Phase II study of PX-866 in recurrent glioblastoma.
Bibliographic record
Abstract
2051 Background: Glioblastoma (GBM) is the most aggressive malignancy of the central nervous system. The majority of GBM have genetic changes that increase the activity of the phosphatidylinositol-3-OH kinase (PI3K) signal transduction pathway, critical for cell motility, proliferation, and survival. We present the interim results of PX-866, an oral PI3K inhibitor, in patients (pts) with recurrent GBM. Methods: Pts with histologically confirmed GBM at first recurrence after treatment with chemoradiation and adjuvant temozolomide are given PX-866 8 mg daily on this single-arm phase II study. MRI and clinical exam are done every 8 weeks to determine treatment response. The trial has a 2-stage design with dual endpoints of objective response and early progression (within 8 weeks). In Stage I, 15 pts are evaluated and if 0 responses and 10 or more early progressions are seen, enrolment will stop. Otherwise, Stage II will enrol another 15 pts for efficacy analysis. Tumour tissue is collected for analysis of potential markers of PI3K inhibitory activity (PTEN, EGFRvIII, PIK3CA mutations). Results: Seventeen pts have been enroled to date: 14 evaluable for response and 15 for toxicity. Median age was 54 years (range 35-70), with 7 females and 10 males. No pts had received treatment for recurrent GBM, and median time between initial diagnosis and study enrolment was 300 days (range: 113-447 days). Pts have received a median of one 8-week cycle of PX-866 (range: 1-4). Twelve pts have discontinued therapy, 9 due to disease progression and 3 due to grade 3/4 liver enzyme abnormalities. Other adverse effects have included fatigue (10 pts/1 grade 3), diarrhea (6 pts/3 grade 3), nausea (7 pts/0 grade 3), vomiting (6 pts/0 grade 3), lymphopenia (14 pts/3 grade 3). Stage I response data are premature; it is not yet known if the trial will continue to Stage II. Archival tissue is available on all patients and is undergoing analysis. Conclusions: This is one of the first trials of a PI3K inhibitor in pts with recurrent GBM. PX-866 has been relatively well tolerated. Stage I response data are premature; while it is not yet known if the criteria will be met to continue to Stage II, prolonged SD has been observed in some pts. The correlative biomarker assays underway will be important to understand this observation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.005 | 0.002 |
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 source (direct Gemma or distilled Codex), 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".