Immune Checkpoint Inhibitor Safety with Pre-existing Rheumatoid Arthritis Save

Lancet Rheumatology has published a retrospective analysis showing patients receiving immune checkpoint inhibitors (ICI) for cancer have the same outcomes (mortality and severe immune-related adverse events (irAEs)) even when they have pre-existing rheumatoid arthritis (RA).

Among 11,901 patients from the Mass General Brigham Integrated Health Care System and the Dana-Farber Cancer Institute who were treated wtih ICI, they matched 87 patients with pre-existing RA (met 2010 ACR–EULAR criteria) against 203 non-rheumatoid arthritis comparators. The median age was 71·2 years and 61% were female.

PD-1 inhibitors were the most common ICI used (92% vs 93% in RA and non-RA respectively) and the most common cancer was Lung cancer (49% vs 56%)), followed by melanoma (24% vs 25%). 

Mortality was seen in 69% of RA and 63% of the comparators (adjusted HR 1·16; 0·86–1·57; p=0·30).

All-grade immune-related AE were more so in RA (61% vs 49%) than comparators (adjusted HR 1·72;1·20–2·47]; p=0·058).  There were two (1%) deaths (Gr 5) from myocarditis, in the comparator group.

Inflammatory arthritis flares were predictably more common in RA patients than controls (48% vs. 7%; p<0·0001), but RA patients were less likely to have rash/dermatitis (6% vs 14%; p=0·048), endocrinopathy (2% vs 11%; p=0·0078), colitis/enteritis (7% vs 14% p=0·094), and hepatitis (3% vs 9%; p=0·043), compared to non-RA cancer patients on ICI.

Cancer patients, with pre-existing RA, who were treated with immune checkpoint inhibitors no increase in mortality risk. While they did have an increased risk of mild RA flares, they tended to have less of the other irAE events compared to non-RA patients.  RA patients can safely receive immune checkpoint inhibitors for cancer treatment.