Telomere Elongation and Clinical Improvement in Telomeropathy Patients: A Prospective Clinical Trial of Nandrolone in Telomeropathies

Telomeres are a complex of hexameric repetitive DNA sequences at the end of linear chromosomes. Telomeres erode during mitosis, and this process is accelerated in patients carrying germline pathogenic mutations in telomere-biology genes (Calado and Young, NEJM 2009). In vitro, the exposition to androgens stimulates TERT transcription and telomerase activity of lymphocytes and bone marrow CD34+ cells (Calado et al. Blood 2009). In a phase 1-2 prospective trial, the use of danazol led to telomere elongation in patients with telomeropathies (Townsley et al. NEJM 2016). The hematological response was observed in 79% of evaluable patients. Here, we describe a phase 1-2 single-center prospective study assessing the safety and the effect of the male hormone nandrolone decanoate on telomere erosion in patients with telomere diseases (ClinicalTrials.gov Identifier: NCT02055456). Entry criteria comprised patients older than two-year-old with age-adjusted mean telomere length below the 1st percentile ± identified mutations in telomerase complex genes, associated with at least one cytopenia and/or diagnosis of idiopathic pulmonary fibrosis (IPF). Patients were treated with nandrolone decanoate intramuscular at a dose of 5 mg/kg every 14 days for 24 months. The primary efficacy end point was a 20% decrease in the annual rate of telomere erosion, and the incidence of toxic effects was the primary safety end point. Secondary endpoints were hematologic response and pulmonary response. Flow-FISH was used to determine the telomere length of peripheral blood leukocytes. From May 2014 to October 2017, 20 consecutive patients were eligible for participation, and 17 were enrolled. The median age was 36 years (range, 4 - 59 years), and five patients were female. In all but one patient germline pathogenic mutations were identified (TERT, 7; RTEL1, 4; TERC, 2; WRAP53, 1; TINF2, 1; and SAMD9, 1). Eleven patients were diagnosed with bone marrow failure (9 with moderate and one with severe AA, and one with myelodysplasia). Four patients were diagnosed with IPF, and 2 patients had both moderate AA and IPF. One patient diagnosed with IPF had received an allogeneic bone marrow transplant before enrollment. Four patients had additional hepatic involvement, and 5 displayed cutaneous features of dyskeratosis congenita. The most common adverse events associated with drug were elevations in liver enzyme levels in 88%, acne in 59%, and virilization in 59%. Severe adverse events possibly related to drug occurred in six instances. Dose reductions were necessary in 5 patients due to severe or moderate adverse events. Seven patients withdrew from the study before 2 years: two patients discontinued therapy due to grade 3 adverse events (depression and acne); one patient sought alternative therapies; and four patients died during the study period, two due progressive IPF and two due intracranial hemorrhage. Out the 17 patients enrolled, a total of 15 reached 12 months of treatment and 13 were evaluable (one patient was transplanted and telomere length not evaluated; and for one patient the telomere sample was missing). Ten patients met the primary efficacy end point, showing telomere elongation. As of July 2019, nine patients reached 24 months of treatment and telomere length measured for seven patients at this time-point; all of them met end point criteria and showed telomere elongation at two years. The average increase in telomere length at 12 months was 1,119 bp (95% CI, 180-2,059 bp; P<0.04), and 1,257 bp (95% CI, 675-1,839 bp; P<0.02) at 24 months. The hematologic response rate was 60% at 3 months and 80% at 6 months. Only one patient relapsed during nandrolone use. Five of 8 transfusion-dependent patients became transfusion-independent, and one patient showed a reduction in transfusion requirements >50%. The pulmonary response rate was observed in 2 of 6 patients who had a pulmonary disease at baseline, and one patient eventually became oxygen-independent. In our study, nandrolone decanoate treatment was safe and led to telomere elongation in patients with telomeropathies. Nandrolone also improved hematologic function in patients with marrow failure. Pulmonary function remained stable or ameliorated in two-thirds of patients with pulmonary involvement. Known nandrolone side effects were common, especially liver toxicity and virilization.