An early warning system
The most common reactions were colitis, pneumonitis, and rash.
The reactions were often tough to manage, the authors reported. Eighty patients (68%) required steroids, and 27 (23%) required steroids plus additional immunosuppressives, such as tumor necrosis factor blockers, particularly for colitis and renal, rheumatologic, and neurologic complications. Rheumatologic events required a median corticosteroid course of 15 months plus additional immunosuppression in half of cases and often left patients with ongoing morbidity.
“Often, the skin is one of the first and most easily visible immune-related adverse event that develops,” said Bernice Kwong, MD, director of the supportive dermato-oncology program at Stanford (Calif.) University, who was not involved in the study and was approached for comment.
Presentations can range from small itchy plaques to total body dermatitis. It is something to be aware of, because the skin can act as an early warning system to catch internal organ damage earlier, she said.
On a positive note, the investigators found no indication that the effect of immunotherapy was diminished by delayed reactions and their treatment.
Managing events “gets a little complicated” when anti-PD-1 drugs are still being administered, but “we have successfully utilized systemic steroid pulses for several weeks without impeding the efficacy of the therapy. For the lichenoid and psoriasiform dermatitis, topical steroids and oral retinoids have been useful and can be used concurrently with immunotherapy,” Dr. Friedman said.
Question on treatment duration
No obvious factors were predictive of delayed events, including previous autoimmune disease or earlier reactions, which usually affected different organs, the authors said.
The findings raise a question about the appropriate duration of anti-PD-1 therapy, at least for melanoma.
The standard duration of adjuvant therapy was empirically determined to be 1 year for melanoma, and trials support anti-PD-1 therapy for up to 2 years for metastatic disease.
However, the authors suggest that “shorter treatment duration may reduce the risk of delayed irAE” and may be sufficient for patients who have a complete response.
“This should be considered when making decisions regarding therapy continuation in responding patients,” they wrote.
Ongoing clinical trials are investigating the optimal duration of therapy, they wrote.
No outside funding was reported. Dr. Johnson has been an adviser for Array Biopharma, BMS, Iovance, Jansen, Merck, and Novartis and has received research funding from BMS and Incyte. Other investigators reported similar ties. Dr. Choi, Dr. Kwong, and Dr. Friedman have disclosed no relevant financial relationships.
A version of this article first appeared on Medscape.com.