The clinical significance of detecting minimal residual disease (MRD) in B‐lineage acute lymphoblastic leukaemia (ALL) was evaluated by quantitative flow cytometry using a combination of TdT with ...CD10 and CD19. 53 patients with B‐cell precursor ALL were followed during and after completion of treatment (median follow‐up 23 months). Nine patients relapsed and MRD had been detected in six of them, 5–15 weeks before relapse despite morphological complete remission. 43 patients remain in clinical remission and in none of these was MRD detected. Disease‐free survival based on the detection of MRD by flow cytometry showed a statistically significant difference between both groups (P < 0.0001). The absence of MRD correlates with a low relapse rate, whereas the presence of MRD predicted early relapse. This study has shown that flow cytometry can improve the morphologic assessment of bone marrow (BM) remission status in B‐lineage ALL. The finding of < 5% blasts in BM aspirates did not correlate with ‘true’ remission in a proportion of cases as residual leukaemic blasts were detected by flow cytometry in nine samples from six patients. On the other hand, the presence of > 5% blasts assessed by morphology was not necessarily a feature of relapse in five patients as these cells were shown to have a phenotype identical to normal TdT‐negative B‐cell precursors. Quantitative flow cytometry was more informative than conventional morphology to assess remission status and showed a strong correlation with clinical outcome. This methodology is useful to define MRD in the majority of patients with B‐lineage ALL and should be tested in prospective clinical trials.
The LRF CLL4 trial randomised 777 previously untreated patients with Binet stage progressive A, B or C disease between January 1999 and October 2004 to receive either Chlorambucil, Fludarabine or ...Fludarabine and Cyclophosphamide. Interphase FISH for deletions of chromosome 6q, 11q, 13q, 17p and trisomy 12, IgVH gene mutational status (98% cut off), CD38 (7% cut off) and ZAP70 (10% cut off) expression were measured at randomisation on 579, 523, 535 and 478 patients respectively. Leukemic cells from 39 patients utilised the VH3-21 gene of whom 33 had homologous CDR3's. Among the biological markers, log rank analysis showed that >20% p53 loss, del 11q, unmutated VH genes, high CD38 and high ZAP 70 correlated with disease progression or death (Table 1) but not deletion of chromosome 6q, 13q and trisomy 12 (p=0.7, 0.3 and 0.2 respectively). There was no difference in PFS or response duration between the 52 patients with 5–20% p53 loss and the 494 patients with no p53 loss. Multivariate Cox regression analysis showed that >20% p53 loss (p<0.0001), unmutated IgVH genes (p=0.0001), deletion of 11q (p=0.02) and male gender (p=0.03) were independent risk factors for short PFS. The effects of stage and age were overridden by FISH abnormalities. High ZAP70 expression was only significant when VH gene mutation status was not included in the model. CD38 expression was only significant in univariate analysis.
Table 1VariableProgression or Death/NUnivariate p-value(log rank test)GenderMale384/5730.002Female111/20417q(p53)No131/546<0.00005Yes21/33IgVHUnmutated105/203<0.00005Mutated225/320del 11qNo288/463<0.00005Yes87/116ZAP70Negative140/2420.003Positive158/236CD38Negative110/2010.0001Positive227/334
Among the 320 unmutated cases there was no significant difference in PFS between those with 100% homology (227 cases) and those with 99% or 98% homology to the germline sequence (93 cases). Mutated VH3-21 cases were more likely to express ZAP70 than other mutated cases, p=0.004. Excluding patients with >20% p53 loss, patients using the VH3-21 gene had similar progression free survival (PFS) to those remaining patients with unmutated VH genes and an inferior PFS to those with mutated VH genes (2p=0.0001). The adverse prognostic significance of 11q deletions was not clearly evident in an interim analysis presented at ASH ‘05. Patients can now be divided into 3 risk groups (Table 2). This risk stratification provides the basis of evaluating differing treatment modalities for each risk group in subsequent clinical trials.
Table 2Risk GroupDefinitionProgression or Death/NUnivariate p-value (log-rank test)3 yr PFSPoor>20%p53 loss28/330%StandardUnmutated VH or 11q deletion or VH3-21208/292<0.0000124.7%GoodMutated VH(excl VH3–21)79/16155.0%
BACKGROUND: zeta-Chain associated protein (ZAP)-70 has been proposed as a surrogate marker for immunoglobulin heavy-chain variable region (IgVH) mutation in chronic lymphocytic leukemia (CLL), but it ...is still not clear whether it is an independent prognostic factor. METHODS: The authors evaluated ZAP-70 expression by flow cytometry in 201 untreated patients and correlated ZAP-70 levels with CD38 expression, genetic abnormalities detected by fluorescence in situ hybridization (FISH), and the time from diagnosis to first treatment. RESULTS: Fifty-seven patients (28%) were positive for ZAP-70 (ge 20%). Positive ZAP-70 status was associated with advanced disease stage, atypical morphology, CD38-positive status, trisomy 12, del(6q), or no detectable abnormalities; negative ZAP-70 status was correlated with del(13q) as a sole abnormality. The treatment-free interval (TFI) was 17.7 months for ZAP-70- positive patients and 44.6 months for ZAP-70-negative patients (P < 0.001). Multivariate analysis in 117 patients identified advanced stage, CD38 ge 7%, and the absence of del(13q) as a sole abnormality as independent factors for short TFI. Excluding FISH, ZAP-70 status acquired independent prognostic value along with CD38 status. The authors proposed a risk model that combines ZAP-70 and CD38 to identify patients who are likely to progress. When both markers were positive, the TFI was 12 months; when both were negative, the median TFI was 54 months; a median TFI of 26 months was observed in patients who had discordant results (P < 0.00001). CONCLUSIONS: The current findings suggested that both ZAP-70 and CD38 should be tested prospectively in all patients with early-stage CLL. Cancer 2005.
One of the most intriguing features of chronic lymphocytic leukemia (CLL) is its clinical heterogeneity. The mutational status of immunoglobulin heavy chain variable region (IgVH) genes is one of the ...most powerful predictors of overall survival (OS) and progression-free survival (PFS). The expression of the tyrosine kinase ZAP-70 in CLL cells has been proposed as a surrogate marker for the mutational status of IgVH genes. Recent reports suggest that ZAP-70 over-expression is an independent prognostic factor for shorter OS and PFS. There is little information about correlation between ZAP-70 expression and other clinical and biological features in CLL. The aims of this study are 1) to evaluate prospectively ZAP-70 expression in a series of CLL patients; 2) to correlate this with clinical stage, lymphocyte morphology, CD38 expression and chromosomal abnormalities detected by FISH and 3) to analyze the independent prognostic value of ZAP-70 in predicting time to first treatment (treatment free interval, TFI). ZAP-70 expression was analyzed using four-colour flow cytometry (as described by Crespo et al, NEJM 2003; 348:1764–75). 201 previously untreated CLL patients were evaluated at diagnosis (32%) or during the disease course. Amongst them, 143 patients were entered in the LRF CLL4 trial. Clinical stage at the time of the study was A in 92 patients (A progressive in 46), B in 63 and C in 46. 28% were ZAP-70 positive (+) (cut-off ≥ 20% of CD5/CD19+ cells). ZAP-70 positivity was associated with prevalence of stage B/C at diagnosis (p=0.004), CLL with >10% prolymphocytes (CLL/PL) or atypical morphology (p<0.001), CD38 positivity (regardless of the cut-off point) (p<0.001), trisomy12 (p=0.001), del(6)(q21) (p=0.05) or no detectable abnormalities (0.002). ZAP-70 negative (−) cases presented more often with del(13)(q14) (p<0.001). There were no significant differences in the frequency of del(11)(q23) or delp53 between ZAP-70(+) and ZAP-70(−) cases. Median time from diagnosis to first treatment (treatment free interval, TFI) was 17.7 months for ZAP-70(+) and 44.6 months for ZAP-70(−) cases (p<0.001). The presence of the following parameters was associated with short TFI in univariate analysis: male sex (p=0.02), atypical morphology (p=0.02), clinical stage B/C (p<0.001), ZAP-70(+) (p<0.001), CD38+ (p<0.001), absence of del(13)(q14) (p<0.001), presence of delp53 (p=0.05). Multivariate analysis is being performed. In conclusion, we document a significant correlation between ZAP-70 over-expression in CLL and other adverse prognostic factors (such as CD38 and advanced stage), provide new data concerning its association with cytogenetic abnormalities detected by FISH and demonstrate the prognostic value of ZAP-70 expression.
The CLL4 trial randomised 777 previously untreated patients between Chlorambucil (Chlor), Fludarabine (Fluda) and Fludarabine with Cyclophosphamide (FC). The median follow-up is 21 months. VH gene ...mutation status using a 98% cut off, CD38 expression using a 7% cut off, ZAP70 expression (Orchard et al Lancet 2004) and interphase FISH were measured on samples taken at randomisation. In an interim analysis 253/397 patients had unmutated VH genes. 32 patients utilised the VH3-21 gene, of whom 27 showed restricted HCDR3 usage. 343/535 were CD38 positive and 131/261 were ZAP70 positive. 10/24 VH 3-21 cases were ZAP 70 positive, of whom 7 were unmutated. There was no significant association between VH genes and age, sex or a positive DAT. There were significant correlations between VH gene mutations and CD38, ZAP70 and FISH results.
Association of VH genes with CD38, ZAP70 and FISH results.CD38+ZAP 70+p53 lossDel 11qDel 6q21Del 13qTrisomy 12VH Unmutated119 (58%)110 (72%)21 (9%)48 (22%)18 (10%)109 (45%)50 (21%)VH Mutated30 (25%)17 (16%)3 (2%)13 (11%)6 (6%)97 (73%)13 (10%)p=<0.0001<0.00010.02<0.0090.2<0.00010.008% = % of all cases with known VH mutation status
Logistic regression including age, stage, gender, VH mutations and genetic factors shows that stage (p=0.002), VH genes (p=0.05), p53 loss (p=0.02) and del 11q (p=0.01) affect response. Response rates by VH gene mutation status and treatment arm are given in table 2.
Response rates according to VH mutation status and treatment armChlor UnmutChlor MutFluda UnmutFluda MutF/C UnmutF/C MutCR/NPR24 (25%)23 (42%)25 (43%)18 (55%)37 (58%)23 (70%)PR43 (45%)19 (34%)21 (36%)10 (30%)21 (33%)10 (30%)NR/PD29 (30%)13 (24%)12 (21%)5 (15%)6 (9%)0 (0%)p (trend)0.070.30.1%=% of all unmutated or mutated cases receiving a particular treatment
Analysis of variance shows that both VH genes (p=0.01) and treatment (p<0.0001) have an effect on response with no significant interaction. Among 104 patients with unmutated VH genes and both ZAP 70 expression and response data available, there was no significant difference in response rates between ZAP positive and negative cases. In univariate analysis p53 loss (p<0.00005), unmutated VH genes (p=0.003), CD38 positivity (p=0.06) but not ZAP70 positivity correlate with poor overall survival. In multivariate Cox regression analyses, age (p<0.0001) stage (p=0.01) and p53 loss (p<0.0001) are significant for survival. When patients with p53 loss are excluded unmutated VH genes (p=0.007) but not CD38 or ZAP70 positivity are significant. In conclusion p53 loss identifies a small group of patients with both poor response to treatment and short survival. In the remaining cases, unmutated VH genes are associated with a relatively poor response independent of treatment arm, and with a shorter survival.
Gender is not widely regarded as a prognostic indicator in CLL. However, the combined data from three MRC randomised trials, CLL1, 2 and 3, and two observational studies for patients with Binet stage ...A, CLL2A and 3A, over a period of 20 years (1978-1998) totalling 2370 patients, showed a significant survival advantage for women (2p<0.0001). Cox regression analysis of the three randomised trials showed that gender, age, stage and response to therapy were independent prognostic variables. The response to treatment for women was also better than for men receiving the same therapies. The LRF CLL4 randomised trial, which started in 1999 shows the same trend. Preliminary results in 444 patients Binet stages A progressive, B and C showed the same CR/Nod.PR for both sexes (43.5%) but a higher PR rate in women (45%) vs men (36.5%) and a lower proportion of women non-responders to first line therapy (11.5% vs 20%). A number of laboratory investigations in CLL4, which included FISH analysis with five probes, VH mutational status, CD38 and ZAP-70 expression by flow cytometry, showed differences between the sexes, which were significant for 17p and 11q deletions combined and CD38, always in favour of women, as shown in Tables 1 and 2.
The clinical and laboratory results suggest that CLL is biologically more benign in women. Women have a lower incidence of CLL, an overall higher incidence of stage A (41.7%) than men (27.3%) in CLL 1, 2, 2A, 3 and 3A and respond better to treatment in all the trials. These differences may be underlined by a higher proportion of 13q del as sole abnormality, a lower proportion of 17p (p53 locus) and 11q deletions and lower levels of CD38. Data on VH mutations and ZAP-70 point in the same direction but the number of cases studied is still small. An additional factor that may play a role in the better outcome for women relates to the effect of oestrogen derivatives which are known to target selectively superoxide dismutase and induce cell kill (Huang et al, Nature 407, 390, 2000).
Table 1: FISH analysis by gender (Dohner hierarchical model)
Abnormality17p del11q delTrisomy 1213q delOthersMen (286)12%19%10%34%25%Women (94)7%13%11%44%25%p value**0.052* = Combined p value < 0.05 (Chi-Square test)
Table 2: Other biological markers
CD38 negative (<30%)VH mutatedZAP-70 negativeMen173/335 (52% )51/149 (34%)94/192 (49%)Women68/100 (68%)23/52 (44%)42/68 (62 %)p value<0.005NS0.07
Abnormalities of the
TP53
gene in chronic lymphocytic leukaemia (CLL) are associated with large cell transformation, short survival and resistance to purine analogue therapy. Deletion of one allele ...and somatic mutation of the remaining allele have been described as the main mechanism of
TP53
inactivation in CLL, but its relationship with p53 protein expression remains unclear. We studied 103 CLL patients using fluorescence in situ hybridisation (FISH) to detect allelic loss at chromosome 17p and immunohistochemistry (IHC) to test for p53 protein overexpression.
TP53
deletion (≥10% of cells) was found in 21 cases (20.4%) and no deletion in 82 (79.6%). By IHC, 16 cases (15.5%) showed p53 protein expression and 87 (84.5%) were negative. There was a good correlation between FISH and IHC in 86 cases (83.5%;
p
< 0.001) and these comprised ten cases positive for both assays and 76 negative cases. The remaining 17 cases had discrepant results: 11 cases showed
TP53
deletion and were p53 negative, and six cases had strong expression of protein and no
TP53
deletion (FISH). Seventy-two patients (70%) received fludarabine. The majority (86%) of patients without abnormalities of
TP53
responded to fludarabine and only eight cases were resistant. Within the rest, all patients positive with both methods were refractory, 60% of cases with overexpression without deletion and 40% of cases with deletion without protein overexpression were non-responders to fludarabine. Our findings indicate that IHC is a simple method and provides useful complementary information to FISH analysis for the evaluation of
TP53
dysfunction. Both methods can be carried routinely to identify patients with a high chance to be resistant to fludarabine containing regimens (
p
= 0.0003).
Early Plasmodium falciparum and P. vivax infection requires parasite replication within host hepatocytes, referred to as liver stage (LS). However, limited understanding of infection dynamics in ...human LS exists due to species-specificity challenges. Reported here is a reproducible, easy-to-manipulate, and moderate-cost in vivo model to study human Plasmodium LS in mice; the ectopic huLiver model. Ectopic huLiver tumors were generated through subcutaneous injection of the HC-04 cell line and shown to be infectible by both freshly dissected sporozoites and through the bite of infected mosquitoes. Evidence for complete LS development was supported by the transition to blood-stage infection in mice engrafted with human erythrocytes. Additionally, this model was successfully evaluated for its utility in testing antimalarial therapeutics, as supported by primaquine acting as a causal prophylactic against P. falciparum. Presented here is a new platform for the study of human Plasmodium infection with the potential to aid in drug discovery.
BackgroundData suggest that immunomodulation induced by DNA hypomethylating agents can sensitize tumors to immune checkpoint inhibitors. We conducted a phase 1 dose-escalation trial (NCT02998567) of ...guadecitabine and pembrolizumab in patients with advanced solid tumors. We hypothesized that guadecitabine will overcome pembrolizumab resistance.MethodsPatients received guadecitabine (45 mg/m2 or 30 mg/m2, administered subcutaneously on days 1–4), with pembrolizumab (200 mg administered intravenously starting from cycle 2 onwards) every 3 weeks. Primary endpoints were safety, tolerability and maximum tolerated dose; secondary and exploratory endpoints included objective response rate (ORR), changes in methylome, transcriptome, immune contextures in pre-treatment and on-treatment tumor biopsies.ResultsBetween January 2017 and January 2020, 34 patients were enrolled. The recommended phase II dose was guadecitabine 30 mg/m2, days 1–4, and pembrolizumab 200 mg on day 1 every 3 weeks. Two dose-limiting toxicities (neutropenia, febrile neutropenia) were reported at guadecitabine 45 mg/m2 with none reported at guadecitabine 30 mg/m2. The most common treatment-related adverse events (TRAEs) were neutropenia (58.8%), fatigue (17.6%), febrile neutropenia (11.8%) and nausea (11.8%). Common, grade 3+ TRAEs were neutropaenia (38.2%) and febrile neutropaenia (11.8%). There were no treatment-related deaths. Overall, 30 patients were evaluable for antitumor activity; ORR was 7% with 37% achieving disease control (progression-free survival) for ≥24 weeks. Of 12 evaluable patients with non-small cell lung cancer, 10 had been previously treated with immune checkpoint inhibitors with 5 (42%) having disease control ≥24 weeks (clinical benefit). Reduction in LINE-1 DNA methylation following treatment in blood (peripheral blood mononuclear cells) and tissue samples was demonstrated and methylation at transcriptional start site and 5’ untranslated region gene regions showed enriched negative correlation with gene expression. Increases in intra-tumoural effector T-cells were seen in some responding patients. Patients having clinical benefit had high baseline inflammatory signature on RNAseq analyses.ConclusionsGuadecitabine in combination with pembrolizumab is tolerable with biological and anticancer activity. Reversal of previous resistance to immune checkpoint inhibitors is demonstrated.
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