Table 3.

Quotations from patients with ICI-induced IA representing five themes

Theme	Illustrative quotes
1. Awareness gap and diagnostic delay	It took me by such surprise, I think. You get so many handouts and literature on immunotherapy […] but they didn’t have anything about [arthritis]. Pt 7 (F) In fact, one of the selling points, so to speak, was that, “Oh, immunotherapy doesn’t have any side effects. Pt 9 (M) [The doctor] said, “Oh nobody else has [arthritis]-- I haven’t seen that on anybody else.” Pt 12 (F)
2. Descriptors of ICI-induced IA and relationships to other adverse events	My hands, I couldn’t bend my hands […] [they] were red and inflamed. I couldn’t open up doors, turn a wheel, open a car door. I couldn’t open any kind of bottles. I had trouble picking up anything at all. I never had anything in my life and I still don’t. I have this cancer and they treated me with it. And removed it. And then I was good. I was on [ICI therapy] just about 3 years and then I had to stop it because, oh my God, I went to see my regular doctor so that I could get slips so that I could go for physical therapy because I was losing the use of my hands completely. Pt 12 (W) You kind of think of the arthritis as-- if your elbow and hand doesn’t work you’re like, oh my God, is that going to be like that the rest of my life? Whereas I’m not worried about having diarrhea the rest of my life. You can be treated or whatever. Pt 10 (M) Well, the fatigue and the arthritis are, you know, always present in the background. The colitis, I haven’t had a problem with. Pt 5 (F) My hands were acting up. They probably got severe this year, early in the year […] and then it kept coming like a lion at me. I came down here and then I started the prednisone and the hands started backing off, and then all of a sudden it went from my hands. […] That’s what it is. It was backing away and then it’s fierce. Pt 12 (W)
3. Emotional and quality of life impact in ICI-induced IA	To be told that you have arthritis was odd. [I] wasn’t upset. And I hope that I have a long, a lot longer, time to live. Pt 2 (W) I was pretty devastated because up until that point where the knee pain started, I had made a really big recovery from the beginning of the whole process of being diagnosed and the big surgeries that I had right away. Pt 8 (F) It was just very limiting. Was very frustrating. Because I felt like I was a hundred. I fought for two and a half years to beat cancer and then I can’t do anything. Pt 2 (F) I can live with it until the day that it completely debilitates me for some reason. I’m still here. So that’s all that matters. Pt 10 (M) I found each of those hobbies more difficult to do. I couldn’t hold certain tools, and I’d be dropping screws, and it led to a lot of amount of frustration. I’d have to stop, because I didn’t want to get all frustrated and get all in a sour mood. (Pt 9, M)
4. Fear and decision making	[The doctor] was just trying a lot of different medications and combinations of medications [for the arthritis], and also kind of having to deal with the unknown of how this would affect my melanoma, so [she was] having to be really careful about that and dealing with my fears of how that’s going to affect my melanoma. Pt 8 (F) I would be hard pressed to say that I would have continued as long as I did in the trial if I had known [about the side effects]. The other option, of course, is to be dead, but you know at some point it becomes a toss up. Pt 1 (F) My hope with the immunotherapy was […] that if any little seeds of cancer had spread elsewhere in my body, or remained in my body, that the immunotherapy would knock those out and I’d get a clean start. And at this point if I would have had to reverse the effect of the immunotherapy, I would consider it. Pt 13 (M) And [my oncologist] doesn’t say anything directly [only] makes comments < If you choose to suppress your immune system like that > […] you’d be sitting there thinking, <He doesn’t think I should be doing that>. […] I don’t know what I’m going to do. […] What I don’t want to do is continue down a path where I’m taking a drug [DMARD] that can give me cancer that no one can tell me if it’s going to work or not. Pt 11 (M)
5. Contextual factors including social support	Other people would say, “Well, compared to being dead from cancer, having arthritis, this isn’t that bad.” But in retrospect, it’s easy to say, when you don’t have it. Pt 9 (M) During the immunotherapy phase I was getting my strength back and […] my family especially were very excited […], and plus them being so far away they weren’t really seeing me. I’d have a friend take a picture of me but only when I felt like I was looking better < laughs > and so they were all very optimistic about it, concerned but optimistic at that point, whereas before they were very concerned. And during the arthritis part, I don’t even think they were aware of that. Pt 13 (M)