LAUSR

4106 Background: Approved systemic therapies for advanced NETs have showed limited tumor shrinkage and no data of activity after progression to prior targeted agents (TA) is available. Lenvatinib, a potent VEGFR1-3 & FGFR1-4 inhibitor may increase efficacy and revert primary and acquired resistance to TA. We report the final results of the TALENT trial. Methods: Two independent cohorts were included: panNETs and giNETs. All pts had baseline documented progression disease (PD) by RECIST. For panNETs, PD to TA was mandatory, regardless of prior therapy with somatostatin analogs (SSAs) or chemotherapy (CHT); and for giNETs, PD on SSAs. Pts were treated with lenvatinib at 24 mg qd until PD or intolerable toxicity. The primary endpoint was overall response rate (ORR) by central radiology review. Progression-free (PFS) and overall survival (OS) were assessed by investigator. With 55 pts per arm, our study was powered to identify an ORR ≥25% (90% power, 5% α-error). Results: We recruited 111 pts: 55 panNETs and 56 giNETs (78% from small intestine). Prior therapies were CHT 32%, SSAs 87%, everolimus 70% and sunitinib 30% for panNETs. ORR was 29%, 42.3% for panNETs and 16.3% for giNETs. With a median follow-up of 19 m, PFS and OS for panNETs were 15.5 m (95% CI 11.3-not reached (NR)) and 29.2 m (95% CI 23.2-NR); and 15.4 m (95% CI 11.5-19.4) and NR for giNETs, respectively. Pts who obtained a response by RECIST had a significantly better PFS compared with non-responders (NR vs 11.2 m in panNETs (p=0.004); 37.2 m vs 14.9 m in giNETs (p=0.005). In the subgroup analyses, all pts obtained the same benefit in PFS and ORR, including tumor grade, prior therapies, hormone release, primary location and tumor burden. The most frequent G3/4 adverse events were hypertension (22%), fatigue (11%) and diarrhea (11%). Dose reductions/interruptions were needed in 91.8% with a median dose of 20 mg qd. Conclusions: To our knowledge, we report the highest ORR by central radiology assessment with a TA in this setting. Lenvatinib showed a promising PFS and OS in a pretreated population with benefit across subgroups. Further development in advanced NETs is warranted. Clinical trial information: NCT02678780.