Quantitation of Minimal Residual Disease in Patients with Chronic Lymphocytic Leukemia Using LNA-Modified Fluorescently Labeled Probes and Real-Time PCR Technology.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2331-2331
Author(s):  
Sona Pekova ◽  
Ludmila Saudkova ◽  
Lukas Smolej ◽  
Miroslav Prucha ◽  
Tomas Kozak
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Tumor Cell ◽  
Real Time ◽  
Real Time Pcr ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
Specific Primers ◽  
Pcr Technology ◽  
Minimal Residual

Abstract Background: Patients with chronic lymphocytic leukemia (CLL) relapse even after aggressive therapies and stem cell transplantation. As the therapeutical goal today is to clear off the tumor cell burden as much as possible, highly sensitive assays for minimal residual disease (MRD) evaluation and monitoring are needed. At present, many patients with not only germline IgVH sequences, but also with hypermutated IgVH genes are being treated, with the need for a sensitive and specific MRD monitoring. The original notion of MRD follow-up in CLL was based on the usage of JH-gene specific TaqMan hybridization probes. At present, due to the vast diversity of B-clonal rearrangements to be detected, the original idea has been challenged and the methodology should be modified. Aims: Since the hypermutation process does not restrict itself to the VH segments only and might afflict the JH segment as well, the molecular tools for the monitoring of CLL clonal rearrangements must be versatile enough to allow for the detection and quantitation of virtually any sequence possible. Moreover, the technique must meet the criteria for high sensitivity and specificity. We present here a novel methodology for MRD monitoring in CLL, based on LNA technology (Locked Nucleic Acids) and quantitative Real-Time PCR. Methods: 59 patients with the diagnosis of CLL were enrolled into our MRD study (22 females, 37 males, median age 59.1 yrs). 33 out of 59 individuals had unmutated IgVH genes (4 females, 29 males), 26 out of 59 patients had mutated IgVH genes (15 females, 11 males). For each patient, clone-specific primers were designed and their clonal VH sequences were molecularly cloned to construct the quantitation standards. In one patient, allelic inclusion has been identified (VH1–8 and VH3–30, both mutated), and for this individual, clone-specific primers and standards have been constructed for both rearrangements. To quantify the individual clonal VH transcripts, LNA-modified fluorescently labeled probes targeted against individual gene segments were employed. For any of 6 (7) IgVH families with unmutated VH genes, family-specific consensus LNA-modified probes were used. For those CLL cases with heavily hypermutated genes, ProbeLibrary™ was employed. For quantitation experiments, ABL was used as the control gene. Results: The LNA-modified probes are distinguished by a very high specificity and sensitivity (reaching to 10−8, in contrast to flow cytometry with its detection limit being 10−4). The LNA-based assays allow for precise monitoring of the residual tumor cell burden in CLL patients, especially during those periods of time, when other, less sensitive techniques fail to trace the malignant clone. Conclusions: LNA-modified probes and Real-Time PCR technology represent a highly versatile, specific and extremely sensitive methodology for the monitoring of MRD in chronic lymphocytic leukemia. We strongly advocate their usage in the molecular follow-up of MRD in the setting of CLL (and possibly other B-cell malignancies with hypermutated VH gene sequences as well).

TP53, SF3B1, and NOTCH1 mutations and outcome of allotransplantation for chronic lymphocytic leukemia: six-year follow-up of the GCLLSG CLL3X trial

Blood ◽  
2013 ◽  
Vol 121 (16) ◽  
pp. 3284-3288 ◽  
Author(s):  
Peter Dreger ◽  
Andrea Schnaiter ◽  
Thorsten Zenz ◽  
Sebastian Böttcher ◽  
Marianna Rossi ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Disease Control ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
Key Points ◽  
Tumor Clone ◽  
Minimal Residual ◽  
Notch1 Mutations

Key Points This trial update shows that allotransplantation can provide long-term minimal residual disease–negative disease control in poor-risk chronic lymphocytic leukemia. Six-year survival is close to 60% and is independent of the presence of TP53, SF3B1, and NOTCH1 mutations in the tumor clone.

Bone Marrow May Be More Informative Than Peripheral Blood To Evaluate Minimal Residual Disease During 1st and 2nd Year Follow Up After First-Line Fludarabine, Cyclophosphamide, and Rituximab For Chronic Lymphocytic Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1621-1621
Author(s):  
Paolo Strati ◽  
Michael J. Keating ◽  
Susan O'Brien ◽  
Jan A. Burger ◽  
Alessandra Ferrajoli ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Chronic Lymphocytic Leukemia ◽  
Peripheral Blood ◽  
Residual Disease ◽  
Response Assessment ◽  
Lymphocytic Leukemia ◽  
First Line ◽  
Final Response ◽  
Minimal Residual

Abstract Background Minimal Residual Disease (MRD) status at end of first-line chemoimmunotherapy is an independent prognostic factor for patients (pts) with chronic lymphocytic leukemia (CLL). In the CLL8 trial of the German CLL Study Group, peripheral blood (PB) was monitored for MRD during follow up. Because the microenvironment is important for CLL cell growth and survival and typically it is the last site to eliminate residual disease with chemoimmunotherapy, bone marrow (BM) might be a more reliable site to monitor MRD. Methods Two-hundred thirty-seven pts with CLL and an indication for therapy (IWCLL-WG 2008) received first-line fludarabine, cyclophosphamide, and rituximab (FCR) on protocol between 09/2008 and 09/2012. MRD was prospectively assessed in BM and/or PB by flow cytometry using the highly sensitive international standardized approach, 2 months after the last course of treatment (final response assessment) and every 3-6 months thereafter. Kaplan-Meier estimates were compared using the log-rank test. Results Sixty-one percent of pts were male, 21% were >65 years old, 40% had Rai stage III-IV, 41% had beta2-microglobulin (B2M) ≥4 mg/L, 61% had unmutated IGHV, and 21% had FISH analysis positive for deletion 11q and 7% for deletion 17p. Seventy-five percent of pts received ≥3 total courses of FCR. The complete remission (CR) and overall response (OR) rates were 65 and 97%, respectively. BM MRD negativity was achieved in 59% of pts at final response assessment. For monitoring, BM MRD was assessed in 121 pts during the 1st year and in 30 pts during the 2nd year after completion of treatment with FCR; all samples were serial. PB MRD was assessed in 106 pts during the 1st year and in 57 during the 2nd year of follow up; again all samples were serial. BM MRD negativity was observed in 63 (52%) pts during the 1st year of follow up and in 15 (50%) pts during the 2nd year. PB MRD negativity was observed at the same staging times in 81 (76%) and 29 (51%) pts, respectively. Concurrent BM and PB samples were taken during the 1st year in 51 pts, and in 6 pts during the 2nd year of follow up. We evaluated the association between MRD negativity during the 1st and 2nd year of follow-up and progression-free survival (PFS). BM MRD positive status was associated with shorter PFS when assessed during both the 1st and 2nd year of follow up (p<0.001 and p=0.001, respectively; Figure). In contrast, PB MRD positive status did not correlate with PFS for either time (p=0.15 and p=0.79, respectively; Figure). Conclusions After first-line FCR for pts with CLL, positive BM MRD may identify pts at higher risk for progression. Based on this finding, BM may be preferred to assess MRD status and pts with positive BM MRD could be considered for maintenance or consolidation strategies. Additional studies confirming these findings are warranted. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Serial Minimal Residual Disease Evaluation in Patients with Chronic Lymphocytic Leukemia Under Long-Term Venetoclax Treatment

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1876-1876
Author(s):  
Thomas Lew ◽  
Mary Ann Anderson ◽  
Constantine S. Tam ◽  
Sasanka Handunnetti ◽  
Dennis Carney ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Board Of Directors ◽  
Median Time ◽  
Research Funding ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
Advisory Committees ◽  
Minimal Residual

Abstract Background The selective BCL2 inhibitor venetoclax (Ven) achieves an overall response rate of approximately 75-80% as a single agent in relapsed and refractory chronic lymphocytic leukemia/small lymphocytic lymphoma (RR-CLL/SLL)1. At one year ~75% of patients (pts) are progression-free at the approved monotherapy dose of 400 mg/day1,2 and Ven is the only novel agent with a significant rate of minimal residual disease (MRD) negativity (MRD-neg)3. The temporal pattern of MRD levels and systematic long term follow up of pts stratified by their MRD status on Ven have not been reported. We report the long term outcomes according to MRD status for 59 pts with RR-CLL/SLL who attained objective disease response to Ven, and the temporal patterns of change in MRD. Methods We reviewed the clinical outcomes to July 2018 of 67 pts with RR-CLL/SLL enrolled since June 2011 on early phase clinical studies of Ven at our two hospitals. Analysis was restricted to the 59 pts who achieved a partial response or complete response by iwCLL criteria. Pts initially received 150-1200mg Ven/day (45 ≥400mg/day) on one of three ongoing trials: Phase 1 Ven monotherapy (NCT01328626) (n=36), Phase 1b Ven plus rituximab (NCT01682616) (n=14), or Phase 2 Ven monotherapy in del(17p) CLL/SLL (NCT01889186) (n=9). For this analysis MRD-negativity was defined as <1 cell in 10-4 leukocytes by ERIC criteria, or no cells with a CLL phenotype when <400,000 cells were analyzed in an assay with a minimum sensitivity of 0.1%. Of those pts reported as MRD-neg this was confirmed at a level of 10-4 in 71%4. Unless otherwise specified, MRD-neg refers to status in the bone marrow (BM) and pts who were not tested were considered to be MRD-pos (n=2 pts). Landmark analyses of time to progression (TTP) by MRD status used the median time to achievement of MRD-neg. Fisher exact test was used to assess the association of clinical, biological and treatment variables with achievement of MRD-neg. TTP and time to MRD-neg were estimated using the method of Kaplan-Meier, and comparisons among groups used the log-rank (Mantel-Cox) test. Results Of the 59 pts who achieved an objective response to Ven, 21 (36%) achieved MRD-neg in the BM and 26 (44%) in the PB. Of the 38 pts who did not achieve BM MRD-neg, 36 (95%) had at least one BM assessment on treatment; the two remaining pts did not clear MRD in the PB. The strongest positive predictor for the achievement of BM MRD-neg was treatment with Ven plus rituximab (9 of 14 [64%]) achieved vs 13 of 45 [27%] on Ven monotherapy (p=0.02)). Complex karyotype was a negative predictor in pts receiving ≥400mg/day. TP53 aberrant state (mutation and/or del(17p)), bulky adenopathy >5cm and fludarabine-refractoriness were not significantly associated with achievement of MRD-neg, irrespective of dose (table 1). The median time to MRD-neg was 8.2 (range 2 - 46) mths for BM (fig 1A) and 5 (range <1 - 50) mths for PB, with 22/26 (85%) pts who achieved PB MRD-neg doing so within 12 mths of starting Ven. 25/26 had a contemporaneous or subsequent BM aspirate and 20 (80%) achieved BM MRD-neg after a median of 3 (<1 - 17) further mths. After a median follow up of 25 (range 2 - 55) mths since attainment of BM MRD-neg, 8/21 (38%) pts have developed confirmed re-emergence of BM MRD, and a further 2 pts have re-developed PB MRD-pos. Median time to reemergence of BM MRD has not been reached (59% BM MRD relapse free at 2 years post attainment). In a landmark analysis from median time to BM MRD-neg (8.2 mths), TTP by iwCLL criteria was significantly longer among BM MRD-neg pts (n = 21; median TTP 65 mths [95% CI 47 - undefined]) than BM MRD-pos pts (n = 31; median 22 mths [95% CI 14 - 39]; Hazard Ratio (HR) 0.11; p<0.0001) (figure 1B). Similar patterns held for the equivalent landmark analysis according to PB MRD (HR 0.21; p = 0.0002). Conclusions Venetoclax frequently induces BM MRD-neg, and pts achieving BM MRD-neg have very durable responses. Combined Ven plus rituximab increases the rate of BM MRD-neg. With Ven therapy, PB MRD status appears to be a reasonable surrogate for BM MRD status, but further validation is required. Achievement of BM MRD-neg should be the aim of therapy with Ven and Ven-based combination approaches may be the most effective way to achieve this.Roberts; N Engl J Med; 2016;374:311-22.Stilgenbauer; Lancet Oncol; 2016;17:768-78.Seymour; Lancet Oncol; 2017;18:230-40.Rawstron; Leukemia; 2016;30:929-36. Disclosures Lew: Walter and Eliza Hall: Employment, Patents & Royalties. Anderson:Genentech: Research Funding; AbbVie, Inc: Research Funding; Walter and Eliza Hall: Employment, Patents & Royalties. Tam:Janssen: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Beigene: Honoraria, Other: Travel funding; Beigene: Honoraria, Other: Travel funding; Pharmacyclics: Honoraria, Travel funding; Gilead: Honoraria; Pharmacyclics: Honoraria; Roche: Honoraria; AbbVie: Honoraria, Research Funding; Gilead: Honoraria; Roche: Honoraria. Roberts:AbbVie: Research Funding; Walter and Eliza Hall: Employment, Patents & Royalties: Employee of Walter and Eliza Hall Institute of Medical Research which receives milestone and royalty payments related to venetoclax; Genentech: Research Funding; Janssen: Research Funding. Seymour:Celgene: Consultancy; AbbVie: Consultancy, Honoraria, Research Funding; F. Hoffmann-La Roche Ltd: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genentech Inc: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Honoraria, Research Funding.

scholarly journals Fixed Duration of Venetoclax-Rituximab in Relapsed/Refractory Chronic Lymphocytic Leukemia Eradicates Minimal Residual Disease and Prolongs Survival: Post-Treatment Follow-Up of the MURANO Phase III Study

2019 ◽  
Vol 37 (4) ◽  
pp. 269-277 ◽  
Author(s):  
Arnon P. Kater ◽  
John F. Seymour ◽  
Peter Hillmen ◽  
Barbara Eichhorst ◽  
Anton W. Langerak ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Disease Progression ◽  
Minimal Residual Disease ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
Fixed Duration ◽  
Low Level ◽  
High Level ◽  
Minimal Residual

Purpose The MURANO study demonstrated significant progression-free survival (PFS) benefit for fixed-duration venetoclax-rituximab compared with bendamustine-rituximab in relapsed/refractory chronic lymphocytic leukemia. With all patients off treatment, we report minimal residual disease (MRD) kinetics and updated outcomes. Methods Patients were randomly assigned to 2 years of venetoclax plus rituximab during the first six cycles, or six cycles of bendamustine-rituximab. Primary end point was PFS. Safety and peripheral blood (PB) MRD status—at cycle 4, 2 to 3 months after end of combination therapy (EOCT), and every 3 to 6 months thereafter—were secondary end points. Results Of 194 patients, 174 (90%) completed the venetoclax-rituximab phase and 130 (67%) completed 2 years of venetoclax. With a median follow-up of 36 months, PFS and overall survival remain superior to bendamustine-rituximab (hazard ratio, 0.16 [95% CI, 0.12 to 0.23]; and hazard ratio, 0.50 [95% CI, 0.30 to 0.85], respectively). Patients who received venetoclax-rituximab achieved a higher rate of PB undetectable MRD (uMRD; less than 10−4) at EOCT (62% v 13%) with superiority sustained through month 24 (end of therapy). Overall, uMRD status at EOCT predicted longer PFS. Among those with detectable MRD, low-level MRD (10−4 to less than 10−2) predicted improved PFS compared with high-level MRD (10−2 or greater). At a median of 9.9 months (range, 1.4 to 22.5 months) after completing fixed-duration venetoclax-rituximab, overall only 12% (16 of 130) of patients developed disease progression (11 high-level MRD, three low-level MRD). At the end of therapy, 70% and 98% of patients with uMRD remained in uMRD and without disease progression, respectively. Conclusion With all patients having finished treatment, continued benefit was observed for venetoclax-rituximab compared with bendamustine-rituximab. uMRD rates were durable and predicted longer PFS, which establishes the impact of PB MRD on the benefit of fixed-duration, venetoclax-containing treatment. Low conversion to detectable MRD and sustained PFS after completion of 2 years of venetoclax-rituximab demonstrate the feasibility of this regimen.

Qualitative and Quantitative PCR Monitoring of MRD: Practical Implications of a Surrogate Marker for GVL Effect after RIC Allogeneic Transplantation in Relapsed Chronic Lymphocytic Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1659-1659
Author(s):  
Lucia Farina ◽  
Cristiana Carniti ◽  
Anna Dodero ◽  
Antonio Vendramin ◽  
Anna Raganato ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Real Time ◽  
Real Time Pcr ◽  
Lymphocytic Leukemia ◽  
Molecular Monitoring ◽  
Molecular Remission ◽  
Relapse Risk ◽  
Post Transplant ◽  
Tumor Load

Abstract Reduced intensity allogeneic stem cell transplantation (RIC alloSCT) is a therapeutic option for poor risk relapsed chronic lymphocytic leukemia (CLL) and can lead to 50% of progression-free survivors. The aims of this study were: to assess the “molecular quality” of clinical remission after RIC alloSCT in CLL patients; to investigate whether molecular remission (MR) can correlate with a lower relapse risk; to understand the clinical role of molecular monitoring in post-transplant immunotherapy. Twenty-nine patients with a molecular marker (heavy chain gene immunoglobulin rearrangement, IgH) were monitored for minimal residual disease (MRD). All patients had a relapsed disease; 75% had an unmutated IgH; cytogenetic analysis was available in 13 patients at first relapse, and 5 of them (38%) showed a 17p deletion. Median age at transplant was 60 years (range, 44–69). Median number of previous chemotherapy was 3 (range, 1–6) and 29% of patients failed autologous transplant. Eleven patients (38%) were chemorefractory before transplant. The conditioning regimen included thiotepa-cyclophosphamide-fludarabine in HLA identical sibling transplants (n=21), and an in vivo T cell depletion in haploidentical and unrelated alloSCT (n=8). Molecular monitoring was performed by nested-PCR on bone marrow using CDR-2 and CDR-3-derived patient-specific primers. For real-time PCR a FR3-derived probe was used. Post-transplant samples were amplified including the pre-transplant sample as positive control, and ΔCT was calculated after normalization for GAPDH gene. Eight patients (28%) were PCR-negative: 4 of them (14%) have been always PCR-negative while 4 patients (14%) experienced a delayed clearance of MRD during the first year after transplant. All these patients are alive and in CR at the median follow-up of 24 months (range, 3–71). Seven patients (24%) showed a mixed pattern of PCR positivity and negativity: one patient died of secondary acute leukemia, another patient had a nodal relapse, the others are in CR at a median follow-up of 30 months (range, 6–60). Fourteen patients (48%) were always PCR-positive: 7 of them relapsed after a median time of 9 months (range, 3–12); 2 patients died of TRM in MR; 5 patients are alive and in CR after a median follow-up of 15 months (range, 3–24). Relapse risk was higher for PCR-positive patients compared to PCR-mixed/negative patients (p=0.014). Eighty percent of PCR-mixed/negative patients experienced GVHD compared to 43% of PCR-positive patients (p=0.06). In 5 PCR-positive patients real-time PCR was carried out. In 3 patients that did not relapse a decreasing tumor load was detected; these patients were affected by extensive chronic GVHD. In the other 2 patients after an initial reduction, the tumor load increased on day +300 and +270: both patients relapsed on days +420. In conclusion, in poor risk relapsed CLL clinical and molecular remission can be achieved in a sizeable fraction of patients after RIC alloSCT. Persistent PCR positivity correlates with a high incidence of relapse and requires novel treatments, while a mixed-PCR pattern can be observed without clinical relapse.

Eradication of Minimal Residual Disease with Alemtuzumab in Chronic Lymphocytic Leukemia Is Associated with Prolonged Survival and Is an Appropriate Theraputic Endpoint for Relapsed CLL.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3114-3114 ◽  
Author(s):  
Hazem A. Sayala ◽  
Paul Moreton ◽  
Ben Kennedy ◽  
Guy Lucas ◽  
Michael Leach ◽  
...  
Keyword(s):  
Chronic Lymphocytic Leukemia ◽  
Minimal Residual Disease ◽  
Median Survival ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
End Point ◽  
Long Term Follow Up ◽  
Minimal Residual

Abstract Eradication of minimal residual disease (MRD) in chronic lymphocytic leukemia (CLL) is emerging as a desirable therapeutic end point predicting for better outcome. The monoclonal antibody alemtuzumab (Mabcampath) is approved for patients with fludarabine refractory CLL. We previously published 91 patients with relapsed CLL (74 men and 17 women, median age 58 years [range, 32 to 75 years]; 44 fludarabine-refractory) who received a median of 9 weeks (range 1 to 16) of alemtuzumab, 30mg 3x a week after dose escalation, between 1996 and 2003. 84 patients had i.v. alemtuzumab and 7 received it subcutaneously. Responses to alemtuzumab according to NCI-WG criteria were complete remission (CR) in 32 patients (36%), partial remission (PR) in 17 (19%) and no response (NR) in 42 (46%). Detectable CLL to a level of less than one CLL cell in 10,000 leucocytes, assessed by four-color MRD flow cytometry, was eradicated from the blood and marrow in 18 patients (20%). 8 of these 18 patients were fludarabine refractory. We report here the results of long term follow up of this cohort of patients after a median follow up of 77 months (range 5 to 123 months). Median survival was significantly longer in patients achieving MRD negative responses compared with those with detectable CLL at the end of therapy. The median survival for all 18 MRD negative responders has not been reached but was 87 months for the 8 fludarabine-refractory patients achieving MRD negativity. Overall survival for the 18 patients with MRD-negative remissions was 66% at 72 months (see Figure). MRD positive CR patients had a median survival of 56 months, MRD positive PR patients a median survival of 42 months and non-responders a median survival of 14 months. The median treatment-free interval prior to alemtuzumab for the 18 MRD negative patients was 8 months (range 4 to 35). Excluding planned stem cell transplantation performed in CR, the median time to next treatment for the 18 MRD negative patients was 114 months and 72% (13/18) have required no further therapy. Therefore alemtuzumab can induce MRD negative remissions in CLL resulting in a clear survival advantage with 66% of MRD negative patients alive 6 years after alemtuzumab. The markedly increased treatment-free survival and excellent survival for MRD negative patients strongly suggests that achieving an MRD negative remission is an appropriate therapeutic end-point in relapsed CLL. Figure Figure

Abbreviated Regimen with 4 Cycles of Fludarabine, Cyclophosphamide and Rituximab (FCR) in Physically Fit Patients with Chronic Lymphocytic Leukemia Who Achieve Early Complete Remission with Undetectable Minimal Residual Disease: Safety and Efficacy Follow-up Results of a Single Center Experience

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 1739-1739 ◽  
Author(s):  
Carolina Pavlovsky ◽  
Isolda Fernandez ◽  
Miguel A Pavlovsky ◽  
Adriana Galeano ◽  
Federico Sackmann ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Chronic Lymphocytic Leukemia ◽  
Minimal Residual Disease ◽  
Residual Disease ◽  
Lymphocytic Leukemia ◽  
Secondary Neoplasms ◽  
Safety And Efficacy ◽  
Grade 3 ◽  
Minimal Residual

Abstract Introduction: Chemoimmunotherapy with 6 cycles of fludarabine, cyclophosphamide and rituximab (FCR) is considered standard therapy for physically fit patients with chronic lymphocytic leukemia (CLL). Due to treatment toxicity, some patients are unable to undergo standard 6 cycles of FCR. We evaluated safety and efficacy of abbreviating FCR treatment to 4 cycles in a cohort of 35 untreated physically fit CLL patients who achieved CR with negative minimal residual disease (MRD). Patients and methods: Within 150 physically fit CLL patients treated with FCR on 1st line at our Center, from April 2003 to November 2014, a subgroup of 35 patients interrupted treatment after achieving negative MRD at the end of the 4th cycle. Median age at start of treatment was 62.8 years (34-81). Binet A/B: 24pts and C: 11. CD38 expression was positive (>7% off cells) in 57.1% and negative in 9% of the pts. A bone marrow biopsy was performed at start of treatment and 1 month post 4th cycle. Response was assessed in peripheral blood (PB) or bone marrow (BM). Negative MRD was defined as < 10-4. We used NCI criteria for response modified for the evaluation of MRD by flow cytometry. Progression was defined according to the NCI recommendations. Overall survival (OS) was defined as the time of initiation of therapy until death or last follow-up and progression free survival (PFS) as the time to progression. Data analysis included frequency and contingency tables, survival curves were plotted by the Kaplan Meier method. Treatment schedule: Fludarabine 25 mg/m2 IV day 1-3, cyclophosphamide 250 mg/m2 IV day 1-3, rituximab 375 mg/m2 IV day 3 cycle 1 and day 1 cycles 2-4, in all cycles every 28 days. Results: All 35 patients had negative MRD in PB after one month post 4th cycle. In addition, 28 had bone marrow evaluation showing CR with negative MRD in all of them. No splenomegaly nor hepatomegaly, enlarged lymphadenopathies nor lymphocytosis was observed in all the patients with negative MRD. After a median follow-up of 57 months (7 -141), median PFS was 65.8 months, not being yet reached the median of OS. PFS and OS at 72 months was 46% and 68% respectively. A total of 10 pts ( 3.5%) died: 7 on progressive disease, 3 on secondary neoplasms. Patients who progressed before 24 months had a median of survival of 22 months; median not reached on the group who progressed after 24 months (p=0.0001). Neutropenia grade 3-4 and infectious events were observed in 25.7% and 9.1% during all cycles respectively. Grade 3-4 neutropenia showed to increase over time (Cycle 1: 24%, Cycle 4: 39%). There was no treatment related death. Conclusion: With a long median follow-up, abbreviating treatment to 4 courses of FCR in patients who obtained negative MRD showed durable remissions with high PFS and OS at 72 months, minimizing treatment related toxicity. Sixty five percent of the patients who progressed after 24 months are still alive. Large randomized trials will be necessary to confirm our data. Disclosures Pavlovsky: Bristol Myers Squibb: Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria, Speakers Bureau. Pavlovsky:Novartis: Honoraria, Speakers Bureau; Janssen: Honoraria, Speakers Bureau.

Sign in / Sign up

Export Citation Format

Share Document