Stage I findings of a two-stage phase II study to assess the efficacy, safety, and tolerability of barasertib (AZD1152) compared with low-dose cytosine arabinoside (LDAC) in elderly patients (pts) with acute myeloid leukemia (AML)

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Background: Barasertib is the pro-drug to barasertib-hQPA, a selective Aurora B kinase inhibitor with preliminary anti-AML activity in a Phase I/II study (Löwenberg et al. Blood 2011;118:6030). Methods: AML pts aged ≥60 y considered unsuitable for intensive chemotherapy were randomized 2:1 to open-label barasertib 1200 mg (7-day iv infusion) or LDAC 20 mg (sc twice daily for 10 days) in 28-day cycles (NCT00952588). The primary endpoint was improved objective complete response rate (OCRR: CR + CRi [Cheson criteria, but requiring CRi confirmation ≥21 days after first appearance, with partial recovery of platelets and neutrophils]). Secondary endpoints included duration of response (DoR), overall survival (OS) and safety. Results: 74 pts (barasertib, 48; LDAC, 26) received treatment and all completed ≥1 cycle. A significant improvement in OCRR was observed with barasertib (35.4% [17/48] vs 11.5% [3/26]; difference, 23.9% [95% CI, 2.7-39.9]; P<0.05); barasertib responses were seen in all cytogenetic risk groups and appeared to be durable (median DoR [range], 82 [28-321] days; vs LDAC 30-85 days). Although not formally sized to compare OS data, a trend favoring barasertib was observed (HR=0.88, 95% CI, 0.49-1.58; P=0.663; median OS, 8.2 vs 4.5 mo). Stomatitis and febrile neutropenia were the most common adverse events (AEs) in the barasertib arm with higher incidences vs LDAC (71% vs 15%; 67% vs 19%, respectively). Grade ≥3 AEs with a greater incidence in the barasertib arm were febrile neutropenia (50% vs 19%), stomatitis (29% vs 0%) and pneumonia (25% vs 8%); grade ≥3 infection rates were also higher with barasertib (40% vs 23%). For both arms, there were similar discontinuation rates due to AEs (barasertib 8.3% vs LDAC 7.7%), deaths due to AEs (12.5% vs 11.5%) and 30-day mortality (12.5% vs 15.4%). Cumulative toxicities were not observed with barasertib treatment. Conclusions: In this population with poor prognosis using standard chemotherapy, barasertib showed a significant improvement in OCRR vs LDAC, and a safety profile that was manageable and consistent with previous studies.

Assessment of age as its own risk factor in AML

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Background: Patients’ age is an important issue in treatment decisions for AML, while its role in this disease remains poorly explained. Methods: In the AMLCG 1999 trial 1223 patients (pts) were 16-59y and 1470 pts were 60-85y of age. Their treatment was randomized between TAD-HAM vs HAM-HAM induction (TAD, standard dose thioguanine, cytarabine, daunorubicin 60mg/m² x 3; HAM, high-dose cytarabine 3g/m² x 6, mitoxantrone 10mg/m² x 3), TAD consolidation and monthly maintenance vs autologous SCT, any chemotherapy + vs - G-CSF priming. All randomization was done upfront. Pts of <60y received routine double induction and full dose HAM while pts of 60+y preferentially received only one course induction and HAM at 1g instead of 3g cytarabine /m² x 6. Results: With little differences according randomizations, pts <60y and 60+y achieved a complete remission rate (CR) of 70.2% and 53.5% (p<.001), overall survival (OS) at 5y of 41.3% and 12.9% (p<.001) and a relapse rate (RR) of 49.0 and 72.0% (p<.001). We also focussed on pts around 60y of age and compared the 172 pts of 57-59y with the 261 pts of 60-62y excluding pts undergoing allogeneic stem cell transplantation. According to their similar age the two groups showed similar baseline characteristics. In contrast and due to the cut-off point for age adaption at 60y they differed considerably in treatment. Expressed by the cumulative dosage of cytarabine, the difference between the two groups was by factor 2.9. This difference, however, did not translate into a different outcome being 62% vs 60% CR, 28% vs 21% 5y OS (p=0.25), and 73% vs 73% RR at 5y. A multivariable analysis in all pts between 16 and 85y of age identified cytogenetik/ molecular risk and age as a continuous variable, to be risk factors predicting CR, OS, as well as RR. In pts of 16-60y those below and above the median age of 47y differed in their CR rate by 75% vs 66% (p<.001), their OS by 49% vs 35% (p<.001) and in their RR by 45% vs 53% (p=.007). In pts of 60-85y those below and above the median age of 67y differed in their CR rate by 57% vs 51% (p=.023), and their OS by 16% vs 11% (p<.001), while their RR was similarly 71%. Conclusions: The outcome in pts with AML is substantially determined by patients’ age as its own risk factor, and not by treatment intensity.

Efficacy and tolerability of lenalidomide (LEN) in patients (pts) 75 and older versus those younger than 75 with RBC transfusion-dependent low/int-1-risk MDS and del 5q

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Background: LEN is the approved treatment for pts with RBC transfusion-dependent Low/Int-1-risk MDS and del 5q. In 2 multicenter trials (MDS-003/-004) LEN lead to RBC transfusion independence (TI) for ≥ 26 wks in 35–58% of pts and cytogenetic response (CyR) in 25–73%. Most common grade (G) 3–4 adverse events (AE) were neutropenia and thrombocytopenia, a safety concern in elderly pts. We evaluated efficacy and tolerability of LEN in pts ≥ 75 y vs < 75 y in MDS-003/-004 trials. Methods: Pts received LEN 5 mg × 28 d, 10 mg × 21 d, or 10 mg × 28 d (all 28 d cycles). Dose reductions were required for G4 neutropenia (both trials) and platelet counts < 30 x 109/L (MDS-003) or < 25 x 109/L (MDS-004). Results: 32% of the 286 pts were ≥ 75 y. Baseline (BL) characteristics, LEN treatment, and optional G-CSF use are shown in Table. In pts ≥ 75 y vs < 75 y: RBC-TI ≥ 26 wks was 39 vs 47% (P = NS); CyR was 64 vs 54% (P = NS); 2-y AML progression rates were 10 vs 19% (P = NS); 2-y overall survival rates were 62 vs 73% (P = .001); G3–4 AE: neutropenia (63 vs 76%; P = .024), thrombocytopenia (56 vs 49%; P = NS), infection (36 vs 20%; P = .003); median time to recovery to ANC > 1 x 109/L was 0.7 vs 0.7 mo (P = NS) and to platelet counts > 100 x 109/L was 3.3 vs 1.7 mo (P = NS). 59% pts ≥ 75 y and 49% pts < 75 y discontinued LEN due to AE (33 vs 26%; P = NS), lack of effect (32 vs 49%; P = NS), or death (15 vs 6%; P = NS). Dose reduction and discontinuation rates are shown in Table. Conclusions: Pts ≥ 75 y and < 75 y had comparable response and AML progression rates. In pts ≥ 75 y, LEN appears to be well tolerated but the higher infection rate justifies close follow-up. [Table: see text]

High activity of sorafenib in FLT3-ITD-positive acute myeloid leukemia synergizes with allo-immune effects to induce sustained responses

Preliminary evidence suggests that the multikinase inhibitor sorafenib has clinical activity in FLT3-ITD-positive (FLT3-ITD) acute myeloid leukemia (AML). However, the quality and sustainability of achievable remissions and clinical variables that influence the outcome of sorafenib monotherapy are largely undefined. To address these questions, we evaluated sorafenib monotherapy in 65 FLT3-ITD AML patients treated at 23 centers. All but two patients had relapsed or were chemotherapy-refractory after a median of three prior chemotherapy cycles. Twenty-nine patients (45%) had undergone prior allogeneic stem cell transplantation (allo-SCT). The documented best responses were: hematological remission in 24 patients (37%), bone marrow remission in 5 patients (8%), complete remission (with and without normalization of peripheral blood counts) in 15 patients (23%) and molecular remission with undetectable FLT3-ITD mRNA in 10 patients (15%), respectively. Seventeen of the patients without prior allo-SCT (47%) developed sorafenib resistance after a median treatment duration of 136 days (range, 56-270 days). In contrast, allo-SCT patients developed sorafenib resistance less frequently (38%) and significantly later (197 days, range 38-225 days; P=0.03). Sustained remissions were seen exclusively in the allo-SCT cohort. Thus, sorafenib monotherapy has significant activity in FLT3-ITD AML and may synergize with allogeneic immune effects to induce durable remissions.

New comprehensive cytogenetic scoring system for primary myelodysplastic syndromes (MDS) and oligoblastic acute myeloid leukemia after MDS derived from an international database merge

PURPOSE

The karyotype is a strong independent prognostic factor in myelodysplastic syndromes (MDS). Since the implementation of the International Prognostic Scoring System (IPSS) in 1997, knowledge concerning the prognostic impact of abnormalities has increased substantially. The present study proposes a new and comprehensive cytogenetic scoring system based on an international data collection of 2,902 patients.

PATIENTS AND METHODS

Patients were included from the German-Austrian MDS Study Group (n = 1,193), the International MDS Risk Analysis Workshop (n = 816), the Spanish Hematological Cytogenetics Working Group (n = 849), and the International Working Group on MDS Cytogenetics (n = 44) databases. Patients with primary MDS and oligoblastic acute myeloid leukemia (AML) after MDS treated with supportive care only were evaluated for overall survival (OS) and AML evolution. Internal validation by bootstrap analysis and external validation in an independent patient cohort were performed to confirm the results.

RESULTS

In total, 19 cytogenetic categories were defined, providing clear prognostic classification in 91% of all patients. The abnormalities were classified into five prognostic subgroups (P < .001): very good (median OS, 61 months; hazard ratio [HR], 0.5; n = 81); good (49 months; HR, 1.0 [reference category]; n = 1,809); intermediate (26 months; HR, 1.6; n = 529); poor (16 months; HR, 2.6; n = 148); and very poor (6 months; HR, 4.2; n = 187). The internal and external validations confirmed the results of the score.

CONCLUSION

In conclusion, these data should contribute to the ongoing efforts to update the IPSS by refining the cytogenetic risk categories.

Prevalence and dynamics of bcr-abl kinase domain mutations during imatinib treatment differ in patients with newly diagnosed and recurrent bcr-abl positive acute lymphoblastic leukemia

Imatinib is highly effective in newly diagnosed, but not in relapsed, Philadelphia chromosome positive acute lymphoblastic leukemia (Ph+ ALL). BCR-ABL tyrosine kinase domain (TKD) mutations are associated with acquired imatinib resistance, but their role in primary resistance is uncertain. Using highly sensitive ligation-PCR and denaturing high-performance liquid chromatography (DHPLC), we identified baseline TKD mutations in 21% and 42% of imatinib-naïve patients with newly diagnosed (n=26) or recurrent (n=65) Ph+ ALL, respectively (P=ns). Within 4 weeks of starting the imatinib treatment, absolute levels of mutant bcr-abl transcripts increased significantly in patients with advanced, but not with de novo, Ph+ ALL. The net expansion of pre-existing mutant clones during imatinib treatment resulted in the rapid appearance of initially undetectable TKD mutations, which after 4 weeks were detectable in 70% of patients with advanced disease. There was a high degree of concordance between the type of mutations detected at relapse and during initial imatinib treatment. The profoundly different outgrowth dynamics of leukemic clones with bcr-abl mutations in imatinib-treated patients who differ in their disease history, provides clinical-translational evidence for a contributory role of non-mutational resistance mechanisms, possibly induced by prior chemotherapy. Moreover, the prevalence of pre-existing, clinically relevant TKD may have been underestimated in tyrosine kinase inhibitor-naïve patients with Ph+ ALL.

Addition of AEG35156 XIAP antisense oligonucleotide in reinduction chemotherapy does not improve remission rates in patients with primary refractory acute myeloid leukemia in a randomized phase II study

BACKGROUND

XIAP (X-linked inhibitor of apoptosis protein) is an inhibitor of caspases 3 and 9 that is overexpressed in acute myeloid leukemia (AML) and may contribute to chemoresistance. We report an open-label randomized phase II trial of reinduction chemotherapy with and without the XIAP antisense oligonucleotide AEG35156 in patients with AML who did not achieve remission with initial induction chemotherapy.

METHODS

Twenty-seven patients with AML who were refractory to initial induction chemotherapy were randomized and treated with AEG35156 (650 mg) in combination with high-dose cytarabine and idarubicin. Thirteen patients were randomized and treated with high-dose cytarabine and idarubicin alone. The rates of response and toxicity were determined.

RESULTS

Of the 27 patients assigned to AEG35156 in combination with high-dose cytarabine and idarubicin, 3 died during reinduction chemotherapy, 5 achieved complete remission (CR), and 6 achieved CR with incomplete platelet count recovery (CRp), for an overall response rate of 41%. Of the 13 patients assigned to the control arm of the study, none died during reinduction, 6 achieved CR, and 3 achieved CRp, for an overall response rate of 69%. The differences in response rates between patients in the AEG35156 and control arms were not statistically different (P = 0.18 by the χ(2) test).

CONCLUSIONS

The addition of AEG35156 to reinduction chemotherapy was well tolerated but did not improve rates of remission. Therefore alternative therapeutic strategies should be explored in patients with AML refractory to induction chemotherapy.

Coalesced multicentric analysis of 2,351 patients with myelodysplastic syndromes indicates an underestimation of poor-risk cytogenetics of myelodysplastic syndromes in the international prognostic scoring system

PURPOSE

The International Prognostic Scoring System (IPSS) remains the most commonly used system for risk classification in myelodysplastic syndromes (MDSs). The IPSS gives more weight to blast count than to cytogenetics. However, previous publications suggested that cytogenetics are underweighted in the IPSS. Here we investigate the prognostic impact of cytogenetic subgroups compared with that of bone marrow blast count in a large, multicentric, international patient cohort.

PATIENTS AND METHODS

In total, 2,351 patients with MDS who have records in the German-Austrian and the MD Anderson Cancer Center databases were included and analyzed in univariate and multivariate models regarding overall survival and risk of transformation to acute myeloid leukemia (AML). The data were analyzed separately for patients treated with supportive care without specific therapy, with AML-like chemotherapy, or with other therapy regimens (low-dose chemotherapy, demethylating agents, immune modulating agents, valproic acid, and cyclosporine).

RESULTS

The prognostic impact of poor-risk cytogenetic findings (as defined by the IPSS classification) on overall survival was as unfavorable as an increased (> 20%) blast count. The hazard ratio (compared with an abnormal karyotype or a bone marrow blast count < 5%) was 3.3 for poor-risk cytogenetics, 4.8 for complex abnormalities harboring chromosomes 5 and/or 7, and 3.1 for a blast count of 21% to 30% (P < .01 for all categories). The predictive power of the IPSS cytogenetic subgroups was unaffected by type of therapy given.

CONCLUSION

The independent prognostic impact of poor-risk cytogenetics on overall survival is equivalent to the impact of high blast counts. This finding should be considered in the upcoming revision of the IPSS.

Low-dose decitabine versus best supportive care in elderly patients with intermediate- or high-risk myelodysplastic syndrome (MDS) ineligible for intensive chemotherapy: final results of the randomized phase III study of the European Organisation for Research and Treatment of Cancer Leukemia Group and the German MDS Study Group

PURPOSE

To compare low-dose decitabine to best supportive care (BSC) in higher-risk patients with myelodysplastic syndrome (MDS) age 60 years or older and ineligible for intensive chemotherapy.

PATIENTS AND METHODS

Two-hundred thirty-three patients (median age, 70 years; range, 60 to 90 years) were enrolled; 53% had poor-risk cytogenetics, and the median MDS duration at random assignment was 3 months. Primary end point was overall survival (OS). Decitabine (15 mg/m(2)) was given intravenously over 4 hours three times a day for 3 days in 6-week cycles.

RESULTS

OS prolongation with decitabine versus BSC was not statistically significant (median OS, 10.1 v 8.5 months, respectively; hazard ratio [HR], 0.88; 95% CI, 0.66 to 1.17; two-sided, log-rank P = .38). Progression-free survival (PFS), but not acute myeloid leukemia (AML) -free survival (AMLFS), was significantly prolonged with decitabine versus BSC (median PFS, 6.6 v 3.0 months, respectively; HR, 0.68; 95% CI, 0.52 to 0.88; P = .004; median AMLFS, 8.8 v 6.1 months, respectively; HR, 0.85; 95% CI, 0.64 to 1.12; P = .24). AML transformation was significantly (P = .036) reduced at 1 year (from 33% with BSC to 22% with decitabine). Multivariate analyses indicated that patients with short MDS duration had worse outcomes. Best responses with decitabine versus BSC, respectively, were as follows: complete response (13% v 0%), partial response (6% v 0%), hematologic improvement (15% v 2%), stable disease (14% v 22%), progressive disease (29% v 68%), hypoplasia (14% v 0%), and inevaluable (8% v 8%). Grade 3 to 4 febrile neutropenia occurred in 25% of patients on decitabine versus 7% of patients on BSC; grade 3 to 4 infections occurred in 57% and 52% of patients on decitabine and BSC, respectively. Decitabine treatment was associated with improvements in patient-reported quality-of-life (QOL) parameters.

CONCLUSION

Decitabine administered in 6-week cycles is active in older patients with higher-risk MDS, resulting in improvements of OS and AMLFS (nonsignificant), of PFS and AML transformation (significant), and of QOL. Short MDS duration was an independent adverse prognosticator.

Cytogenetic follow-up by karyotyping and fluorescence in situ hybridization: implications for monitoring patients with myelodysplastic syndrome and deletion 5q treated with lenalidomide

In patients with low and intermediate risk myelodysplastic syndrome and deletion 5q (del(5q)) treated with lenalidomide, monitoring of cytogenetic response is mandatory, since patients without cytogenetic response have a significantly increased risk of progression. Therefore, we have reviewed cytogenetic data of 302 patients. Patients were analyzed by karyotyping and fluorescence in situ hybridization. In 85 patients, del(5q) was only detected by karyotyping. In 8 patients undergoing karyotypic evolution, the del(5q) and additional chromosomal aberrations were only detected by karyotyping. In 3 patients, del(5q) was only detected by fluorescence in situ hybridization, but not by karyotyping due to a low number of metaphases. Karyotyping was significantly more sensitive than fluorescence in situ hybridization in detecting the del(5q) clone. In conclusion, to optimize therapy control of myelodysplastic syndrome patients with del(5q) treated with lenalidomide and to identify cytogenetic non-response or progression as early as possible, fluorescence in situ hybridization alone is inadequate for evaluation. Karyotyping must be performed to optimally evaluate response.