C-type lectin receptors (CLRs) play critical roles as pattern-recognition receptors (PRRs) for sensing Candida albicans infection, which can be life-threatening for immunocompromised individuals. Here we have shown that Dectin-3 (also called CLECSF8, MCL, or Clec4d), a previously uncharacterized CLR, recognized α-mannans on the surfaces of C. albicans hyphae and induced NF-κB activation. Mice with either blockade or genetically deleted Dectin-3 were highly susceptible to C. albicans infection. Dectin-3 constantly formed heterodimers with Dectin-2, a well-characterized CLR, for recognizing C. albicans hyphae. Compared to their respective homodimers, Dectin-3 and Dectin-2 heterodimers bound α-mannans more effectively, leading to potent inflammatory responses against fungal infections. Together, our study demonstrates that Dectin-3 forms a heterodimeric PRR with Dectin-2 for sensing fungal infection and suggests that different CLRs may form different hetero- and homodimers, which provide different sensitivity and diversity for host cells to detect various microbial infections.

EGF activates NF-kB, and constitutively activated NF-kB contributes to EGFR mutation-associated tumorigenesis, but it remains unclear precisely how EGFR signaling leads to NF-kB activation. Here we report that CARMA3, a caspase recruitment domain (CARD)-containing scaffold molecule, is required for EGF-induced NFkB activation. CARMA3 deficiency impaired the activation of the IKK complex following EGF stimulation, resulting in a defect of EGF-induced IkBa phosphorylation and NF-kB activation. We found that CARMA3 and Bcl10 contributed to several characteristics of EGFR-associated malignancy, including proliferation, survival, migration, and invasion. Most importantly, CARMA3 contributed to tumor growth in vivo. Our findings elucidate a crucial link between EGFR-proximal signaling components and the downstream IKK complex, and they suggest a new therapeutic target for treatment of EGFR-driven cancers. Cancer Res; 71(6); 2183-92. Ó2011 AACR.

Polygalacturonase (PG) is an essential hydrolytic enzyme responsible for pectin degradation and thus plays an important role in fruit softening and other cell separation processes. PG protein is encoded by a multigene family, however, the members of PG gene family in kiwifruit (Actinidia chinensis) have not been extensively identified. In this study, a total of 51 AcPG genes in kiwifruit genome were identified. They are phylogenetically clustered into seven clades, and of them AcPG4 and AcPG18 with other known PG genes involved in fruit softening from peach, pear, papaya and melon form a small cluster together. The members of kiwifruit PG gene family consist of three to nine exons and two to eight introns, and their exon/intron structures are generally conserved in all clades except the clade D and E. During fruit softening of kiwifruit ‘Donghong’ under ambient temperature, cell wall modifying enzymes, including PG, PL (pectate and pectin lyases), and PE (pectinesterase, also known as pectin methylesterase, PME) showed a different activity profile, and of them, PG and PE activities largely correlated with the change of pectin content and firmness. Moreover, only 11 AcPG genes were highly or moderately expressed in softening fruit, and of which three AcPG genes (AcPG4, AcPG18, and AcPG8, especially the former two) has been found to strongly correlate with the profile of PG activity and pectin content, as well as fruit firmness, suggesting that they maybe play an important role in fruit softening. Thus, our findings not only benefit the functional characterization of kiwifruit PG genes, but also provide a subset of potential PG candidate genes for further genetic manipulation.

dependent increase in acH3K27 and acH3K18 (EC50 83.4 ± 1.3 -269.9 ± 0.8 nM). YF2 was chosen as the lead compound because it demonstrated functional effect on acetylation and selective cytotoxicity in EP300 mutated verses WT Conclusion: Ex-vivo high-throughput drug screening discovers entity/genotype-specific vulnerabilities. BCR inhibitors lead to alteration of drug sensitivity pattern which can be assessed and may form the basis for optimized combination treatment. Our data of drug response profiles and Omics characterization will provide a unique tool to query molecular determinants of response and thus provide hypothesis for clinical trials.

Background - Combination of ibrutinib plus rituximab (IR) has generated significant efficacy and safety data in relapsed patients (pts) with MCL. In this single institution phase II trial, we investigated the efficacy and safety of using an IR combination followed by short course (4 cycles) of R-HCVAD/MTX-ara-C as consolidation in previously untreated young (age ≤ 65 years) pts with MCL. We hypothesized that using a chemo-free induction will mitigate the toxicities and risk of second cancers which are associated with the use of intensive chemoimmunotherapy regimen in these pts. Methods - We enrolled 131 previously untreated young (≤65 years) pts with MCL. This study is registered with a ClinicalTrials.gov identifier number NCT02427620. Pts received IR induction (part-A), until they achieved complete remission (CR) for up to a maximum of 12 cycles, followed by a maximum of 4 cycles of R-HCVAD/R-MTX-ara-C (part-B) as consolidation. None of the patients received stem cell transplant or maintenance therapy. The primary objective was to assess overall response rate (ORR), [defined as either a partial response (PR) or a complete response (CR)] after part A. Adverse events were coded as per CTCAE version 4. Among evaluable samples, minimal residual disease (MRD) by flow cytometry at best response, clonal evolution using circulating tumor DNA (ctDNA), baseline somatic mutations and baseline gene expression profile (GEP) are being evaluated. Results - Among the 131 pts, the median follow up was 22 months (1.4-48.70). Eighty percent were males. Median age was 56 yrs (range - 35-65). Forty nine percent had high Ki-67 (≥30%), 80% had low risk simplified MIPI score and 85% pts had initial marrow involvement. Fifteen pts had aggressive MCL (blastoid/pleomorphic), 17 pts had complex karyotype and 83% had positive SOX-11 expression. Median number of cycles on IR in part A was 7 (1-12). At week 16 on part A, the ORR was 95% (22% CR and 73% PR) and 5% pts had stable disease. Overall best response (ORR) on part A of therapy was 100% (88% CR and 12% PR) and at the time of last follow up after completion of part A and part B, ORR was 100% (94% CR). Among evaluable pts, MRD- negative CR rate assessed by bone marrow flow cytometry performed at best response at any phase of treatment was 78%. Among the 10 pts with TP53 mutations, 70% had a CR on part A alone. Overall, the median PFS and OS were not reached (3 year 85% and 97% respectively). Nine pts had relapsed after treatment, including 3 who transformed. Among these 9 pts, 7/9 pts had Ki-67% ≥ 30% and 3/9 pts had aggressive histology MCL. The PFS and OS were not significantly different among pts with high and low Ki-67% and among pts with/without achieving CR on part A and while PFS was significantly shorter in pts with aggressive MCL histology (p=0.005) but not the OS. Overall 3 pts died (one on study due to splenic hematoma, cardio-pulmonary arrest and was on IR for 1 month, one expired outside and was off study after discontinuation due to encephalitis and another expired outside and discontinued due to disease transformation). Twenty one pts came off study for various reasons [nine disease progression (including 3 transformation), 8 pt choice, 3 intolerance and one second cancer]. Grade 3-4 toxicities on part A were 4% myelosuppression and 8% each with fatigue, myalgia and rashes and 4% mucositis. None had grade 3-4 atrial fibrillation or bleeding. GEP was performed in 18 pts (2 PR, 16 CR on part A). Pts in PR had higher expression of HES1 while those in CR had significantly higher expression of CTLA4 and ITK genes compared with those in PR. Targeted DNA sequencing was done in 18 pts at baseline, one pt with PR had NSD2, KMT2C and another pt had TP53 mutations and had CR. Conclusions - Excellent responses were observed with IR combination which is a chemo-free induction treatment strategy for young pts with MCL. This treatment approach has a strong potential to change the treatment paradigm in MCL pts to minimize the toxicity from chemoimmunotherapy without compromising the treatment efficacy and safety. Disclosures Wang: Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pharmacyclics: Honoraria, Research Funding; Acerta Pharma: Consultancy, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding, Speakers Bureau; VelosBio: Research Funding; Loxo Oncology: Research Funding; Celgene: Honoraria, Research Funding; Juno Therapeutics: Research Funding; Aviara: Research Funding; Dava Oncology: Honoraria; MoreHealth: Consultancy, Equity Ownership; BioInvent: Consultancy, Research Funding; Guidepoint Global: Consultancy; Kite Pharma: Consultancy, Research Funding. Lee:Seattle Genetics, Inc.: Research Funding. Westin:Genentech: Other: Advisory Board, Research Funding; Curis: Other: Advisory Board, Research Funding; Unum: Research Funding; 47 Inc: Research Funding; Janssen: Other: Advisory Board, Research Funding; Novartis: Other: Advisory Board, Research Funding; Juno: Other: Advisory Board; Celgene: Other: Advisory Board, Research Funding; MorphoSys: Other: Advisory Board; Kite: Other: Advisory Board, Research Funding. Nastoupil:Bayer: Honoraria; Celgene: Honoraria, Research Funding; Gilead: Honoraria; Genentech, Inc.: Honoraria, Research Funding; Novartis: Honoraria; TG Therapeutics: Honoraria, Research Funding; Spectrum: Honoraria; Janssen: Honoraria, Research Funding. Neelapu:Precision Biosciences: Consultancy; Kite, a Gilead Company: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Unum Therapeutics: Consultancy, Research Funding; Poseida: Research Funding; Cell Medica: Consultancy; Karus: Research Funding; Acerta: Research Funding; Pfizer: Consultancy; Celgene: Consultancy, Research Funding; Novartis: Consultancy; Cellectis: Research Funding; Incyte: Consultancy; Allogene: Consultancy; BMS: Research Funding. Fowler:TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding.

No abstract

Background - Mantle cell lymphoma (MCL) generally affects patients with a median age of 71 years. Majority of elderly MCL patients are transplant ineligible and are not suitable for intensive chemoimmunotherapy. Considering these limitations, our efforts are focused on developing "chemotherapy-free" modalities to treat these patients. We have previously reported high efficacy from a combination of ibrutinib with rituximab (IR) in relapsed MCL (Wang M et al Lancet Oncology 2015). We will now present the efficacy/safety analysis of our single center, phase II clinical trial using IR in previously untreated elderly (age ≥65 years) patients (pts) with MCL. Methods - We enrolled previously untreated elderly (≥65 years) MCL pts (n=50) in this study (NCT01880567). Pts with Ki-67% ≥ 50%, blastoid/pleomorphic histology and those with clinically uncontrolled co-morbidities (including atrial fibrillation) were excluded from this study. Pts received IR combination - ibrutinib 560 mg orally daily for 28 days (one cycle) continued until disease progression or discontinued for any reason. Rituximab was given on days 1, 8, 15 and 22 +/- 1 day by intravenous infusion (IV) at a fixed dose of 375 mg/m2 (Cycle 1, followed by rituximab on day 1 of every cycle starting in Cycles 3 - 8. Following cycle 8, rituximab was given on day 1 of every other cycle for up to 2 years. The primary objective was to assess the response rate and safety of IR in elderly MCL. Among evaluable samples, minimal residual disease (MRD) by flow cytometry at best response and whole exome sequencing (WES) from baseline tissue samples was performed. Results - Forty nine pts were included in this analysis. Median age was 71 years (range 65-84), 75% were males, ECOG PS was (0/1) in 48 (98%) pts, 16% had high risk simplified MIPI score and 28% had high risk biologic MIPI score. Forty seven patients (96%) had initial bone marrow involvement by MCL. The Ki-67% was low (<30%) in 37 (76%) and high (≥30-50%) in 12 (24%) pts, and 9% had complex karyotype. Eleven pts had prior history of atrial fibrillation. Overall, the median number of IR cycles was 16 (1-47). At the time of last follow up, 30 pts remained on study and 19 (39%) discontinued therapy for various reasons - atrial fibrillation (n=7; 3 had new onset and 4 had prior history of atrial fibrillation), disease progression (n=4), bleeding (n=3; 2 were on systemic anticoagulation and one pt was on aspirin 81 mg), infections (n=2) and one pt each due to myocardial infarction, esophageal cancer (unlikely related to drug) and patient choice. Dose reduction was performed in 26 (53%) pts for various reasons (7 atrial fibrillation, 6 infections, 5 bleeding, 3 myalgias and 5 miscellaneous). Most frequent grade 3-4 toxicities were 14% myalgias, 14% fatigue, 10% shortness of breath, 8% neutropenia and 8% new onset atrial fibrillation. Most of the atrial fibrillation events occurred early on in 2015-2016. These events were very infrequent in most recently enrolled pts which underwent meticulous cardiology screening and follow up. Seven pts were not evaluable for response assessment. The best overall response (ORR) was 98% (60% CR, 38% PR, 2% stable disease). Median number of IR cycles to reach CR was 8 (3-23). Thirty nine pts had baseline PET done and 34/39 were positive (87%) at baseline, of these 34 pts, 31 were evaluable for PET based response and 26/31 (84%) had CR, 4/31 (13%) had PR. Among the evaluable patients (n=26), minimal residual disease (MRD) negative CR by flow cytometry at best response was observed in 21 (81%). Overall, the median follow up was 28 months (6-42) and the median duration of pts on study was 19 months (range 1-45). Four pts progressed (3 transformed to blastoid/pleomorphic MCL) on study after taking IR for 4, 9, 13 and 33 months. Two pts died (one due to disease progression and another unknown etiology). The Median PFS and OS were not reached. Among pts with low and high Ki-67%, median PFS was not reached in both groups (p=0.26) and OS was not reached (p=0.01). Pts who achieved CR had a clear trend of longer PFS and OS compared to those who didn't achieve CR. Conclusions - IR combination is an excellent frontline treatment option for elderly pts with MCL. Pts with baseline arrhythmias or pre-existing cardiac comorbidities could be managed cautiously and successfully while on this combination and are recommended to closely follow up with cardiology and may need an adjustment of anti-arrhythmic or ibrutinib dosing for optimal management. Disclosures Lee: Seattle Genetics, Inc.: Research Funding. Westin:Juno: Other: Advisory Board; 47 Inc: Research Funding; Unum: Research Funding; Celgene: Other: Advisory Board, Research Funding; Novartis: Other: Advisory Board, Research Funding; Genentech: Other: Advisory Board, Research Funding; Kite: Other: Advisory Board, Research Funding; Janssen: Other: Advisory Board, Research Funding; MorphoSys: Other: Advisory Board; Curis: Other: Advisory Board, Research Funding. Nastoupil:Spectrum: Honoraria; TG Therapeutics: Honoraria, Research Funding; Novartis: Honoraria; Janssen: Honoraria, Research Funding; Gilead: Honoraria; Genentech, Inc.: Honoraria, Research Funding; Bayer: Honoraria; Celgene: Honoraria, Research Funding. Neelapu:Celgene: Consultancy, Research Funding; Merck: Consultancy, Research Funding; Acerta: Research Funding; BMS: Research Funding; Cellectis: Research Funding; Kite, a Gilead Company: Consultancy, Research Funding; Cell Medica: Consultancy; Pfizer: Consultancy; Precision Biosciences: Consultancy; Incyte: Consultancy; Novartis: Consultancy; Karus: Research Funding; Poseida: Research Funding; Unum Therapeutics: Consultancy, Research Funding; Allogene: Consultancy. Fowler:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Abbvie: Membership on an entity's Board of Directors or advisory committees, Research Funding; TG Therapeutics: Membership on an entity's Board of Directors or advisory committees, Research Funding; Roche: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding. Wang:Juno Therapeutics: Research Funding; Aviara: Research Funding; Acerta Pharma: Consultancy, Research Funding; Dava Oncology: Honoraria; Loxo Oncology: Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding, Speakers Bureau; MoreHealth: Consultancy, Equity Ownership; Kite Pharma: Consultancy, Research Funding; Guidepoint Global: Consultancy; BioInvent: Consultancy, Research Funding; VelosBio: Research Funding; Celgene: Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding, Speakers Bureau; Pharmacyclics: Honoraria, Research Funding. OffLabel Disclosure: Ibrutinib and rituximab in frontline mantle cell lymphoma

Background Mantle cell lymphoma (MCL) is a rare and aggressive B-cell lymphoma characterized by poor prognosis. Although remarkable therapeutic advances have been made by covalent Bruton's tyrosine kinase (BTK) inhibition and CAR T cell therapy, therapeutic resistance inevitably occurs and leads to dismal clinical outcome. Pirtobrutinib (LOXO-305) is a next-generation, highly selective and non-covalent BTK inhibitor. A phase 1/2 BRUIN study showed that pirtobrutinib demonstrated promising efficacy in heavily pretreated MCL patients with or without prior covalent BTK inhibition. Here, we investigated the mechanism of action of pirtobrutinib in MCL cells in vitro and proposed the potential combination therapy in a venetoclax-resistant xenograft model. Methods MCL cell proliferation was monitored by trypan blue exclusion assay after 24-, 48- and 72-hour treatment with pirtobrutinib and ibrutinib. We performed Annexin V/PI staining to measure the apoptosis inductive effects. Cell cycle analysis using propidium iodide (PI) DNA staining was conducted to compare cell cycle progression kinetics between pirtobrutinib and ibrutinib. We performed RNAseq analysis in Z138 cells to compare differentially expressed genes (DEGs) between pirtobrutinib and ibrutinib treatment. Western blotting was utilized to detect specific signaling proteins. Mino-venetoclax-R cells were inoculated subcutaneously into NSG mice and used for in vivo drug efficacy determination. Results Compared to covalent BTK inhibitor ibrutinib, the novel non-covalent BTK inhibitor pirtobrutinib was more potent in inhibiting MCL cell proliferation in a panel of MCL cell lines, especially in ibrutinib/venetoclax resistant cell lines (pirtobrutinib vs. ibrutinib, p&lt;0.01). Treatment with pirtobrutinib (10μM) for 24 hours induced higher levels of apoptosis than that by ibrutinib in all the MCL cell lines tested (p&lt;0.05), which was also confirmed at the molecular level by stronger caspase-3 activation and PARP cleavage. To understand the mechanism of action, we performed whole transcriptomic profiling by RNAseq analysis using Z138 cells treated with/without pirtobrutinib or ibrutinib. Pirtobrutinib treatment resulted in upregulation of 137 genes and downregulation of 97 genes compared to the ibrutinib treatment (adjusted p&lt;0.05). In addition to the downregulated MYC targets and PI3K/Akt pathway, gene set enrichment analysis (GSEA) revealed a significant enrichment for G2/M checkpoints and E2F targets signatures (key genes: PLK1, CDKN1A and CCNB1) in pirtobrutinib treated cells. Consistently, follow-up studies showed that γH2AX level was highly increased upon pirtobrutinib treatment. Pirtobrutinib treatment but not ibrutinib treatment resulted in G2/M cell cycle arrest. The blockade of cell cycle progression is positively correlated with decreased protein levels of critical regulators of S and G2/M phase transition such as cyclin B and CDC25C. BTK inhibitor (ibrutinib) in combination with venetoclax has shown great efficacy in preclinical models and in MCL patients. Therefore, here we assessed the in vivo efficacy of pirtobrutinib in combination with venetoclax with side-by-side comparison to ibrutinib & venetoclax in the Mino-venetoclax-R mouse model. Pirtobrutinib & venetoclax combination enhanced the efficacy of pirtobrutinib in restraining the tumor size (p&lt;0.001) in the xenograft model. Notably, this novel combinatorial treatment exerted much higher potency than ibrutinib and venetoclax combination therapy (p&lt;0.001). In addition, the pirtobrutinib & venetoclax combination was well tolerated and did not reduce overall mouse body weights compared with the vehicle treated mice. Conclusions Pirtobrutinib overcame both ibrutinib and venetoclax resistance in MCL cells in vitro and in vivo. G2/M checkpoints and E2F targets pathways were significantly enriched in both cases. Pirtobrutinib & venetoclax showed better in vivo efficacy in MCL models than combination of ibrutinib & venetoclax. Figure 1 Figure 1. Disclosures Wang: Genentech: Consultancy; Juno: Consultancy, Research Funding; Kite Pharma: Consultancy, Honoraria, Research Funding; Clinical Care Options: Honoraria; CAHON: Honoraria; InnoCare: Consultancy, Research Funding; Moffit Cancer Center: Honoraria; Molecular Templates: Research Funding; Oncternal: Consultancy, Research Funding; DTRM Biopharma (Cayman) Limited: Consultancy; Hebei Cancer Prevention Federation: Honoraria; Lilly: Research Funding; Loxo Oncology: Consultancy, Research Funding; BioInvent: Research Funding; OMI: Honoraria; Miltenyi Biomedicine GmbH: Consultancy, Honoraria; Imedex: Honoraria; Physicians Education Resources (PER): Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Bayer Healthcare: Consultancy; Chinese Medical Association: Honoraria; Dava Oncology: Honoraria; Celgene: Research Funding; Mumbai Hematology Group: Honoraria; Acerta Pharma: Consultancy, Honoraria, Research Funding; BeiGene: Consultancy, Honoraria, Research Funding; Newbridge Pharmaceuticals: Honoraria; CStone: Consultancy; BGICS: Honoraria; The First Afflicted Hospital of Zhejiang University: Honoraria; Scripps: Honoraria; Epizyme: Consultancy, Honoraria; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; VelosBio: Consultancy, Research Funding; Anticancer Association: Honoraria.