EMA Panel Backs Approval of Lutathera for GEP-NETs

Stefano Buono

The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) has recommended approval of Lutathera (lutetium [¹⁷⁷Lu] oxodotreotide) for the treatment of patients with unresectable or metastatic, progressive, well-differentiated (grade 1 and grade 2), somatostatin receptor positive gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

The positive CHMP opinion is based on the phase III NETTER-1 trial, which compared Lutathera with high-dose octreotide LAR for patients with grade 1 or 2 metastatic midgut NETs. In this trial, there was a 79% reduction in the risk of progression or death with Lutathera compared with octreotide. The European Commission will now make a final approval decision on Lutathera for use in the European Union.

“We are proud to achieve this important milestone. Peptide Receptor Radionuclide Therapy (PRRT) has been included in both the ESMO and European Neuroendocrine Tumor Society (ENETS) guidelines as a treatment option for certain NET indications since 2012, and now…Lutathera is the very first PRRT to have achieved a positive CHMP opinion. We look forward to collaborating with the European health authorities to make…Lutathera widely available as soon as possible. To date, more than 1700 NET patients across 10 European countries have already received the treatment under compassionate use and named patient programs,” Stefano Buono, CEO of Advanced Accelerator Applications, the manufacturer of Lutathera, said in a statement.

In NETTER-1, 229 patients with midgut NETs who progression on standard-dose octreotide (30 mg) were randomized to Lutathera (n = 116) or high-dose octreotide (n = 113). Four doses of Lutathera were administered at 7.4 GBq every 8 weeks in combination with octreotide at 30 mg for symptom control. In the control arm, patients received octreotide LAR at 60 mg every 4 weeks, which was the control arm recommended by the FDA and European Medicines Agency.

Baseline characteristics were well balanced between the two arms. The mean age of patients in the investigational arm was 63 years (±9) and the mean BMI was 25 (±5). The primary tumor site was the ileum (74%) and the most common sites of metastasis were the liver (84%), lymph nodes (66%), and other locations (35%). All patients had somatostatin receptor-positive tumors, the majority of which were grade 4 on the Krenning scale (60%).

The primary endpoint of the study was progression-free survival (PFS). Secondary endpoints focused on objective response rates (ORR), overall survival (OS), and safety.

Median PFS had not been reached in the Lutathera arm compared with 8.4 months in the high-dose octreotide arm (HR, 0.21; 95% CI, 0.13-0.33; P <.0001). The estimated median PFS was approximately 40 months with Lutathera.

The ORR with Lutathera was 18% versus 3% with octreotide (P = .0008). There was 1 complete response with Lutathera and 17 partial responses. The stable disease rate with Lutathera was 66% versus 62% with octreotide.

An adverse event (AE) of any grade was experienced by 96% of those in the Lutathera arm versus 86% of those in the octreotide group. Eighty-six percent and 31% of patients, in the Lutathera and octreotide groups, experienced treatment-related AEs, respectively. Treatment related serious AEs were experienced by 9% of patients treated with Lutathera versus 1% in the octreotide arm. Five patients discontinued the study due to Lutathera-related AEs.

The most common grade 3/4 AEs in the Lutathera group versus high-dose octreotide, respectively, were lymphopenia (9% vs 0%), vomiting (7% vs 0%), nausea (4% vs 2%), diarrhea (3% vs 2%), abdominal pain (3% vs 5%), fatigue (2% vs 2%), and thrombocytopenia (2% vs 0%). Grade 3/4 liver enzyme increases were seen in those treated with Lutathera that were not apparent in the high-dose octreotide arm, including AST increase (4% vs 0%), ALT increase (4% vs 0%), and bilirubin increase (2% vs 0%).

Lutathera consists of the somatostatin analog octreotide connected with the beta and gamma emitting radiopharmaceutical ¹⁷⁷Lutetium (¹⁷⁷Lu). The 2 components are connected using the chelator DOTA. Lutathera represents a new generation of PRRT, and has been tested in several single-arm studies. In these trials, the median PFS ranged from 1 to 3 years.

In December 2016, the FDA issued a complete response letter (CRL) to Advanced Accelerator Applications informing the company that its new drug application for Lutathera as a treatment for patients with GEP-NETs would need to be resubmitted.

The CRL, which followed a discipline review letter issued in November 2016, requested new subgroup data, a safety update, and that revisions be made to the previously submitted data. The letter did not request the initiation of additional studies of Lutathera.

Strosberg JR, Wolin EM, Chasen B, et al. NETTER-1 phase III: Efficacy and safety results in patients with midgut neuroendocrine tumors treated with 177Lu-DOTATATE. J Clin Oncol. 2016;34 (suppl; abstr 4005).

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At the interim analysis of OS there was a 60% reduction in the risk of death seen with Lutathera versus octreotide (HR, 0.398; 95% CI, 0.21-0.77; P = .0043); however, the prespecified P value for statistical significance at the interim analysis was <.000085. Eighty-eight percent of patients in the Lutathera arm remained alive versus 77% in the octreotide group.