ALBERT

Description: Background: Survival of pts with chronic lymphocytic leukemia (CLL) ranges from a few years to a normal lifespan. Clinical stages (i.e. Rai, Binet) are the basis for CLL prognostication but do not reflect the complex biology of CLL, which ultimately shapes the disease heterogeneity. Recently, a CLL-International Prognostic Index (CLL-IPI) which includes five clinical and biological variables (i.e. age, IGHV mutational status, del(17p), beta2-microglobulin [B2M] and Rai or Binet stages) and stratifies pts into four different categories has been proposed. This prognostic index is obtained by the sum of the score given to each parameter and includes dichotomized continuous variables. The aim of this study was to determine whether a prognostic model based only on biomarkers could separate CLL patients with different outcomes and simplify the CLL-IPI. Material and Methods: Five hundred twenty-four CLL pts from the Hospital Clínic, Barcelona, in whom information at diagnosis included age, clinical stage (Rai and Binet), IGHV mutational status, B2M, and FISH-cytogenetics were analyzed. For validation purposes a cohort of 417 pts from the Brno Hospital, Czech Republic was used. The two series included patients as seen in clinical practice. Primary endpoints were overall survival (OS) and time to first treatment (TTFT). The internal validity of the models was evaluated using bootstrapping, and the discriminatory value by c-statistics. Double sided P values 〈 .05 were considered significant. Results: First, we confirmed that all five covariates included in the CLL-IPI were independently predictive of OS. Both sets of five covariates (age + B2M + IGHV + FISH + Rai or Binet) were incorporated into the regression models. All four patient subgroups had a significantly different survival (c-statistic: 0.72), although the high- and very-high risk groups overlapped and the number of patients in the very-high-risk group was small. We then evaluated all possible combinations of these five covariates to identify the simplest model with robust discriminatory value. A prognostic model based on IGHV mutational status + FISH [del(17p) and/or del(11q)] separated three subgroups of pts [i.e, good-biomarkers (mutated IGHV + no poor FISH cytogenetics), intermediate-biomarkers (either unmutated IGHV or poor FISH cytogenetics), and poor biomarkers (unmutated IGHV + poor FISH cytogenetics)] with different prognosis (c-statistic: 0.68). In the Barcelona series, the good-biomarkers category identified around 50% of pts from the whole series whose survival did not differ from the general population; patients with intermediate-biomarkers had a projected 10-year survival of 68%. Finally, the poor-biomarkers category captured pts with a projected 10-year survival of 17%. The corresponding TTFTs at 3 years from diagnosis were 16%, 50% and 63%, respectively (Figure). Furthermore, it separated patients with different outcome within clinical stages, notably Binet A or Rai 0, and across all age groups. This model was fully validated in the Brno series. Conclusions: The biomarkers-only CLL prognostic model presented here is based on the two most important CLL biomarkers (i.e. IGHV mutational status and FISH cytogenetics) which are included as a backbone in the CLL-IPI and other CLL prognostic systems. This model is simple, easy to apply and to remember; it separates three groups of pts rather than four; it does not contain continuous variables; it can be applied to younger and older pts, and has clinical implications. This prognostic model could be useful in CLL prognostication either alone or in combination with clinical stages and warrants prospective validation, including in patients receiving targeted therapies. Figure Figure. Disclosures Montserrat: Pharmacyclics: Consultancy; Vivia Biotech: Equity Ownership; Janssen: Honoraria, Other: travel, accommodations, expenses; Gilead: Consultancy, Other: Expert Testimony; Morphosys: Other: Expert Testimony.

Description: Background and objective. Idelalisib is an oral inhibitor of the p110δ isoform of PI3K (phosphoinositide 3-kinase) approved in Europe and USA as monotherapy in relapsed/refractory follicular lymphoma (FL) after 2 previous lines of therapy based on a phase 2 study (Gopal et al, N Eng J Med 2014). However, there are scarce data on the use of idelalisib in clinical practice (Eyre et al, Br J Haematol 2017). The objective of this study was to analyze the efficacy and toxicity of idelalisib in relapsed/refractory FL patients in clinical practice in Spanish hospitals of GELTAMO group (GELT-IDE-2018-02 Study). Patients and Methods. Retrospective study of relapsed/refractory FL patients treated with idelalisib as salvage therapy in clinical practice. Demographic and clinical and biological variables were analyzed at FL diagnosis and at the time of idelalisib therapy, as well as its efficacy and toxicity. Results. A total of 43 patients from 20 hospitals were included. At time of idelalisib therapy, median age was 63 years (range 44-83), number of previous lines of therapy was 3 (2-7), 42% (n=18) were refractory to last previous treatment and 42% (n=18) had received an autologous stem cell transplantation (SCT); 56% (n=24) had progressed in the first 24 months after FL diagnosis (POD24). Median duration of treatment with idelalisib at time of analysis was 8.1 months (1.1-37.4) and 28/43 patients (65%) discontinued therapy, 13 due to progression, 12 due to adverse events (AE) and 3 due to physician's decision. Overall response rate (ORR) was 73% (32% CR) and median PFS 14.6 months (95% CI 0-32.2), with a trend to be higher in non-POD24 group (median PFS of 9.4 months [95% CI 1.7-16.9] in POD24 vs. 27 months [95% CI NA] in non-PO24 patients, p=0.082); median duration of response to idelalisib was 25.1 months (95% CI 13.1-37.6). Median overall survival (OS) was not reached at the time of analysis, with a 2-year OS of 74% (95% CI 58%-90%) (Figure). In 4 patients, an allogeneic SCT was performed after idelalisib. A total of 86% (n=37) of patients showed any AE, being in 56% (n=24) of grade ≥3 AE. Toxicities of grade ≥3 more frequent were: neutropenia (23% of patients), diarrhea (23%), infections (23%: pneumonia in 4 patients, CMV infection in 2, febrile neutropenia in 1 and other infections in 3 [1 of them died due to Aspergillus infection]), and increased transaminases (9%). Conclusions. In this series of patients with relapsed/refractory FL, several previous lines of therapies and factors associated with poor prognosis, the treatment with idelalisib was associated with efficacy and toxicity similar to published studies. These results support the use of idelalisib as an option for FL patients with multiple or poor risk relapses. Financial support: Gilead Figure. Progression-free survival (PFS) and overall survival (OS) for patients with follicular lymphoma treated with idelalisib. Figure Disclosures Sancho: SERVIER: Honoraria; SANOFI: Honoraria; Novartis: Consultancy, Honoraria; CELGENE: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; JANSSEN: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; ROCHE: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; GILEAD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; CELLTRION: Consultancy; Kern-Pharma: Honoraria; Sandoz: Consultancy. Lopez Jimenez:GILEAD SCIENCES: Honoraria, Other: Education funding. Ramirez Payer:GILEAD SCIENCES: Research Funding. Cordoba:Janssen: Consultancy, Honoraria, Speakers Bureau; Servier: Consultancy, Honoraria, Speakers Bureau; Kyowa-Kirin: Consultancy, Honoraria, Speakers Bureau; Gilead: Consultancy, Research Funding, Speakers Bureau; Roche: Honoraria, Speakers Bureau; FUNDACION JIMENEZ DIAZ UNIVERSITY HOSPITAL: Employment; Celgene: Consultancy, Honoraria, Speakers Bureau; Pfizer: Consultancy. Martín:Kiowa Kirin: Consultancy; Gilead: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Other: Travel Expenses, Research Funding; iQone: Consultancy; Teva: Research Funding; Janssen: Honoraria, Other: Travel Expenses, Research Funding; Roche: Consultancy, Honoraria, Other: Travel Expenses; Servier: Honoraria, Other: Travel Expenses. Armando:Roche: Consultancy, Research Funding; Janssen: Research Funding; Gilead: Consultancy, Research Funding; Celgene: Consultancy, Research Funding.

Description: Introduction: Genomic studies of chronic lymphocytic leukemia (CLL) have uncovered 〉80 potential driver mutations. The vast majority of these mutations affect coding regions, and just two potential drivers have been identified in non-coding elements. Aim: To describe the biological and clinical impact of a recurrent A〉C mutation at the third base of the small nuclear RNA U1, the non-coding component of the spliceosome involved in the recognition of the 5' splice site (5'SS). Methods: Whole-genome sequencing (WGS) and RNA-seq from 318 CLL patients were used to identify and characterize a highly recurrent A〉C point mutation occurring at position 3 of the U1 snRNA gene (g.3A〉C mutation). The U1 wild-type and mutant forms were introduced into three CLL cell lines (JVM3, HG3, MEC1) to validate in vitro the predicted effect of this alteration. We screened two independent cohorts including a total of 1,314 CLL patients for the presence of the mutation using the rhAmp SNP genotyping assay, and integrated the U1 mutational status with well-known driver alterations, IGHV and epigenetic subgroups, and clinical parameters. Results: The U1 mutation was found in 8/78 (10.3%) CLL cases analyzed by WGS. Given its role in 5'SS recognition by base-pairing, we reasoned that this mutation was likely to alter the splicing and expression patterns of CLL. We were able to confirm widespread specific alterations in the transcriptome by comparing RNA-seq data between wild-type and g.3A〉C mutated samples. Applying this knowledge to an algorithm aimed to infer the U1 mutational status from expression data, we were able to identify 4 mutated cases among 240 additional cases that had RNA-seq but no WGS. In total, 12/318 (3.8%) CLL patients analyzed by WGS and/or RNA-seq harbored this mutation. This g.3A〉C U1 mutation changes the preferential A-U base-pairing between U1 and 5'SS to C-G base-pairing, creating novel splice junctions and altering the splicing pattern of 3,193 introns in 1,519 genes. In addition to altered splicing, 869 genes were differentially expressed between mutated and wild-type cases. We identified specific cancer genes (e.g. MSI2, POLD1, or CD44) and pathways (B-cell receptor signaling, promotion of apoptosis, telomere maintenance, among others) altered by the U1 mutation. To confirm a causal link between this mutation and splicing changes, we introduced exogenous U1 genes with or without the mutation into three cell lines. Subsequent RNA-seq of these cell lines recapitulated the altered splicing and expression patterns observed in CLL patients. We next screened for the presence of the U1 mutation 1,057 patients (cohort 1) using the rhAmp assay and it was found in 30 (2.8%) cases. The distribution of the mutation was similar in Binet stages and CLL vs monoclonal B-cell lymphocytosis. However, the U1 mutation was almost always found in IGHV unmutated CLL (29/30, p=9.0e-11) and within the naïve-like CLL epigenetic subgroup (p=3.7e-7). None of the U1 mutated cases had mutations in the SF3B1 splicing factor. Considering only pre-treatment CLL samples, U1 mutation was associated with a shorter time to first treatment independently of the Binet stage, IGHV mutational status, epigenetic subgroups, and mutations in the well-known CLL drivers SF3B1, NOTCH1, ATMor TP53. In cohort 2 (n=257), this mutation was found in 13 (5.1%) patients, confirming its enrichment in IGHV unmutated cases, naïve-like epigenetic subgroup, and splicing modulation. Despite the relatively small number of pre-treatment samples carrying the U1 mutation (7/178) and short follow-up of the patients (median 2.6 years), the effect of this mutation on time to first treatment in cohort 2 was compatible with the one observed in cohort 1. Finally, we screened for the U1 mutation a cohort of diffuse large B-cell lymphoma (n=108), mantle cell lymphoma (n=101), follicular lymphoma (n=87), splenic marginal zone lymphoma (n=12), acute myeloid leukemia (n=52), and myelodysplastic syndrome (n=67). The mutation was not present in any of the samples analyzed. Conclusions: Here we have reported that the third base of the small nuclear RNA U1 is recurrently mutated in CLL, proved its effect in splicing and gene expression, and shown that this mutation is independently associated with faster disease progression. The g.3A〉C U1 mutation represents a novel non-coding driver alteration in CLL with potential clinical and therapeutic implications. Disclosures Ramirez Payer: GILEAD SCIENCES: Research Funding. Terol:Astra Zeneca: Consultancy; Gilead: Research Funding; Abbvie: Consultancy; Janssen: Consultancy, Research Funding; Roche: Consultancy. Lopez-Guillermo:Celgene: Consultancy, Research Funding; Janssen: Research Funding; Roche: Consultancy, Research Funding; Gilead: Consultancy, Research Funding.

Description: Introduction: Previous studies have highlighted the potential of cell-free DNA (cfDNA) to assess the mutational profile and copy number alterations (CNA) in diffuse large B-cell lymphoma (DLBCL), usually performed in tissue biopsies, both at diagnosis and relapse. In addition, the quantitative levels of cfDNA might be a surrogate of the lymphoma tumor burden and could therefore predict response to therapy, progression-free survival (PFS) and overall survival (OS). The aim of this study was to analyze the mutational profile and CNA at diagnosis using cfDNA, to compare these results with those obtained from formalin-fixed paraffin-embedded (FFPE) biopsies, and to estimate the correlation of pre-treatment levels of cfDNA with FDG-PET/CT Total Metabolic Tumor Volume (TMTV) and their impact in the outcome of DLBCL patients. Methods: We included 79 patients (41M/38F , median age 63 years) diagnosed with DLBCL according to the WHO criteria in a single institution between 2016 and 2018. All patients received chemoimmunotherapy. After frontline treatment, 56 patients achieved a complete (CR) response, 4 partial response, 16 were refractory, including 7 early deaths, and in 3 cases the response was not yet evaluable. Samples were obtained at diagnosis before starting treatment. cfDNA extraction was performed from 2-4 mL of plasma collected in PAXgene Blood ccfDNA tubes (Qiagen) and size distribution of DNA fragments was analyzed using the Agilent 2100 Bioanalyzer. Tumor genomic DNA (gDNA) was isolated from FFPE diagnostic tissue biopsies. A panel of 115 genes was enriched using a hybridization capture-based protocol from 10-30 ng of cfDNA and 150 ng of gDNA (ThruPlex Tag-seq kit and SureSelectXT enrichment reagents, Agilent Technologies) and sequenced in a MiSeq instrument (Illumina). CNA were examined using CNVkit software toolkit. cfDNA levels were reported as haploid genome equivalents per mL of plasma and expressed as a base 10 logarithm (log hGE/mL). Quantitative analysis of TMTV was performed using the semiautomatic MIM software, with a fixed SUV〉2.5 thresholding method for segmentation. Results: A median of 15.6 ng/mL (range: 4-754 ng/mL) of cfDNA was obtained. At least one mutation could be detected in 69/79 cases (87.3%). The median number of mutations per sample was 6 (range: 0-41 mutations). The genes most frequently mutated at diagnosis in plasma samples were KMT2D, TP53, TNFRSF14, MYD88, BCL2, SOCS1, CREBBP, MYC and EP300. In 45 cases, paired FFPE samples were available. Sensitivity of cfDNA to detect mutations in baseline FFPE samples was 69% (95%CI: 64.1-73.9). In 28 of the 45 cases, 〉70% of the mutations were observed both in the cfDNA and FFPE samples. In the remaining 17 cases, the number of mutations identified in cfDNA was lower than the one observed in the FFPE sample (Figure 1a). Of note, most of the cases in which mutations were not detected in the cfDNA corresponded to localized stages (11/17, 65%) and/or primary extranodal DLBCL (12/17, 71%). The CNA profile in cfDNA was similar to that reported in tissue, with recurrent deletions of TNSFRS14 (11%), TNFAIP3 (14%), CDKN2A (7%), or TP53 (7%), as well as gains of REL (7%) or BCL2 (5%), among others (Figure 1b). Median pre-treatment TMTV (N=48) was 292 cm3 (0-4,171 cm3). Higher TMTV predicted for a poorer PFS (HR 4.85; p=0.005). cfDNA concentration significantly correlated with TMTV (R=0.546, p3 log hGE/mL) had a significantly lower CR rate, PFS, and OS than those with low levels (CR rate, 47% vs. 92%, p

Description: Introduction Outcomes for follicular lymphoma (FL) patients are generally good. Clinical and biological variables have been studied to identify patients at higher risk of early relapse, which markedly impacts survival. However, the genetic landscape of FL according to its clinical behavior (need of treatment and timing of relapse) is not well characterized, which was the aim of the present study. Patients and Methods We included 67 samples from 55 grade 1-3A FL patients from a single institution [55 samples at diagnosis (D), and 12 at relapse (R)]. Five groups were defined according to their clinical behavior: never required treatment after 〉5 years (y) of follow-up [never treated (NT), n=7]; treated and did not relapse after 〉9 y of follow-up, [non-relapsed (NR), n=19]; treated and relapsed beyond 24 months of frontline therapy [late relapse (LR), n=14]; treated and relapsed within 24 months of frontline treatment [early relapse (ER), n=11]; and primary refractory (PR, n=4). Of the 48 treated patients, 96% received R-CHOP. Patients developing histologic transformation were not included. DNA was extracted from FFPE tissue biopsies. Copy number alterations (CNA) were assessed in 50 D and 11 R samples [OncoScan CNV Assay (Thermofisher)], and single nucleotide variants (SNV) and insertions/deletions (indels) in 51 D and 10 R samples using a B-cell malignancy NGS panel examining 121 genes (SureSelectXT, Agilent Technologies). Genes and genomic regions were considered altered if they harbored SNV/indels and/or CNA. For comparisons and plotting, only the 52 D samples with both NGS and CNA data were considered. Non-parametric statistical tests were used. Results Median age was 56 y (range, 26−79), and 30 patients (55%) were female. Forty-two patients (76%) had stage III-IV disease, without significant differences among groups. Thirteen patients (25%) had a high-risk FLIPI score, a percentage that was higher in the LR and PR groups (50 and 67%, respectively, P=0.02). With a median follow-up of 12.9 y, 10-y overall survival estimates were 71, 100, 74, 82, and 0% for NT, NR, LR, ER, and PR patients, respectively. We detected CNA in all samples, with a median number of 7 (range, 1−27) for D samples, and of 6 (2−19) for R samples. We also identified SNV/indels in all samples, with a median number of 10 (1−23) for D samples, and of 9 (3−18) for R samples. The most commonly altered genes at diagnosis were KMT2D (82%), CREBBP (73%), SPEN (38%), TNFRSF14 (38%), ARID1A (33%), and BCL2 (33%) (Figure). There were no significant differences in the number of altered genes/regions among the five groups. Genes or regions with significantly different alteration frequency among groups were: CARD11 (57, 12, 0, 9, and 0% for NT, NR, LR, ER, and PR, respectively, P=0.014), CD70 (12% for NR, 50% for PR, and 0 for the remaining groups P=0.026), HIST1H1B (29% for NT, and 0% for the remaining groups, P=0.020), HVCN1 (43, 6, 0, 18, and 0% for NT, NR, LR, ER, and PR, respectively, P=0.048), KLHL6 (12% for NR, 75% for PR, and 0 for the remaining groups, P=0.002), PRKCB (0, 6, 0, 18, 50%, P=0.037), and 13q14.2-q14.3 loss (DLEU1/DLEU2) (24% for NR, 50% for PR, and 0 for the remaining groups, P=0.015). Two genes had a significantly lower alteration rate comparing the cases with a favorable (NT, NR, LR) and more aggressive (ER, PR) clinical behavior: CIITA (22 vs. 53%, P=0.043), and PRKCB (3 vs. 27%, P=0.044). Of the 51 patients for which the m7-FLIPI was calculated, six (12%) had a high-risk score. Of note, none of the high-risk patients belonged to the NT or NR groups. No significant differences were found in the number of altered genes/regions between D and R, or in the alteration frequency of each gene/region. We identified the presence of an ancestral common precursor cell with a divergent evolution in all paired cases. The median percentage of shared alterations between D and R was 50% (range 28−63%). Conclusions In this comprehensive genetic analysis of 55 FL patients, categorized into five groups according to their clinical behavior, alterations in the chromatin modifying genes KMT2D and CREBBP were the most frequent, and CIITA and PRKCB were more frequently altered in cases with a shorter duration of response. These data warrant further study of the mechanisms underlying these mutations, mutual exclusivity/co-occurrence, and relationships with B-cell biology and the tumor microenvironment. Disclosures Nadeu: Janssen: Honoraria. Giné:Gilead: Research Funding; Janssen: Research Funding; Roche: Research Funding. Armando:Janssen: Research Funding; Roche: Consultancy, Research Funding; Gilead: Consultancy, Research Funding; Celgene: Consultancy, Research Funding.