NANOSNET

Hi, was hoping for feedback on this difficult case. Main question is whether anyone has any experience trying Tepezza for patients with MG/ TED overlap.

66-year-old Caucasian male with onset of diplopia in July 2024, subsequently diagnosed with generalized MG (AChR binding antibody positive 12.60 [0-0.24]).
MG has been treated with Mestinon (pyridostigmine) now on 60 mg TID, Cellcept (mycophenolate) now on 750 mg BID, prednisone now on 5 mg daily, Rystiggo (rozanolixizumab-noli) infusion (recently received final infusion in course)- no improvement, previously received Vyvgart (efgartigimod alfa-fcab)- no improvement, considering Ultomiris (ravulizumab-cwvz) as next step.
No history of thymectomy. Of note, on pravastatin 80 mg.
History of Graves' in remission (per endo), no history of TED. Previously treated with methimazole (off treatment since Feb 2025). TPO positive 68 [0-34], TSI and TRAb normal, currently euthyroid.

I ordered baseline orbital imaging and findings are suggestive of TED. The read of the CT "Proptotic appearing globes and enlargement of the muscle bellies of the extraocular muscles with fatty attenuation and disproportionate involvement of the inferior and medial rectus muscles. Relative sparing of the anterior tendons. Constellation of findings is nonspecific, but compatible with thyroid associated orbitopathy."

Clinically he does not appear proptotic or inflamed. He does have orbital pain and obviously diplopia.

I wonder if, after a washout period since he just finished Rystiggo, whether Tepezza could be considered. I spoke to the medical liason from the drug company this morning and essentially reaffirmed lack of evidence in these types of cases. My main concern would be exacerbating his MG given the possible muscle side effects.

Thanks for your thoughts,

Ola Pietraszkiewicz

I have had a patient that had double vision and positive MG antibodies. Treated with mestinon, steroids and measurements improved some but still symptomatic. I put him in vyvgart and he improved some but still double and it got bigger actually after about 4 rounds of vyvgart . Repeated a scan of the orbit and his muscles were enlarged compared to prior scan. we started him on Tepezza and the double resolved rather quickly. I did not find any issues of Tepezza on the MG and in fact he has gone through 2 rounds of Tepezza due to a flare. We did stop the mg meds about a month before Tepezza started. Good luck with the patient. Let us know how it goes because it will be something seen again. 

Thanks for the feedback. I'm going to see the patient back in a couple weeks for repeat measurements, forced ductions, and Hertel measurements. He really didn't appear proptotic, so I do think that part may be an overcall by radiology. In May 2025 (previous eye exam before seeing me) he had an XT measuring 55. When I saw him 2 weeks ago, he had a RHT of 2 in primary and upgaze, 10 in right gaze and 6 in left gaze. He had a small XT of 2 in primary and down gaze. He doesn't have either ptosis or lid retraction. He does have saccadic/ jerky smooth pursuits. I think his bigger issue is the myasthenia, but I wonder if treatment of TED (albeit chronic) could help him. I'm not convinced, but he is willing to try anything. My main concern is not causing harm. Thanks again and I will keep you posted.