Soak and smear: “I’m obsessed” with this technique of a 20-minute soak in plain water followed by application of steroid ointment, said Dr. Allais, referring to a small study published in 2005 that reported a complete response after 2 weeks in 60% of patients with psoriasis, atopic dermatitis, and other inflammatory skin conditions (none had cancer), who had failed prior systemic therapy. All patients had at least a 75% response.
The method offers a way to “avoid the systemic immunosuppression we’d get with prednisone,” she said. One just needs to make sure the older patient can get in and out of their tub safely.
ICI-induced bullous pemphigoid (BP): BP occurs more frequently in the ICI setting, compared with the general population, with a median time to development of 8.5 months after ICI initiation. It is associated in this setting with improved tumor response, but “many oncologists stop anticancer treatment because of this diagnosis,” she said.
In the supportive oncodermatology space, however, ICI-induced BP exemplifies the value of tailored treatment regimens, she said. A small multi-institutional retrospective cohort study published in 2023 identified 35 cases of ICI-BP among 5636 ICI-treated patients and found that 8 out of 11 patients who received biologic therapy (rituximab, omalizumab, or dupilumab) had a complete response to ICI-BP without flares following subsequent ICI cycles. And while statistical significance was not reached, the study showed that no cancer-related outcomes were worsened.
“If you see someone with ICI-induced BP and they have a lot of involvement, you could start them on steroids and get that steroid-sparing agent initiated for approval. ... And if IgE is elevated, you might reach for omalizumab,” said Dr. Allais, noting that her favored treatment overall is dupilumab.
Risk factors for the development of ICI-induced BP include age > 70, skin cancer, and having an initial response to ICI on first imaging, the latter of which “I find fascinating ... because imaging occurs within the first 12 weeks of treatment, but we don’t see BP popping up until 8.5 months into treatment,” she noted. “So maybe there’s a baseline risk factor that could predispose them.”
Caution with antibiotics: “I try to avoid antibiotics in the ICI setting,” Dr. Allais said, in deference to the “ever-important microbiome.” Studies have demonstrated that the microbiomes of responders to ICI treatment are different from those of nonresponders, she said.
And a “fascinating” study of patients with melanoma undergoing ICI therapy showed not only a higher abundance of Ruminococcaceae bacteria in responders vs nonresponders but a significant impact of dietary fiber. High dietary fiber was associated with significantly improved overall survival in the patients on ICI, with the most pronounced benefit in patients with good fiber intake and no probiotic use. “Even wilder, their T cells changed,” she said. “They had a high expression of genes related to T-cell activation ... so more tumor-infiltrating lymphocytes.”
A retrospective study of 568 patients with stages III and IV melanoma treated with ICI showed that those exposed to antibiotics prior to ICI had significantly worse overall survival than those not exposed to antibiotics. “Think before you give them,” Dr. Allais said. “And try to tell your older patients to eat beans and greens.”
Dr. Allais reported having no relevant disclosures.
A version of this article first appeared on Medscape.com.