Phase 1 results of PTC596, a novel small molecule targeting cancer stem cells (CSCs) by reducing levels of BMI1 protein.
Bibliographic record
Abstract
2574 Background: PTC596 is an oral investigational new drug that reduces levels of BMI1, a protein required for CSC survival. PTC596 reduced the number of CSCs in preclinical models and slowed growth rates of tumor xenografts in rodent models. The primary objectives of this first-in-human trial of PTC596 were to determine safety, dose-limiting toxicities (DLTs), maximum tolerated dose (MTD), and pharmacokinetics (PK). Secondary objectives included exploratory assessments of biological efficacy, pharmacodynamic changes and anti-tumor activity. Methods: A Phase I multi-center, open-label study was conducted in patients with advanced solid tumors using a modified 3+3 design, followed by a dose-confirmatory 10-patient expansion. PTC596 was administered using bodyweight-adjusted twice-per-week (biw) oral dosing in 4 week cycles. Dose escalation and MTD were based on observed cycle 1 DLTs. Anti-tumor activity was assessed by RECIST 1.1. Results: A total of 31 patients with a broad range of tumor types were enrolled at dose levels of 0.65 (N = 3), 1.3 (N = 3), 2.6 (N = 3), 5.2 (N = 11), 7 (N = 8) and 10 mg/kg (N = 3). Nausea, vomiting, and diarrhea were the most common all grade adverse events, though usually mild and manageable. At 10 mg/kg one patient experienced DLTs of neutropenia, mucositis, and thrombocytopenia. The other two patients at this dose level also experienced poor tolerability with Grade 2 nausea, vomiting, and diarrhea that may be partially due to the overall pill burden and excipients. The recommended dose for the expansion and further study was 7 mg/kg. Over the dosing range, plasma concentrations of PTC596 increased in an approximately dose-proportional manner and at doses of 2.6 mg/kg and above exceeded those associated with activity in vitro and in vivo models. Best response was stable disease in 5 patients including two with minor radiographic reductions in tumor volume. Conclusions: PTC596 is tolerable with manageable gastrointestinal side effects. At 7 mg/kg biw exposures exceeded those associated with preclinical activity and future clinical studies are planned for this first-in class molecule that targets CSCs. Clinical trial information: NCT02404480.
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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 | 0.005 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".