Anastrozole plus leuprorelin in early maturing girls with compromised growth: the “GAIL” study

PURPOSE: Aromatase inhibitors have been used to increase predicted adult height (PAH) in boys but in girls only in McCune-Albright syndrome. We investigated whether anastrozole combined with leuprorelin for up to 2 years is safe and effective in improving PAH in girls with early puberty and compromised growth, compared to leuprorelin alone. METHODS: The “GAIL” study: girls treated with an aromatase inhibitor and an LHRH analogue, ISRCTN11469487, was a 7-year prospective phase IIa study with parallel design, performed at Athens Medical Center (C-A), and Attikon University Hospital, Athens, Greece (C-B). Forty girls, consecutively referred for early puberty (onset 7.5–9 years) with a PAH <−2 or >1.5 SD lower than their target height (TH), were included. Twenty started on leuprorelin sc/im 0.3 mg/kg/month plus anastrozole 1 mg/d p.o. (group-A, C-A) and 20 on leuprorelin (group-B, C-B) for 2 years or until the age of 10 years. Groups did not differ in age, height, BMI, bone age advancement (BAA), and distance of PAH from TH. Follow-up was at 6, 12, 18, and 24 m. RESULTS: Reduction in BAA was significantly higher in group-A compared to group-B already by 6 m. Despite the transiently significant decrease in height velocity in group-A, gain in PAH SD was almost double by 12 and 18 m vs group-B and reached the maximum of +1.21 ± 0.45 (7.51 cm) vs +0.31 ± 0.37 (1.92 cm, p = 0.001) in group-B at 24 m. Group-A had no clinical or biochemical hyperandrogenism, unchanged normal bone density, and lumbar spine X-rays. CONCLUSION: The co-administration of anastrozole with leuprorelin safely improves PAH in girls with compromised growth.