How comparable are patient outcomes in the "real-world" with populations studied in pivotal AML trials?

Despite an increasing desire to use historical cohorts as "synthetic" controls for new drug evaluation, limited data exist regarding the comparability of real-world outcomes to those in clinical trials. Governmental cancer data often lacks details on treatment, response, and molecular characterization of disease sub-groups. The Australasian Leukaemia and Lymphoma Group National Blood Cancer Registry (ALLG NBCR) includes source information on morphology, cytogenetics, flow cytometry, and molecular features linked to treatment received (including transplantation), response to treatment, relapse, and survival outcome. Using data from 942 AML patients enrolled between 2012-2018, we assessed age and disease-matched control and interventional populations from published randomized trials that led to the registration of midostaurin, gemtuzumab ozogamicin, CPX-351, oral azacitidine, and venetoclax. Our analyses highlight important differences in real-world outcomes compared to clinical trial populations, including variations in anthracycline type, cytarabine intensity and scheduling during consolidation, and the frequency of allogeneic hematopoietic cell transplantation in first remission. Although real-world outcomes were comparable to some published studies, notable differences were apparent in others. If historical datasets were used to assess the impact of novel therapies, this work underscores the need to assess diverse datasets to enable geographic differences in treatment outcomes to be accounted for.

Cereblon pathway biomarkers and immune profiles in patients with myeloma receiving post-ASCT lenalidomide maintenance (LEOPARD)

LEOPARD was a single arm, phase II study of lenalidomide (LEN) and alternate day prednisolone maintenance in patients with newly diagnosed multiple myeloma (MM) following autologous stem cell transplantation (ASCT). Sixty patients were enrolled. Estimated median potential follow-up was 44 m, median PFS was 38.3 m, median OS was not reached (landmark 36 m OS: 71.4%). Correlative immunohistochemistry performed on pre-ASCT trephines demonstrated high MM tumor cereblon (total/cytoplasmic) was associated with superior OS (p = .045, p = .031, respectively), whereas high c-Myc was associated with inferior PFS (p = .04). Patients with high cereblon (total/nuclear) were more likely to improve depth of response, whereas patients with high c-Myc were less likely, suggesting alternative/more effective post-ASCT strategies for patients with high c-Myc need identification. Peripheral blood immune profiling (mass cytometry) informed a more sustained response to LEN maintenance, demonstrating enrichment of activated/cytotoxic NK cells and cytotoxic T cells in patients with durable responses, contrasting with enrichment of B-regs in early relapsers.

Treatment practice and outcomes in FLT3-mutant acute myeloid leukemia in the pre-midostaurin era: a real-world experience from Australian tertiary hospitals

Recent regulatory approval of midostaurin, a FLT3 targeting small molecular inhibitor, will likely lead to increased use of midostaurin in combination with intensive chemotherapy for patients with FLT3-mutant AML. Translation of clinical trial results into everyday practice has its challenges. This study compared the relevance of the trial population and practices studied in the midostaurin registration study (RATIFY) with real-world practice in terms of patient factors, chemotherapy, mutation-specific frequencies and clinical outcomes among patients with FLT3-mutant AML in the pre-midostaurin era (2010-2015) in Australia. We observed substantial diversity of chemotherapy regimens used in the community and limitations of the generalizability of eligibility criteria used in RATIFY (such as age and hyperleukocytosis). This study provides real-world historical data that may be used for comparison with future trial cohorts incorporating FLT3 inhibitors into the management of FLT3-mutant AML and highlights the inherent difficulties in translating clinical trial data into routine practice.

Identifying and targeting pathogenic PI3K/AKT/mTOR signaling in IL-6-blockade-refractory idiopathic multicentric Castleman disease

BACKGROUND

Idiopathic multicentric Castleman disease (iMCD) is a hematologic illness involving cytokine-induced lymphoproliferation, systemic inflammation, cytopenias, and life-threatening multi-organ dysfunction. The molecular underpinnings of interleukin-6(IL-6)-blockade refractory patients remain unknown; no targeted therapies exist. In this study, we searched for therapeutic targets in IL-6-blockade refractory iMCD patients with the thrombocytopenia, anasarca, fever/elevated C-reactive protein, reticulin myelofibrosis, renal dysfunction, organomegaly (TAFRO) clinical subtype.

METHODS

We analyzed tissues and blood samples from three IL-6-blockade refractory iMCD-TAFRO patients. Cytokine panels, quantitative serum proteomics, flow cytometry of PBMCs, and pathway analyses were employed to identify novel therapeutic targets. To confirm elevated mTOR signaling, a candidate therapeutic target from the above assays, immunohistochemistry was performed for phosphorylated S6, a read-out of mTOR activation, in three iMCD lymph node tissue samples and controls. Proteomic, immunophenotypic, and clinical response assessments were performed to quantify the effects of administration of the mTOR inhibitor, sirolimus.

RESULTS

Studies of three IL-6-blockade refractory iMCD cases revealed increased CD8+ T cell activation, VEGF-A, and PI3K/Akt/mTOR pathway activity. Administration of sirolimus significantly attenuated CD8+ T cell activation and decreased VEGF-A levels. Sirolimus induced clinical benefit responses in all three patients with durable and ongoing remissions of 66, 19, and 19 months.

CONCLUSION

This precision medicine approach identifies PI3K/Akt/mTOR signaling as the first pharmacologically-targetable pathogenic process in IL-6-blockade refractory iMCD. Prospective evaluation of sirolimus in treatment-refractory iMCD is planned (NCT03933904).

FUNDING

Castleman's Awareness & Research Effort/Castleman Disease Collaborative Network, Penn Center for Precision Medicine, University Research Foundation, Intramural NIH funding, and National Heart Lung and Blood Institute.

A multicenter retrospective comparison of induction chemoimmunotherapy regimens on outcomes in transplant-eligible patients with previously untreated mantle cell lymphoma

Mantle cell lymphoma (MCL) is an uncommon and typically aggressive form of lymphoma. Although often initially chemosensitive, relapse is common. Several induction and conditioning regimens are used in transplant-eligible patients, and the optimal approach remains unknown. We performed an international, retrospective study of transplant-eligible patients to assess impact of induction chemoimmunotherapy and conditioning regimens on clinical outcomes. We identified 228 patients meeting inclusion criteria. Baseline characteristics were similar among the induction groups except for some variation in age. The type of induction chemoimmunotherapy received did not influence overall response rates (ORRs) (0.43), progression-free survival (PFS) (P > .67), or overall survival (OS) (P > .35) on multivariate analysis (PFS and OS). Delivery of autologous stem cell transplant (ASCT) was associated with favorable PFS and OS (0.01) on univariate analysis only; this benefit was not seen on multivariate analysis-PFS (0.36) and OS (0.21). Compared with busulfan and melphalan (BuMel), the use of the carmustine, etoposide, cytarabine, melphalan (BEAM)-conditioning regimen was associated with inferior PFS (HR = 2.0 [95% CI 1.1-3.6], 0.02) but not OS (HR = 1.1 [95% CI 0.5-2.3], 0.81) on univariate analysis only. Within the limits of a retrospective study and modest power for some comparisons, type of induction therapy did not influence ORR, PFS, or OS for transplant-eligible patients with MCL. International efforts are required to perform randomized clinical trials evaluating chemoimmunotherapy induction regimens.

Correction: High expression of HMGA2 independently predicts poor clinical outcomes in acute myeloid leukemia

Since the publication of the original article the authors noticed the the affiliation details for Paresh Vyas are incorrect. The correct affiliation details for this author are given below.

High expression of HMGA2 independently predicts poor clinical outcomes in acute myeloid leukemia

In acute myeloid leukemia (AML), risk stratification based on cytogenetics and mutation profiling is essential but remains insufficient to select the optimal therapy. Accurate biomarkers are needed to improve prognostic assessment. We analyzed RNA sequencing and survival data of 430 AML patients and identified HMGA2 as a novel prognostic marker. We validated a quantitative PCR test to study the association of HMGA2 expression with clinical outcomes in 358 AML samples. In this training cohort, HMGA2 was highly expressed in 22.3% of AML, mostly in patients with intermediate or adverse cytogenetics. High expression levels of HMGA2 (H + ) were associated with a lower frequency of complete remission (58.8% vs 83.4%, P < 0.001), worse 3-year overall survival (OS, 13.2% vs 43.5%, P < 0.001) and relapse-free survival (RFS, 10.8% vs 44.2%, P < 0.001). A positive HMGA2 test also identified a subgroup of patients unresponsive to standard treatments. Multivariable analyses showed that H + was independently associated with significantly worse OS and RFS, including in the intermediate cytogenetic risk category. These associations were confirmed in a validation cohort of 260 patient samples from the UK NCRI AML17 trial. The HMGA2 test could be implemented in clinical trials developing novel therapeutic strategies for high-risk AML.

High expression of HMGA2 independently predicts poor clinical outcomes in acute myeloid leukemia

In acute myeloid leukemia (AML), risk stratification based on cytogenetics and mutation profiling is essential but remains insufficient to select the optimal therapy. Accurate biomarkers are needed to improve prognostic assessment. We analyzed RNA sequencing and survival data of 430 AML patients and identified HMGA2 as a novel prognostic marker. We validated a quantitative PCR test to study the association of HMGA2 expression with clinical outcomes in 358 AML samples. In this training cohort, HMGA2 was highly expressed in 22.3% of AML, mostly in patients with intermediate or adverse cytogenetics. High expression levels of HMGA2 (H + ) were associated with a lower frequency of complete remission (58.8% vs 83.4%, P < 0.001), worse 3-year overall survival (OS, 13.2% vs 43.5%, P < 0.001) and relapse-free survival (RFS, 10.8% vs 44.2%, P < 0.001). A positive HMGA2 test also identified a subgroup of patients unresponsive to standard treatments. Multivariable analyses showed that H + was independently associated with significantly worse OS and RFS, including in the intermediate cytogenetic risk category. These associations were confirmed in a validation cohort of 260 patient samples from the UK NCRI AML17 trial. The HMGA2 test could be implemented in clinical trials developing novel therapeutic strategies for high-risk AML.

Activating KIR Haplotype Influences Clinical Outcome Following HLA-Matched Sibling Hematopoietic Stem Cell Transplantation

Natural killer cells are thought to influence the outcome of hematopoietic stem cell transplant (HSCT), impacting on relapse, overall survival, graft versus host disease and the control of infection, in part through the complex interplay between the large and genetically diverse killer immunoglobulin-like receptor (KIR) family and their ligands. This study examined the relationship between KIR gene content and clinical outcomes including the control of opportunistic infections such as cytomegalovirus in the setting of human leucocyte antigen (HLA)-matched sibling HSCT in an Australian cohort. The presence of the KIR B haplotype which contain more activating receptors in the donor, in particular centromeric B haplotype genes (Cen-B), was associated with improved overall survival of patients with acute myeloid leukemia (AML) undergoing sibling HSCT and receiving myeloablative conditioning. Donor Cen-B haplotype was also associated with reduced acute graft versus host disease grades II-IV whereas donor telomeric-B haplotype was associated with decreased incidence of CMV reactivation. In contrast, we were not able to demonstrate a reduced rate of relapse when the donor had KIR Cen-B, however relapse with a donor Cen-A haplotype was a competing risk factor to poor overall survival. Here we show that the presence of donor activating KIR led to improved outcome for the patient, potentially through reduced relapse rates and decreased incidence of acute GvHD translating to improved overall survival. This article is protected by copyright. All rights reserved.

Idarubicin Dose Escalation During Consolidation Therapy for Adult Acute Myeloid Leukemia

Purpose Higher doses of the anthracycline daunorubicin during induction therapy for acute myeloid leukemia (AML) have been shown to improve remission rates and survival. We hypothesized that improvements in outcomes in adult AML may be further achieved by increased anthracycline dose during consolidation therapy. Patients and Methods Patients with AML in complete remission after induction therapy were randomly assigned to receive two cycles of consolidation therapy with cytarabine 100 mg/m² daily for 5 days, etoposide 75 mg/m² daily for 5 days, and idarubicin 9 mg/m² daily for either 2 or 3 days (standard and intensive arms, respectively). The primary end point was leukemia-free survival (LFS). Results Two hundred ninety-three patients 16 to 60 years of age, excluding those with core binding factor AML and acute promyelocytic leukemia, were randomly assigned to treatment groups (146 to the standard arm and 147 to the intensive arm). Both groups were balanced for age, karyotypic risk, and FLT3-internal tandem duplication and NPM1 gene mutations. One hundred twenty patients in the standard arm (82%) and 95 patients in the intensive arm (65%) completed planned consolidation ( P < .001). Durations of severe neutropenia and thrombocytopenia were prolonged in the intensive arm, but there were no differences in serious nonhematological toxicities. With a median follow-up of 5.3 years (range, 0.6 to 9.9 years), there was a statistically significant improvement in LFS in the intensive arm compared with the standard arm (3-year LFS, 47% [95% CI, 40% to 56%] v 35% [95% CI, 28% to 44%]; P = .045). At 5 years, the overall survival rate was 57% in the intensive arm and 47% in the standard arm ( P = .092). There was no evidence of selective benefit of intensive consolidation within the cytogenetic or FLT3-internal tandem duplication and NPM1 gene mutation subgroups. Conclusion An increased cumulative dose of idarubicin during consolidation therapy for adult AML resulted in improved LFS, without increased nonhematologic toxicity.

Efficacy and toxicity of PACEBOM chemotherapy in relapsed/refractory aggressive lymphoma in the rituximab era

AIM

Relapsed/refractory (R/R) aggressive lymphoma outcomes are poor. There is no standard treatment. PACEBOM (prednisolone, doxorubicin, cyclophosphamide, etoposide, bleomycin, vincristine and methotrexate) has shown efficacy for several lymphoma subtypes in published reports. We evaluate PACEBOM+/-rituximab for R/R aggressive lymphomas in this millennium.

METHODS

In this retrospective, single-center study, R/R aggressive lymphoma patients who received PACEBOM or its derivatives were identified from the pharmacy database. Demographic, treatment, toxicity and survival data were collected.

RESULTS

A total of 37 eligible patients were identified. Histological subtypes included 20 Diffuse Large B-Cell Lymphoma (DLBCL), 10 T-Cell Lymphoma (TCL) and 7 Hodgkin lymphoma. All DLBCL patients had received prior rituximab. Thirty-one (84%) received second-line PACEBOM. Median number of cycles was six (1-6). Eighteen out of 20 B-cell lymphoma patients received R-PACEBOM. Overall response rate was 65%, 70% and 71% in patients with DLBCL, TCL and Hodgkin lymphoma respectively. Thirteen patients underwent autologous stem cell transplant post-PACEBOM. Median follow-up was 49 months (3-201). Most common grade 3-4 toxicities were neutropenia (46%), anemia (24%) and thrombocytopenia (16%). No additional toxicity was seen in patients who received rituximab.

CONCLUSION

In this cohort, PACEBOM is active in R/R aggressive lymphoma with manageable toxicity and can be safely combined with rituximab. Outcomes were similar to reports of other salvage regimens. PACEBOM remains a suitable option for R/R aggressive lymphoma, in patients exposed to prior rituximab and those planned for autologous stem cell transplant.

The mTOR inhibitor everolimus in combination with azacitidine in patients with relapsed/refractory acute myeloid leukemia: a phase Ib/II study

Therapeutic options are limited in relapsed/refractory acute myeloid leukemia (AML). We evaluated the maximum tolerated dose (MTD) and preliminary efficacy of mammalian target of rapamycin (mTOR) inhibitor, everolimus (days 5–21) in combination with azacitidine 75 mg/m² subcutaneously (days 1–5 and 8–9 every 28 days) in 40 patients with relapsed (n = 27), primary refractory (n = 11) or elderly patients unfit for intensive chemotherapy (n = 2). MTD was not reached following everolimus dose escalation (2.5, 5 or 10 mg; n = 19) to the 10 mg dose level which was expanded (n = 21). Major adverse events (grade > 2) were mostly disease-related: neutropenia (73%), thrombocytopenia (67%), mucositis (24%) and febrile neutropenia (19%). Overall survival (OS) of the entire cohort was 8.5 months, and overall response rate (ORR; including CR/CRi/PR/MLFS) was 22.5%. Furthermore, a landmark analysis beyond cycle 1 revealed superior OS and ORR in patients receiving 2.5 mg everolimus with azoles, compared to those without azoles (median OS 12.8 vs. 6.0 months, P = 0.049, and ORR 50% vs. 16%, P = 0.056), potentially due to achievement of higher everolimus blood levels. This study demonstrates that everolimus in combination with azacitidine is tolerable, with promising clinical activity in advanced AML.

The addition of dexamethasone to bortezomib for patients with relapsed multiple myeloma improves outcome but ongoing maintenance therapy has minimal benefit

Despite the common practice of combining dexamethasone (Dex) with bortezomib (Bz) in patients with multiple myeloma (MM), until now there has been few prospective trials undertaken. We undertook a trial that recapitulated the original APEX study except that dexamethasone was incorporated from cycle 1. We also incorporated an exploratory maintenance component to the study. Twenty sites enrolled 100 relapsed/or refractory MM patients utilizing eight 21 day cycles of IV Bz [1.3 mg/m(2) ; Day (D) 1, 4, 8, 11] and three 35 day cycles; Bz (1.3 mg/m(2) ; Day (D) 1, 8, 15, 22). Our study was registered at www.clinicaltrials.gov (NCT00335348). Patients with stable disease or better received maintenance Bz (1.3 mg/m(2) ) every 14 days until progression. Dexamethasone (20 mg) was given for 2 days with each Bz dose. A prospectively defined matched-analysis of primary (overall response rate; ORR) and secondary endpoints [Complete Response (CR) and time to progression (TTP)] compared our cohort to those on the Bz arm of the APEX trial. The addition of Dex improved ORR by 20% (56% vs. 36%) [odds ratio 0.44 (0.24-0.80)]. The median TTP was also significantly longer (10.1 vs. 5.1 months) (hazard ratio 0.50, 95% CI: 0.35-0.72, P = 0.0002) and our landmark analysis demonstrated that this was largely due to the early use of dexamethasone, as we were unable to demonstrate any benefit of bortezomib/dexamethasone maintenance therapy.

Polymorphism in human cytomegalovirus UL40 impacts on recognition of human leukocyte antigen-E (HLA-E) by natural killer cells

Natural killer (NK) cell recognition of the nonclassical human leukocyte antigen (HLA) molecule HLA-E is dependent on the presentation of a nonamer peptide derived from the leader sequence of other HLA molecules to CD94-NKG2 receptors. However, human cytomegalovirus can manipulate this central innate interaction through the provision of a "mimic" of the HLA-encoded peptide derived from the immunomodulatory glycoprotein UL40. Here, we analyzed UL40 sequences isolated from 32 hematopoietic stem cell transplantation recipients experiencing cytomegalovirus reactivation. The UL40 protein showed a "polymorphic hot spot" within the region that encodes the HLA leader sequence mimic. Although all sequences that were identical to those encoded within HLA-I genes permitted the interaction between HLA-E and CD94-NKG2 receptors, other UL40 polymorphisms reduced the affinity of the interaction between HLA-E and CD94-NKG2 receptors. Furthermore, functional studies using NK cell clones expressing either the inhibitory receptor CD94-NKG2A or the activating receptor CD94-NKG2C identified UL40-encoded peptides that were capable of inhibiting target cell lysis via interaction with CD94-NKG2A, yet had little capacity to activate NK cells through CD94-NKG2C. The data suggest that UL40 polymorphisms may aid evasion of NK cell immunosurveillance by modulating the affinity of the interaction with CD94-NKG2 receptors.

Fludarabine, cytarabine, granulocyte-colony stimulating factor and amsacrine: an effective salvage therapy option for acute myeloid leukemia at first relapse

Improved therapeutic options for relapsing patients with acute myeloid leukemia (AML) are urgently needed. Poor outcomes following salvage therapy have been reported in those with short initial remission duration, adverse risk karyotype, prior allograft, older age, FLT3-internal tandem duplication (ITD) AML and prior high-dose cytarabine (HiDAC) induction therapy. We present a cohort of 58 patients (aged 18-70) treated with fludarabine, cytarabine, granulocyte-colony stimulating factor (G-CSF) and amsacrine (FLAG-amsacrine) as salvage chemotherapy for AML at first relapse. 83% had received prior HiDAC-based therapy. The overall complete remission (CR/CR with incomplete blood count recovery [CRi]) rate was 59%, with median event-free survival (EFS) and overall survival (OS) of 6.9 and 10.6 months, respectively. FLAG-amsacrine was an effective bridge to allogeneic transplant with 38% successfully transplanted with excellent outcomes (median OS not reached). FLAG-amsacrine was also effective in elderly patients (≥ 60 years), with 61% achieving second remission. The regimen was well tolerated, with 30- and 42-day treatment-related mortality of 3.4% and 13.8%, respectively. Outcomes remained poor in those with short initial remission duration (<6 months). We conclude that FLAG-amsacrine is a useful salvage option for AML at first relapse.

Reduced-intensity conditioned allogeneic haematopoietic stem cell transplantation results in durable disease-free and overall survival in patients with poor prognosis myeloid and lymphoid malignancies: eighty-month follow-up

The long-term outcome of patients with haematological malignancies treated with reduced-intensity conditioned allogeneic peripheral blood stem cell transplantation is not known. We report the outcome of 79 patients with poor-risk myeloid and lymphoid malignancies transplanted with reduced-intensity conditioning (RIC) regimens. The diagnoses include AML/myelodysplastic syndrome (n=43), non Hodgkin's lymphoma (n=30), Hodgkin's lymphoma (n=3), ALL (n=2) and CML (n=1). For the entire cohort, the disease-free survival (DFS) and OS were 61.2 and 35.7%, respectively. Twenty patients relapsed, 18 within the first three years, and 14 patients succumbed to progressive disease. Overall, 31 patients died from transplant-related complications within the first three years. Day 100 non-relapse mortality correlated with a higher total nucleated cell dose in the graft (odds ratio: 3.9). For those in CR at 3 years, the DFS and OS were 84.2 and 81.1%, respectively. Furthermore, of 43 patients with active disease at the time of transplantation, 16 remained in CR after 3 years. The majority of the long-term survivors were functioning independently. One patient died from a second malignancy. No post-transplant lymphoproliferative disorder was seen. In conclusion, durable disease control was achieved after RIC allogeneic stem cell transplantation for patients with advanced myeloid and lymphoid malignancies.

Disease status at autologous stem cell transplantation and the cell of origin phenotype are important predictors of outcome in patients with neurologic (central nervous system) relapse of diffuse large B-cell lymphoma undergoing autologous stem cell transplantation

Neurologic relapse of systemic diffuse large B-cell lymphoma (DLBCL) is associated with poor outcome. The existing literature about this specific entity is very limited. We present a retrospective analysis of patients with neurological relapse of DLBCL and correlate the outcome according to the disease stage at autologous stem cell transplantation (ASCT) and the cell of origin phenotype. Totally, 11 patients with neurologic relapse of DLBCL underwent ASCT, seven in complete remission (CR) and four with active disease. The conditioning regimens included LACE (six), BEAM (two), and Bu/Mel (three). Ten patients relapsed after ASCT. All patients with CNS relapse died of progressive disease. Patients with systemic relapse were salvaged by further treatment. The median disease free survival (DFS) and overall survival (OS) for patients in CR at ASCT is far superior than those with active disease at ASCT (24 and 33 months versus 3 and 5 months, respectively). For patients undergoing ASCT in CR, the germinal centre (GC) phenotype is associated with a superior DFS and OS as compared to non GC phenotype (36 and 40 months versus 3.5 months and 5 months, respectively). Patients with neurological relapse of DLBCL have a poor outcome after ASCT; the outcome is worse for patients with non-GC phenotype irrespective of the disease stage at ASCT.

The PRKAR1A gene is fused to RARA in a new variant acute promyelocytic leukemia

We report the molecular and cytogenetic characterization of a novel variant of acute promyelocytic leukemia (APL). The bone marrow showed 88% hypergranular promyelocytes, and the karyotype was 47,XY,+22 [5]/46,XY[30]. Fluorescence in situ hybridization (FISH) indicated disruption and deletion of the 5′-end of the RARA gene. Treatment with all-trans retinoic acid, idarubicin, and arsenic trioxide induced cytogenetic complete remission without morphologic evidence of residual leukemia. The diagnostic marrow was negative for PML-RARA transcripts by reverse transcription–polymerase chain reaction (RT-PCR), but an atypical product was observed. Sequencing showed partial homology to the PRKAR1A gene, encoding the regulatory subunit type I-α of cyclic adenosine monophosphate–dependent protein kinase. RT-PCR using specific primers for PRKAR1A and RARA amplified 2 transcript splice variants of a PRKAR1A-RARA fusion gene, and PRKAR1A and RARA FISH probes confirmed the fusion. This novel PRKAR1A-RARA gene rearrangement is the fifth variant APL in which the RARA partner gene has been identified and the second known rearrangement of PRKAR1A in a malignant disease. This trial was registered at www.actr.org.au with the Australian Clinical Trials Registry as number 12605000070639.

Efficacy and safety of imatinib in patients with chronic myeloid leukemia and complete or near-complete cytogenetic response to interferon-alpha

BACKGROUND

Interferon-alpha (IFN-alpha) confers a survival advantage for the minority of patients with chronic myeloid leukemia (CML) who achieve a complete cytogenetic response. The question of whether IFN-alpha-responsive patients can experience further improvements with imatinib has not been answered. Imatinib offers clear quality of life advantages. Furthermore, patients who achieve a major molecular response (MMR) while receiving imatinib are likely to remain progression free.

METHODS

A total of 23 patients treated for a median of 4.5 years with IFN-alpha (range, 1.6-14.3 years) who had achieved a complete (Philadelphia chromosome [Ph] negative, n = 15 patients) or near-complete (1-10% Ph, n = 8 patients) cytogenetic response were studied. The primary objective was to determine whether ceasing therapy with IFN-alpha and switching to 12 months of imatinib treatment at a dose of 400 mg/day could improve the molecular response as assessed by real-time quantitative polymerase chain reaction of BCR-ABL transcript levels. Safety was also assessed.

RESULTS

Every patient who had not achieved an MMR while receiving IFN-alpha (n = 16 patients) achieved an MMR after a median of 3 months of imatinib treatment. Significant BCR-ABL reductions (median, 63-fold; range, 18-425-fold) occurred in 15 of these patients. Every patient who had already achieved an MMR while receiving IFN-alpha (n = 7 patients) maintained an MMR while receiving imatinib. No patients discontinued imatinib due to toxicity, but 1 patient withdrew consent.

CONCLUSIONS

These data suggest that switching IFN-alpha-responsive patients to imatinib leads to a rapid improvement in achieving an MMR, a response with established prognostic value, and is well tolerated. The study should help patients and their physicians make evidence-based decisions regarding the potential benefits and risks of switching to imatinib.

14thInternational HLA and Immunogenetics Workshop: report on hematopoietic cell transplantation

Deciphering the role of human leukocyte antigen (HLA), killer immunoglobulin like receptor, and immune response genes in a model as complex as unrelated donor hematopoietic cell transplantation is a challenge. The allelic diversity of these genes is shaped by the race and ethnicity of transplant donors and recipients. Coupled with the genetic polymorphism is the complexity of clinical phenotypes of transplant populations: donor and recipient demographic characteristics and the regimens used by transplant physicians to prepare patients for transplantation and to prevent and treat graft-vs-host disease (GVHD). Furthermore, GVHD is itself a complex disease shaped by both genes and 'environment'. How does one begin to deconstruct the genetic barrier to understand risk factors important to transplant outcome? To begin with, population-based studies, particularly retrospective ones, benefit from adequate sample sizes to measure genetic effects. The more homogeneous the population for variables that influence clinical endpoints, the higher the likelihood that a real genetic effect can be uncovered. Even so, the feasibility of studies can be hampered if genotype and clinical data are not both complete and precise. For studies of HLA, diversity of alleles and antigens contributed by ethnically different transplant populations is an asset, because not only can a broader range of HLA mismatches be studied but they provide the opportunity for side-by-side analyses that may yield clues as to why transplant outcomes differ between populations.

Equivalent survival for sibling and unrelated donor allogeneic stem cell transplantation for acute myelogenous leukemia

Recent studies have shown comparable survival outcomes for unrelated donor (URD) stem cell transplantation in chronic myelogenous leukemia compared to sibling donors. We compared outcomes for 105 patients aged 16 to 59 years undergoing URD transplants for acute myelogenous leukemia (AML) who were reported to the Australasian Bone Marrow Transplant Recipient Registry between 1992 and 2002, and a strictly selected matching set of 105 HLA-matched sibling donor (MSD) transplants. There was no significant difference between URD and MSD controls in the distributions of time from diagnosis to transplant, donor-recipient sex match, prior therapies, donor age, or performance status. The median follow-up of live URD patients was 4.4 years and for live MSD controls was 6.3 years. There were 18 good risk (complete remission [CR]1) and 87 poor risk (>CR1) recipients in both URD and sibling groups. Five-year disease-free survival (DFS) was not significantly different for good-risk URD and sibling donor recipients (62% versus 40%, P = .2), or poor-risk URD and sibling recipients (21% versus 25%, P = .2). In a stratified multivariate Cox regression model, the independent adverse risk factors for DFS were recipient cytomegalovirus positivity (P = .01) and the interaction of URD and earlier year of transplant (P = .006). Both neutrophil and platelet engraftment were significantly more rapid in the sibling group, but transplant-related mortality at 100 days was not significantly different. There was no difference in the cumulative incidence of acute graft-versus-host disease grade II or above at 100 days. Relapse occurred in 28% of good risk URD subjects and 16% of siblings (P = .3), and in poor risk subjects 39% and 29%, respectively (P = .2). Based on this data, URD allografts should be considered in AML patients without a matched sibling donor. This study provides a rationale for a larger prospective study of risk factors in allogeneic transplantation for AML and a guide on the subset of patients who may most benefit from an unrelated donor allograft in AML.

Non-HLA immunogenetic polymorphisms and the risk of complications after allogeneic hemopoietic stem-cell transplantation

BACKGROUND

Existing data indicate that non-human leukocyte antigen (HLA) immunogenetic polymorphisms influence the risk of complications after allogeneic hemopoietic stem-cell transplantation. However, prior studies have been limited by small sample size and limited genotyping.

METHODS

We examined 22 polymorphisms in 11 immunoregulatory genes including cytokines, mediators of apoptosis, and host-defense molecules by polymerase chain reaction using sequence-specific primers in 160 related myeloablative transplants. Associations were confirmed in two independent cohorts.

RESULTS

An intronic polymorphism in the tumor necrosis factor gene (TNF 488A) was associated with the risk of acute graft-versus-host disease (GVHD) (odds ratio [OR] 16.9), grades II to IV acute GVHD (OR 3.3), chronic GVHD (OR 12.5), and early death posttransplant (OR 3.4). Recipient Fas -670G and donor interleukin (IL)-6 -174G were independent risk factors for acute GVHD. Recipient IL-10 ATA and Fas -670 genotype were independent risk factors for chronic GVHD. Recipient IL-1beta +3953T was associated with hepatic acute GVHD, and Fas -670G was associated with major infection.

CONCLUSIONS

These results highlight the potential importance of cytokine and apoptosis gene polymorphisms in stem-cell transplantation, and indicate that non-HLA genotyping may be useful to identify individuals at the highest risk of complications and new targets for therapeutic intervention.

Autologous peripheral blood stem cell transplantation for peripheral neuropathy secondary to monoclonal gammopathy of unknown significance

A 40-year-old patient presented with rapidly progressing peripheral neuropathy secondary to monoclonal gammopathy of unknown significance (MGUS). He became severely debilitated, being wheelchair-bound, despite treatment with chemotherapy, intravenous immunoglobulin and plasma exchange. He was subsequently treated with high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT). He has made remarkable recovery at 12 months post transplantation. We propose that high-dose chemotherapy and autologous PBSC transplantation may have a role in the treatment of severe, progressive and treatment-resistant MGUS-related peripheral neuropathy.

Effects of glycosylated recombinant human granulocyte colony-stimulating factor after high-dose cytarabine-based induction chemotherapy for adult acute myeloid leukaemia

The Australian Leukaemia Study Group (ALSG) investigated whether G-CSF would accelerate haemopoietic recovery after induction treatment for acute myeloid leukaemia (AML) intensified with high-dose cytarabine, and therefore improve response rates and survival. Patients were randomised to receive lenograstim (glycosylated recombinant human G-CSF) 5 microg per kg body weight subcutaneously daily from day 8 after starting chemotherapy, or no cytokine, following chemotherapy with cytarabine 3 g/m2 every 12 h on days 1, 3, 5, and 7, together with idarubicin 9 or 12 mg/m2 on days 1, 2, and 3, plus etoposide 75 mg/m2 on days 1 to 7 inclusive. Patients had untreated AML, and were aged 16 to 60 years. Overall, 54 evaluable patients were randomised to receive lenograstim and 58 to no cytokine. Patients in the lenograstim arm had a significantly shorter duration of neutropenia <0.5 x 10(9)/l compared to patients in the no cytokine arm (median 18 vs 22 days; P = 0.0005), and also shorter duration of total leucopenia <1.0 x 10(9)/l (17 vs 19 days; P = 0.0002), as well as a reduction in duration of treatment with therapeutic intravenous antibiotics (20 vs 24 days; P= 0.015) and a trend to reduced number of days with fever >38.0 degrees C (9 vs 12 days; P = 0.18). There were no differences between the two groups in platelet recovery, red cell or platelet transfusions, or non-haematological toxicities. For patients achieving CR after their first induction course, a reduction in the time to the start of the next course of therapy was observed in the lenograstim arm, from a median of 40.5 days to a median of 36 days (P = 0.082). The overall complete response rates to chemotherapy were similar, 81% in the lenograstim arm vs 75% for the no cytokine arm (P = 0.5), and there was no significant difference in the survival durations. We conclude that the granulopoietic stimulating effect of G-CSF is observed after induction therapy for AML intensified by high-dose cytarabine, resulting in an improvement in a number of clinically important parameters with no major adverse effects.

A rapid limiting dilution assay for measuring frequencies of alloreactive, interleukin-2-producing T cells in humans

A limiting dilution analysis (LDA) has been established which measures the total numbers of alloreactive interleukin-2 (IL-2)-secreting T cells in human peripheral blood mononuclear cells (PBMC). A significant advantage over most previous LDA is that the assay may be completed in approximately 48 h since an IL-2-dependent 'indicator' cell line is used to reduce assay time. Results are reproducible and correlate with the degree of HLA class II antigenic disparity between responder and stimulator cells. Use of both PBMC and Epstein-Barr virus-transformed B lymphoblastoid cell lines (B-LCL) as stimulator cells permits estimation of the frequency of Epstein-Barr virus-specific T cells in different responder individuals. A modification of the assay may also be used to measure the frequencies of 'primed' alloreactive cells, i.e., those alloreactive cells which have previously encountered their specific stimulating alloantigen. Use of the assay in the clinical context of bone marrow and renal transplantation is discussed.