Emerging evidence shows an association between immune checkpoint inhibitor therapy and osteoporosis, with the agents linked to increased fracture risk in cancer patients.

The latest research, in BMJ Oncology, found that the rate of major osteoporotic fracture increased in patients with melanoma early after initiation of immunotherapy, such as pembrolizumab.

While arthritis is a well-documented musculoskeletal side effect of immune checkpoint inhibitor (ICI) therapy, the full impact of the drug on bone is still not well understood, and osteoporosis has not to date been recognised as an adverse effect.

Professor John Eisman, an endocrinologist and past director of osteoporosis at the Garvan Institute of Medical Research in Sydney, noted that the new study showed an absolute risk that was “significant but small”, at less than 1%.