My husband has been treated for bullous pempigoid for 7 weeks. He was diagnosed with a biopsy. I’m assuming the diagnosis was correct. His dr didn’t want to give steroids so they put him on Dupixent. Well, here we are 7 weeks later and it got worse so they put him on 40 mg of pretisone a day. A steroid. Been on it for 4 weeks with the Dupixent. No change. Meanwhile this medication costs $800.00 a month. Very discouraging. I would stay away from this medication. I wish I had an answer. So sorry.