FDA approved a new radioactive drug to treat certain digestive tract cancers

Lutathera (lutetium-177 dotatate) has been approved by the FDA for treating of a type of rare cancer called Gastro-EnteroPancreatic NeuroEndocrine Tumors (GEP-NETs). GEP-NETs can be present in the pancreas or in parts of the gastrointestinal tract (e.g. the stomach, intestines, rectum). Approximately 1 out of 27,000 people are diagnosed with GEP-NETs per year.

How it works:

Lutathera is a type of “Peptide-Receptor Radionuclide Therapy”; basically, it is made up of a small protein that is labelled with a radioactive tag. Once Lutathera enters a person’s bloodstream and reaches the tumor site, it attaches to another protein present on the surface of the tumor cells called the somatostatin receptor. This binding results in the drug entering the tumor cell, where it then releases its radioactive rays, causing damage to the tumor cell from within. Since Lutathera’s actions depend on the presence of the somatostatin receptor, the drug would only effective for somatostatin receptor-positive GEP-NETs.

The approval of Lutathera for GEP-NETs was supported by two studies:

  1. In the first study, 229 patients with advanced somatostatin receptor-positive GEP-NETs were randomised to receive either Lutathera in combination with octreotide (which is currently the standard treatment for GEP-NETs), or just octreotide alone. The group receiving Lutathera showed a 79% reduction in risk for disease progression compared to the group who only received octreotide  (p < 0.0001). The response rate* was 18% in the group receiving Lutathera, compared to only 3% in the other group (p<0.001).
  2. The second study involved 1,214 patients with somatostatin receptor-positive tumors, although only 360 of them had GEP-NETs. Patients initially enrolled in the study received the radiopharmaceutical agent as part of an “expanded-access program”, which is a way for patients with life-threatening diseases to access investigational drugs. Complete or partial tumor shrinkage was reported in 16% of these 360 patients.

Reported side effects:

Common short-term effects:

Vomiting, nausea, hyperglycaemia (high blood sugar), hypokalaemia (low potassium), lymphopenia (low white blood cells/and therefore also low immunity)

Serious long-term effects:

Myelosuppresion (low levels of blood cells), development of blood cancers, damage to the kidneys and liver, abnormal levels of hormones in the body, and infertility.

Other on-going clinical trials using Lutathera:

  • Study assessing the safety of Lutathera given in combination with nivolumab in patients with small cell lung cancer and inoperable neuroendocrine tumor of the lung
  • Study assessing safety and efficacy of Lutathera for treating pheochromocytoma and paraganglioma (these are rare tumors that usually form near the adrenal gland or in the neck region).

 

*”Response rate” is the percentage of patients who had a response according to the Response Evaluation Criteria In Solid Tumors (RECIST), a set of criteria defining whether tumors in cancer patients improve, stay the same, or worsen during treatment.

About Rina Soetanto

Rina Soetanto is currently doing her PhD in molecular biology. She also has an extensive background in pharmacology and pre-clinical cancer research, as well as an undergraduate science degree from the Australian National University with a double major in neuroscience and immunology.

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