1161MO Lanreotide Autogel (LAN) and Temozolomide (TMZ) Combination Therapy in Progressive Thoracic Neuroendocrine Tumours (tnets): ATLANT Study Results

LAN and TMZ are among the main therapies recommended for progressive TNETs but prospective data are lacking. We present safety and efficacy outcomes of this combination in progressive TNETs. ATLANT was a 12-month, phase II, multicentre, single-arm, open-label study. Eligible patients had unresectable, locally advanced or metastatic, well-differentiated TNETs (bronchial or thymic, typical or atypical carcinoid) with baseline radiological progression (RECIST v1.1) in the previous 12 months. Patients received subcutaneous LAN 120 mg and oral TMZ 250 mg/day over 5 days, every 28 days. Primary endpoint: disease control rate (DCR) at 9 months (RECIST v1.1 complete response, partial response or stable disease [clinically relevant: ≥30%, unacceptable: ≤10%]). Data were analysed using exact binomial proportion tests for one-way tables. Patients (N=40; 60% male) had a mean (SD) age of 64.9 (11.8) years. The primary tumour site was: lung, 90%; thymus, 10% (typical, 20.0%; atypical, 52.5%; carcinoid, 27.5%). Mitotic count (mitoses/2 mm2): <2: 30%; ≥2–<10: 42.5%; ≥10: 2.5%; not done: 25%. Ki-67 expression (N=20): <4%: 10%; 4–<25%: 80%; ≥25%: 10%. TNM staging: primary tumour TX: 5.1%, T0: 46.2%, T1: 7.7%, T2: 12.8%, T3: 10.3%, T4: 17.9%; regional lymph node N0: 56.4%, N1: 2.6%, N2: 23.1%, N3: 17.9%; distant metastasis M0: 5.1%, M1: 94.9%. Locally assessed DCR at 9 months (ITT population; N=40) was 35.0% (95% CI: 20.63; 51.68) (significantly higher than 10% p<0.0001 but not superior to 30% p=0.297). Median progression-free survival was 37.1 (95% CI: 24.1; 52.9) weeks. In total, 97.5% of patients had treatment-emergent adverse events (TEAEs; >90% of TEAEs were Grade 1/2), 9 (22.5%) patients had serious TEAEs (of which 2 were treatment related), 2 TEAEs led to withdrawal of study treatment, and 2 led to death. The observed TEAEs were in line with the known individual drug profiles, and there were no new or unexpected AEs. Most common TEAEs included nausea (52.5%), vomiting (32.5%) and diarrhoea (30.0%). These results suggest that the LAN and TMZ combination was generally well tolerated and could be an effective regimen for managing progressive TNETs.