Programmed death-1 (PD-1) is an inhibitory molecule expressed on activated T cells, however, the biological context in which PD-1 controls T cell tolerance remains unclear. Using two-photon laser-scanning microscopy, we showed that unlike naïve or activated islet antigen-specific T cells, tolerized islet antigen-specific T cells moved freely and did not swarm around antigen-bearing dendritic cells (DC) in pancreatic lymph nodes. Inhibition of T cell receptor (TCR)-driven stop signals depended on continued PD-1-PD-L1 interactions, as antibody blockade of PD-1 or PD-L1 decreased T cell motility, enhanced T cell-DC contacts, and caused autoimmune diabetes. CTLA-4 blockade did not alter T cell motility or abrogate tolerance. Thus, PD-1-PD-L1 interactions maintain peripheral tolerance by mechanisms fundamentally distinct from those of CTLA-4.

Purpose The MURANO study demonstrated significant progression-free survival (PFS) benefit for fixed-duration venetoclax-rituximab compared with bendamustine-rituximab in relapsed/refractory chronic lymphocytic leukemia. With all patients off treatment, we report minimal residual disease (MRD) kinetics and updated outcomes. Methods Patients were randomly assigned to 2 years of venetoclax plus rituximab during the first six cycles, or six cycles of bendamustine-rituximab. Primary end point was PFS. Safety and peripheral blood (PB) MRD status—at cycle 4, 2 to 3 months after end of combination therapy (EOCT), and every 3 to 6 months thereafter—were secondary end points. Results Of 194 patients, 174 (90%) completed the venetoclax-rituximab phase and 130 (67%) completed 2 years of venetoclax. With a median follow-up of 36 months, PFS and overall survival remain superior to bendamustine-rituximab (hazard ratio, 0.16 [95% CI, 0.12 to 0.23]; and hazard ratio, 0.50 [95% CI, 0.30 to 0.85], respectively). Patients who received venetoclax-rituximab achieved a higher rate of PB undetectable MRD (uMRD; less than 10−4) at EOCT (62% v 13%) with superiority sustained through month 24 (end of therapy). Overall, uMRD status at EOCT predicted longer PFS. Among those with detectable MRD, low-level MRD (10−4 to less than 10−2) predicted improved PFS compared with high-level MRD (10−2 or greater). At a median of 9.9 months (range, 1.4 to 22.5 months) after completing fixed-duration venetoclax-rituximab, overall only 12% (16 of 130) of patients developed disease progression (11 high-level MRD, three low-level MRD). At the end of therapy, 70% and 98% of patients with uMRD remained in uMRD and without disease progression, respectively. Conclusion With all patients having finished treatment, continued benefit was observed for venetoclax-rituximab compared with bendamustine-rituximab. uMRD rates were durable and predicted longer PFS, which establishes the impact of PB MRD on the benefit of fixed-duration, venetoclax-containing treatment. Low conversion to detectable MRD and sustained PFS after completion of 2 years of venetoclax-rituximab demonstrate the feasibility of this regimen.

PURPOSE In previous analyses of the MURANO study, fixed-duration venetoclax plus rituximab (VenR) resulted in improved progression-free survival (PFS) compared with bendamustine plus rituximab (BR) in patients with relapsed or refractory chronic lymphocytic leukemia (CLL). At the 4-year follow-up, we report long-term outcomes, response to subsequent therapies, and the predictive value of molecular and genetic characteristics. PATIENTS AND METHODS Patients with CLL were randomly assigned to 2 years of venetoclax (VenR for the first six cycles) or six cycles of BR. PFS, overall survival (OS), peripheral-blood minimal residual disease (MRD) status, genomic complexity (GC), and gene mutations were assessed. RESULTS Of 389 patients, 194 were assigned to VenR and 195 to BR. Four-year PFS and OS rates were higher with VenR than BR, at 57.3% and 4.6% (hazard ratio [HR], 0.19; 95% CI, 0.14 to 0.25), and 85.3% and 66.8% (HR, 0.41; 95% CI, 0.26 to 0.65), respectively. Undetectable MRD (uMRD) at end of combination therapy (EOCT) was associated with superior PFS compared with low MRD positivity (HR, 0.50) and high MRD positivity (HR, 0.15). Patients in the VenR arm who received ibrutinib as their first therapy after progression (n = 12) had a reported response rate of 100% (10 of 10 evaluable patients); patients subsequently treated with a venetoclax-based regimen (n = 14) had a reported response rate of 55% (six of 11 evaluable patients). With VenR, the uMRD rate at end of treatment (EOT) was lower in patients with GC than in those without GC ( P = .042); higher GC was associated with shorter PFS. Higher MRD positivity rates were seen with BIRC3 and BRAF mutations at EOCT and with TP53, NOTCH1, XPO1, and BRAF mutations at EOT. CONCLUSION Efficacy benefits with fixed-duration VenR are sustained and particularly durable in patients who achieve uMRD. Salvage therapy with ibrutinib after VenR achieved high response rates. Genetic mutations and GC affected MRD rates and PFS.

Purpose: The oncogenic PI3K/Akt/mTOR pathway is an attractive therapeutic target in cancer. However, it is unknown whether the pathway blockade required for tumor growth inhibition is clinically achievable. Therefore, we conducted pharmacodynamic studies with GDC-0068, an ATP competitive, selective Akt1/2/3 inhibitor, in preclinical models and in patients treated with this compound. Experimental Design: We used a reverse phase protein array (RPPA) platform to identify a biomarker set indicative of Akt inhibition in cell lines and human-tumor xenografts, and correlated the degree of pathway inhibition with antitumor activity. Akt pathway activity was measured using this biomarker set in pre- and post-dose tumor biopsies from patients treated with GDC-0068 in the dose escalation clinical trial. Results: The set of biomarkers of Akt inhibition is composed of 10 phosphoproteins, including Akt and PRAS40, and is modulated in a dose-dependent fashion, both in vitro and in vivo. In human-tumor xenografts, this dose dependency significantly correlated with tumor growth inhibition. Tumor biopsies from patients treated with GDC-0068 at clinically achievable doses attained a degree of biomarker inhibition that correlated with tumor growth inhibition in preclinical models. In these clinical samples, compensatory feedback activation of ERK and HER3 was observed, consistent with preclinical observations. Conclusion: This study identified a set of biomarkers of Akt inhibition that can be used in the clinical setting to assess target engagement. Here, it was used to show that robust Akt inhibition in tumors from patients treated with GDC-0068 is achievable, supporting the clinical development of this compound in defined patient populations. Clin Cancer Res; 19(24); 6976–86. ©2013 AACR.

Introduction: The randomized Phase III MURANO study (NCT02005471) compared fixed-duration VenR with standard bendamustine-rituximab (BR) in R/R CLL. Deep responses with uMRD were associated with superior progression-free survival (PFS) of VenR vs BR with 48 months (mo) follow-up (f/u). We now report long-term MRD kinetics and updated efficacy outcomes, including re-exposure to VenR (to be presented), with a 5 year (yr) median follow-up (clinical cutoff date May 8, 2020). Methods: As published, pts were randomized to VenR (Ven 400 mg daily for 2 yrs + standard dose R for the first 6 mo) or B (70 mg/m2)R (6 mo). A sub-study was introduced in 2018, allowing pts who developed progressive disease (PD) following Tx with BR or VenR to receive the MURANO VenR regimen. PFS was based on investigator assessment. Peripheral blood MRD was analyzed centrally by allele-specific oligonucleotide polymerase chain reaction and/or flow cytometry. Pts were categorized by MRD status as previously reported, using <10-4 threshold for uMRD. MRD conversion was defined as 2 consecutive assays detecting MRD or PD in pts who previously had uMRD. Genomic complexity (GC) and del(17p) status were assessed by array comparative genomic hybridization. GC was defined as ≥3 copy number variations (CNV). All p-values are descriptive. Results: 389 pts were enrolled (VenR, n=194; BR, n=195). With a median f/u of 59.2 (range, 0-71.5) mo, the PFS benefit with VenR over BR was sustained (HR, 0.19 [95% CI: 0.15-0.26]; p<0.0001). Median PFS was 53.6 (95% CI: 48.4-57.0) mo for VenR and 17.0 (95% CI: 15.5-21.7) mo for BR. For pts who completed the full 2 yrs of Ven Tx (n=130), PFS estimates 36 mo post-end of treatment (EOT) were ~51.1% (95% CI: 40.2-61.9). Overall survival (OS) benefit was maintained for pts treated with VenR vs BR (HR, 0.40 [95% CI: 0.26-0.62]; p<0.0001), with 5-yr OS estimates of 82.1% (95% CI: 76.4-87.8) for VenR and 62.2% (95% CI: 54.8-69.6) for BR. Improved OS outcome was observed among the VenR pts that reached EOT without PD and had uMRD (83/118) compared with those with MRD (35/118), with 3-yr post-EOT survival estimates of 95.3% (95% CI: 90.0-100.0) vs 85.0% (95% CI: 72.8-97.2), respectively (Figure 1). Of the pts with uMRD at EOT, 32/83 had not shown PD and remained uMRD at the 5-yr update, 4/83 had PD without prior confirmed MRD conversion and 47/83 had MRD conversion. Median time to MRD conversion from EOT was 19.4 (95% CI: 8.7-28.3) mo. Of the 47/83 pts with confirmed MRD conversion, 19 subsequently developed PD by International Workshop on CLL criteria with a median time to PD from MRD conversion of 25.2 (95% CI: 19.4-30.4) mo. These 19 pts exhibited more rapidly increasing rates of MRD post-EOT than pts that had MRD conversion but were PD-free (Figure 2). Among pts that were uMRD at EOT, the baseline presence of del(17p), GC and unmutated immunoglobulin heavy chain gene (IGVH) were each associated with increased risk of MRD conversion and subsequent PD post-EOT (Table 1). All 4 pts with del(17p) experienced MRD conversion with subsequent PD. 8/18 (44%) pts with GC vs 8/40 (20%) pts without GC eventually converted to MRD and developed PD. The rate of MRD conversion with eventual PD was also higher among those with unmutated IGVH (21/56; 37%) than those without (1/23; 4%). Once uMRD at EOT was achieved, pts without del(17p) or GC, or with mutated IGVH, were more likely to maintain uMRD or experience MRD conversion without subsequent PD at this follow-up (Table 1). No new safety signals were identified. Excluding non-melanoma skin cancers, 2 second primary malignancies (VenR [acute myeloid leukemia and multiple myeloma]) were reported since the previous update. Rates of Richter transformation remained balanced between treatment arms (7 on VenR, 6 on BR). Following PD on the main study, 29 pts were enrolled in the sub-study (re-treatment; n=21, crossover; n=8). Further data on their biologic profile, updated response rates, and MRD in the re-treatment cohort will be presented. Conclusions: Five-yr data from MURANO demonstrate sustained PFS and OS benefit with VenR vs BR. In the VenR cohort, uMRD at EOT is associated with improved OS. Unmutated IGVH, del(17p) and GC (≥3 CNV) are associated with higher rates of MRD conversion and subsequent PD after attaining uMRD at EOT. Overall, a substantial proportion of pts who completed Ven Tx retained uMRD 36 mo after treatment cessation, displaying durable response following 2-yr fixed-duration VenR. Disclosures Kater: Janssen: Research Funding; Celgene: Research Funding; Abbvie: Research Funding; Roche: Research Funding; Genentech: Research Funding. Kipps:Pharmacyclics/ AbbVie, Breast Cancer Research Foundation, MD Anderson Cancer Center, Oncternal Therapeutics, Inc., Specialized Center of Research (SCOR) - The Leukemia and Lymphoma Society (LLS), California Institute for Regenerative Medicine (CIRM): Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Honoraria, Research Funding; Gilead: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Oncternal Therapeutics, Inc.: Other: Cirmtuzumab was developed by Thomas J. Kipps in the Thomas J. Kipps laboratory and licensed by the University of California to Oncternal Therapeutics, Inc., which provided stock options and research funding to the Thomas J. Kipps laboratory, Research Funding; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; VelosBio: Research Funding; Ascerta/AstraZeneca, Celgene, Genentech/F. Hoffmann-La Roche, Gilead, Janssen, Loxo Oncology, Octernal Therapeutics, Pharmacyclics/AbbVie, TG Therapeutics, VelosBio, and Verastem: Membership on an entity's Board of Directors or advisory committees. Eichhorst:F. Hoffmann-LaRoche: Consultancy, Honoraria, Other: travel support, Research Funding; Gilead: Consultancy, Honoraria, Other: travel support, Research Funding; ArQule: Consultancy, Honoraria, Other: travel support, Research Funding; Oxford Biomedica: Consultancy, Honoraria, Other: travel support, Research Funding; Novartis: Consultancy, Honoraria, Other: travel support, Research Funding; Janssen-Cilag: Consultancy, Honoraria, Other: travel support, Research Funding; AbbVie: Consultancy, Honoraria, Other: travel support, Research Funding; AstraZeneca: Consultancy, Honoraria, Other: travel support, Research Funding; BeiGene: Consultancy, Honoraria, Other: travel support, Research Funding; Celgene: Consultancy, Honoraria, Other: travel support, Research Funding. Hillmen:Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company), Research Funding, Speakers Bureau; Astra Zeneca: Honoraria; F. Hoffmann-La Roche: Honoraria, Research Funding; Pharmacyclics: Research Funding; Gilead: Research Funding. D'Rozario:F. Hoffmann-La Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees. Owen:AbbVie, F. Hoffmann-La Roche, Janssen, Astrazeneca, Merck, Servier, Novartis, Teva: Honoraria. Assouline:AbbVie: Consultancy, Honoraria, Speakers Bureau; AstraZeneca: Consultancy, Honoraria, Speakers Bureau; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria, Research Funding; Pfizer: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Speakers Bureau; Takeda: Research Funding. Lamanna:MingSight: Other: Institutional research grants, Research Funding; Astra Zeneca: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Oncternal, Verastem, TG Therapeutics: Other: Institutional research grants, Research Funding; Pharmacyclics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Juno: Other: Institutional research grants, Research Funding; Loxo: Research Funding; Genentech: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Gilead: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees; Bei-Gene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Abbvie: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: Institutional research grants, Research Funding; Octapharma: Research Funding; Columbia University Medical Center: Current Employment; Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees. Robak:Abbvie, Pharmacyclics, Gilead, GlaxoSmithKline, Novartis, Janssen, Roche, Acerta, AstraZeneca, BioGene, UCB: Research Funding; Abbvie, Pharmacyclics, Novartis, Janssen, Acerta, AstraZeneca, BioGene, UCB, Sandoz: Honoraria; Sandoz, Janssen, AbbVie, Roche, Gilead: Consultancy. de la Serna:F. Hoffmann-La Roche, Abbvie, Pharmacyclics, Gilead, GlaxoSmithKline, Novartis, Janssen, Roche, Acerta, AstraZeneca, BioGene, UCB: Research Funding; Abbvie, AstraZeneca: Other: Travel, Accommodations, Expenses; Abbvie, Janssen: Speakers Bureau; Gilead, AstraZeneca, Abbvie, Janssen, Sandoz, F. Hoffmann-La Roche: Consultancy; Abbvie, Pharmacyclics, Novartis, Janssen, Acerta, AstraZeneca, BioGene, UCB, Sandoz: Honoraria. Jaeger:F. Hoffmann-La Roche: Honoraria, Research Funding. Cartron:Celgene: Consultancy, Honoraria; F. Hoffmann-La Roche: Consultancy, Honoraria; Sanofi: Honoraria; Gilead: Honoraria; Jansen: Honoraria; Abbvie: Honoraria. Montillo:Gilead: Honoraria, Speakers Bureau; AbbVie: Honoraria, Speakers Bureau; F. Hoffmann-La Roche: Honoraria, Research Funding; Janssen: Honoraria, Speakers Bureau; Astra Zeneca: Honoraria; Verastem: Honoraria. Mellink:Genentech, Inc: Research Funding; Amsterdam University Medical Centre: Current Employment. Chyla:AbbVie: Current Employment, Current equity holder in publicly-traded company. Wilson:Roche Products Limited: Current Employment. Wu:Genentech, Inc.: Current Employment, Current equity holder in publicly-traded company; F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Jiang:F. Hoffmann-La Roche: Current equity holder in publicly-traded company; Genentech, Inc.: Current Employment. Lefebure:F. Hoffmann-La Roche: Current Employment, Current equity holder in publicly-traded company. Boyer:Roche: Current Employment, Current equity holder in publicly-traded company, Other: TRAVEL, ACCOMMODATIONS, EXPENSES (paid by any for-profit health care company). Seymour:Mei Pharma: Consultancy, Honoraria; Nurix: Honoraria; Morphosys: Consultancy, Honoraria; Gilead: Consultancy; AstraZeneca: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Honoraria, Research Funding; F. Hoffmann-La Roche: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Celgene: Consultancy, Honoraria, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau.