IND 205B: A phase II study of the PI3K inhibitor PX-866 and continued abiraterone/prednisone in patients with recurrent or metastatic castration resistant prostate cancer (CRPC) with PSA progression on abiraterone/prednisone.
Bibliographic record
Abstract
279 Background: PX-866 is an irreversible, pan-isoform inhibitor of Class I PI-3K. In part A of this study, PX-866 as a single agent was well tolerated and showed modest activity in CRPC but did not meet a priori benchmarks as a single agent in unselected patients (pts). As androgen receptor inhibition promotes PI3K activity in PTEN-loss PC models, the addition of PX-866 in patients whose PSA is rising on abiraterone acetate plus prednisone (AA+P) may reverse resistance and phase B of the study tested this hypothesis clinically. Methods: In this multicentre, phase II study, CRPC pts with PSA progression on AA+P received PX-866, 8mg daily on a 6-week cycle while continuing AA+P. Primary endpoint was lack of progression at 12 weeks (PCWG2 criteria). Secondary endpoints included PSA and objective response rates. PX-866 would be deemed worthy of further study if at least four of 25 pts were progression free at 12 weeks. Results: 25 pts were accrued and all are evaluable for toxicity and PSA response. Eleven pts had measurable disease of which 11 are evaluable for objective response. Median age was 72, ECOG PS was 0/1 in 10/15 pts. Eighteen pts received prior chemotherapy. Median number of cycles was 2 (range 1–3). 52% of pts received at least 90% of planned dose of PX-866. Most common adverse events (AEs) were fatigue (21 patients), diarrhea, (18), nausea (13), vomiting (11) and anorexia (12); one patient discontinued because of protocol therapy toxicity (grade 3 anemia). Other grade 3 AEs (one patient for each) were diarrhea, vomiting, fatigue, AST and ALT elevation and lymphocyte and platelet changes. Six pts were progression free at 12 weeks. No objective or PSA responses were seen. Of the pts with measurable disease, best objective response was stable disease in six (2.3-3.6m) and best PSA response was non-response in eight pts. Conclusions: The addition of PX-866 to AA+P in unselected pts progressing on AA+P shows no evidence of antitumour effects. Strategies to combine PI3K inhibition with AR targeted therapies should consider initiation earlier in the disease course and/or recruiting a selected population. Clinical trial information: NCT01331083.
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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 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.004 |
| Insufficient payload (model declined to judge) | 0.006 | 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".