Abstract: Introduction. The association of Azacitidine (AZA) and Lenalidomide (LEN), either administered concurrently (Sekeres, 2010; 2012; 2017), or sequentially (Platzbecker, 2013; Di Nardo 2015; Mittelman 2016; Narayan 2016) has proven effective in Myelodysplastic Syndromes (MDS), however the optimum dose and schedule remains unknown. The aim of this study was to evaluate the efficacy and safety of the combination vs the sequential use of AZA and LEN in higher-risk MDS pts. Primary endpoint: ORR, defined as the Rate of Complete Remission (CR), Partial Remission (PR), Marrow Complete Remission (mCR), and Hematological Improvement (HI), following the IWG criteria (Cheson, 2006). Secondary endpoints: a) rate of CR; b) duration of responses; c) overall survival (OS). Methods. This is a randomized, phase II, multicenter, open label study, including pts with MDS with IPSS risk High or Intermediate-2, without previous treatment with AZA or LEN. ARM 1 (combined treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 1-21), orally, every 4 weeks. ARM 2 (sequential treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 6-21), orally, every 4 weeks. The induction treatment was planned for 8 cycles. For responder patients the same treatment was continued until disease progression or unacceptable toxicity. Results. From March 2013, 44 pts (27 males), median age: 72 (48-83 yrs) were enrolled, from 13 hematologic Centers. At baseline, IPSS risk was: Intermediate-2: 31 pts; High: 9 pts; not determined (N.D.) (because of lack of cytogenetic data): 2 pts. (all with RAEB-2). In 2 pts IPSS risk was Intermediate-1, but they were enrolled because of severe thrombocytopenia and neutropenia, respectively. IPSS-R risk was: intermediate: 8 pts; High: 16 pts; Very-High: 18 pts; N.D.: 2 pts. In 5 pts (11.4%) del(5q) was present (additional cytogenetic alterations: 1 in 1 pt, and 〉 1 in 4 pts , respectively). 21 pts were randomly assigned to ARM 1, and 23 pts to ARM 2. Treatment was given for a median of 8.5 (1-52) cycles; in ARM 1: 9 (1-51) cycles; in ARM 2: 8 (1-52) cycles, respectively. Median follow-up: 15 (2-54) months; 47 (37-54) months for survivors. 10/44 pts (22.7%) did not complete at least 6 cycles of treatment for causes other than disease progression (6 pts for adverse events, 2 pts for consent withdrawal and 2 pts for medical decision), and were not considered evaluable for response. Among the 34/44 pts (77.3%) evaluable for response, 26/34 pts (ORR: 76.5 %) showed a favourable response to treatment. Intention-to-treat (ITT) analysis: ORR: 59.1%. First response was observed after a median of 2 (1-8) cycles. The Best Response achieved was: CR: 8 pts (23.5%) (ITT: 18.1%), PR: 1 pt (2.9%) (ITT: 2.2%), mCR: 3 pts (8.8%) (ITT: 6.8%), HI: 8 pts (23.5%) (ITT: 18.1%), mCR+HI: 6 pts (17.6%) (ITT: 13.6%). The remaining 8 pts showed either Stable Disease (SD) (6 pts, 17.6%) or Disease Progression (DP) (2 pts, 5.9%). Among the 27 pts (21 evaluable for response) with an abnormal karyotype at baseline, ORR was 66.7% (ITT: 51.8%) and 4 pts achieved complete cytogenetic response. Median duration of hematologic response: 10.5 months. 34 pts (77,3%) died , and 17 pts (38.6%) showed progression to AML. Grade 〉 2 non haematological toxicity: 54.5%. Median OS: 15 months. No significant differences between the 2 arms were observed, in terms of ORR (ARM 1: 76.5%, ITT: 61.9%; ARM 2: 76.5%, ITT: 56.5%), CR rate (ARM 1: 17.6%, ITT: 14.3%; ARM 2: 29.4%, ITT: 21.7%), grade 〉 2 non haematological toxicity (ARM 1: 66.7%; ARM 2: 43.5%), AML incidence (ARM 1: 28.6%; ARM 2: 47.8%) and OS (ARM 1: 14 months; ARM 2: 16 months), but the median response duration was significantly longer in ARM 2 (18 months) as compared to ARM 1 (6 months) (p=0.0459). At the time of last analysis, 5/44 (11.4%) patients, 1/21 (4.8%) in ARM 1, and 4/23 (17.4%) in ARM 2, were still maintaining the haematological response, and were still in treatment, after 54, 54, 52, 51 and 37 months, and after 52, 51, 33, 48 and 35 cycles of therapy, respectively. The changes observed during treatment in mutational status of inositide-specific genes and microRNA expression profiling were related to clinical outcome, predicting a negative response to therapy. Conclusions. Our results confirm the efficacy of both AZA+LEN treatment regimens in higher-risk MDS pts, in terms of ORR and OS, although pts treated with the sequential regimen showed a significantly longer duration of haematological response. Disclosures Finelli: Celgene: Other: speaker fees, Research Funding; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees, Other: speaker fees; Janssen: Membership on an entity's Board of Directors or advisory committees, Other: speaker fees. Candoni:Janssen: Honoraria, Speakers Bureau; Celgene: Honoraria, Speakers Bureau; Gilead: Honoraria, Speakers Bureau; Pfizer: Honoraria, Speakers Bureau; Merck SD: Honoraria, Speakers Bureau. Gobbi:Novartis: Consultancy; Janssen: Consultancy; Ariad: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy; Pfister: Membership on an entity's Board of Directors or advisory committees. Rigolin:Gilead: Research Funding. Cavo:GlaxoSmithKline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Adaptive Biotechnologies: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol-Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Abstract: Introduction. Azacitidine (AZA) is the standard of care of higher-risk myelodysplastic syndromes (MDS), but the duration of clinical response is limited, and outcome after AZA failure is dismal. Several studies have demonstrated the efficacy and safety of combining AZA with Lenalidomide (LEN), either administered concurrently or sequentially, however the optimum dose and schedule for this combination remains unknown. The aim of this study was to evaluate the efficacy and safety of the combination vs the sequential use of AZA and LEN in higher-risk MDS pts (IPSS score risk: High or INT-2), and to look for possible biomarkers able to predict response. Primary endpoint: ORR, defined as the Rate of Complete Remission (CR), Partial Remission (PR), Marrow Complete Remission (mCR), and Hematological Improvement (HI), following the International Working Group (IWG) criteria (Cheson, 2006). Methods. This is a randomized, phase II, multicenter, open label study, including pts with MDS (WHO 2008 classification) with International Prognostic Scoring System (IPSS) risk High or Intermediate-2, without previous treatment with AZA or LEN. ARM 1 (combined treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 1-21), orally, every 4 weeks. ARM 2 (sequential treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 6-21), orally, every 4 weeks. The induction treatment was planned for 8 cycles (32 weeks). For responder patients (CR, PR, mCR, or HI) the same treatment was continued until disease progression or unacceptable toxicity. A sample size of 44 pts was planned. Results. From March 2013, 44 pts (27 males), with a median age of 72 (48-83 yrs) were enrolled, from 13 hematologic italian Centers. At baseline, IPSS risk was: Intermediate-2: 31 pts; High: 9 pts; not determined (N.D.) (because of lack of cytogenetic data): 2 pts. (all with RAEB-2). In 2 pts IPSS risk was Intermediate-1, but they were enrolled because of severe thrombocytopenia and neutropenia, respectively. IPSS-R risk was: intermediate: 8 pts; High: 16 pts; Very-High: 18 pts; N.D.: 2 pts. In 5 pts (11.4%) del(5q) was present. 21 pts were randomly assigned to ARM 1, and 23 pts to ARM 2. 34/44 pts (77.3%) completed ≥ 6 cycles of treatment, and are evaluable for response. The remaining 10 pts (4 in ARM 1 and 6 in ARM 2) are not evaluable for response, as they discontinued treatment before completing the 6th cycle because of adverse events (6 pts, 13.6%), consent withdrawal (2 pts, 4.5%) or medical decision (2 pts, 4.5%), respectively. Treatment was given for a median of 8.5 (1-37) cycles; in ARM 1: 9 (1-32) cycles, in ARM 2: 8 (1-37) cycles, respectively. 6 pts (ARM 1: 2; ARM 2: 4) are still on treatment. Pts have been followed for a median of 15 (2-37) months for all subjects, for a median of 32 (18-37) months for survivors. Among the 34 pts evaluable for response, 26/34 pts (ORR: 76.5 %) showed a favourable response to treatment. The Best Response achieved was: CR: 8 pts (23.5%), PR: 1 pt (2.9%), mCR: 3 pts (8.8%), HI: 8 pts (23.5%), mCR+HI: 6 pts (17.6%). The remaining 8 pts showed either Stable Disease (SD) (6 pts, 17.6%) or Disease Progression (DP) (2 pts, 5.9%). First Response was detected after a median of 2 (1-8) cycles. The median duration of hematologic response was 10.5 months. A grade 〉 2 non hematologic toxicity was observed in 54.5 % of pts, and an emerging (from grade 0-2 to 〉 2) hematologic toxicity in 27.3% of pts. In 61.4% of pts LEN dose was reduced because of hematologic or non-hematologic toxicity. 32 pts (72.7%) died , and 17 pts (38.6%) showed progression to AML. Median overall survival (OS) was 15 months. No significant differences between the 2 arms were observed, in terms of ORR, CR rate, toxicity, AML incidence and OS, but there was a trend (although still not significant) towards a longer median duration of response in the sequential arm: ARM 1: 6 months; ARM 2: 18 months (p=0.0847). MDS cells showed alterations of the inositide-dependent signalling as well as an altered microRNA profile. In particular, responder cases showed a frequent downregulation of miR-3613 and mir-4668, that were upregulated in non responder cases. Further analyses are ongoing. Conclusions. Our results confirm the efficacy of both AZA+LEN treatment regimens in higher-risk MDS pts, in terms of ORR, although the sequential schedule seems to induce more durable responses. Moreover, possible relationships with signal transduction pathways and microRNA profile are under evaluation. Disclosures Finelli: Novartis: Other: Speaker fees; Celgene: Other: Speaker fees; Celgene: Research Funding. Gobbi:Janssen: Consultancy, Honoraria; Novartis: Consultancy, Research Funding; Roche: Honoraria; Takeda: Consultancy; Gilead: Honoraria; Celgene: Consultancy; Mundipharma: Consultancy, Research Funding. Cavo:Bristol-Myers Squibb: Consultancy, Honoraria; Millennium: Consultancy, Honoraria; Celgene: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen-Cilag: Consultancy, Honoraria.

Abstract: Introduction. Azacitidine (AZA) is able to induce hematologic responses in 50-60 % of patients (pts) with Myelodysplastic Syndromes (MDS) and moreover to prolong survival in higher risk MDS pts. Recently, several studies have evaluated the efficacy and safety of combining, in high-risk MDS pts, AZA with Lenalidomide (LEN), either administered concurrently (Sekeres, 2010; 2012), or sequentially (Platzbecker, 2013), in both cases showing promising results, although in a limited number of pts. The aim of this study was to evaluate the efficacy and safety of the combination vs the sequential use of AZA and LEN in high-risk MDS pts (IPSS score risk: High or INT-2). Primary endpoint: ORR, defined as the Rate of Complete Remission (CR), Partial Remission (PR), Marrow Complete Remission (mCR), and Hematological Improvement (HI), following the International Working Group (IWG) criteria (Cheson, 2006). Methods. This is a randomized, phase II, multicenter, open label study, including pts with MDS (WHO 2008 classification) with International Prognostic Scoring System (IPSS) risk High or Intermediate-2, without previous treatment with AZA or LEN. ARM 1 (combined treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 1-21), orally, every 4 weeks. ARM 2 (sequential treatment): AZA: 75 mg/m2/day (days 1-5) I.C. + LEN: 10 mg/day (days 6-21), orally, every 4 weeks. The induction treatment was planned for 8 cycles (32 weeks). For responder patients (CR, PR, mCR, or HI) the same treatment was continued until disease progression or unacceptable toxicity. A sample size of 44 pts was planned. Results. From March 2013, 44 pts (27 males), with a median age of 72 (48-83 yrs) were enrolled, from 13 hematologic italian Centers. At baseline, WHO diagnosis was: RCMD: 2 pts; RCMD-RS: 1 pt ; RAEB-1: 11 pts; RAEB-2: 30 pts; IPSS risk was: Intermediate-2: 31 pts; High: 9 pts; not determined (N.D.) (because of lack of cytogenetic data): 2 pts. (all with RAEB-2). In 2 pts IPSS risk was Intermediate-1, but they were enrolled because of severe thrombocytopenia and neutropenia, respectively. IPSS-R risk was: intermediate: 8 pts; High: 16 pts; Very-High: 18 pts; N.D.: 2 pts; IPSS cytogenetic risk was: Good: 17 pts; Intermediate: 11 pts; Poor: 14 pts; N.D.: 2 pts. 21 pts were randomly assigned to ARM 1, and 23 pts to ARM 2. At the time of this analysis, enrolment of the planned 44 pts was completed. 34/44 pts (77.3%) completed ≥ 6 cycles of treatment, and are evaluable for response. The remaining 10 pts (4 in ARM 1 and 6 in ARM 2) are not evaluable for response, as they discontinued treatment before completing the 6th cycle because of adverse events (6 pts, 13.6%), consent withdrawal (2 pts, 4.5%) or medical decision (2 pts, 4.5%), respectively. Treatment was given for a median of 8 (1-28) cycles; in ARM 1: 9 (1-22) cycles, in ARM 2: 8 (1-28) cycles, respectively. Among the 34 pts evaluable for response, 26/34 pts (ORR: 76.5 %) showed a favourable response to treatment. The Best Response achieved was: CR: 8 pts (23.5%), PR: 1 pt (2.9%), mCR: 3 pts (8.8%), HI: 8 pts (23.5%), mCR+HI: 6 pts (17.6%). The remaining 8 pts showed either Stable Disease (SD) (6 pts, 17.6%) or Disease Progression (DP) (2 pts, 5.9%). First Response was detected after a median of 2 (1-8) cycles. Responder pts were: 13/17 (ORR: 76.5 %) in ARM 1 (3 CR; 1 PR; 1 mCR; 4 HI, 4 mCR+HI), and 13/17 (ORR: 76.5 %) in ARM 2 (5 CR; 2 mCR; 4 HI; 2 mCR+HI), respectively. Overall, the median duration of response was 8.5 (2-23) months: 6 (2-19) months in ARM 1; 16 (2-23) months in ARM 2. A grade 〉 2 non hematologic toxicity was observed in 24/44 (54.5 %) pts (ARM 1: 66.7%; ARM 2: 43.5%). 27/44 pts (61.4 %) (ARM 1: 61.9%; ARM 2: 60.9%) had a dose reduction of LEN because of hematologic or non-hematologic toxicity. 22 pts (50%) died (ARM 1: 47.6%; ARM 2: 52.2%). 14 pts (31.8%) (ARM 1: 23.8%; ARM 2: 39.1%) showed progression to AML. Overall, median survival was 13 (1-28) months; ARM 1: 13 (1-25) months; ARM 2: 14 (2-28) months. Conclusions. Our results confirm the efficacy of both AZA + LEN treatment regimens in high-risk MDS pts. Moreover, at a molecular level, a significant increase of phosphoinositide-specific phospholipase C (PI-PLC) beta1 and/or PI-PLCgamma1 expression was associated with a favourable clinical response to treatment. Responder cases also showed an increase of Beta-globin expression, hinting at a specific contribution of LEN on erythroid activation Disclosures Finelli: Janssen: Other: Speaker; Novartis: Other: Speaker; Celgene: Other: Speaker, Research Funding. Visani:Celgene: Research Funding. Cavo:Janssen-Cilag, Celgene, Amgen, BMS: Honoraria.

Abstract: Although pathogenesis of small vessel disease is poorly understood, increasing evidence suggests that endothelial dysfunction may have a relevant role in development and progression of small vessel disease. In this cross-sectional study, we investigated the associations between imaging signs of small vessel disease and blood biomarkers of endothelial dysfunction at two different time points in a population of ischaemic stroke patients. Patients and methods In stroke patients treated with intravenous thrombolysis, we analysed blood levels of von Willebrand factor, intercellular adhesion molecule-1, vascular cell adhesion molecule-1 and vascular endothelial growth factor. Three reviewers independently assessed small vessel disease features using computed tomography. At baseline and 90 days after the index stroke, we tested the associations between single and combined small vessel disease features and levels of blood biomarkers using linear regression analysis adjusting for age, sex, hypertension, diabetes, smoke. Results A total of 263 patients were available for the analysis. Mean age (±SD) was 69 (±13) years, 154 (59%) patients were male. We did not find any relation between small vessel disease and endothelial dysfunction at baseline. At 90 days, leukoaraiosis was independently associated with intercellular adhesion molecule-1 (β = 0.21; p = 0.016) and vascular cell adhesion molecule-1 (β = 0.22; p = 0.009), and lacunes were associated with vascular endothelial growth factor levels (β = 0.21; p = 0.009) whereas global small vessel disease burden was associated with vascular endothelial growth factor (β = 0.26; p = 0.006). Discussion Leukoaraiosis and lacunes were associated with endothelial dysfunction, which could play a key role in pathogenesis of small vessel disease. Conclusions Small vessel disease features and total burden were associated with endothelial dysfunction 90 days after the stroke, whereas there was no relation during the acute phase. Our results suggest that endothelial dysfunction, particularly vascular endothelial growth factor, is involved in pathological process of small vessel disease.

Abstract: Background: The genetically heterogeneous and poor survival group of Philadelphia negative (Ph-) B-ALL group that doesn’t have the most recurrent adult rearrangements (t(9;22); t(1;19); t(4;11)) is collectively referred to as “triple negative” (Ph-/-/-). CRLF2 is frequently altered in adult B-ALL, especially in Ph-like pts (50-75% of cases). Alterations that lead, in the majority of cases, to a CRLF2 overexpression. Adult pts with CRLF2 upregulated have poor outcome and novel strategies are needed to improve it. Aims: Understand the genomic background of all Ph-/-/- ALL and subsequently clustering Ph-/-/- considering CRLF2 overexpression event, in order to define new biomarkers in these subgroups. Pts and Methods: Ph-/-/- pts were sequenced by WES (44pts/93 samples) and 92 B-Other pts were analyzed with NGS target seq (NTS) to validate the 8 most mutated genes (Fig1A). GEP were performed on 55 Ph-/-/-, 29 B-ALL Ph+ and on 7 donors. We cluster triple negative GEP data with our validated pipeline, based on CRLF2 upregulation and in a top ten-gene list. Ph-/-/- ALL samples were then characterized for the presence of gene fusions, Copy Number Alterations (CNAs) and mutations using different approaches (Pancancer and/or RNASeq; dMLPA-MRC-Holland; SNP Array; 454 Junior and PCR). Results: WES analysis identified some recurrent mutated genes (NRAS, PAX5, KRAS, PTPN11, EP400, JAK2, TP53, CREBBP) previously reported to be involved in B-ALL, confirming the pivotal roles of these gene in ALL. For the first time we described a little known gene PKHD1L1 as highly mutated (7.2%). TP53 was the most mutated gene (Fig1A) and that between these gene is the only one associated to a worst OS (p=0.004). Combining our new Ph-/-/- GEP clustering, WES, NTS, Fusion and CNA results we identify a defined 2-clusters-subdivision (Gr1 and Gr2). The Gr2 (14.1% of all B-ALL) is characterized by CTGF, CRLF2 and CD200 (Gr2=3C-up; Fig 1B) co-overexpression. The Gr2 GEP is similar to Ph+ one (Fig1C). Gr1 represents 46.9% of all B-ALL. Fusion, CNA and mutational screening done, detected that 3C-Up group has a higher frequency of Ph-like associated lesions (primarily CRLF2, JAK2, IL7R mut or del), that mainly affect JAK-STAT pathway. Also IKZF1 and EBF1 deletions are significantly associated to Gr2 (p=0.003; p=0.016). RAS pathway genes are highly affected in Gr1. We also validated not previously described fusions. Notably p53 pathway is enriched in both groups but with different deregulated genes: CHEK2 is upreg in the group1 and CDK6 in the Gr2. Preliminary data seems to confirm an higher effect on cell viability of a TKI on Gr2 primary cell pt (vs Gr1 pt). Conclusions: we identified a new signature, related to CRLF2 high expression, to classify Ph-/-/- ALL B. This new subclassification identifies new potential therapeutic targets with available drugs (α-CTGF, α-CD200, CDK2, CHK2 and CDK6 inhibitors; TKIs already effective on Ph+ and Ph-like) to test. Citation Format: Anna Ferrari, Silvia Vitali, Valentina Robustelli, Andrea Ghelli Luserna di Rorà, Eugenio Fonzi, Simona Righi, Carmen Baldazzi, Michela Tebaldi, Samanta Salvi, Cristina Papayannidis, Giovanni Marconi, Mariachiara Fontana, Enrica Imbrogno, Antonella Padella, Giorgia Simonetti, Alessandra Santoro, Jesus María Hernández-Rivas, Maria Teresa Bochicchio, Fabiana Mammoli, Benedetta Giannini, Nicoletta Testoni, Daniele Calistri, Massimiliano Bonafè, Gastone Castellani, Elena Sabattini, Daniel Remondini, Giovanni Martinelli. “3c-up” a new adult Philadelphia negative acute lymphoblastic leukemia subgroup: Novel molecular markers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2140.