Rheumatological immune-related adverse events (irAEs) related to checkpoint inhibitor use in cancer patients appear to respond well to the usual rheumatology therapies, according to data presented at the ACR 2017 meeting in San Diego.
A small retrospective study from the Royal Melbourne Hospital and Peter MacCallum Cancer Centre found 13 of 18 patients treated with either pembrolizumab or nivolumab developed de novo rheumatological irAEs including inflammatory arthritis, polymyalgia rheumatica, myositis and fasciitis.
Patients were receiving anti-PD1 therapy for metastatic disease including melanoma, non-small cell lung cancer, or head and neck squamous cell carcinoma.
Three patients experienced flare of existing rheumatic disease while two patients had no flare of existing rheumatic disease.
Most patients (12 of 16) required prednisone at doses ≥10mg/day. DMARDs were used in five cases and one patient received intravenous immunoglobulin. None of the patients in the case series received biologic therapy.
Dr Emma Mitchell, a rheumatology registrar now at Austin Health, told the limbic the study found 14 patients had partial or complete response to their rheumatological therapy. Three had stable disease and only one had progressive disease.
“We don’t have any prospective data but with our patients prednisone seems to have been effective in controlling the symptoms however most have not been able to wean off the steroids.”
She said rheumatologists had to be mindful of the usual side effects of prednisone in patients however there were also other important considerations.
“At this point in time we don’t know if rheumatology treatments will impact on the efficacy of the checkpoint inhibitors. It’s a new multidisciplinary set of conditions that we are likely to encounter more often as checkpoint inhibitors become more widely available for different cancers.”
“At this stage we know that patients can have new disease and flares of existing disease and we don’t really know whether these represent the same disease we usually treat or whether they are a separate entity due to the checkpoint inhibitors.”
She said collaboration with oncology colleagues was critical before making treatment decisions such as the degree of immunosuppression.
“The goal of rheumatology treatment in this context is to try and treat symptoms sufficiently to allow patients to continue with their oncology therapy. We need to collaborate closely with oncology about what is safe and what they are comfortable with us giving.”
“Patients can have serious side effects to any of the oncology drugs and the aim of the game is to put the cancer in remission. If there are severe side effects then patients and oncologists will consider other options.”
“At the end of the day, if the patients wants to continue the therapy, that’s only something that individual patients can decide. There have been cases where patients decide not to continue that therapy and equally there have been cases where patients with severe side effects elect to continue their cancer therapy.”