Peptide receptor radionuclide therapy, or PRRT, has been a standard treatment for somatostatin receptor positive gastroenteropancreatic neuroendocrine tumours (GEP-NETs) for several years – usually after another therapy has stopped working. NETTER-2 is the first randomised Phase 3 trial to test PRRT earlier, as a first-line treatment, and the results have shifted how clinicians are thinking about when to use it.

NETTER-2 enrolled people with newly diagnosed (within six months), somatostatin receptor positive, well-differentiated grade 2 and grade 3 advanced GEP-NETs. Participants were randomised to either lutetium Lu 177 dotatate (Lutathera) plus 30 mg long-acting octreotide, or to high-dose 60 mg long-acting octreotide alone. Median progression-free survival was 22.8 months in the Lutathera arm versus 8.5 months in the octreotide-only arm – a 72% reduction in the risk of disease progression or death (hazard ratio 0.276). The objective response rate, which is the proportion of patients whose tumours measurably shrank, was 43% with Lutathera versus 9.3% with octreotide alone.

No new or unexpected safety issues were reported. Most side effects were mild to moderate – nausea, diarrhoea, and abdominal pain were the most common in the Lutathera group, with low rates of serious lymphocyte count drops. Around 88% of people in the Lutathera arm completed all four planned treatment cycles. The trial principal investigator, Dr Simron Singh of the University of Toronto, described the results as "practice-changing" for newly diagnosed patients with significant unmet need.

For New Zealand patients, this matters in two ways. First, it strengthens the evidence base for PRRT being offered earlier in the treatment pathway rather than held back as a later option, particularly for higher-grade disease. Second, it gives clinicians and Pharmac a clearer picture when weighing future funding and access decisions. The national PRRT service in Auckland (Lutate) remains in place – your specialist can tell you whether you are likely to be eligible and where you would sit in the treatment sequence.