Abstract 5303: Correlative results from PRELUDE, a phase III study of enzastaurin (ENZA) vs placebo (PBO) in patients (pts) with high-risk diffuse large B-cell lymphoma (DLBCL) following a response to R-CHOP therapy
Bibliographic record
Abstract
Abstract Background: Protein kinase Cβ (PKCβ) is critical for B-cell signaling and survival and overexpression of PKCβ in DLBCL is associated with inferior survival. ENZA, an oral serine/threonine kinase inhibitor, targets PKCβ. Here we report immunohistochemical (IHC) and fluorescence in-situ hybridization (FISH) correlative analyses. Methods: PRELUDE (NCT00332202) was a phase III, double-blind maintenance study of 758 pts with DLBCL who were randomized 2:1 to ENZA 500 mg daily (1125-mg loading dose) (n = 504) or PBO (n = 254), respectively, following CR to induction therapy with R-CHOP. The primary endpoint was disease-free survival (DFS). Overall survival (OS) and assessment of biomarkers specific to ENZA and DLBCL were secondary endpoints. Pre-treatment formalin-fixed, paraffin-embedded samples were assessed via IHC staining in a blinded manner (Eric Hsi) for cell of origin (COO) using Hans’ algorithm. In addition, IHC was performed for c-MYC, BCL2, BCL6, FOXP1, and MUM1 (10% increments/% tumor cells stained), markers relevant to ENZA, including PKCβ2. FISH was performed to identify translocations involving c-MYC, BCL2, and BCL6. Cox regression was used to determine statistical associations between efficacy outcomes and dichotomized markers, adjusting for treatment and additional baseline covariates. All tests of association were conducted at a 2-sided α = 0.05. Results: There was no difference in 4-year DFS (70% vs 71%) or OS (81% vs 82%) between ENZA and PBO arms, respectively. A total of 243 (32%) pts had ≥1 evaluable sample available for IHC and FISH. There was no difference in outcome for pts based on COO (GCB vs non-GCB). Independent of treatment, significant associations were observed for BCL2 (pre-specified cutpoint 20%) and MUM1 (cutpoint 30%) with OS, and FOXP1 (cutpoint 80%) by IHC with DFS (HR [95% CI]: 2.19 [1.01-4.73]), p = 0.031; 1.97 [1.04-3.71], p = 0.032; 1.74 [1.04-2.90], p = 0.032, respectively). Associations were not significant for other IHC markers, including c-MYC and BCL6. Low PKCβ2 (<50% expression) had numerically better (but not significant) DFS/OS vs high PKCβ2. Dual translocation lymphoma by FISH was identified in two pts (1.2%) each for c-MYC/BCL2 and c-MYC/BCL6, and one pt (0.6%) had a triple hit involving c-MYC/BCL2/BCL6. Conclusions: No difference in outcomes between treatment arms was observed for the trial. Independent of treatment, COO was not prognostic of outcomes. Pts with low PKCβ2 expression had numerically better DFS/OS compared with high PKCβ2 expression. Significant treatment-independent associations were observed for BCL2 and MUM1 with OS and for FOXP1 with DFS (low IHC expression corresponded to better outcomes). The small number of double hit and triple hit lymphomas seen in the study may reflect the enrollment of CR patients with more favorable biology. Citation Format: Eric D. Hsi, Kerry J. Savage, Sonali M. Smith, Fritz Offner, Scott P. Myrand, Thomas M. Habermann, Donald E. Thornton, Boris K. Lin, Tuan S. Nguyen, Oday Hamid, Michael Crump. Correlative results from PRELUDE, a phase III study of enzastaurin (ENZA) vs placebo (PBO) in patients (pts) with high-risk diffuse large B-cell lymphoma (DLBCL) following a response to R-CHOP therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5303. doi:10.1158/1538-7445.AM2015-5303
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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 | 0.003 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 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) | 0.003 | 0.001 |
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".