FRONTIER: FAPi radioligand open-label, phase 1 study to evaluate safety, tolerability and dosimetry of [Lu-177]-PNT6555—A dose escalation study for treatment of patients with select solid tumors.
Bibliographic record
Abstract
TPS3161 Background: Fibroblast activation protein alpha (FAP) is a 170 kDa transmembrane glycoprotein expressed during development, active tissue remodeling, and cancer. Overexpression on cancer-associated fibroblasts in the tumor microenvironment, and on some cancer cells of mesenchymal origin, leads to the presence of FAP in > 90% of epithelial tumors, making FAP a compelling anti-cancer target. PNT6555, a potent FAP-targeting compound with rapid clearance from normal tissues and prolonged tumor retention in preclinical models 1 , is a radioligand consisting of a DOTA chelator (1,4,7,10-tetraazacyclododecane-1,4,7,10- tetraacetic acid) and a FAP-targeting moiety (Bz-D-Ala-boroPro) connected via an aminomethyl linker. The corresponding gallium-68 and lutetium-177 chelates constitute the imaging and therapeutic theranostic pair of PNT6555 under evaluation in this phase I study. Methods: FRONTIER (NCT05432193) is a multicenter, open-label, multi-dose phase I study of PNT6555 in participants with pancreatic ductal adenocarcinoma, esophageal cancer, colorectal cancer, melanoma skin cancer, cholangiocarcinoma, or soft tissue sarcoma solid tumors with FAP over-expression. The primary aim is to evaluate the safety and tolerability of [Lu-177]-PNT6555 in order to determine a recommended phase II dose (RP2D). Dosimetry, pharmacokinetics, and tumor and immune responses will also be assessed for [Lu-177]-PNT6555, as well as safety, tolerability, and diagnostic performance of [Ga-68]-PNT6555 PET/CT. Key eligibility criteria include being refractory to prior treatment with no alternative available therapeutic options, having adequate organ function, and being FAP-positive on [Ga-68]-PNT6555 PET/CT scan, defined as ≥50% of lesions with an SUV max of ≥1.5x the liver SUV mean . [Ga-68]-PNT6555 will be dosed at 120 - 220 MBq (3.2 - 5.9 mCi), with PET/CT initiated 90 (±30) min later. FAP-positive participants will receive [Lu-177]-PNT6555 once every 6 weeks for up to 6 cycles. Starting at 4 GBq (108 mCi) ±10%, [Lu-177]-PNT6555 may be escalated by 4 GBq, with a maximum planned dose of 12 GBq. De-escalation by 2 GBq may also occur. Dose finding will be guided by the modified toxicity probability interval (mTPI-2) statistical design with a targeted toxicity rate of 30%. The planned total sample size is 30, with targets of 3-12 DLT evaluable patients per dose level. Cohort 1 has been completed without a DLT. Enrollment to cohort 2 began in January 2023. 1. Hallet R, et al. Pre-clinical characterization of the novel fibroblast activation protein (FAP) targeting ligand PNT6555 for the imaging and therapy of cancer. Presented at SNMMI Annual Meeting April 2022; Vancouver, BC, Canada. Clinical trial information: NCT05432193 .
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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 | 0.004 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.003 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".