Phase Ib/II open-label, randomized evaluation of atezolizumab (atezo) + Imprime PGG (Imprime) + bevacizumab (bev) vs regorafenib (rego) in MORPHEUS: Microsatellite-stable (MSS) metastatic colorectal cancer (mCRC).
Bibliographic record
Abstract
3559 Background: The MORPHEUS platform consists of multiple, global, open-label, randomized Phase Ib/II trials designed to identify early efficacy and safety signals of treatment (tx) combinations across cancers. Here, atezo (anti-PD-L1) was tested with Imprime and bev (anti-VEGF) for MSS mCRC, a poorly immunogenic cancer generally resistant to checkpoint inhibitors. Imprime acts as a pathogen-associated molecular pattern that, when bound to anti-β glucan antibodies (ABA), activates the innate immune system with the potential to 1) promote priming and expansion of tumor-specific T cells, 2) promote M2-M1 macrophage polarization and 3) enhance the immunomodulatory effects of atezo and bev. Therefore, we hypothesized that atezo + Imprime + bev would induce an antitumor response beyond that of rego, a standard-of-care multikinase inhibitor, in patients (pts) with MSS mCRC. Methods: Pts with MSS mCRC unselected for the Imprime-specific biomarker (ABA) and refractory to 1-2 prior lines of standard therapy received atezo (1200 mg IV every 3 weeks [q3w]) + Imprime (4 mg/kg IV on Days 1, 8, 15) + bev (7.5 mg/kg IV q3w) or control tx with rego (160 mg orally days 1-21; dose escalation to 160 mg during Cycle 1 allowed per institutional guidelines). The primary endpoint was objective response rate (ORR; investigator-assessed RECIST 1.1); secondary endpoints included disease control rate (DCR; response or stable disease ≥ 12 weeks), progression-free survival (PFS), overall survival (OS) and safety. Results: Pts were followed-up for ≥18 wk. 15 pts received atezo + Imprime + bev and 13 received rego. Grade (Gr) 3/4 tx-related adverse events (TRAEs) were seen in 13% of atezo + Imprime + bev and 62% of rego pts. No Gr 5 AEs occurred in atezo + Imprime + bev pts and 1 (8%) was reported in a rego pt. One pt in each arm (7% vs 8%, respectively) withdrew from tx due to a TRAE. No radiological responses were seen in either arm. Five pts (33%) receiving atezo + Imprime + bev and 8 (62%) receiving rego had stable disease as best response. DCR was 13% with atezo + Imprime + bev and 23% with rego. Median PFS was 1.5 mo (95% CI: 1.4, 2.8) and 2.8 mo (95% CI: 1.6, 3.1), and median OS was 5.7 mo (95% CI: 4.4, 10.5) and 10.2 mo (95% CI: 4.8, NE) with atezo + Imprime + bev and rego, respectively. There was no apparent correlation between baseline PD-L1 expression or CD8+ lymphocyte tumor infiltration and clinical benefit. Further, the systemic exposure of atezo, Imprime and bev and immunogenicity of atezo and bev are in line with previous clinical experience. Additional biomarker, pharmacokinetics and anti-drug antibody data will be shown. Conclusions: Atezo + Imprime + bev was well tolerated; toxicities were consistent with the safety profiles of the individual agents. No efficacy signal was identified with atezo + Imprime + bev in pts with MSS refractory mCRC. Clinical trial information: NCT03555149.
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.002 |
| 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 | 0.003 |
| Insufficient payload (model declined to judge) | 0.006 | 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".