Improved Remission Duration Research Articles

CD4+/CD8+ Selection of Anti-AML ENG-T Cells Affects Long-Term T-Cell Persistence in Vitro and Survival in an AML Xenograft Model

Background: Immunotherapies have shown dramatic anti-cancer efficacy in pediatric hematopoietic malignancies. Despite initial disease clearance, relapse rates are high, demanding product improvement. Manufacture of engineered cellular immunotherapies involves expansion of effector cells from patient or donor peripheral blood mononuclear cells (PBMCs) ex vivo prior to patient infusion. Expansion methods in pre-clinical studies of engineered T-cell therapies often call for activating T cells from whole PBMCs using anti-CD3 and anti-CD28 co-stimulation. However, clinical production of T-cell therapies has shifted towards selecting CD4+ and CD8+ cells prior to activation due to higher product efficacy seen in clinical trial. Many acute myeloid leukemias (AML) are CD4+, introducing the risk of blast contamination during CD4+ selection. We questioned whether CD8+ T cells alone could be used to manufacture our clinical T cell product and sought to determine how selection affected our T cells. Understanding the biological impact of manufacturing changes between pre-clinical and clinical production is imperative for clinical translation. Methods: We have engineered T cells to secrete a CD123xCD3 binding bispecific engager molecule (CD123-ENG) to treat AML. Primary T cells were isolated from PBMCs, selected with microbeads, activated, and transduced with replication incompetent retroviral vectors. Unselected T cells were compared to CD4+, CD8+, or CD4+ and CD8+ selected T cells. T-cell transduction was confirmed with flow cytometry. Expression and secretion of CD123-ENG was confirmed with ELISA. Antigen-specific T-cell activation was determined by quantifying cytokine secretion in the presence of CD123+ target cell lines. Short-term cytotoxicity was examined in vitro against CD123+ target cell lines in 18-hour bioluminescence assays. T-cell serial cytotoxicity and persistence were tracked in 10-day serial stimulation studies using an IncuCyte live cell imaging system. Cytokines present during T-cell manufacture and serial stimulation were detected and quantified with Luminex multiplex assays. Immunophenotype and exhaustion markers were analyzed using flow cytometry. In vivo anti-AML cytotoxicity and T-cell persistence were determined in an AML xenograft model. Results: In our studies, unselected, CD4+, CD8+, and CD4+/CD8+ selected CD123-ENG T cells showed no differences in activation, cytotoxicity, or immunophenotype when evaluated in short-term assays. Mice harboring human AML treated with CD4+/CD8+ selected CD123-ENG T cells had improved survival compared to mice treated with unselected and CD8+ selected CD123-ENG T cells. CD4+ T cells alone provided the best survival advantage. In addition, CD4+/CD8+ selected T cells had longer persistence when challenged by serial target cell stimulations in vitro. T cells expanded from whole PBMCs were exposed to cytokines likely to emanate from non-T cells during early manufacture. These cytokines were characteristic of those produced by myeloid cells in an inflammatory environment, and may explain functional differences observed in vivo. Conclusions: Durable anti-cancer response in patients is associated with T-cell persistence and CD4+/CD8+ pre-selection of CD123-ENG may therefore improve remission duration in patients. CD4+ and CD4+/CD8+ selected T cells provided the longest survival in vivo, dissuading us from further investigating CD8+ CD123-ENG as an AML treatment. We are actively exploring additional mechanistic determinants of the observed phenotypic differences with and without selection. Optimizing cellular immunotherapy will improve patient outcomes. It is essential that engineered cellular research products intended for clinical translation be produced by the same methods used for clinical manufacture to increase the predictive power of pre-clinical data. The use of biological correlatives to predict T-cell product function will better support successful translation. Acknowledgements: This research was funded in part by NCI Contract No. HHSN26120150003I/HHSN26100077.

The long-term effect of biologics in patients with ulcerative colitis emerging from a large Japanese cohort

To gain a better understanding of the effects of biologics, we evaluated clinical outcomes in patients with moderate to severe exacerbations of ulcerative colitis (UC). This retrospective, multicenter study retrieved the entire clinical courses of UC patients who began treatments between 2004 and 2018. All exacerbations and clinical parameters, including treatment details for exacerbations and both remission and re-exacerbation dates, were identified during the observation period. Two different endpoints, the cumulative incidence rates of surgical resection and re-exacerbation, were evaluated separately in moderate to severe exacerbation events. Among 1401 patients, 1626 exacerbation events were determined according to a partial Mayo score (remission: < 2, mild: 2–4, moderate: 5–7, and severe: > 7). During the observation period, as administration rates of biologics increased, both surgical resection and hospitalization rates decreased, for 959 moderate to severe exacerbation events. We confirmed that biologics significantly reduced the cumulative re-exacerbation rate in moderate to severe exacerbation events during the study period compared with suboptimal therapies (a 0.507-fold decreased risk according to COX regression analysis, P < 0.001). However, they had not enough impact in reducing the cumulative incidence rate of surgical resection in moderate to severe exacerbation events that were corticosteroid-refractory or dependent (a 0.878-fold decreased risk according to COX regression analysis, P = 0.606). Biologics may improve remission duration, but these agents had no significant impact in reducing the risk of surgical resection in moderate to severe active UC.

Updated results from a phase II study of mini-hyper-CVD (mini-HCVD) plus inotuzumab ozogamicin (INO), with or without blinatumomab (Blina), in older adults with newly diagnosed Philadelphia chromosome (Ph)-negative B-cell acute lymphoblastic leukemia (ALL).

7011 Background: INO and Blina improve overall survival (OS) in patients (pts) with relapsed/refractory B-ALL. The use of these agents in older adults in the frontline setting may allow for use of less chemotherapy and improve remission duration and OS compared to standard therapies. Methods: Pts ≥60 years with newly diagnosed Ph-negative B-cell ALL received mini-HCVD for up to 8 cycles. Initially, INO was given at 1.3-1.8mg/m2 on day 3 of cycle 1 and 0.8-1.3mg/m2 on day 3 of cycles 2-4. Rituximab (if CD20+) and prophylactic IT chemotherapy were given for the first 4 cycles. Responding pts received POMP maintenance for up to 3 years. Beginning with pt #50, INO was given in fractionated doses each cycle (0.6 mg/m2 on day 2 and 0.3 mg/m2 on day 8 of cycle 1; 0.3 mg/m2 on day 2 and 8 of cycles 2-4) and 4 cycles of Blina were given following 4 cycles of mini-HCVD plus INO. Maintenance was with 12 cycles of POMP and 4 cycles of Blina (1 cycle of Blina after 3 cycles of POMP). Results: Characteristics of the 80 pts are shown in Table. 6 pts were in complete remission (CR) at enrollment. Among 74 evaluable pts, 73 (99%) responded (CR in 89%). MRD negativity by flow was achieved in 80% of pts after 1 cycle and in 94% overall. The 30-day mortality rate was 0%. Among 79 responders, 11 (14%) relapsed, 4 (5%) underwent SCT, 33 (42%) remain in ongoing continuous remission, and 31 (39%) died in remission. Notably, 6 pts (8%) developed veno-occlusive disease, 1 after subsequent SCT. With a median follow-up of 55 months, the 5-year continuous remission and OS rates were 76% and 47%, respectively. Age ≥70 and poor-risk cytogenetics were associated with worse outcomes. The inferior outcomes in pts ≥70 years was primarily due to higher rates of death in CR. The 5-year OS for pts age 60-69 years without poor-risk cytogenetics (n=37), age 60-69 with poor-risk cytogenetics (n=13), age ≥70 without poor-risk cytogenetics (n=24) and age ≥70 with poor-risk cytogenetics (n=6) were 69%, 39%, 36% and 0%, respectively. Conclusions: The combination of mini-HCVD plus INO, with or without Blina, in older adults with newly diagnosed Ph-negative ALL resulted in an overall response rate of 99% and a 5-year OS rate of 47%. Particularly favorable outcomes were seen in pts age 60-69 years without poor-risk cytogenetics (5-year OS: 69%). Chemotherapy-free regimens may improve outcomes in pts age ≥70 years, and novel agents/regimens are still needed for those with poor-risk cytogenetics. Clinical trial information: NCT01371630. [Table: see text]

Is There a Best Initial Treatment for a New Patient With Low Grade Follicular Lymphoma.

The treatment landscape for newly diagnosed follicular lymphoma (FL) has dramatically changed over the past decade, first with the advent of rituximab and then with the activity of old and new drugs, like bendamustine and lenalidomide, in this disease. The efficacy and tolerability of rituximab has led to a paradigm shift for the management of patients with low volume FL for many oncologists. Despite the lack of a survival benefit seen with this approach, many now use this single agent in patients who had historically been observed. Likewise, its use as maintenance therapy following successful front-line induction therapy of patients with symptomatic FL, with either rituximab alone or specific chemoimmunotherapy regimens, has improved remission duration and widely been adopted. As newer chemoimmunotherapy regimens, like bendamustine and rituximab, have superior outcomes with improved tolerability, upfront treatment options are redefined and questions emerge: whom do maintenance strategies benefit, and what is the optimal sequencing of therapies? Finally, as newer targeted and potentially better tolerated therapies demonstrate efficacy in the relapsed setting, their use, both in combination with and in place of chemotherapy, is being explored. The promising regimen of lenalidomide with rituximab is being compared with chemoimmunotherapy in a randomized fashion. Cure remains elusive, however, in advanced stage disease and so safety and tolerability, in addition to efficacy, remain important endpoints.

Patients with chronic lymphocytic leukemia with high-risk genomic features have inferior outcome on successive Cancer and Leukemia Group B trials with alemtuzumab consolidation: subgroup analysis from CALGB 19901 and CALGB 10101

Alemtuzumab consolidation has been investigated to improve remission duration after fludarabine-based induction for chronic lymphocytic leukemia (CLL). The impact on genomic high-risk disease remains unknown. Cancer and Leukemia Group B (CALGB) 19901 and 10101 enrolled previously untreated patients to receive alemtuzumab consolidation after fludarabine-based induction. Immunoglobulin heavy chain gene (IGVH) mutation status and interphase cytogenetics were assessed retrospectively. Treatment response with these alemtuzumab-containing regimens was similar, regardless of genomic risk, except for patients harboring del(17p), where few complete remissions were observed. Progression-free survival (PFS) was similar between IGVH groups, but overall survival (OS) was inferior in IGVH unmutated patients (p = 0.03). Cytogenetic risk group was associated with PFS and OS (p = 0.01 for both), with similarly short PFS in patients with del(17p) and del(11q) and particularly short OS in patients with del(17p). Cytogenetic risk group remained signficantly associated with PFS and OS when controlling for other prognostic factors (PFS: p = 0.009; OS: p = 0.02), as did the negative association of IGVH unmutated disease with OS (p = 0.004). Results were similar when restricting to patients who received at least one dose of alemtuzumab consolidation, demonstrating limited ability to overcome the poor outcome associated with high-risk genetic features (ClinicalTrials.gov identifiers: NCT00004857, NCT00098670).

Mature Results From ECOG Study E1405 – A Phase II Study of VcR-CVAD with Maintenance Rituximab for Previously Untreated Mantle Cell Lymphoma

AbstractAbstract 153▪▪This icon denotes a clinically relevant abstract IntroductionModified R-hyperCVAD is a well-tolerated induction regimen with a high response rate in MCL. We hypothesized that the incorporation of bortezomib (Velcadea) into this regimen would enhance the complete response rates. We further hypothesized that the addition of maintenance rituximab (MR) would improve remission duration. The new regimen, VcR-CVAD with MR, was tested for safety and efficacy in the Eastern Cooperative Oncology Group. MethodsEligible patients had histologically confirmed, previously untreated MCL, PS 0–2, and adequate end organ function. The treatment plan included: bortezomib 1.3 mg/m2 days 1 and 4, rituximab 375 mg/m2 IV day 1, cyclophosphamide 300 mg/m2 IV over 3 hrs q 12 hrs × 6 doses days 1–3, doxorubicin 50 mg/m2 continuous infusion over 48 hrs days 1–2, vincristine 1 mg IV day 3, dexamethasone 40 mg po days 1–4. Cycles were repeated every 21 days for 6 cycles and all patients received G-CSF support. Patients achieving SD, PR, or CR received MR administered as 4 weekly treatments every 6 months for 2 years (protocol therapy). Patients could elect to receive high dose chemotherapy and autologous stem cell transplantation (SCT) off protocol rather than MR. The primary endpoint of the trial was the CR rate, defined as PET-negative, marrow-negative, to VcR-CVAD induction therapy. ResultsSeventy-five eligible patients were enrolled between 5/07 and 10/08. Baseline characteristics include median age 62 (40–76), 58M:17F, 92% stage III/IV, and 40% with elevated LDH. MIPI risk distribution included 37% low, 36% intermediate, 19% high, 8% unknown. Sixty-eight patients (91%) completed VcR-CVAD induction therapy. Reasons for treatment discontinuation included PD (1), toxicity (4), and patient preference (2). The ORR was 97% (73/75), CR rate 68% (51/75) and PR rate 29% (22/75). Of the 22 PR patients, 11 were so coded due to no bone marrow evaluation and/or PET imaging post therapy. The CR rate in the 64 completely restaged patients was 80%. Forty-four patients proceeded to protocol planned MR while 22 patients received SCT consolidation off protocol. With a median follow up of 3.6 years, the 3-yr PFS for the MR cohort (n = 44) and entire cohort (n = 75) are 73% and 74%, respectively. OS at 3-yrs is 88%, with no difference between MR and SCT patients. The major toxicity of the induction treatment regimen was expected myelosuppression. Grade 3–4 non-hematologic toxicities were rare. No patients developed grade 3–4 neuropathy. There were no serious toxicities during MR. There were no treatment related deaths. ConclusionThe VcR-CVAD induction produced high overall OR (97%) and CR rates (68%) in a representative MCL patient population treated in a cooperative group setting. The 3-yr PFS (74%) and OS (88%) are highly encouraging. Remissions in patients receiving MR were as durable as patients receiving SCT consolidation. The value of bortezomib, when added to conventional chemotherapy, is currently being tested in a randomized intergroup trial (E1411). Disclosures:Kahl:Genentech: Consultancy, Research Funding; Roche: Consultancy; Millennium: Consultancy, Research Funding. Off Label Use: Bortezomib as frontline treatment of mantle cell lymphoma. Smith:Millennium: Research Funding. Advani:Genentech: Research Funding. Horning:Genentech: Employment; Roche: Equity Ownership.

Exploiting antitumor immunity to overcome relapse and improve remission duration

Cancer survivors often relapse due to evolving drug-resistant clones and repopulating tumor stem cells. Our preclinical study demonstrated that terminal cancer patient’s lymphocytes can be converted from tolerant bystanders in vivo into effective cytotoxic T-lymphocytes in vitro killing patient’s own tumor cells containing drug-resistant clones and tumor stem cells. We designed a clinical trial combining peginterferon α-2b with imatinib for treatment of stage III/IV gastrointestinal stromal tumor (GIST) with the rational that peginterferon α-2b serves as danger signals to promote antitumor immunity while imatinib’s effective tumor killing undermines tumor-induced tolerance and supply tumor-specific antigens in vivo without leukopenia, thus allowing for proper dendritic cell and cytotoxic T-lymphocyte differentiation toward Th1 response. Interim analysis of eight patients demonstrated significant induction of IFN-γ-producing-CD8+, -CD4+, -NK cell, and IFN-γ-producing-tumor-infiltrating-lymphocytes, signifying significant Th1 response and NK cell activation. After a median follow-up of 3.6 years, complete response (CR) + partial response (PR) = 100%, overall survival = 100%, one patient died of unrelated illness while in remission, six of seven evaluable patients are either in continuing PR/CR (5 patients) or have progression-free survival (PFS, 1 patient) exceeding the upper limit of the 95% confidence level of the genotype-specific-PFS of the phase III imatinib-monotherapy (CALGB150105/SWOGS0033), demonstrating highly promising clinical outcomes. The current trial is closed in preparation for a larger future trial. We conclude that combination of targeted therapy and immunotherapy is safe and induced significant Th1 response and NK cell activation and demonstrated highly promising clinical efficacy in GIST, thus warranting development in other tumor types.

Induction Therapy with Novel Agents Improves Relapse-Free Survival After Autologous Stem-Cell Transplantation in Multiple Myeloma

Abstract 4494 Introduction:Multiple myeloma (MM) is still an incurable disease. Initial treatment depends on age, risk stratification and co-morbidities. High-dose therapy followed by autologous stem-cell transplantation (ASCT) is the standard of care in transplant eligible patients.In recent years, novel agents became a promising role in newly diagnosed, relapsed myeloma as well as in maintenance treatment. Bortezomib, a proteasome inhibitor, and thalidomide or lenalidomide, immunomodulatory agents have been found to be superior to chemotherapy regimens. Methods:121 adult patients (50 female, 71 male) with a median age of 53.5 years at diagnosis underwent autologous stem-cell transplantation at the Medical University of Vienna between June 1985 and September 2010. Median age at ASCT was 57.4 years.46 patients received novel therapeutic agents, such as VDT (bortezomib, dexamethasone, thalidomide), Rd (lenalidomide, low dose dexamethasone) and VD (bortezomib, dexamethasone), whereas 75 patients were treated on the basis of chemotherapy schedules, e.g. VAD-based (vincristine, doxorubicin, dexamethasone). Results:Progression-free survival (PFS) after ASCT was 7.9 months (6,4 – 9,3, 95% CI) after treatment with chemotherapy, whereas it was increased to 21,6 months (5 – 38,1, 95% CI) after initial treatment with either bortezomib and/or thalidomide/lenalidomide (p= 0.001).Post-induction VGPR or better was superior with new agents compared to chemotherapy, 34,1% versus 11,9%, respectively. Post-transplant VGPR or better was as high as 68% after initial therapy with novel agents prior to transplant, whereas VGPR or better was reached in 48.6% in patients receiving chemotherapy. Conclusion:Novel agents significantly prolong relapse-free survival in patients eligible for autologous stem-cell transplantation. Previous studies showed improved remission duration with thalidomide or lenalidomide maintenance after ASCT. The data of maintenance therapy after ASCT at our department will be presented at the meeting. Disclosures:No relevant conflicts of interest to declare.

Interferon Maintenance Prolongs Remission Duration After Rituximab-Containing Induction In First-Line Advanced Stage Follicular Lymphoma Patients – a Retrospective Analysis of the German Low-Grade Lymphoma Study Group (GLSG)

AbstractAbstract 2864 Background:Rituximab (R) maintenance in first remission of follicular lymphoma (FL) has recently been shown to improve remission duration as compared to observation only (Salles et al., ASCO 2010). During the nineties of the last century, maintenance using interferon alpha (IFN) had been shown to be effective in indolent lymphoma (Solal-Celigny et al., NEJM 1993, Hagenbeek et al., JCO 1998). Therefore IFN-maintenance became a standard in GLSG trials after 1995. However, data on the impact of IFN after R-containing chemotherapy are rare. We performed a retrospective analysis of GLSG trials in which we compared the outcome of patients who received IFN-maintenance and patients who did not start any form of consolidation or maintenance therapy after achieving a partial or complete remission. We adjusted the analysis for potential confounders that might have influenced the decision not to start IFN-maintenance. Methods:In the GLSG first-line trials “CHOP vs. MCP” and “CHOP vs. R-CHOP” patients younger than 60 years had been randomized between consolidating high-dose radiochemotherapy followed by autologous stem cell transplantation (ASCT) and IFN-maintenance. For all responding patients older than 60 years, IFN-maintenance was intended. All patients with FL achieving a partial or complete remission after MCP, CHOP, or R-CHOP who did not start ASCT were included in the current analysis. Patients intended for IFN who did not start IFN-maintenance were compared to patients who started IFN-maintenance. We compared patient and treatment characteristics between these groups in order to detect possible reasons why IFN-maintenance was not started. Remission duration (RD) was calculated from the end of induction to relapse or death. RD was censored at the latest follow-up date in patients without event, but also when a new antilymphoma therapy was initiated without any sign of progression. No censoring was done for any form of dose reduction or stopping of IFN, which was recommended in the trials if inacceptable side effects were observed. We compared RD with IFN-maintenance to observation only by Kaplan-Meier-curves and log rank test and we adjusted for the potential confounders FLIPI, performance status, R-containing induction and remission status in multiple Cox-Regression. In order to assess the impact of IFN-maintenance after R-containing induction, we performed a subgroup analysis of R-CHOP treated patients. Results:Of 1306 FL patients with clinical remission, ASCT was started in 306 patients and documentation concerning postremission therapy was missing in 21 patients. In 719 (73%) of the remaining 979 patients IFN-maintenance was started, whereas 260 patients did not receive IFN-maintenance. Patients in which IFN-maintenance was started were not more frequently younger than 60 years (59% vs. 55%, p=0.24), and not more frequently in a better performance status (ECOG 0–1: 93% vs. 91%, p=0.33). There was only a trend to better FLIPI (LR/IR/HR 13%/41%/46% vs. 15%/34%/52%, p=0.10) as compared to patients with observation only. Patients with IFN-maintenance had not more frequently achieved a CR (19% vs. 21%, p=0.65), but more patients had been treated without Rituximab during induction (57% vs. 37%, p<0.0001). According to our analysis patients with IFN-maintenance had a significantly prolonged RD (hazard ratio 0.73, 95% CI 0.59 to 0.91, p=0.0045) which was even more pronounced after adjustment for FLIPI factors, performance status, Rituximab containing induction, and remission status (adjusted hazard ratio 0.59, 95% CI 0.47 to 0.74, p<0.0001). In 309 (65%) of 473 patients treated with R-CHOP IFN-maintenance was started. RD after 3 years was 78% vs. 64% (p=0.0007) and the adjusted hazard ratio for IFN-maintenance was 0.57 (95% CI 0.39 to 0.84 p=0.0042). Conclusions:Although this is not a randomized comparison, our analysis shows that the impact of IFN, which was observed before using R-containing therapy may still be valid in the era of immunochemotherapy. Since R-maintenance seems more effective and has less side effects, IFN-maintenance will no longer be the first choice for maintenance therapy in FL. However, it seems relevant to keep in mind that IFN is still an active substance in lymphoma therapy and may be a therapeutic option when rituximab maintenance is not possible. It may also be relevant for future investigations in lymphoma therapy. Disclosures:Dreyling:Johnson & Johnson:.Hiddemann:Roche: Honoraria, Research Funding.

R-CHOP/R-DHAP Compared to R-CHOP Induction Followed by High Dose Therapy with Autologous Stem Cell Transplantation Induces Higher Rates of Molecular Remission In MCL: Results of the MCL Younger Intergroup Trial of the European MCL Network

AbstractAbstract 965 Background and Methods:In the MCL younger trial of the European MCL Network, patients up to 65 years with stage II-IV mantle cell lymphoma were randomized to either a standard arm with 6 cycles of 3-weekly R-CHOP, stem cell mobilization with DexaBEAM and myeloablative treatment with 12 Gy TBI, 2×60mg/kg cyclophosphamide and autologous stem cell transplantation (ASCT) (Arm A), or an experimental treatment arm including 6 cycles of alternating R-CHOP/R-DHAP followed by a high dose Ara-C containing myeloablative therapy with 10 Gy TBI, 4×1.5 g/m2 Ara-C, 140mg/m2 melphalan and ASCT (Arm B). In addition to clinical response assessment, minimal residual disease (MRD) was prospectively monitored on the molecular level by real time quantitative (RQ-) PCR in both arms. MRD samples were collected at diagnosis, at midterm (after 4 induction cycles), after induction (6 cycles), and in 3-monthly intervals after ASCT until clinical progression. MRD results were evaluated according to ESG criteria (van der Velden, Leukemia 2007) and compared to clinical response and outcome. RQ-PCR was designed to reach a sensitivity of 10E-5, MRD negativity (MRD-) was defined as a negative RQ-PCR result with a technical assay sensitivity of at least 10E-04. Molecular response (MR) was defined as MRD- in peripheral blood (PB) and/or bone marrow (BM) at any sampling time point. Results:Until May 2010, 307/422 patients randomized in Germany or France had MRD samples available and a molecular marker for RQ-PCR (158 patients of the R-CHOP arm and 149 of the R-CHOP/R-DHAP arm). Overall 2374 samples, 1639 PB and 735 BM were evaluated for MRD. Clinical parameters as stage, LDH elevation, bone marrow infiltration and MIPI were distributed equally in both groups. Based on 173/307 (56%) patients with available midterm samples, MRD clearance was significantly higher in the experimental arm with 36/84 (43%) MRD- patients compared to only 12/89 (13%) in the standard arm; p<0.0001). This difference was confirmed in both, PB (50/80 (63%) vs. 18/84 (21%); p<0.0001) and BM (31/71 (44%) vs. 12/75 (16%); p=0.0003).After completion of induction 90% of R-CHOP and 94% of R-CHOP/R-DHAP patients achieved a clinical response with a CR rate of 26% and 39%, respectively. The rate patients achieving a MR was significantly higher in the R-CHOP/R-DHAP arm (60/82 (73%) vs. 29/92 (32%) after R-CHOP; p<0.0001). BM clearance from lymphoma cells was inferior after R-CHOP only (MRD- 17/71 (24%) compared to R-CHOP/R-DHAP (MRD- 39/57 (68%)). Accordingly, MRD- in the PB was achieved after R-CHOP in only 40/86 patients (47%) compared to 63/79 (80%) in the R-CHOP/R-DHAP arm. Achievement of BM MR after induction was associated with a significantly improved remission duration in the pooled treatment arms (89% vs. 74% at 24 months, p=0.0017).High-dose consolidation followed by ASCT demonstrated a high impact on tumor reduction in the pooled treatment arms and increased the BM MR rate from 50% to 75% (p = 0.0001, paired samples). This improvement was more prominent in the R-CHOP arm (29% to 65%; p = 0.0023) than in the experimental arm (76% to 88%; p=0.18). Remarkably, sustained PB MR during the first year after ASCT was predictive for outcome in both treatment arms (pooled cohort n = 135, 94% vs. 63% ongoing remissions at 2 years, p=0.0001) R-CHOP: 92% vs. 67%, p=0.0224 and R-CHOP/R-DHAP : 96% vs. 53%, p=0.0016). Conclusion:RQ-PCR is an excellent tool to quantitatively determine the impact of different treatment modalities on tumor clearance and revealed the superiority of the high dose Ara-C containing treatment arm early during treatment. Furthermore it underlines the importance of ASCT consolidation in MCL.Thus, MRD seems to be prognostically more relevant than clinical and morphological complete response assessment and was confirmed as a reliable early predictor of clinical outcome in MCL. Disclosures:Ribrag:LFB: Honoraria, Research Funding; servier: Research Funding; celgene: Research Funding; pfizer: Honoraria; novartis: Honoraria.

Timed Sequential Induction Therapy with Cytarabine and Mitoxantrone In Acute Myeloid Leukemia (AML): A Well-Tolerated Regimen with High Response Rates In Older Patients and Transformed AML.

AbstractAbstract 1068 Background:Patients with AML who are eligible for chemotherapy are traditionally treated with infusional cytarabine and an anthracycline. CR rates with this combination have been approximately 50–60% with an induction mortality of 10–25%. However, this treatment is less effective in older patients in terms of CR attainment, remission duration, and overall survival.We present a retrospective analysis of an induction regimen that was designed based on the concept of timed sequential therapy. An initial pulse of chemotherapy is administered to eradicate cells in S phase. This is followed by a rest period during which previously quiescent cells that enter the cell cycle can be targeted by a second pulse of chemotherapy. The regimen incorporates high dose cytarabine, which has been shown to improve remission duration when used in induction, and dose-intensified anthracycline therapy, which has been shown to improve outcomes in younger patients. This report highlights the responses and tolerability of the study regimen, particularly in elderly patients and patients with prior myelodysplastic syndrome (MDS). Patients and Methods:One hundred sixty six patients were treated with timed sequential chemotherapy from 1998–2009. The treatment consisted of two doses of cytarabine 2 gm/m2 IVPB over 3 hours administered 12 hours apart followed by one dose of mitoxantrone 30 mg/m2 IVPB over 1 hour on days 1 and 5. Data on pre-therapy cytogenetics and MDS was collected for each patient. Remission status was assigned per the IWG response criteria for AML. Results:Median age of the patients was 54.5 years (range 17–85). There were eighty males and eighty-six females. Out of 166 patients, 11 (6.6%) patients had favorable, 83 (50%) had intermediate, and 72 (43.4%) had unfavorable karyotypes. One-third of the patients (57 pts) had AML transformed from MDS.The overall response rate (ORR: CR+CRi+CRp) for all patients was 69.9%. In patients who had de novo AML, the ORR was 79.8%, regardless of age. Patients over age 60 with de novo AML had an ORR of 74%. For those patients under the age of 60, the ORR was 82%. The ORR for patients with transformed AML was 52.6% (53% in pts over age 60, 52% in pts less than 60).The 30 day mortality rate was 3.4% (6/166). Five of the six patients who died had an unfavorable karyotype with 2 patients having therapy-related AML. The 30 day mortality for patients older than 60 was 3.3% (2/61) and for all patients was 3.6% (6/166). The 60 day mortality rate in all patients was 10.8% (18/166). Of the additional 12 patients, seven died from progressive disease and only 3 died of suspected therapy-related complications. Grade 3/4 hematologic toxicities were the most common adverse events seen. Conclusion:This is a convenient, 2-day induction regimen that is well-tolerated with comparatively low 30 and 60 day mortality and high response rates in older patients and those patients with AML transformed from MDS. This would be an excellent initial regimen for remission induction in a select population of patients in whom novel consolidation or maintenance therapies can be incorporated to further improve outcome. Disclosures:No relevant conflicts of interest to declare.

Bortezomib and Dexamethasone as Maintenance therapy in Relapse/Refractory multiple myeloma Patients

Background: Despite the advances in the treatment for multiple myeloma (MM) in the past decade, it still remains an incurable haematological disease and the majority of patients still experience relapse. Bortezomib is a novel proteasome inhibitor approved for the treatment of MM patients. Several studies have demonstrated its efficacy as front-line therapy and in relapsed, advanced MM but no data are available as maintenance therapy (MT) in refractory/relapsed MM.Patients and methods: The aim of this study is to evaluate the safety and the efficacy of bortezomib/dexamethasone MT (1.3 mg/mq bortezomib on days 1 and 15; 20 mg dexamethasone on days 1–2 and 15–16 in a 28-day cycle for a total of 6 cycles) in patients with refractory/relapse MM who responded to salvage therapy.Results: From October 2004 until April 2008, 40 MM patients have been enrolled. The characteristics of the patients were as follows: 20 males and 20 females, median age was 70 years (IQR:66–75). Median haemoglobin value was 10.85 (IQR:10.175–12.225) and 7 (18%) patients had a renal failure. Skeletal disease was present in 27 (68%) patients. The median number of prior therapies was 2 (1–4). The salvage therapy included bortezomib as single agent or in combination with steroids and/or thalidomide in 12 patients (30%). Median time from diagnosis to the first dose of MT was 41 months (IQR:26–59). The median number of bortezomib infusion was 8 (1–18). After a median follow up of 13 months (IQR:6–31), 10 patients died for PD and 4 patients for infections. The MT improved the quality of response and converted in 1 CR and 4 VGPR the PR after salvage therapy in 5 patients; moreover, we observed a remarkable decreased of M component in 11 patients. The median time to progression was 23 months (95%CI: 8-not reached) with a progression free-survival at 1 year of 69% (95%CI: 50–82). The overall survival at 1 years was 63% and the cumulative incidence of death due to PD adjusted for competitive risk event was 25% (95%IC:10–41). In a univariate analysis the response rate to MT was not significantly affected by age, sex, number or type of previous therapy and haemoglobin concentration. Non-dose-limiting toxicities included neuropathy grade 1 (12 pts), herpes zoster reactivation (2 pts) and gastrointestinal affections (1 pts).Conclusion: The combination bortezomib/dexamethasone can be safely administered as a maintenance therapy in relapse/refractoy MM. These preliminary data suggest that bortezomib/dexametasone MT can improve remission duration and also quality of response with an acceptable toxicity.

Molecular Remission after Combined Immunochemotherapy Is of Prognostic Relevance in Patients with MCL: Results of the Randomized Intergroup Trials of the European MCL Network

Two randomized intergroup trials of the European MCL Network investigating the impact of different combined immunochemotherapy protocols for patients with stage II-IV mantle cell lymphoma (MCL) followed by autologous stem cell transplantation for patients <65 yrs and a rituximab or interferon maintenance treatment for patients > 65 yrs are currently performed.Patients and methods: 182 German patients with evidence for peripheral blood (PB) involvement as demonstrated by consensus IGH-PCR at diagnosis were analyzed for quantitative PB involvement and molecular response (MR) by Real Time Quantitative (RQ) IGH-PCR. The results were evaluated according to ESG criteria (van der Velden, Leukemia 2007) and were compared to clinical parameters at diagnosis and outcome.Results: Patients had a median age of 61 years, an elevated LDH in 37%, B-symptoms in 42% and extranodal involvement in 36%. According to the MIPI prognostic index 20% had an adverse, 37% an intermediate and 43% a good prognosis. Median level of circulating MCL cells in PB at initial diagnosis were 6×10−2 (range 2×10-4 to 8×10-1) and correlated significantly with clinical parameters as advanced stage (p=0.0016), elevated LDH (p= 0.0026), bone marrow infiltration (p= 0.0001) and MIPI prognostic index (p<0.0001). MR after induction was achieved in 55% (67/121) of all evaluable patients and correlated with stage (p=0.058), the presence of B-symptoms (p=0.016) and BM infiltration at diagnosis (p=0.011). Interestingly, the rate of MR was higher in patients receiving the protocol for elderly than for young patients (69% vs. 45% p=0.0006). This effect was especially prominent in the BM with an MRD clearance of 65% in elderly compared to only 35% in younger patients (p<0.0001). BM was more sensitive for MRD detection compared to PB after rituximab containing treatment. Of 62 paired samples only 2 BM samples were BM MRD- with concomitant MRD+ in the PB, whereas 13 MRD- PB samples demonstrated MRD+ in the corresponding BM (p=0.045). Patients achieving a MR in the BM after induction demonstrated a significantly improved remission duration compared to MRD+ patients (100% vs. 66% at 24 months, p=0.0285, median observation time 15 months).Conclusion: Quantitative detection of circulating MCL cells improves clinical risk assessment and staging accuracy. Furthermore RQ-PCR allows to evaluate the impact of different treatment modalities on tumor clearance in PB and BM. This is the first randomized trial demonstrating that achievement of MR by combined immunochemotherapy might be an early indicator for treatment outcome in MCL.

Outcomes of Hematopoietic Stem Cell Transplantation for Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL).

Considerable advancements have been made in our understanding of the biology and treatment of CLL/SLL. Despite these advances, CLL/SLL essentially remains an incurable illness. Hematopoietic stem cell transplantation (HSCT) has been used in an attempt to improve remission duration and survival. However little high level data exists on outcomes for patients (pts) undergoing HSCT for CLL/SLL. We evaluated the long-term survival of 65 CLL/SLL pts who underwent allogeneic or autologous HSCT from 1995 until 2006 at the University of Nebraska Medical Center. The median duration of follow-up for surviving pts is 8.8 years. The median age was 49 years and there was no significant difference in age between the autologous and allogeneic groups. Thirty nine pts underwent allogeneic HSCT (n=25 matched related donor, n=14 matched unrelated donor) and 26 pts underwent autologous HSCT. For the group undergoing allogeneic HSCT, the stem cell source was mobilized peripheral blood progenitor cells in 74% and bone marrow in 26%. In the autologous HSCT group, 81% of pts received peripheral blood and 19% received bone marrow as their stem cell source. In the autologous group there were 19 deaths (10 from progression) over the period of follow-up. In the allogeneic group there were 29 deaths (including 8 from acute regimen related toxicity, 9 from infection, 3 from complications of GVHD, 1 from late pulmonary toxicity, one from PTLD, one from MDS/AML) and 10 pts are alive at end of follow-up. One hundred day mortality was significantly higher in the allogeneic group (20% vs. 6%; p=0.05). For the allogeneic group the cumulative incidence of grade II-IV acute graft versus host disease (GHVD) was 64% (95% confidence interval [CI]=47–76) and the cumulative incidence of chronic extensive GHVD was 50% (95% CI=29–68). One-year progression free survival (PFS) was significantly better among autologous SCT when compared to allogeneic HSCT (77% versus 45%; P=0.006), but at 5 years these differences were no longer apparent. Similarly, one-year overall survival (OS) was significantly better for autologous SCT (81% versus 48%; P=0.003) but at 5 years these differences were no longer significant (49% versus 31%; p=0.15). Among all patients undergoing allogeneic HSCT, 5-year PFS was significantly higher for patients with SLL vs. CLL (36% vs. 25%; P=0.04). In addition, 5 year OS was better for pts with SLL compared to CLL (51% vs. 33%, P=0.06). There was no difference in PFS or OS following autologous SCT between patients with a diagnosis of CLL versus SLL. The group of pts undergoing autologous HSCT demonstrates no plateau on the PFS curve, whereas for pts undergoing allogeneic HSCT there is a suggestion of a plateau in PFS at approximately 25%. In conclusion, CLL/SLL patients undergoing allogeneic SCT had a higher incidence of early treatment related mortality, mainly from regimen related toxicity and infection. In a subgroup analysis pts with CLL appear to have an inferior PFS compared with pts with SLL. This difference may be due to a more prominent underlying immune deficiency in CLL patients that leads to a higher probability of treatment related mortality. Pts with CLL/SLL undergoing autologous HSCT had a lower incidence of treatment related mortality, but there is no evidence of a plateau in progression-free survival.

Maintenance therapy in multiple myeloma

Therapeutic advances in the treatment of multiple myeloma have significantly improved remission duration and overall survival (OS). These strategies have included the use of immunotherapy (interferon), novel agents (bortezomib, thalidomide, and lenalidomide), corticosteroids, and chemotherapy. While novel agents have had a major impact on response rates with initial therapy, most patients with multiple myeloma will eventually relapse. In the setting of minimal residual disease following standard dose or high-dose therapy, a number of different 'maintenance' strategies have emerged to prolong the duration of initial or subsequent remissions. The impact of these strategies on OS and event-free survival (EFS) is critically important, as the use of ineffective maintenance therapy adds the burden of additional cost, morbidity, and may reduce quality of life. Truly successful maintenance therapy will be effective in the setting of minimal residual disease, and will improve not only EFS, but also OS. This review summarizes the currently available data in the maintenance setting for multiple myeloma, and will discuss potential future trials to further address this important issue.

Improved survival in a retrospective cohort of 28 dogs with insulinoma

To determine the survival times for a cohort of dogs with insulinoma and to describe the impact of medical therapy both in non-surgical cases and in surgical cases following relapse. A retrospective study of dogs with insulinoma is presented. The Kaplan-Meier method is used to evaluate the survival characteristics of this population. Twenty-eight dogs were included in the study. The median survival time for all dogs was 547 days. Nineteen patients underwent partial pancreatectomy. The median survival time for this group was 785 days and for those subsequently receiving prednisolone therapy on relapse it was 1316 days. Perioperative complications are discussed. Survival times in this study exceed those in other studies published previously. In part, this is explained by an improved remission duration following surgery compared with previous reports. More striking though is the longevity of patients following institution of medical therapy. These data give strong objective support to the role of medical therapy in the management of canine insulinoma, including following relapse after surgically induced remission.

Kinetics of Immune Responses and Tumor Burden in Patients with Indolent B Cell Lymphomas Receiving Recombinant Idiotype Vaccination as the Sole Treatment.

Immunization of patients with B-cell non-Hodgkin's lymphoma with the individual idiotype expressed by the malignant clone can induce tumor-specific immune responses that correlate with improved remission duration and survival rates after cytoreductive chemotherapy. We have developed a production method for a recombinant idiotype vaccine based on expression of Fab fragments in E. coli. Intradermal administration of this vaccine mixed with lipid-based adjuvant and subcutaneous coadministration of GM-CSF has excellent immunogenicity as demonstrated by a high and idiotype-specific immune response rate in a phase I trial in advanced lymphoma patients with a severely impaired immune status (Bertinetti et al., Cancer Research 2006). Of a cohort of 15 patients with newly diagnosed or relapsed indolent B cell malignancies who had not been treated with conventional cytoreductive therapy and received 6 monthly immunizations of this idiotype vaccine, we observed 6 cases (40%) with objective quantitative evidence of tumor regression. 5 of these patients were in primary “watch and wait” situation for indolent NHL, and 1 follicular lymphoma patient had recurrence of nodal disease after a complete remission achieved in the phase I trial. At weeks 0, 8, 24, 36, and 52 after initiation of vaccination, staging examinations were performed including enumeration of circulating tumor cells by quantitative real-time PCR, and immune responses were assessed by ELISPOT and ELISA. Beginning with the 4th vaccination, evidence for reduction of nodal disase was noted in 5 cases, 4 of which achieved an objective partial response after all 6 scheduled immunizations according to standard staging criteria. These patients received continuing vaccinations in intervals of 1–3 months, and no progression has occurred after a follow-up of 9–32 months. Of 6 patients who had detectable lymphoma cells in the peripheral blood, 4 showed a continuous, at least 10fold decrease of the number of circulating lymphoma cells during the course of the vaccination. Two of the partial responders had never evidence for circulating tumor cells. A T cell response to the vaccine developed in 4/5 evaluated patients with evidence of tumor regression and in 3/6 patients without evidence for a clinical response. These cellular responses were maintained at stable levels during the vaccination and continued to be present 6 months after the last vaccination. Humoral immune responses were induced in 5/5 patients with declining tumor burden and in 2/6 non-responders. In 3 cases, the anti-idiotypic antibody titers declined after 6 months. In cases where anti-idiotype antibodies of IgM and IgG isotype occurred, IgM preceded the appearance of IgG. All objective clinical responders mounted a combined cellular and humoral immune response. The temporal association of immune responses with tumor regression provides support for the assumption that recombinant idiotype vaccination in the chosen format may play a causal role for a favorable disease course in previously untreated indolent lymphomas and may hence obviate the need for cytoreductive chemotherapy for extended time periods.

Follicular lymphoma: today’s treatments and tomorrow’s targets

Over the past two decades, the incidence of follicular lymphoma has increased. Contemporary treatments include combinations of chemotherapy and monoclonal antibodies, radioimmunotherapy, new targeted agents and stem-cell transplantation. Prognostic tools are becoming more important in helping clinicians and patients decide on the most appropriate therapeutic regimens. Gene expression profiling and biomarkers are promising additions to this armamentarium. When patients do require therapy, the addition of rituximab to chemotherapy seems to improve remission duration and may improve overall survival. Radioimmunotherapy capitalises on the capacity to target radiation directly to malignant cells, and is currently approved for the treatment of relapsed/refractory follicular lymphoma. Further investigation is needed to clarify the role of stem-cell transplantation in follicular lymphoma. Only well-designed clinical trials can provide answers to the many questions that remain regarding the optimal treatment and sequence of treatments for patients with follicular lymphoma.

An hGM‐CSF DNA‐Cationic Lipid Complexed Autologous Tumor Cell Vaccine did not Improve Remission Duration in Dogs with Lymphoma

Introduction: Lymphoma is one of the most common cancers in dogs and while clinical remission can be induced using chemotherapy, very few dogs are cured. Since cytokine‐adjuvanted autologous whole‐tumor‐cell vaccines (ATCV) can induce potent antitumor immune responses against otherwise non‐immunogenic cancers we initiated a study of such an approach in dogs with lymphoma.Methods: Following achievement of a complete remission using a 19‐week CHOP‐based chemotherapy protocol, 51 dogs with B‐cell lymphoma were randomized to receive 8 treatments (4 weekly, then 4 additional at q2wk intervals) of vaccine or lipid‐equivalent placebo. Dogs were followed monthly for assessment of remission duration and survival. Surrogate indices of immune response (delayed‐type hypersensitivity, interferon‐γ quantitative RT‐PCR, lymphocyte proliferation, and flow cytometry for lymphoma‐specific antibodies) were also investigated before and after vaccination.Results: No significant difference in median remission duration was observed between dogs receiving vaccine (277 days) or placebo (258 days); the Kaplan‐Meier curves were virtually super‐imposable. No significant differences in surrogate indices of immune response were noted pre‐ and post‐vaccination.Conclusions: In this context, an hGM‐CSF DNA‐cationic lipid complexed ATCV vaccine did not enhance remission duration in dogs with lymphoma, likely due to lack of vaccine‐induced tumor‐specific immunity.

Prolonging remission with rituximab maintenance therapy

Maintenance therapy using rituximab is currently under consideration as a means of prolonging remission in patients with indolent non-Hodgkin’s lymphoma. A phase II trial using rituximab as first-line therapy followed by maintenance treatment was carried out in patients with previously untreated indolent non-Hodgkin’s lymphoma. The overall response rate improved from 47% (7% complete response) after initial treatment to 73% (37% complete response) after maintenance treatment; median progression-free survival was 37 months. A similar study in patients with previously untreated chronic lymphocytic leukemia or small lymphocytic lymphoma (SLL) also showed some improvement in response rates after maintenance therapy and a median progression-free survival of 19 months. The improved remission duration suggested in these phase II trials has been confirmed in a randomized, phase III trial performed by the Swiss Group for Clinical Cancer Research. Patients with follicular non-Hodgkin’s lymphoma who had objective response or stable disease after a standard 4-week course of rituximab were randomized to either observation or further maintenance rituximab treatment. Median event-free survival was longer in patients who received maintenance therapy (23 v 12 months; P = .02). The toxicity of maintenance rituximab has been minimal in all trials to date. Although prolongation of progression-free survival has been shown in all completed trials, multiple other questions regarding maintenance rituximab are being addressed in ongoing trials. These include optimum schedule/duration, use after initial chemotherapy/rituximab combinations, efficacy versus retreatment at progression, and efficacy in other B-cell neoplasms.