Randomized Trial of Intermediate-Dose Cytarabine in Induction and Consolidation

Author Manuscript Published OnlineFirst on February 6, 2020; DOI: 10.1158/1078-0432.CCR-19-3433 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited.

Randomized trial of intermediate-dose cytarabine in induction and consolidation

therapy in adults with acute myeloid leukaemia.

Hui Wei1,2,3+, Ying Wang2,3+, Robert Peter Gale4, Dong Lin3, Chunlin Zhou3, Bingcheng Liu3, Shaowei Qiu3, Runxia Gu3, Yan Li3, Xingli Zhao3, Shuning Wei3, Benfa Gong3, Kaiqi Liu3, Xiaoyuan Gong3, Yuntao Liu3, Guangji Zhang3, Zhen Song2, Yang Wang5, Wei Li5, Yingchang Mi1,2,3, Jianxiang Wang1,2,3#

1State Key laboratory of Experimental Hematology, 2National Clinical Research Center for Blood Disease, 3Leukaemia Center, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences; 4Hematology Research Centre, Division of Experimental Medicine, Department of Medicine, Imperial College London, London, United Kingdom; 5State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Peking Union Medical College & Chinese Academy of Medical Sciences

+ Equal contribution # Lead corresponding authour

Running title: Intermediate-dose cytarabine in adult AML

Key words: Acute myeloid leukemia, cytarabine, remission induction, consolidation therapy, intermediate-dose

Supported in part by The National Key Research and Development Program for Precision Medicine (2017YFC0909800) (to Jianxiang Wang), CAMS Innovation Fund for Medical Sciences (2016-I2M-1-001) (to Jianxiang Wang), Foundation for Innovative Research Groups of the Natural Science Foundation of China

Downloaded from clincancerres.aacrjournals.org on September 28, 2021. © 2020 American Association for Cancer Research. Author Manuscript Published OnlineFirst on February 6, 2020; DOI: 10.1158/1078-0432.CCR-19-3433 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited.

(81421002) (to Jianxiang Wang), State Key Program of National Natural Science of China (81770181, 81430004) (to Jianxiang Wang). National Institute of Health Research (NIHR) Biomedical Research Centre funding scheme (to Robert Peter Gale). The funder had no role in the study-design, data collection, analyses, interpretation, developing the typescript or the decision to publish the typescript. Authours had access to all study data.

Correspondence Dr. Jianxiang Wang, State Key laboratory of Experimental Hematology, Leukaemia center, National Clinical Research Center for Blood Disease, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Nanjing Rd 288, Tianjin, 300020, China. T +86 22 23909120; F +86 22 27301963; E [email protected]. OR

Dr.Yingchang Mi, State Key laboratory of Experimental Hematology, Leukaemia center, National Clinical Research Center for Blood Disease, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Nanjing Rd 288, Tianjin, 300020, China. T +86 22 23909172; F +86 22 27301963; E [email protected].

Conflict-of-interest: None

The word count: 2911

The total number of figures and tables: 6

Translational Relevance: Cytarabine is commonly-used in acute myeloid leukaemia (AML). Whether an induction regimen with intermediate-dose cytarabine would be more effective than one with conventional dose is unknown. Also, there is controversy whether high-dose cytarabine is better than an intermediate-dose combined with other drugs for post-remission therapy. In this open-label, randomized, parallel controlled trial, we show intermediate-dose cytarabine induction combined daunorubicin and omacetaxine mepesuccinate produced a higher rate of complete remissions, better event- and disease-free survival (EFS and DFS) and survival compared with conventional-dose cytarabine with no increase in early deaths in young adults with new-diagnosed de novo AML. In contrast, there was no difference in cumulative incidence of relapse (CIR), DFS or survival between intermediate- and high-dose cytarabine given for post-remission consolidation.

Abstract

Purpose Cytarabine, 100-200 mg/mE+2/d, is commonly-used in induction

therapy of acute myeloid leukaemia (AML). Whether a higher dose of cytarabine

would be more effective is unknown. Also, there is controversy whether

high-dose cytarabine is better than an intermediate-dose combined with other

drugs for post-remission therapy. In this open-label, randomized, parallel

controlled group study, roles of intermediate-dose cytarabine were investigated.

Subjects and Methods Subjects with AML age 15-55 years were randomized to

receive daunorubicin, omacetaxine mepesuccinate and conventional- or

intermediate-dose cytarabine. Subjects achieving complete remission were

randomized to receive 3 courses of high-dose cytarabine or 2 courses of

intermediate-dose cytarabine with daunorubicin in the 1st and mitoxantrone in the

2nd course. The primary endpoint was disease-free survival (DFS).

Results 591 subjects were randomized to intermediate- (N=295) or

conventional-dose (N=296) cytarabine group. Three-year DFSs were 67% (95%

confidence interval [CI], 61-73) in the intermediate-dose cohort compared with 54%

(95%CI, 48-61) in the conventional-dose cohort (Hazard Ratio [HR]=0.67; 95%CI,

0.51-0.89; P=0.005). Three-year survivals were 68% (95%CI, 63-74) and 59%

(95%CI, 53-65; HR=0.720 95%CI, 0.56-0.94; P=0.014). Two course of

intermediate-dose cytarabine with daunorubicin or mitoxantrone resulted in

similar DFS and survival as three course of high-dose cytarabine when used for

post-remission therapy.

Conclusions Induction therapy with intermediate-dose cytarabine with

daunorubicin and omacetaxine mepesuccinate increases DFS and survival in

persons with AML age 15-55 years compared with conventional-dose cytarabine.

Introduction

Cytarabine is a common component of induction therapy of acute myeloid

leukaemia (AML). Cytarabine, 100-200 mg/mE+2/d for 5-10 d, typically 7 d, is

typically combined with daunorubicin, 60-90 mg/mE+2/d for 3 days1-3. Higher

doses of cytarabine, namely intermediate-dose (1-2 g/mE+2/d) and high-dose

(2-3 g/mE+2/d) were tested in several clinical trials with contradictory results4-10.

Some studies reported no survival benefit4-6 whereas others reported better

relapse-free survival (reviewed in Supplementary Table S1)4-8, 10. These

multi-centre studies included subjects of diverse ages which might explain some

discordances as might centre effects.

The standard remission induction regimen in China is cytarabine and

daunorubicin combined with omacetaxine mepesuccinate (homoharringtonine).

Because of the bone marrow suppression associated with homoharringtonine the

dose of daunorubicin is typically reduced to 40 mg/mE+2/d for 3 days rather than

the 60 mg/mE+2/d used when homoharringtonine is not given (reviewed in

Supplementary Table S2)11-18. In the pilot study for this trial we used

intermediate-dose cytarabine combined with daunorubicin and homoharringtonine.

Three-year disease-free survival (DFS) was 63% (95% confidence interval [CI],

51-76) and three-year survival, 59% (95%CI,46-71)13.

High-dose cytarabine is commonly used as post-remission (consolidation)

therapy19-23. Intermediate-dose cytarabine alone or combined with other drugs

are also widely-used for post-remission therapy12, 13, 21, 24, 25. In our study we also

compared efficacy of high-dose cytarabine versus intermediate-dose cytarabine

combined with daunorubicin and mitoxantrone for post-remission therapy.

Subjects and Methods

Study-Design and Participants

This study was an open-label, randomized, parallel cohort single-center trial

conducted at the Blood Disease Hospital, Chinese Academy of Medical Science

from September 1, 2010 to January 13, 2016 registered at www.chictr.org.cn

(identifier: ChiCTR-TRC-10001202). The study was approved by the Hospital

Ethics Committee and conducted in accordance with the Declaration of Helsinki.

Subjects gave written informed consent.

Newly-diagnosed persons with de novo AML excluding acute progranulocytic

leukaemia age 15-<55 years were eligible. Main inclusion criteria were: (1) AML

according to WHO classification (2008)26; (2) ECOG performance score ≤2; (3)

cardiac ejection-fraction determined by echocardiography ≥50%; (4) serum total

bilirubin concentration <1.5×upper limit normal (ULN), aspartate aminotransferase

and alanine aminotransferase concentrations <2.5×ULN, serum creatinine

concentration <2.0×ULN and cardiac enzymes <2.0 ULN.

There were two 1:1 randomization which were computer-generated with allocation

concealment in an unreadable computer system which investigators could access

only after a subject was enrolled. Randomization sequence was generated with

SAS. Treating physicians and subjects were not blinded to therapy-assignment

but investigators assessing outcomes and statisticians were.

Treatment

Eligible subjects were randomly-assigned to conventional- (100 mg/mE+2/d days

1-7 as a 12-h IV infusion) or intermediate-dose cytarabine (100 mg/mE+2/d days

1-4 as a 12-h IV infusion and 1 g/mE+2 every 12 h as a 3-h IV infusion on days

5-7). Subjects also received daunorubicin (40 mg/mE+2/d on days 1-3) and

omacetaxine mepesuccinate (2 mg/mE+2/d on days 1-7). A CONSORT flow

diagram and treatment scheme are displayed in Figures 1 and 2. Criteria for

response and relapse followed the Report of the National Cancer

Institute-Sponsored Workshop27. For subjects randomized to conventional-dose

cytarabine, a 2nd induction course, identical to the 1st, could be given if a partial

remission was achieved after 1st induction cycle and when blood cell counts

recovered. From March 1, 2013 subjects randomized to receive

conventional-dose cytarabine with bone marrow blasts ≥10 percent on d 14

could receive a 2nd induction course of cytarabine (100 mg/mE+2/d on days 1-5

as a 12-h IV infusion) and daunorubicin (45 mg/mE+2/d days 1-3). Subjects

randomized to receive intermediate-dose cytarabine did not receive a 2nd

induction course because of hematopoietic toxicity.

Subjects achieving a complete remission were randomized to receive three

courses of high-dose cytarabine (3 g/mE+2 days 1-3 every 12 h as a 3-h IV

infusion) or two courses of intermediate-dose cytarabine (1.5 g/mE+2 at the same

schedule) with daunorubicin (40 mg/mE+2/d on days 1-3) in the 1st and

mitoxantrone (6 mg/mE+2/d on days 1-3) in the 2nd courses. The 2nd

randomization was not stratified for induction regimen. Subjects could receive 4

cycles of intrathecal methotrexate, cytarabine and dexamethasone to prevent

CNS leukaemia if they agreed. G-CSF was given from day 7 after chemotherapy

until neutrophils were >0.5 x10E+9/L. Subjects with intermediate- or adverse-risk

leukaemia could receive an allogeneic haematopoietic cell transplant based on

criteria of the National Comprehensive Cancer Network (NCCN) 28.

Outcomes

The primary endpoint was DFS. Co-secondary endpoints included rates of

complete remission, event-free survival (EFS), cumulative incidence of relapse

(CIR), survival and deaths within <30 d. Subgroup analyses were exploratory.

DFS in subjects achieving complete remission was defined as the interval from

complete remission to relapse or death from any cause and censored at last

follow-up visit or contact. EFS was defined as the interval from randomization to

assessment of response after the induction cycle if the subject failed to achieve a

complete remission, the date of relapse in subjects achieving a complete

remission or the date of death, whichever occurred first. Survival was defined as

the interval from 1st randomization to death. CIR was measured from the date of

complete remission to relapse. Death without relapse was defined as a competing

event in calculating the CIR. Deaths within <30 d were measured from day of 1st

randomization. Follow-up of living subjects was censored at last visit or contact.

Durations of neutrophils <0.5x10E+9/L and platelets <25x10E+9/L were analyzed

in subjects achieving complete remission after only one course defined as the

interval from beginning induction therapy to neutrophils ≥0.5×10E+9/L and

platelets ≥25×10E+9/L.

Statistical analyses

We assumed a remission rate of 60 percent. We then used the Lakatos method to

calculate sample size of 533 subjects equally divided between the cohorts and

171 events to detect a hazard ratio of 0.65 assuming the three-year DFSs were

41% in the conventional-dose cytarabine induction regimen group and 56% in the

intermediate-dose cytarabine induction regimen group with 80 percent power at a

0.05 significance level in a two-sided log-rank test. Study duration was

estimated at 4 years.

All randomized subjects were included in analyses of complete remission, EFS,

survival and death <30 d by intent-to-treat. All randomized subjects achieving

complete remission were included in DFS and CIR analyses by intent-to-treat.

DFS, EFS, and survival were calculated by the Kaplan-Meier method. Log-rank

test was used for univariable analyses and the proportional hazard model of Cox

for multivariable analyses of DFS, EFS, and survival. CIR was calculated by

using the competing-risk analysis considering of death as a competing event29.

Data were analyzed with and without censoring of transplant recipients at the time

of transplant. Age and WBC were analyzed as continuous variables in

multivariable analyses. To test factors associated with complete remission, χ2

and Fisher exact tests were used in univariable analyses and in a multiple logistic

regression model for multivariable analyses. We also performed sensitivity

analyses of the remission induction cohorts excluding subjects in the

conventional-dose cytarabine cohort receiving a 2nd induction cycle for DFS, EFS,

and survival. Statistical tests were two-sided with a significance level set at 0.05.

Analyses were done with SAS (version 9.4).

Results

Between September 1, 2010 to January 13, 2016, 596 subjects age 15-<55 years

with de novo newly-diagnosed AML were enrolled. Five subjects were

subsequently excluded because of incorrect diagnoses (N=3), withdrawal of

consent (N=1) and ineligibility (N=1). 320 (54%) were male. Median age was 36

years (range, 15-55 years). 296 subjects were randomly-assigned to receive

conventional- and 295 to receive intermediate-dose cytarabine. The cohorts were

balanced for baseline variables including sex, age, baseline WBC and cytogenetic

risk group (Table 1). 6 subjects in the conventional-dose cohort did not complete

the 1st induction cycle because of severe infection (N=4), tumor lysis syndrome

(N=1) and acute myocardial infarction (N=1). The same was so for 2 subjects in

the intermediate-dose cytarabine cohort because of severe infection. These 8

subjects are included in the intent-to-treat analyses. Median follow-up of

survivors is 49 months (range, 5-94 months).

Induction response

485 subjects (82%, 95% Confidence Interval [CI], 79-85) achieved a complete

remission. 208 subjects (70%, 95%CI, 65-76) in the conventional-dose cohort

achieved a complete remission after the 1st induction cycle. Nine subjects

achieved a partial remission after 1st induction cycle. Eight received a 2nd cycle

four of whom subsequently achieved a complete remission. 1 subject did not

receive a 2nd induction course because of bleeding. Before the protocol

amendment on March 1, 2013, 15 of 113 subjects randomized to conventional

induction cohort had bone marrow blasts ≥10 percent on day 14. 13 in the

conventional arm did not achieve complete remission; 2 did. After March 1, 2013,

32 of 183 randomized to conventional induction cohort had bone marrow blasts

≥10 percent on day 14. 23 received a 2nd induction course on d 14 17 of whom

achieved a complete remission. Nine similar subjects did not receive the 2nd

induction course because of infection (N=7), tumor lysis syndrome (N=1) and

refusal (N=1). A CONSORT diagram of subjects in the induction therapy phase

is displayed in Supplementary Figure S1. 256 subjects (87%, 95%CI, 83-91) in

the intermediate-dose cytarabine cohort obtained a complete remission after the

1st induction course compared with 229 (77%, 95%CI, 72-82; P=0.004) in the

conventional-dose cohort after the 1st and 2nd induction courses. Sensitivity

analyses of the cohorts excluding subjects in the conventional-dose cohort

receiving a 2nd induction course indicated a significant improvement in complete

remission rate (78%, 95%CI, 74-83 for conventional-dose vs. 87%, 95%CI, 83-91

for intermediate-dose; P=0.0094).

In multi-variable analyses intermediate-dose cytarabine was independently

associated with a higher complete remission rate (Odds Ratio [OR]=2.09, 95%CI,

1.29-3.39; P=0.003; Supplementary Table S3). Other variables

significantly-correlated with complete remission included cytogenetic risk cohort,

NPM1 mutation, biallelic CEBPA mutation and FLT3-ITD mutation

(Supplementary Table S3).

Consolidation therapy

456 of 485 subjects (94%) achieving a complete remission were

randomly-assigned to receive post-remission therapy with high-dose cytarabine

(N=232) or intermediate-dose cytarabine with daunorubicin for the 1st cycle and

mitoxantrone for the 2nd (N=224). Baseline variables at randomization are

displayed in Table 1. 109 (18%) of 591 randomized subjects, 53 in the

conventional-dose and 56 in intermediate-dose cytarabine induction cohorts

received an allotransplant in 1st complete remission. Median intervals to

transplant were 6 months in both cohorts (ranges, 4-35 months and 4-25 months

for the conventional-dose and intermediate-dose cytarabine induction cohorts,

respectively).

Survival

In subjects achieving complete remission, three-year DFS was 61% (95%CI,

56-65) including 67% (95%CI, 61-73) in the intermediate- and 54% (95%CI, 48-61;

P=0.005; Figure 3A) in the conventional-dose cytarabine induction cohort. In

multi-variable analyses intermediate-dose cytarabine induction regimen was

independently associated with better DFS than conventional-dose cytarabine with

a HR=0.64 (95%CI, 0.48-0.85; P=0.002). Other significant variables for DFS

were WBC at diagnosis, cytogenetic risk cohort, transplant in 1st complete

remission and NPM1 and bi-allelic CEBPA mutations (Supplementary Table S4).

In all subjects, 3-year EFSs and survivals for the intermediate- and

conventional-dose cytarabine induction cohorts were 58% (95%CI, 53-64) vs. 42%

(95%CI, 37-48; P <0.0001; Figure 3B) and 68% (95%CI, 63-74) vs. 59% (95%CI,

53-65; P=0.014; Figure 3C), respectively. In multivariable analyses the

intermediate-dose cytarabine induction regimen was independently associated

with a better EFS and survival with HR=0.63 (95%CI 0.46-0.85; P<0.0001;

Supplementary Table S4) and HR=0.70 (95%CI 0.50-0.97; P=0.03;

Supplementary Table S4). Other variables significantly associated with EFS and

survival were similar including WBC at diagnosis, cytogenetic risk cohort,

transplant in the 1st complete remission and NPM1 and bi-allelic CEBPA

mutations (Supplementary Tables S4).

In sensitivity analyses of the cohorts excluding subjects in the conventional-dose

cohort receiving a 2nd induction course, intermediate-dose induction therapy was

also associated with improved DFS, EFS, and survival compared with

conventional-dose cytarabine (Supplementary Figure S2). The advantage of

intermediate- vs. conventional-dose cytarabine remained significant for DFS

(HR=0.62, [95%CI, 0.46-0.84]; P=0.004; Supplementary Figure S3A), EFS

(HR=0.53, [95%CI, 0.41-0.70]; P=0.0003; Supplementary Figure S3B) and

survival (HR=0.67 [95%CI, 0.51-0.88]; P=0.006; Supplementary Figure S3C) after

censoring subjects at the date of transplant.

In sub-group analysis, subjects in the cytogenetic intermediate- and adverse-risk

cohorts had significantly a higher complete remission rate with intermediate-

compared with conventional-dose cytarabine (84% [95%CI, 78-89] vs. 73%,

[95%CI, 66-79]; P=0.011; and 73%, [95%CI, 47-90] vs. 37% [95%CI, 19-60];

P=0.032). In contrast there was no significant difference in complete remission

rate in favorable-risk group (98% [95%CI, 92-100] vs. 95% [95%CI, 88-99];

P=0.44, for the intermediate-dose and conventional-dose cytarabine induction

cohort, respectively). Intermediate-dose cytarabine was only found to be

associated with better DFS, EFS and survival in subjects with intermediate-risk

cytogenetics. (Supplementary Figure S4). We were unable to determine if there

was a benefit of intermediate-dose cytarabine in the favorable and adverse

cytogenetic cohorts because of small sample sizes.

There were no significant differences in DFS, CIR, or survival between the

consolidation cohorts in the exploratory analysis (Figure 4). This was confirmed in

sensitivity analyses which excluded subjects in the conventional-dose cohort

receiving a 2nd induction course (data not shown) and in sensitivity analyses

censoring subjects receiving a transplant at the date of transplant (Supplementary

Figure S5). Intermediate-dose cytarabine induction improved DFS in both

consolidation cohorts but survival only in the high-dose cytarabine consolidation

cohort compared with the conventional-dose cytarabine induction (Supplementary

Table S5).

Safety and toxicity

Deaths <30 days were similar in the intermediate- and conventional-dose

cytarabine induction cohorts, 1% (95%CI 0.4-3.4) vs. 2% (95%CI 1-5; P=0.36).

Durations of neutrophils <0.5x10E+9/L and platelets <25x10E+9/L were longer for

the intermediate-dose cytarabine cohort compared with the conventional-dose

cohort (20 vs. 21 days; P<0.0001; 20 vs. 22 days; P<0.0001; Table 2). There was

a trend towards more RBC-transfusions in the intermediate- vs. the

conventional-dose cohorts ([U; median], 12 [range, 12-35 U] vs. 11 [range, 0-40

U]; P=0.05). Platelet transfusions were similar ([U; median], 60 U [range, 24-402

U] vs. 60 U [range, 9-392 U]; P=0.11). There was also a trend towards more

bacteremia in the intermediate- vs. conventional-dose induction cohorts (16%, [12,

21%] vs. 12% [8, 15%]; P=0.092). There were no significant differences in

cumulative incidence of death in complete remission between two consolidation

cohorts (Supplementary Figure S6).

Discussion

Our data indicate that intermediate-dose cytarabine induction combined

daunorubicin and omacetaxine mepesuccinate is associated with a higher rate of

complete remissions, better DFS, EFS, and survival compared with

conventional-dose cytarabine with no increase in deaths within <30 days in

persons 15-<55 years with new-diagnosed de novo AML meeting our study-entry

criteria. In contrast, there was no difference in DFS, CIR or survival between

intermediate- and high-dose cytarabine given for post-remission consolidation.

These data are like other reports14, 16, 18. In sub-group analyses the benefit of

intermediate-dose cytarabine induction on DFS, EFS, and survival was limited to

subjects with intermediate-risk cytogenetics.

Studies from HOVON-SAKK, SWOG, ALSG and German AMLCG reported no

improvement in survival with high-dose cytarabine in AML induction therapy4-6, 31.

There are, however, important differences between these studies and ours

outlined in Supplementary Table S1. 1st, we studied intermediate- not high-dose

cytarabine. 2nd, our study included a lower dose of daunorubicin but added

omacetaxine mepesuccinate. 3rd, median age of our study subjects was 36

years compared with 49 and 43 years in the HOVON-SAKK and ALSG trials4,6.

4th, There may be differences in cytogenetics and/or mutation topography of AML

between Chinese and persons of predominately European descent32, 33. 89

percent subjects in our trial were in favorable and intermediate risk group, which

was higher than other randomized clinical trials.

Our data indicate that the benefit of intermediate-dose cytarabine operated

predominately in subjects with intermediate-risk cytogenetics. Because our

subjects were age <55 years we cannot know if this benefit would occur in older

persons. Other studies reported better survival with high-dose cytarabine in

young subjects7,10. We also cannot comment on whether intermediate-dose

cytarabine would have the same benefit in persons receiving a higher dose of

daunorubicin with or without omacetaxine mepesuccinate.

There were two consolidation cohorts in our study: (1) three course of high-dose

cytarabine; or (2) two courses of intermediate-dose cytarabine, the 1st with

daunorubicin and the 2nd with mitoxantrone. We used only two courses of

intermediate-dose cytarabine because of concern over bone marrow toxicity from

the combination with daunorubicin or mitoxantrone. Using a Cox proportional

hazards model in the post-hoc analysis we found that intermediate-dose

cytarabine induction improved DFS in both consolidation cohorts but survival only

in the high-dose cytarabine consolidation cohort compared with

conventional-dose cytarabine induction (Supplementary Table S5). This

discordance persisted even after excluding subjects receiving a transplant in 1st

remission or after relapse. The reason(s) for this discordance is unclear.

There are several important limitations to our study. Some are generic to large

randomized trials in AML such as selection biases, loss of subjects and

withdrawals of consent. We tried to overcome some by our intent-to-treat and

sensitivity analyses. Another limitation is withdrawal of subjects to receive

transplant, a selection bias difficult or impossible to control. However, we

analyzed our data with and without censoring at transplant with similar

conclusions. There was also an imbalance in numbers of induction courses, 1

for the intermediate-dose cytarabine cohort and up to two in the conventional

dose cytarabine cohort. We addressed this issue by excluding subjects in the

conventional-dose cohort receiving a 2nd induction course. There are other

limitations to generalizing our conclusions to other settings such as our use of a

lower dose of daunorubicin (40 mg/mE+2) compared with other countries (60-90

mg/mE+2) and adding omacetaxine mepesuccinate.

In summary, we show a benefit of intermediate-dose cytarabine in induction

therapy in person 15-<55 years with newly-diagnosed de novo AML when

combined with daunorubicin and omacetaxine mepesuccinate. We also found 2

consolidation courses of intermediate-dose cytarabine combined with

daunorubicin and mitoxantrone was as effective as 3 courses high-dose

cytarabine. Our conclusions require confirmation but could improve

therapy-outcomes if validated.

Author contributions

Conception and design Jianxiang Wang, Yingchang Mi. Provision of study

materials or subjects Hui Wei, Ying Wang, Dong Lin, Chunlin Zhou, Bingcheng Liu,

Shaowei Qiu, Runxia Gu, Yan Li, Xingli Zhao, Shuning Wei, Benfa Gong, Kaiqi

Liu, Xiaoyuan Gong, Yuntao Liu, Guangji Zhang. Collection and assembly of

data Hui Wei, Ying Wang, Zhen Song, Yang Wang, Wei Li. Data analysis and

interpretation Jianxiang Wang, Yingchang Mi, Robert Peter Gale, Hui Wei, Ying

Wang, Zhen Song, Yang Wang, Wei Li. Typescript writing Jianxiang Wang,

Robert Peter Gale, Hui Wei. All authors approved the final typescript.

Acknowledgment Supported in part by The National Key Research and

Development Program for Precision Medicine (2017YFC0909800), CAMS

Innovation Fund for Medical Sciences (2016-I2M-1-001), Foundation for

Innovative Research Groups of the Natural Science Foundation of China

(81421002), State Key Program of National Natural Science of China (81770181,

81430004). RPG acknowledges support from the National Institute of Health

Research (NIHR) Biomedical Research Centre funding scheme. Profs. Elihu

H. Estey (Fred Hutchinson Cancer Research Centre), Charles A. Schiffer

(Karmanos Cancer Centre) and Mei-Jie Zhang (Medical College Wisconsin)

kindly reviewed the typescript and provided helpful comments. Funders had no

role in the study-design, analyses, or decision to publish.

Figure Legends

Figure 1. CONSORT flow diagram.

Footnote. NE, not evaluable.

Figure 2. Trial design.

Footnote. AML, acute myeloid leukaemia; R, randomize; CR, complete

remission; PR, partial remission; CD, conventional-dose cytarabine; ID,

intermediate-dose cytarabine; HD, high-dose cytarabine; D, daunorubicin; O,

omacetaxine mepesuccinate; M, mitoxantrone.

Figure 3. Outcomes after induction cytarabine dose randomization. (A) DFS;

(B) EFS; (C) survival

Figure 4. Outcomes after consolidation cytarabine dose randomization. (A) DFS;

(B) CIR; (C) survival.

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Table 1：Baseline clinical and laboratory variables.

Randomization of induction Randomization of consolidation

Conventional Intermediate High-dose (N=232) Intermediate-dose (N=296) (N=295) (N=224) Age <45y 218 231 180 170 ≥45y 78 64 52 54 Median (y; range) 36 (15-54) 35 (15-54) 34.5(15-54) 36 (15-54)

Male 161 159 120 128

WBC (X10E+9/L; median; range) 12.3 (0.6-247) 12.8 (0.7-371) 12.9 (0.7-247) 12.9 (0.8-371) <10 136 131 104 95 ≥10 160 164 128 129

Haemoglobin (g/L; median; 82 (45-163) 81 (41-153) 82 (41-158) 82 (41-163) range) <100 222 231 175 169 ≥100 74 64 57 55

Platelets (x10E+9/L; median; 43 (3-317) 42 (8-356) 39 (7-356) 45 (7-317) range) <50 163 170 138 122

≥50 133 125 94 102

Cytogenetic riska Favorable 80 83 78 72 Intermediate 179 182 135 131 Adverse 19 15 7 11 Unknown 18 15 12 10

NPM1 Mutated 51 38 42 35 Wild-type 228 243 183 173 Unknown 17 14 7 16

FLT3-ITD Positive 35 31 19 25 Negative 259 263 212 198 Unknown 2 1 1 1

CEBPA Bi-allelic Yes 32 43 32 34 No 247 236 189 175 Unknown 17 16 11 15

Induction regimen Conventional -dose cytarabine NA NA 112 103

Intermediate-dose cytarabine NA NA 120 121

Consolidation regimen High-dose cytarabine NA NA Intermediate-dose cytarabine NA NA

Transplant CR1 No 243 239 192 176 Yes 53 56 40 48 aCytogenetic risk was classified according to the Refined Medical Research Council criteria30, NA: not available.

Table 2. Toxicities during induction therapy. Conventional Intermediate P-value

Deaths <30 d (n) 4 7 0.36 Neutrophils (d; median, range)a 20(12, 34) 21(12, 31) <.0001 Platelets (d; median; range)a 20 (12, 40) 22(14, 44) <.0001 Sepsis (n) 40 53 0.14 Bacteria (n) 34 48 0.09 Fungi (n) 6 5 0.77 a Defined in text.

Enrolled Excluded (N=5) Fig 1 (N=596) Wrong diagnoses (N=3) Consent withdrawal (N=1) Ineligible (N=1)

Conventional cytarabine Intermediate cytarabine (CD; N=296 ) (ID; N=295)

No remission (N=61) No remission (N=29) Died (N=4); NE (N=2) Died (N=7); NE (N=3) Complete remission Complete remission (N=229 ) (N=256)

Not randomized (CD, N=14; ID N=15) Subject refusal (N=16); Infection (N=8); Physician refusal (N=2); Heart failure (N=1); Kidney failure Transplant (N=1); Relapse (N=1) Transplant (N=40) (N=48)

High-dose cytarabine (N=232) Intermediate-cytarabine (N=224) CD (N=112); ID (N=120) CD (N=103); ID (N=121) 29 Downloaded from clincancerres.aacrjournals.org on September 28, 2021. © 2020 American Association for Cancer Research. Author Manuscript Published OnlineFirst on February 6, 2020; DOI: 10.1158/1078-0432.CCR-19-3433 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited.

Fig 2

≥10% bone marrow CD-D blasts d 14

CD-DO ID-D ID-M CD-O CD-O CD-M CD-M

AML R PR CD-DO CR R

ID-DO HD HD HD CD-O CD-O CD-M

29 Downloaded from clincancerres.aacrjournals.org on September 28, 2021. © 2020 American Association for Cancer Research. Author Manuscript Published OnlineFirst on February 6, 2020; DOI: 10.1158/1078-0432.CCR-19-3433 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited.

Cytarabine, 100 mg/mE+2/d 12-h IV infusion d 1-4 and 1 g/mE+2 3-h IV infusion ID every 12 h d 5-7; Daunorubicin, 40 mg/mE+2/d d 1-3; Omacetaxine mepesuccinate, 2 mg/mE+2/d d 1-7. Cytarabine, 100 mg/mE+2/d 12-h IV infusion d 1-7; Daunorubicin, 40 mg/mE+2/d CD d 1-3; Omacetaxine mepesuccinate, 2 mg/mE+2/d d 1-7. CD-D Cytarabine, 100 mg/mE+2/d 12-h IV infusion d 1- 5; Daunorubicin, 45 mg/mE+2/d d 1-3. HD Cytarabine, 3 g/mE+2 3-h IV infusion every 12 h d 1-3. Cytarabine, 1.5 g/mE+2 12-h IV infusion d 1- 5; Daunorubicin, 40 mg/mE+2/d d 1- ID-D 3 Cytarabine, 1.5 g/mE+2 12-h IV infusion d 1- 3; Mitoxantrone, 6 mg/mE+2/d d 1- ID-M 3. Cytarabine, 100 mg/mE+2/d 12-h IV infusion d 1-6; Omacetaxine mepesuccinate, CD-O 2.5 mg/mE+2/d d 1-6. Cytarabine, 100 mg/mE+2/d 12-h IV infusion d 1- 6; Mitoxantrone, 6 mg/mE+2/d CD-M d 1-3.

30 Downloaded from clincancerres.aacrjournals.org on September 28, 2021. © 2020 American Association for Cancer Research. Author Manuscript Published OnlineFirst on February 6, 2020; DOI: 10.1158/1078-0432.CCR-19-3433 Author manuscripts have been peer reviewed and accepted for publication but have not yet been edited.

Randomized trial of intermediate-dose cytarabine in induction and consolidation therapy in adults with acute myeloid leukaemia

Hui Wei, Ying wang, Robert Peter Gale, et al.

Clin Cancer Res Published OnlineFirst February 6, 2020.

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