Efficacy of [<sup>67</sup>Cu]Cu-EB-TATE Theranostic Against Somatostatin Receptor Subtype-2–Positive Neuroendocrine Tumors
Bibliographic record
Abstract
β<sup>−</sup>-emitting <sup>177</sup>Lu-octreotate is an approved somatostatin receptor subtype 2 (SSTR2)–directed peptide receptor radionuclide therapy for the treatment of gastroenteropancreatic neuroendocrine tumors (NETs). However,<sup>177</sup>Lu-octreotate has fast pharmacokinetics, requiring up to 4 treatment doses. Moreover, <sup>177</sup>Lu is less than ideal for theranostics because of the low branching ratio of its γ-emissions, which limits its SPECT imaging capability. Compared with <sup>177</sup>Lu, <sup>67</sup>Cu has better decay properties for use as a theranostic. Here, we report the preclinical evaluation of a long-lived somatostatin analog, [<sup>67</sup>Cu]Cu-DOTA-Evans blue-TATE (EB-TATE), against SSTR2-positive NETs. <b>Methods:</b> The in vitro cytotoxicity of [<sup>67</sup>Cu]Cu-EB-TATE was investigated on 2-dimensional cells and 3-dimensional spheroids. In vivo pharmacokinetics and dosimetry were studied in healthy BALB/c mice, whereas ex vivo biodistribution, micro-SPECT/CT imaging, and therapy studies were done on athymic nude mice bearing QGP1.SSTR2 and BON1.SSTR2 xenografts. Therapeutic efficacy was compared with [<sup>177</sup>Lu]Lu-EB-TATE. <b>Results:</b> Projected human effective doses of [<sup>67</sup>Cu]Cu-EB-TATE for male (0.066 mSv/MBq) and female (0.085 mSv/MBq) patients are tolerable. In vivo micro-SPECT/CT imaging of SSTR2-positive xenografts with [<sup>67</sup>Cu]Cu-EB-TATE showed tumor-specific uptake and prolonged accumulation. Biodistribution showed tumor accumulation, with concurrent clearance from major organs over a period of 72 h. [<sup>67</sup>Cu]Cu-EB-TATE was more effective (60%) at eliminating tumors that were smaller than 50 mm<sup>3</sup> within the first 15 d of therapy than was [<sup>177</sup>Lu]Lu-EB-TATE (20%) after treatment with 2 doses of 15 MBq administered 10 d apart. Mean survival of [<sup>67</sup>Cu]Cu-EB-TATE–treated groups was 90 d and more than 90 d, whereas that of [<sup>177</sup>Lu]Lu-EB-TATE was more than 90 d and 89 d against vehicle control groups (26 d and 53 d), for QGP1.SSTR2 and BON1.SSTR2 xenografts, respectively. <b>Conclusion:</b> [<sup>67</sup>Cu]Cu-EB-TATE exhibited high SSTR2-positive NET uptake and retention, with favorable dosimetry and SPECT/CT imaging capabilities. The antitumor efficacy of [<sup>67</sup>Cu]Cu-EB-TATE is comparable to that of [<sup>177</sup>Lu]Lu-EB-TATE, with [<sup>67</sup>Cu]Cu-EB-TATE being slightly more effective than [<sup>177</sup>Lu]Lu-EB-TATE for complete remission of small tumors. [<sup>67</sup>Cu]Cu-EB-TATE therefore warrants clinical development.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".