LAKE BUENA VISTA, FLA. – “Crude and uninformed.”
That’s how Leonard H. Calabrese, DO, described the general approach to managing immune-related adverse events (irAEs) in cancer patients treated with checkpoint inhibitor therapy.
Rheumatologists have the expertise to change that, he said during a presentation at the annual meeting of the Florida Society of Rheumatology.
“The therapy is where it’s at – this is where rheumatologists come into play,” said, professor of medicine and chair of clinical immunology at the Cleveland Clinic.
According to relevant guidelines, such as those recently developed by the American Society of Clinical Oncology/National Comprehensive Cancer Network and the Society for the Immunotherapy of Cancer, irAEs are graded on a severity-based scale. Grade 1 events are mild and generally require observation; grade 2 events may include arthralgias and myalgias that are typically treated with symptomatic therapy; grade 3 events involve more serious conditions and may require hospitalization; and grade 4 events are life-threatening and may require targeted therapies.
“Grade 3 – these would be people with profound polyarthritis, vasculitis, myositis – rely heavily on glucocorticoids, and if patients don’t tolerate glucocorticoids or don’t respond to tapering doses, consider the use of [disease-modifying antirheumatic drugs],” he said, noting that the guidelines are vaguely written and refer to both conventional and biologic DMARDs.
“This is all anecdotal at the present time; this is a story to be discovered as we move along,” he explained.
A recommendation for the use of targeted therapies, such as tumor necrosis factor inhibitors, anti-interleukin (IL)-6, and antimetabolites, in patients with the most advanced disease is similarly vague and just represents “the beginning of the beginning,” he said.
The “crude and uninformed” nature of the current approach to irAEs, as he described it, is related to a failure to consider the immunopathogenesis of specific conditions.
“The oncologists, who have done such an incredible job with this – learning about derm[atitis] and colitis that respond to steroids and infliximab, immediately extrapolated that steroids and infliximab are for everything,” he said. “They give it for pneumonitis, they give it for [central nervous system] disease, they give it for everything.”
However, there’s no pathophysiologic basis for doing so, and not surprisingly, some patients don’t respond.
“Here we are sitting on this amazing armamentarium of targeted therapies and only now just starting to ask the questions: ‘Do they offer benefit for these irAEs? Do they offer risk? Will they blunt the antitumoral response of this?’ ” he said.
A “Personal View” published in Lancet Oncology in January 2019 was among the first from the oncology arena to pose these questions (20:PE54-64.).
“It said, ‘well maybe we should look at the immunopathogenesis of each of these diseases and then pick the therapy – if it’s IL-17 mediated, we’ve got drugs for that; if it’s IL-1 mediated, we’ve got drugs for that; if it’s interferon-mediated, we can deal with that,’ ” he said. “The problem is we don’t yet have detailed immunopathogenic knowledge of these diseases, but it’s coming.”