A radiopharmaceutical from ITM Isotope Technologies Munich reduced the risk of disease progression or death by 33% versus Novartis' targeted molecular therapy Afinitor (everolimus) in patients with gastroenteropancreatic neuroendocrine tumours (GEP-NETs). The outcome of the Phase III COMPETE study was first top-lined in January, with the announcement marking one of only a handful of wins for a radiopharmaceutical in a head-to-head trial. Detailed results were presented Thursday at the European Neuroendocrine Tumor Society (ENETS) annual meeting.The trial compared ITM-11 (177Lu-edotreotide) with Afinitor in 309 patients with inoperable, progressive Grade 1 or 2 somatostatin receptor (SSTR)-positive GEP-NETs. According to ITM, approximately 15% of people in each trial arm were treatment naïve, with the remaining 85% or so having received one prior therapy.Results showed that median progression-free survival (PFS) for ITM's therapeutic was 23.9 months, which was significantly and clinically better than the 14.1 months for Afinitor. In comparison, in the Phase III NETTER-2 trial, Novartis' peptide receptor radionuclide therapy Lutathera (lutetium Lu 177 dotatate) reduced the risk of disease progression or death by 72% as a first-line therapy for patients with SSTR-positive well-differentiated Grade 2/3 advanced GEP-NETs versus high-dose octreotide LAR alone, with median PFS in the two arms of 22.8 months and 8.5 months, respectively.ITM told FirstWord that the choice of Afinitor as a comparator in COMPETE was "backed by scientific evidence of efficacy and high clinical acceptance after market authorisation." The company suggested that this decision set "a higher standard for meeting the primary endpoint in more advanced grade tumours," adding that it hopes "physicians will recognise the higher threshold of our study design."FDA filing this year"These successful results validate our decision to design a pivotal Phase III trial directly comparing a targeted radiopharmaceutical against a targeted molecular therapy," CEO Andrew Carey said. Based on the findings, ITM plans to seek approval of ITM-11 in the US this year; however, the company told FirstWord that it is "currently prohibited" from filing in Europe until 2029 due to orphan drug designation on Lutathera.Top-line results also showed that interim median overall survival (OS) was 63.4 months for ITM-11. That was numerically higher than the 58.7 months seen with Afinitor, but not statistically significant at the current analysis. ITM noted that patients were allowed to start an alternative therapy after disease progression, "potentially confounding" the OS data."These data show unequivocal support for [ITM-11's] potential benefit in extending PFS," remarked study investigator Jaume Capdevila, adding that the radiopharmaceutical's "convenient dosing schedule and favourable safety results reinforce its potential as a compelling new treatment option."In COMPETE, patients were treated with ITM-11 every three months for up to four cycles, or with Afinitor daily for up to 30 months, or until disease progression. Meanwhile, ITM's therapy was well tolerated, with treatment-emergent adverse events occurring at a rate of 82.5%, compared with 97% for Afinitor. However, there was one Grade 2 event of myelodysplastic syndrome in the ITM-11 arm.Growing optionsNeuroendocrine tumours are one of the few cancers that have so far benefited from the approval of radiopharmaceuticals. Novartis currently markets Lutathera as a treatment for SSTR-positive GEP-NETs, while Sanofi also has skin in the game, having reached a deal last year to join forces with RadioMedix and Orano Med on the radioligand medicine AlphaMedix (212Pb-DOTAMTATE).Something that differentiates ITM from other players, however, is that it has worked in the radiopharma space for over 20 years and has manufacturing in-house. "Together, with our global isotopes manufacturing business, robust supply chain and experienced clinical and commercial team, we believe we are uniquely positioned as a standout leader in the fast-growing radiopharmaceutical industry," Carey said.ITM-11 — which combines the therapeutic β-emitting radioisotope lutetium-177 with the synthetic SSTR agonist edotreotide — is also being investigated in the Phase III COMPOSE trial in patients with well-differentiated, aggressive Grade 2 or 3 SSTR-positive GEP-NETs.