Malignancy risk in adults with growth hormone deficiency undergoing long-term treatment with biosimilar somatropin (Omnitrope®): data from the PATRO Adults study.

Background To assess the safety (particularly the occurrence of malignancies) of growth hormone (GH) replacement (Omnitrope®) in adults with GH deficiency, using data from the ongoing PATRO Adults post-marketing surveillance study. Methods PATRO Adults is being conducted in hospitals and specialized endocrinology clinics across Europe. All enrolled patients who receive ⩾1 dose of Omnitrope® are included in the safety population. Malignancies are listed as adverse events under the MedDRA System Organ Class 'neoplasms, benign, malignant and unspecified (including cysts and polyps)'. Results As of July 2018, 1293 patients had been enrolled in the study and 983 (76.0%) remained active in the study. Approximately half [n = 637 (49.3%)] of the patients were GH treatment-naive on study entry. The majority of enrolled patients had multiple pituitary hormone deficiency (n = 1128, 87.2%). A total of 41 on-study malignancies were reported in 33 patients (2.6%; incidence rate 7.94 per 1000 patient-years). The most common cancers were basal cell carcinoma (n = 13), prostate (n = 6), breast, kidney and malignant melanoma (each n = 3). Treatment with Omnitrope® was discontinued following diagnosis of malignancy in 16 patients. The tumors occurred after a mean of 79.4 months of recombinant hormone GH (rhGH) treatment overall. Conclusion Based on this snapshot of data from PATRO Adults, Omnitrope® treatment is tolerated in adult patients with GH deficiency in a real-life clinical practice setting. Our results do not generally support a carcinogenic effect of rhGH in adults with GH deficiency, although an increased risk of second new malignancies in patients with previous cancer cannot be excluded based on the current dataset.