proptosis (p=0.07), diplopia score (p=0.4), or TED duration (p=0.4) at baseline between patients who were retreated and those who were not. 

Eighty-two percent of patients in the retreated group exhibited a significant proptosis response (≥2-mm reduction from baseline) following the initial course. In the not retreated group, 68 percent had a clinically significant proptosis response (p=0.16). 

The mean difference between the end of the first treatment and at baseline before the second treatment was 2 for CAS, 2 mm for proptosis, and 1 for diplopia score. 

Of note, the only significant driver of retreatment was age (p<0.05). Specifically, patients who received repeat treatment were 7 years older than those who did not (60 vs 53 years; p<0.05).