Pooled evidence from cohort studies of patients treated with biologic therapy for rheumatoid arthritis, IBD and psoriasis does not show a statistically significant increased risk of melanoma, a study shows.

However, because the systematic review and meta-analysis found trends toward increased melanoma rates with long-term therapy, a clinically meaningful increase in risk cannot be ruled out, the investigators say.

The UK and Australian researchers found seven eligible studies between 1995 and 2019 involving more than 34,000 patients who received biologics for at least a year and more than 135,000 who were not treated with these drugs. The patients were on therapy for between one and six years on average.

Biologic treatment was positively associated with 20% higher risk of melanoma in patients with IBD and rheumatoid arthritis and 57% higher risk in patients with psoriasis compared with those who received conventional systemic therapy, but the differences were not statistically significant.