ALBERT

Description: INTRODUCTION. Hairy cell leukemia (HCL) is a rare indolent B-cell malignancy, mainly characterized by peripheral cytopenias and splenomegaly. The current standard of treatment for HCL are Nucleoside Analogs (NA) cladribine and pentostatin, which produce remarkably high remission rates and durable responses. Aim of this study was to evaluate efficacy, short- and long-term toxicity of NA in HCL pts treated outside clinical trials. PATIENTS AND METHODS. We retrospectively analyzed 86 HCL patients (pts) treated with NA between 1996 and 2015 in two Hematologic Centers in Italy. The study was conducted in accordance to the Helsinki Declaration of 1964, as revised in 2000. Cladribine and pentostatin were administered according to standard schedules. Response criteria published by Jones et al. (Br J Haematol 2012) were retrospectively applied. Molecular assessment of BRAF-V600E mutation before and after NA therapy using quantitative real-time polymerase chain reaction (qRT-PCR)-based allelic discrimination assay (sensitivity 0.1%) was performed in 10 pts. RESULTS. The median follow-up of pts (71 males and 15 females, median age 53 years) was 5.8 years (range 0.5-28). During the disease course, 86 pts were treated with NA (cladribine n=76, 88%; pentostatin n=10, 12%); 59 pts received NA front-line (cladribine in 56/59 pts, 95%). Among the other 27 pts, receiving NA as second or subsequent line of therapy, 25 had been previously treated with interferon. Median time from diagnosis to the first NA was 3.3 months (range 0-315). Hematological toxicity was observed in 53 of 77 evaluable pts (69%), and was not significantly different with cladribine (72%) or with pentostatin (37%) (p=0.1). Grade 3-4 neutropenia, anemia and thrombocytopenia were observed in 50 (65%), 7 (9%) and 7 (9%) pts respectively. Extra-hematological toxicity was reported in 48 of 79 evaluable pts (61%). The incidence of extra-hematological toxicity with cladribine (63%) and pentostatin (37%) was not statistically different (p=0.2). Grade 3-4 febrile neutropenia was observed in 24 pts (30%); 9 pts (11%) had grade 3-4 infections; 4 pts (5%) had grade 3-4 skin toxicity, 1 pt (1%) had grade 3 hepatic toxicity. Four of 86 pts (5%) developed a second malignancy (prostatic adenocarcinoma n=2, colon adenocarcinoma n=1, diffuse large B cell lymphoma n=1). The median time from NA to second malignancy was 58 months (range 49-111). Four of 86 pts (5%) developed a skin cancer (basal-cell carcinoma n=3, squamous cell carcinoma n=1), after a median time of 59 months (range 16-126). Response was assessed at a median time of 3 months after the end of therapy. Overall Response Rate (ORR) and Complete Remission (CR) Rate were respectively 93% and 63% in the entire cohort, and 98% and 72% in pts treated with NA front-line. The allelic burden of BRAF before and after therapy with NA was available in 10 cases; none of the pts in clinical CR after NA achieved a complete molecular response (Table 1). The median Progression-Free Survival (PFS) for pts treated with NA frontline was 6.5 years. There was a trend toward a longer PFS in pts receiving NA as first-line therapy as compared to those treated in second or subsequent lines (p=0.05). PFS curves according to type of NA and line of therapy are shown in Figure 1. The 5- and 10-year Overall Survival (OS) rates were 96% (95% CI: 85% - 99%) and 90% (95% CI 76%-96%) respectively. OS was similar in pts treated with cladribine orpentostatin (p=0.49). CONCLUSIONS. This study shows that: i) NA are associated with an acceptable toxicity, neutropenia and febrile neutropenia being the main complications of therapy; ii) timing of response assessment may account for a CR rate that is slightly lower than reported in the literature, confirming the importance of waiting at least 4 months for response evaluation as recommended by current guidelines; iii) the persistence of molecular disease also in pts achieving a clinical CR supports the implementation of consolidation strategies aimed at eradicating minimal residual disease to prolong disease-free survival. Table 1. BRAF allelic burden before and after therapy Patient Age (years) Sex Line of Therapy Allelic Burden (%) Clinical Response Pre- Post- 1 33 F 1 21,8 0,1 CR 2 36 M 2 5,4 0,4 CR 3 39 M 1 24,2 0,7 CR 4 54 M 1 10,8 0,3 PR 5 42 F 1 44 1,2 CR 6 53 F 1 7,9 0,2 NV 7 56 M 1 6,5 0,3 CR 8 54 M 1 12,2 0,2 CR 9 32 M 1 35,8 9,5 PR 10 38 M 2 54,4 12,2 PR Figure 1. Progression-free survival according to type of NA and line of therapy Figure 1. Progression-free survival according to type of NA and line of therapy Disclosures Arcaini: Gilead: Consultancy, Other: Advisory Board; Celgene: Consultancy, Other: Advisory Board; Roche: Consultancy, Other: Advisory Board.

Description: Abstract 2638 Although patients with early-stage Hodgkin's lymphoma (HL) overall have a high rate of cure, they cannot be considered as a homogeneous group. In fact, a portion of these patients are resistant to or may relapse after standard treatment. Current prognostic criteria based on clinical and laboratory parameters at diagnosis do not allow to accurately identify the subset of patients with less favorable clinical outcome. In a study aimed at defining new biomarkers for risk stratification, an increased number of tumor-associated macrophages was found to be strongly associated with shortened survival in patients with classic Hodgkin's lymphoma [N Engl J Med. 2010 Mar 11;362(10):875-85]. The aim of this study was to evaluate the clinical significance of the proportion of CD68-positive infiltrating macrophages in patients with early-stage Hodgkin's lymphoma. By using an immunohistochemistry method, we analyzed diagnostic biopsies of 63 patients followed at our institution between 2006 and 2010, and uniformly treated with ABVD (adriamycin, bleomycin, vinblastine, dacarbazine) chemotherapy. Thirty-nine (62%) patients were males and 24 (38%) were females; median age at diagnosis was 30 years (range 17–85). Histological subtype was nodular sclerosis HL in 55 cases, mixed cellularity HL in 3 cases, lymphocyte-rich HL in 3 cases, and not classified in 2 cases. Five patients had subdiaphragmatic disease while 58 had supradiaphragmatic localizations. Forty-four patients with supradiaphragmatic disease were classified in the EORTC unfavorable subset: in detail, 25 patients had B symptoms and ESR ≥30, or ESR ≥50 despite the absence of B symptoms, 29 patients had bulky disease, 7 patients were older than 50 years, and 6 patients had more than 3 nodal areas involved. Thirty-six out of 63 (59%) patients received radiotherapy as a consolidation treatment after chemotherapy. After completion of the therapeutic program, 54 out of 63 (86%) patients obtained complete remission, while 9 (14%) had refractory disease; 15 out of 54 (28%) patients in complete remission relapsed during follow up. Diagnostic biopsies were reviewed by expert hematopathologists and classified into 3 groups according to the intensity of CD68 expression [N Engl J Med. 2010 Mar 11;362(10):875-85]. CD68-positive infiltrate was lower than 5% in 14 patients (group A), between 5 and 25% in 43 patients (group B), and greater than 25% in 6 patients (group C). Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method with observation time calculated from diagnosis. Comparison between survival curves was performed by means of the Gehan-Wilcoxon test. The 2-year OS and PFS in the entire cohort were 98% and 79%, respectively. There was a difference in the 2-year PFS between patients with favorable and those with unfavorable prognosis according to the EORTC risk criteria (100% vs 72%, P

Description: Abstract 3951 Poster Board III-887 Background An increased incidence of second cancers has been reported in some lymphoproliferative disorders. Whether the predisposition to other malignancies is due to disease-related immune-suppression rather than to the carcinogenic role of therapy given to treat the hematologic disease is still poorly understood. Purpose The aims of this study were to assess the frequency, characteristics and factors predicting second cancers in patients with WM and to evaluate whether WM patients are at increased risk of developing other malignancies as compared to an age- and sex-matched control population. Patients and methods The clinical records of 220 consecutive WM patients seen in two Hematologic centres of Northern Italy from 1980 to 2008 were reviewed. All cancers, with exception of non-melanoma skin cancers, were considered for this analysis. Standardized incidence ratios (SIRs), defined as the ratio between observed and expected cases, were used to compare the incidence of second cancers in WM with that of the general population. The number of expected cancers was obtained from age, sex and calendar-specific incidence rates reported by AIRTUM (Associazione Italiana Registri Tumori) for Northern Italy. A multivariate Cox proportional hazards regression model was used to examine risk factors for the development of second cancers. Therapy was analyzed as a time-dependent covariate. Results The median age of patients was 61 years (range: 26-86), 131 (60%) were males and 89 females (40%). The median follow-up was 4.8 years (range: 0.5-25). Overall, 136 patients (62%) with symptomatic WM received therapy, whereas a watch-and-wait policy was adopted in 84 patients (38%) with asymptomatic WM. Among treated patients, first-line therapy consisted of chlorambucil in 93 cases (68%), cyclophosphamide-based regimens in 15 (11%) and nucleoside analogs-containing regimens in 17 (13%). Rituximab was associated to chemotherapy in 19 patients (14%). Details on therapy were not available in 11 cases (8%). Overall, 52 second cancers were observed in 49 patients (22%). Forty-six patients (94%) had one malignancy and 3 (6%) developed two cancers. The types of cancer were: gastrointestinal (n=9, 17%), lung (n=8, 15%), breast (n=7, 13%), urinary tract (n=6, 11%), prostate (n=5, 10%), diffuse large B cell lymphoma (n=5, 10%), myelodysplastic syndrome/acute leukemia (n=3, 6%), brain (n=3, 6%), thyroid (n=2, 4%), mouth (n=2, 4%), other cancers (n=2, 4%). The diagnosis of cancer preceded that of WM in 13 cases (27%), was concomitant (within 3 months) in 6 (12%) and subsequent in 30 (61%). The median time from diagnosis of WM to the occurrence of a subsequent cancer was 4.3 years (range: 0.2-12.9). The cumulative probability of developing a second cancer after WM was respectively 11% at 5 years, 21% at 10 years and 33% at 15 years. As compared to the control population, the risk of second cancer in WM was 1.66 times higher than expected (95% CI: 1.16-2.37, p=0.005), without significant difference between males and females (p=0.7). In multivariate analysis, the risk of second cancer was not influenced by age (p=0.91), sex (p=0.45), reduction of IgG (p=0.91) or IgA (p=0.58) levels. In a time-dependent analysis, therapy given for WM did not increase the risk of developing a second malignancy (hazard ratio: 1.12, p=0.76). Conclusions This study shows that WM are at higher risk of developing second cancers as compared to the general population. We did not find an association between the occurrence of second cancers and treatment of WM. Disease-related immune-suppression may predispose WM patients to develop other malignancies. Disclosures: No relevant conflicts of interest to declare.

Description: Splenic marginal zone B-cell lymphoma (SMZL) is a rare clinical and pathological entity recognized by the WHO classification. SMZL usually presents with isolated splenomegaly, bone marrow involvement, and leukemic picture. Nodal disease is generally rare at diagnosis. When lymphocytes with villous projections are found in peripheral blood, the disease is termed splenic lymphoma with villous lymphocytes (SLVL). High HCV-seroprevalence is frequently reported in SMZL. The disease commonly pursues an indolent course; however, about a third of pts follow a more aggressive course. SMZL is also heterogeneous with respect to the preferential usage of IgVH genes, as well as the percentage of mutation load. No previous studies correlated IgVH rearrangement features with the clinical characteristics of SMZL. The aim of the present study was to determine the tumor-related IgVH gene rearrangement and compare the gene usage and the mutation status with clinical features of 59 pts. Diagnosis was made according to the WHO classification and to the diagnostic criteria for SMZL (Matutes et al., Leukemia 2008). Paraffin sections from lesional tissues (14 spleens, and 59 bone marrow trephines) were available for all pts. Histology and blood smears were reviewed. Total RNA was extracted from PB (n=13) or BM (n=46) mononuclear cells. IgVH gene rearrangements were amplified using 6 family-specific VH leader primers coupled with a 3′ heavy chain joining (JH) primer or with a constant region of cμ chain primer. The sequence obtained from direct sequencing of the clonal PCR product was compared with germline in the IMGT database. Sixty VDJ rearrangements were amplified and 54 were functional. VH1 family was used in 19 rearrangements (32%), VH3 family in 33 (55%) and VH4 family in 8 (13%). The most frequent VH genes were VH1-02 (n=13), VH3-23 (n=15), VH3-30 (n=7) and VH4-34 (n=5) (67% of all sequences). VH was unmutated in 25%. DH segments were assignable in 56/60 rearrangements (all of the VH unmutated and 41/45 of VH mutated). The most frequent DH families were DH2 (n=9) and DH3 (n=21); the most frequent DH genes were DH3-03 (n=8), DH3-22 (n=6) and DH2-02 (n=6). Most rearrangements used JH4 family (n=21), JH5 (n=8), and JH6 (n=19), accounting for 80% of all rearrangements. JH4b (n=14), JH6b (n=10), and JH6c (n=8) were the most common JH genes. Median length of HCDR3 region was 17 aa (range 11–32). For antigen selection analysis P value was 〈 0.05 in 41% for CDRs and in 55% for FRs. No correlation was found among VH and DH families (p=0.1), among VH and JH families (p=0.09) and among DH and JH families (p=0.4). Forty-two % of pts were unmutated in VH1 family, 15% in VH3 family and 25% in VH4 family (p=0.09). Unmutated cases were 7% in VH3-23 group, 46% in VH1-02 group and 14% in VH3-30 group (p=0.03). For clinical correlations we considered only the 54 functional rearrangements. Villous lymphocytes 〉10% were detected in 53% of VH1 pts, in 57% of VH4 pts, and in 17% of VH3 pts (p=0.01). Villous lymphocytes 〉10% were detected in 21% of VH3-23 pts, in 50% of VH1-02 pts and in no VH3-30 pt (p=0.05). Liver involvement was present in 9% of VH3-23 pts, in no VH1-02 pt and in 50% of VH3-30 pts (p=0.009). HCV serology was positive in 7% of VH3-23 pts, 17% of VH1-02 pts and 50% of VH3-30 pts (p=0.04). Serum MC was detected in 50% of VH3-23 pts, in 9% of VH1-02 pts and in 17% of VH3-30 pts (p=0.06). BM was involved in 86% of VH3-23 pts, in 100% of VH1-02 pts and in 50% of VH3-30 pts (p=0.02). A sinusal localization was detected in 67% of VH3-23 pts, in 20% of VH1-02 and in 100% of VH3-30 (p=0.03). Unmutated status was significantly related to a higher percentage of BM infiltration (p=0.003). The proportion of intermediate and high risk patients according to the SMZL score (Arcaini et al. Blood 2006) was higher in the unmutated respect to the mutated group (69% vs 32%, p=0.05). After a median F-UP of 3 yrs, 10 pts died (7 of lymphoma, 3 of causes non related to lymphoma). The median OS was 12 yrs and the median PFS was 2 yrs. OS did not differ among VH families (p=0.9). Median PFS was 2 yrs for mutated pts and 1 yr for unmutated pts. We performed clustering of pts by applying a 2-means clustering algorithm, using as parameters nodal disease, villous lymphocytes 〉10%, HCV serology positive, BM involvement: in cluster 1 VH1 family pts accounted for 20%, VH3 family for 71%, VH4 family for 9%; in cluster 2 VH1 family pts accounted for 47%, VH3 family for 29% and VH4 family for 24% (p=0.01). In conclusion, VH rearrangement analysis in SMZL reveals a non-random preference for VH1-02, VH3-23 and VH3-30 genes, whose use differs according to distinctive clinical features at presentation.

Description: Abstract 2667 Waldenström Macroglobulinemia (WM) is a B-cell lymphoproliferative disorder characterized by bone marrow infiltration by lymphoplasmacytic lymphoma associated with a monoclonal component of IgM type in the serum. WM is often preceded by an IgM monoclonal gammopathy of undetermined significance (IgM-MGUS). The cumulative probability of progression of IgM-MGUS to WM or to other lymphoproliferative disorders is approximately 1.5% per year. Other mature B-cell neoplasms such as splenic marginal zone lymphoma (SMZL) and B-cell chronic lymphoproliferative disorders (B-CLPD) can carry an IgM monoclonal component and should therefore be considered in differential diagnosis with WM. In a study based on parallel sequencing of the whole genome of lymphoplasmacytic cells and paired normal tissue from WM patients, Treon et al (Blood. 2011;118:Abstract 300) have identified a highly recurrent somatic mutation with oncogenic activity in the myeloid differentiation primary response (MYD88) gene, leading to a change from leucine to proline at position 265 of the aminoacid sequence [MYD88 (L265P)]. Targeted Sanger resequencing showed MYD88 (L265P) in 90% of WM patients, but only in a minority of patients with IgM-MGUS or other mature B-cell neoplasms such as SMZL. We developed an allele-specific PCR for the MYD88 (L265P) mutation, and studied 58 patients with WM, 77 with IgM-MGUS, 84 with splenic marginal zone lymphoma (SMZL) and 52 with B-cell chronic lymphoproliferative disorders (B-CLPD). DNA was obtained from bone marrow cells (n=204) and peripheral blood (n=67). The aims of this study were: i) to assess the prevalence of the mutation in WM, IgM-MGUS, SMZL, and B-CLPD; ii) to analyze the relationship between MYD88 (L265P) mutation and clinical phenotype; iii) to evaluate the impact of the mutation on the risk of progression from IgM-MGUS WM or other lymphoproliferative disorders. The MYD88 (L265P) mutation was detected in 58/58 (100%) patients with WM, either asymptomatic (n=39) or symptomatic (n=18), and in 36/77 (47%) patients with IgM-MGUS. In addition, it was detected in 5/84 (6%) patients with SMZL and in 3/52 (6%) with B-CLPD; of these MYD88 (L265P)-positive subjects, 4 SMZL and 2 B-CLPD patients carried a serum IgM monoclonal component, while the remaining B-CLPD patient carried a double (IgM and IgG) monoclonal component. Compared with IgM-MGUS patients with wild-type MYD88, those carrying MYD88 (L265P) had significantly higher levels of IgM (P

Description: Background: Whole genome sequencing (WGS) identified activating CXCR4WHIM somatic mutations in nearly 30% of patients with Waldenstrom's Macroglobulinemia (WM) (Blood 123(11):1637-46). Both nonsense and frameshift CXCR4WHIM mutations occur in WM, with over 30 different types of mutations described within the regulatory carboxyl-terminal domain of CXCR4. CXCR4WHIM mutations almost always occur with activating MYD88 mutations, and impact both disease presentation and treatment outcome (Blood 123(18):2791-6; NEJM 372(15):1430-40.). The clonal architecture of CXCR4WHIM mutations relative to MYD88 mutations and their role in disease evolution remains to be clarified. Methods: We used Sanger sequencing and highly sensitive AS-PCR assays that we developed for the most common CXCR4WHIM mutations (S338X C〉A and C〉G) to evaluate for CXCR4WHIM mutations. In conjunction with an AS-PCR MYD88L265P assay that we previously developed (Leukemia 28(8):1698-707), we also profiled tumor samples for MYD88L265P and CXCR4S338X mutations in 164 WM, 12 IgM MGUS, 20 MZL, 32 CLL, 14 MM, 7 non-IGM MGUS patients, and 32 healthy donors. Next generation transcriptome sequencing data was also performed for validation in select cases. Results: AS-PCR detected CXCR4S338X mutations in WM and IgM MGUS patients not revealed by Sanger sequencing. By combined AS-PCR and Sanger sequencing, CXCR4WHIM mutations were identified in 44/102 (43%), 21/62 (34%), 2/12 (17%), and 1/20 (5%) untreated WM, previously treated WM, IgM MGUS and MZL patients, respectively, but not in CLL, MM, non-IGM MGUS patients or healthy donors. Cancer cell fraction analysis in WM and IgM MGUS patients showed CXCR4S338X mutations were primarily subclonal, with highly variable clonal distribution (median 35.1%, range 1.2%-97.5%; Figure 1). Sanger sequencing identified 3 patients with multiple CXCR4 mutations, which were shown to be compound heterozygous by TA cloning and sequencing of at least 40 clones. The addition of AS-PCR to the Sanger sequencing results also revealed multiple CXCR4WHIM mutations in many individual patients that included homozygous and compound heterozygous mutations that were validated by next generation sequencing that offered a median of 5,819 (range 5,217-12,235) reads that overlapped the mutated loci. Conclusions: Taken together, these findings show that CXCR4WHIM mutations are more common in WM patients than previously revealed by WGS or Sanger sequencing. Moreover, CXCR4 mutations are primarily subclonal supporting their acquisition after MYD88L265P in WM oncogenesis. The exclusive finding of frameshift and nonsense but not missense variants within the carboxyl-terminal domain of CXCR4 suggests that significant selection pressures exist for activating mutations within the WM clone. Lastly, multiple CXCR4WHIM mutations are common in WM patients indicative of targeted genomic instability within the carboxyl-terminal domain of CXCR4. Disclosures No relevant conflicts of interest to declare.

Description: Abstract 3037 Fotemustine (Muphoran), a nitrosourea alkylating agent approved for use in the treatment of metastatic melanoma, has proven to be effective as single agent in relapsed/refractory multiple mieloma (MM). We report preliminary data of a phase II single centre study exploring the feasibility and the efficacy of the combination bortezomib (B) + fotemustine (Mu) + dexamethasone (D) (B-MuD) in relapsed/refractory MM patients. This study has been approved by local ethical committee; all patients (pts) signed written informed consent before the enrolment. MM pts relapsed or refractory after at least one therapy were eligible for the study. Pts who received prior bortezomib-containing regimen were included only if not considered bortezomib-refractory. Fotemustine at the escalating doses of 80 and 100 mg/m2 i.v. on day 1 was associated to Bortezomib 1,3 mg/m2 i.v. on days 1,4,8,11 + Dexamethasone 20 mg orally on days 1–2, 4–5, 8–9, 11–12 of 21-day cycle for a total of 6 cycles. Protocol was amended after the enrolment of the first five pts due to a considerable toxicity. We observed 3 grade 3–4 peripheral neuropathy, 1 grade 3 pneumonia, 4 grade 4 thrombocytopenia and two pts dropped-out (one for grade 3 pneumonia at 2° cycle, and one for grade 4 peripheral neuropathy at 3° cycles). Thus the schedule was modified as following: Fotemustine at escalating doses of 80 and 100 mg/m2 i.v. on day 1, Bortezomib 1,3 mg/m2 i.v. once weekly on days 1, 8, 15, 22, Dexamethasone 20 mg i.v. on days 1, 8, 15, 22 for six 35-day cycles. An interim analysis of feasibility and efficacy was planned after the inclusion of the first two cohort of 6 pts each, treated with escalating dose of Fotemustine according to the amended schedule. Up to now, 18 pts have been enrolled (5 pts before and 13 after the amendment): M/F 10/8, median age 69 years (44-82), median number of previous therapies 2 (1-5). Previous treatments included autologous transplant in 10 pts (59%), bortezomib in 8 pts (44%), oral melphalan in 7 pts (41%) and thalidomide in 12 (71%). After the inclusion of 12 pts the MTD for Fotemustine was established to be 100 mg/m2. No drop-outs were registered after the amendment. Preliminary data on response are available in 10 pts. Nine pts (90%) obtained at least a PR, 8 pts (80%) registered ≥VGPR (CR 10%). At time of this analysis 79 cycles were delivered: 14 before, 65 after the amendment. Eighty-nine AE of any grade were observed, 43 hematological and 46 non-hematological. Thrombocytopenia was the most common AE either before and after the amendment. Need for dose reduction was significantly lower after the amendment. In detail fotemustine was reduced in 14% of cycles before and never after the amendment (p=0.0001), bortezomib dose reduction were performed in 36% of cycles before and 15% after the amendment (p=0.08), dexamethasone dose reduction occurred in 64% of cycles before and 13% after the amendment (p=0.0001). In conclusion, this interim analysis shows that fotemustine in combination with bortezomib and dexamethasone is safe and gives encouraging results in relapsed/refractory myeloma patients with 80% of ≥VGPR. Updated results will be presented at the meeting. Disclosures: No relevant conflicts of interest to declare.

Description: Background: Bisphosphonates (Bi) have been proven to be effective in preventing or delaying skeletal complications in multiple myeloma (MM) with a significant improvement of the quality of life. The 2002 ASCO guidelines indicate that once initiated intravenous Bi should be continued until an evident substantial decline of performance status. Recently, osteonecrosis of the jaw (ONJ) has been reported as complication of intravenous Bi treatment, with an incidence ranging between 6 and 13% and a greater occurrence in patients (pts) receiving zoledronic acid (Zol) than in those treated with pamidronate (Pam). Aim. In this retrospective study we evaluated the incidence of ONJ and of skeletal related events (SRE) in a cohort of MM pts divided in two groups according to the schedule of administration of Bi; group A: monthly administrations until tolerated (standard), group B: monthly administrations during the first year and then every 3 months (reduced). Methods: One hundred and six MM pts (M: 63, F: 43) were included in this study: 51 pts received a standard treatment (group A) and 55 a reduced schedule (group B). Pam 90 mg i.v. was administered as a three hour infusion and Zol 4 mg i.v. as a 15 minutes infusion. SRE was defined as: pathologic fracture, radiation to bone, spinal cord compression with vertebral fracture, hypercalcemia. Results: No difference was found between the two groups concerning pts characteristics at the onset: age, sex, extension of bone disease, status of the disease (progressive or responsive). Twenty pts received only Pam, 42 only Zol and 44 pts Pam followed by Zol. The distribution of the different type of Bi was not different in the two groups. ONJ occurred in 7 pts (6.6%) with a significant difference between the two groups: 6 pts in standard schedule (11.7%) and 1 in the reduced (1.8%), p=0.01, after a median time of 22.8 months in group A, and 37.8 months in the case of group B. Four of out 7 ONJ occurred during the second year of treatment (12–24 months): that period resulted significantly related (p=0.000) to the occurrence of ONJ with respect to the others (24–38 months, 40–100 months). All ONJ occurred in pts treated with Zol alone (5 pts) or with Zol after Pam (2 pts), whereas no cases were observed in Pam alone pts (p= 0.005). The median number of infusions was 20 with comparable results in the two groups (20 in group A, 19 in group B). SRE was observed in 38 pts (35.8%): 16 pts in group A and 22 pts in group B without statistical difference (p=0.6), after a median time of 9.8 months. Conclusions: These results suggest that the reduced schedule of Bi is associated with a significant lower incidence of ONJ and, although the sample size is limited, the appearance of ONJ seems delayed with respect to the standard treatment. Moreover, the incidence of SRE is similar in the two groups. In conclusion, the reduced schedule, could be applied in order to combine the antiresorptive efficacy of Bi with a higher safety and a better compliance.

Description: Abstract 2934 Poster Board II-910 Background: hepatitis C virus (HCV) infection has been associated with increased risk of developing B-cell lymphoprolipherative disorders through chronic immune stimulation. Discordant data have been reported about the prevalence of HCV infection in patients with Waldenström's Macroglobulinemia (WM) and the putative role of HCV in lymphomagenesis of this non-Hodgkin Lymphoma subtype remains controversial. Aim: the current retrospective study was conducted to assess the impact of this infection itself in the clinical and biological features and outcome among WM patients as compared with those with HCV negative WM. Patients and methods: we analyzed 140 WM patients with tested anti-HCV antibody (HCV-Ab). HCV-Ab positivity was detected in 21 cases (15%). Clinical characteristics of patients at diagnosis of WM are reported in the table below. Results: HCV positivity was correlated to lower counts of platelets, neutrophil granulocytes, haemoglobin and with presence of cryoglobulins or autoantibodies and splenomegaly. Interestingly we even found a strong link between the presence of HCV and serum parameters of tumor burden such as beta-2 microglobulin (B2-M) and lactate dehydrogenase (LDH). Furthermore we did not reveal any outcome implications in terms of disease progression needing treatment, time from diagnosis to first therapy, overall survival between HCV- and HCV+ patients. Overall, 88 patients (63%) received treatment for disease progression with schedules including Rituximab in 46 cases (52% of treated patients). Rituximab was administered even in HCV-RNA positive patients associated to Cyclophosphamide and Fludarabine and this did not translate in hepatitis development. HCV-RNA was strictly monitored during immunotherapy and we did not observe any significant flair. Conclusions: in our series of patients HCV infection does not seem to affect clinical outcome of disease. Moreover, in our experience patients with documented infection can receive the same schedule of treatment including intensive chemotherapy even with monoclonal antibodies without development of further toxicity. Disclosures: No relevant conflicts of interest to declare.

Description: Introduction Fludarabine, cyclophosphamide and rituximab (FCR) and bendmaustine rituximab (BR) combinations have both been evaluated as salvage regimens in Waldenstrom's Macroglobulinemia. FCR exerts good quality of responses but there are some concerns regarding its use mainly for tardive myelosuppression and long term toxicity. BR showed to be effective with an excellent short term toxic profile but in literature there are no data on long term follow-up and toxicity. The aim of this study was to evaluate long term outcome and long term toxicity of patients treated with FCR and BR. Patients and Methods We analyzed 87 relapsed and refractory Waldenstrom's Macroglobuklinemia patients enrolled in two retrospective Italian multicenter studies in which FCR or BR were administered as salvage regimens. Patients treated with both bendamustine and fludarabine were excluded from the study. For each treatment group we compared: clinical and disease characteristics, Progression free survival (PFS) defined as progression or death for any cause from the beginning of salvage treatment; Event free survival (EFS) defined as progression or development of major infection, solid tumor, secondary MDS/AML, DLBCL, or death due to any cause. Results Of the 87 patients, 37 had received FCR and 50 BR. The two groups of patients did not differ in sex, median age, median number of prior treatments, previous therapy with alkylating agents, disease status, median IgM level, presence of adenopathies and/or splenomegaly at CT performed before salvage treatment. The significant differences between the two groups were: higher number of patients 〉70 years in the BR group (P=0.01) and lower number of patients previously treated with monoclonal antibody in the FCR population (P