Lutathera Plus Sandostatin Boosts Outcomes in Advanced NETs

Patients with advanced gastric neuroendocrine tumors (NETs) who were treated with Lutathera (Lu 177-dotatate) plus Sandostatin (octreotide) tended to live nearly three times as long before their cancer worsened compared to those who received Sandostatin alone, according to findings from the phase 3 NETTER-2 clinical trial.

This is a “groundbreaking study” and “can be practice changing,” NET expert, Dr. Jaydira del Rivero, of the National Cancer Institute (NCI) Center for Cancer Research, said in a press release from the NCI.

Patients in the trial all had advanced (grade 2 or 3; moderate or severe) NETs in the gastrointestinal tract or pancreas that were not previously treated. Neuroendocrine cancer is a disease that starts in the neuroendocrine cells, which are hormone-producing cells found in locations throughout the body, including the esophagus, stomach, pancreas, intestine and lungs, according to the American Cancer Society. Treatment often involves surgery and depends on the patient and disease characteristics.

Those eligible for the trial had somatostatin receptor-positive high NETs that were diagnosed within six months of trial results. Two-thirds of patients (151 patients) were randomly assigned to receive Lutathera plus Sandostatin, while the other third (75 patients) were randomly assigned to receive Sandostatin, according to the trial’s listing on ClinicalTrials.gov.

Findings, which were published in the Journal of Clinical Oncology, showed that the median progression-free survival (PFS; time patients live before their disease spreads or worsens) was 23 months for the patients given Lutathera and Sandostatin, compared with 8.5 months in the group that received Sandostatin alone.

Additionally, the objective response rate (ORR; percentage of patients whose disease shrinks or disappears from treatment) was also higher for those who received the two-drug regimen, at 43%, compared with 9.3%.

Del Rivero said this is a “striking finding … and unexpectedly high.”

Lutathera was initially approved in the NET space in January 2018 for the treatment of patients with grade 1 or 2 somatostatin receptor-positive gastroenteropancreatic NETs. The approval was based on findings from the NETTER-1 trial, which evaluated the drug in patients who underwent previous treatment.

READ MORE: FDA Approves Lutathera for Gastroenteropancreatic Neuroendocrine Tumors

Now, the NETTER-2 trial is the first to evaluate a Lutathera-containing drug combination in this patient population.

According to the NCI, Lutathera works by binding to a specific protein found in cancer cells. The drug then enters the cancer and uses a radioactive particle called lutetium-177 to kill the tumor cell. Sandostatin, on the other hand, works by reducing the amount of certain hormones that could contribute to the growth and spread of cancer, according to the Cleveland Clinic.

Both treatment groups experienced a similar quality of life, according to the NCI. The most common immediate side effects are nausea, diarrhea and abdominal pain. One patient, however, also developed myelodysplastic syndrome (MDS), which is a type of blood cancer, after being treated with Lutathera.

“The risk of MDS is low,” said Dr. del Rivero. “All of the patient’s [tumor] characteristics need to be taken into consideration … so we can tailor the best treatment option.”
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