Treatment of Anemia in Myelodysplastic Syndromes With
`Granulocyte Colony-Stimulating Factor Plus Erythropoietin: Results
`From a Randomized Phase II Study and Long-Term Follow-Up of 71 Patients
`
`By Eva Hellstro¨ m-Lindberg, Tomas Ahlgren, Yves Beguin, Magnus Carlsson, Jan Carneskog, Inger Marie Dahl,
`Ingunn Dybedal, Gunnar Grimfors, Lena Kanter-Lewensohn, Olle Linder, Michaela Luthman,
`Eva Lo¨ fvenberg, Herman Nilsson-Ehle, Jan Samuelsson, Jon-Magnus Tangen,
`Ingemar Winqvist, Gunnar O¨ berg, Anders O¨ sterborg, and Åke O¨ st
`
`Treatment with erythropoietin (epo) may improve the ane-
`mia of myelodysplastic syndromes (MDS) in approximately
`20% of patients. Previous studies have suggested that treat-
`ment with the combination of granulocyte colony-stimulat-
`ing factor (G-CSF) and epo may increase this response rate.
`In the present phase II study, patients with MDS and anemia
`were randomized to treatment with G-CSF ⴙ epo according
`to one of two alternatives; arm A starting with G-CSF for 4
`weeks followed by the combination for 12 weeks, and arm B
`starting with epo for 8 weeks followed by the combination
`for 10 weeks. Fifty evaluable patients (10 refractory anemia
`[RA], 13 refractory anemia with ring sideroblasts [RARS], and
`27 refractory anemia with excess blasts [RAEB]) were in-
`cluded in the study, three were evaluable only for epo as
`monotherapy and 47 for the combined treatment. The over-
`all response rate to G-CSF ⴙ epo was 38%, which is identical
`to that in our previous study. The response rates for patients
`with RA, RARS, and RAEB were 20%, 46%, and 37%, respec-
`
`APPROXIMATELY 90% of patients with myelodysplastic
`
`syndromes (MDS) present with anemia at diagnosis and
`the majority of the patients develop with time a requirement for
`transfusions of packed red blood cells (RBC).1 In low-risk
`MDS, the anemia is often the only or major clinical problem and
`may give rise to significant morbidity.2 Quality of life is reduced
`due to the low hemoglobin level and in older patients, condi-
`tions such as congestive heart failure and angina pectoris are
`often aggravated. Moreover, repeated transfusions may with
`time cause secondary hemochromatosis.
`The cytopenia in MDS may in some cases be ameliorated or
`improved by treatment with hematopoietic growth factors.
`Granulocyte-macrophage colony-stimulating factor (GM-CSF)
`and granulocyte CSF (G-CSF) are relatively effective in increas-
`ing the number of neutrophils,3-6 but have in randomized studies
`failed to show a positive effect on survival. Moreover, both
`drugs have demonstrated an overall negative effect on the
`
`From the Department of Hematology, Huddinge University Hospital,
`Huddinge, Sweden; Department of Pathology, Karolinska University
`Hospital, Stockholm, Sweden; Department of Hematology, University of
`Lie`ge, Lie`ge, Belgium; The Scandinavian MDS Group, Sweden and
`Norway.
`Submitted December 8, 1997; accepted February 27, 1998.
`Supported by grants from the National Cancer Foundation, Stock-
`holm, Sweden.
`Address reprint requests to Eva Hellstro¨m-Lindberg, MD, PhD,
`Department of Hematology, Huddinge University Hospital, 141 86
`Huddinge, Sweden; e-mail: Eva.Hellstrom-Lindberg@medhs.ki.se.
`The publication costs of this article were defrayed in part by page
`charge payment. This article must therefore be hereby marked ‘‘adver-
`tisement’’ in accordance with 18 U.S.C. section 1734 solely to indicate
`this fact.
`r 1998 by The American Society of Hematology.
`0006-4971/98/9201-0014$3.00/0
`
`tively. Response rates were identical in the two treatment
`groups indicating that an initial treatment with G-CSF was
`not neccessary for a response to the combination. Nine
`patients in arm B showed a response to the combined
`treatment, but only three of these responded to epo alone.
`This suggests a synergistic effect in vivo by G-CSF ⴙ epo. A
`long-term follow-up was made on 71 evaluable patients
`from both the present and the preceding Scandinavian study
`on G-CSF ⴙ epo. Median survival was 26 months, and the
`overall risk of leukemic transformation during a median
`follow-up of 43 months was 28%. Twenty patients entered
`long-term maintenance treatment and showed a median
`duration of response of 24 months.The international prognos-
`tic scoring system (IPSS) was effective to predict survival,
`leukemic transformation, and to a lesser extent, duration of
`response, but had no impact on primary response rates.
`r 1998byTheAmericanSocietyofHematology.
`
`platelet counts.7,8 The risk for leukemic transformation did not
`seem to be changed in actively treated patients. Erythropoietin
`(epo) is a potent stimulator of normal erythropoiesis and may
`also improve the anemia in patients with MDS.9-11 The efficacy
`of epo alone is relatively low, around 20%, and mainly confined
`to patients without the need for pretreatment transfusion.12 In a
`recent meta-analysis the response rate in patients with ring
`sideroblastic anemia (RARS), who generally show a relatively
`good median survival, was only 8%, while it was 21% in
`patients with refractory anemia (RA) and refractory anemia
`with excess blasts (RAEB).12 Other predictors of response were
`absence of the need for an initial transfusion and a serum epo
`level of ⬍200 U/L.
`Epo in combination with several other early-acting or my-
`eloid cytokines has shown synergistic effects on erythropoiesis
`in vitro.13,14 The combination of G-CSF and epo has been
`administered in five clinical studies aiming at improving the
`anemia in MDS. These studies have mainly comprised patients
`with RA, RARS, and RAEB. Two of the studies15,16 showed
`response rates of 42% and 38%, respectively, which suggested
`that the response rate was better than with epo alone. Recently,
`Negrin et al17 published additional data from the American
`study, showing that around 50% of the patients with a response
`to the combination therapy lost their response when G-CSF was
`withdrawn, and some of these patients also regained a response
`when G-CSF was reintroduced. This strongly supports the
`hypothesis of a synergistic effect in vivo of G-CSF and epo.
`The present study was designed as a randomized phase II trial
`to allow an unbiased selection of patients to one of two
`treatment alternatives. It had the following aims: to try to verify
`the response rate from the first Scandinavian study16 in an
`independant cohort of patients with MDS, to study whether a
`need for priming with G-CSF before epo was necessary, to
`study whether in vivo synergy between G-CSF and epo on
`
`68
`
`Blood,Vol 92, No 1 (July 1), 1998: pp 68-75
`
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`
`

`

`TREATMENT OF ANEMIA IN MDS WITH G-CSF ⫹ EPO
`
`69
`
`erythroid response could be proven, and finally to study
`duration of response and long-term outcome. The answers to the
`first three questions were given by the results from the present
`study, while the fourth was approached using data from both the
`first and the second Scandinavian study.
`
`MATERIALS AND METHODS
`
`Patients. Patients in the randomized study were included from
`October 1992 to January 1995. All participating centers used uniform
`diagnostic criteria18 and the diagnosis was confirmed with two bone
`marrow samples over a period of at least 2 months. Disease duration
`was calculated from the date of the confirmatory bone marrow sample.
`Central pathologic review of bone marrow samples before the start of
`treatment and at
`the end of the study was performed by Chief
`Pathologist, Dr Å. O¨ st and copathologist, Dr L. Kanter-Lewensohn. All
`patients signed consent forms and the studies followed guidelines of the
`investigation review boards of Sweden and Norway.
`Inclusion criteria were diagnosis of RA, RARS, or RAEB with either
`hemoglobin levels ⬍100 g/L in combination with symptoms of anemia
`or transfusion-dependent anemia. Patients with active ongoing bleeding
`or transfusion-dependent thrombocytopenia were excluded from the
`trial. The long-term follow-up included in addition all evaluable
`patients from the first Scandinavian study, which has been previously
`described.16
`Treatment. Patients were randomized to one of two alternatives;
`arm A started with G-CSF (filgrastim; Roche Pharmaceutical, Stock-
`holm, Sweden) for 4 weeks and continued with the combination of
`G-CSF ⫹ epo (erythropoietin beta; Boehringer Mannheim, Stockholm,
`Sweden) for 12 weeks; arm B started with epo for 8 weeks and
`continued with the combination for 10 weeks. G-CSF and epo were
`self-administered subcutaneously (SC) and given daily. Treatment was
`started at the lowest dose and dose escalation was performed every 2
`weeks, if necessary. In contrast to the previous Scandinavian study,
`doses were fixed and not given per kilogram body weight. Three dose
`levels of G-CSF (30 to 75 to 150 µg/d, SC) and two dose levels of epo
`(5,000 to 10 000 U/d) were used. A patient was considered evaluable for
`a response to G-CSF and epo if the combination was given for 6 weeks
`or more.
`lactate dehydroge-
`Sampling. Baseline hematologic parameters,
`nase, serum ferritin, serum epo, and soluble transferrin receptor were
`analyzed before and after treatment. Serum epo and transferrin receptor
`levels (serum tfr) were analyzed according to methods described by
`Wide et al19 and Beguin et al.20 Bone marrow sampling was performed
`before and after treatment and a cytogenetic analysis was made before
`treatment in all patients and after treatment in nine of these patients. The
`international prognostic scoring system (IPSS2) was used and a score
`was estimated for each patient.
`Response criteria. A complete erythroid response was defined as an
`increase in hemoglobin to at least 115 g/L. A partial response (PR) was
`defined as an increase in hemoglobin with 15 g/L or more in patients
`with nontransfused anemia and a 100% reduction of transfusion need in
`combination with stable hemoglobin level for ⱖ4 weeks in those with
`pretreatment transfusion need. The aim of the G-CSF treatment was to
`obtain a neutrophil count of 6 to 10 ⫻ 109/L and values within this range
`were considered a complete response (CR). In patients who did not
`reach this range, the neutrophil counts were considered as PRs (3 to 6 ⫻
`109/L), minor responses (1 to 3 ⫻ 109/L), or no response (⬍1 ⫻ 109/L).
`Maintenance treatment and long-term follow-up. Twenty-one evalu-
`able patients were included in the first Scandinavian study on G-CSF ⫹
`epo in MDS between November 1990 and 1992.16 Inclusion criteria
`were identical with those in the present study. A follow-up with regard
`to duration of response, survival, and progression to acute leukemia
`from start of treatment was made on these 21 patients and the 50
`evaluable patients from the present study by the first of January 1997.
`
`Patients in the follow-up analysis were thus included from November
`1990 to January 1995, and the median follow-up from start of treatment
`was 43 months. All patients with an erythroid response in the second
`study were offered maintenance treatment with G-CSF and epo, while
`maintenance treatment in the first study was given on an individual
`basis.
`Statistical analysis. Student’s t-test, Mann-Whitney U-test, and
`analysis of variance (ANOVA) were used for comparison of continuous
`variables, whenever appropriate. ␹2 analysis was used to compare
`categories. Kaplan-Meyer plots were used to describe survival, evolu-
`tion to acute myeloid leukemia (AML), and duration of response.
`
`RESULTS
`
`Patient description. Fifty-six patients with a diagnosis of
`MDS were included in the study; 43 from Sweden and 13 from
`Norway. There were 30 men and 26 women. Median age was 69
`years with a range from 48 to 87 years. Twenty-eight patients
`were randomized to each arm. Four patients were withdrawals;
`two developed acute myeloid leukemia during the interval
`between randomization and start of treatment, one patient was
`diagnosed with AML within 1 week from start of treatment (arm
`B), and one patient (arm B) was diagnosed as having pyoderma
`gangrenosum after 4 weeks of combined treatment. Two
`patients were dropouts; one experienced a deterioration of a
`previously known depression within 2 weeks and refused
`further treatment and another one, living far from the hospital,
`refused to come to visits. Thus, 50 patients (26 men) were
`evaluable for a response to treatment and clinical characteristics
`of these patients are shown in Table 1. The median age in this
`group was 69.5 years (range, 48 to 87). Ten of these patients had
`RA, 13 RARS, and 27 RAEB. Fifteen patients had stable
`anemia and 35 were transfusion-dependent. The degree of
`transfusion need (units per month) was estimated over a period
`of 6 months in those with a disease duration over 6 months. In
`the rest, the minimum time for observation of transfusion need
`was 3 months. Each patient was transfused at
`the same
`hemoglobin level during the course of the study, but there was
`an interindividual variation between patients. Iron stain was
`positive in all patients. Serum creatinine was normal in all but
`three patients; one responder had a serum creatinine of 8%
`above the upper normal
`limit and two nonresponders had
`increases of 10% and 32%, respectively. A cytogenetic analysis
`was done in 46 of the patients, 24 had a normal karyotype and
`22 showed aberrations. Seven patients had deletion 5q-, with six
`as single abnormality. Ten patients had poor prognosis chromo-
`somal patterns according to the risk score described by Green-
`berg et al.2 There were 46 patients evaluable for a IPSS score.
`Eleven had a low score, 19 an intermediate-1 score, 14 an
`intermediate-2 score, and two a high score.
`Three patients in arm B received only the epo and was thus
`not evaluable for a response to the combination treatment.
`These three patients were all nonresponders. Two of these, both
`with known heart disease, died of heart failure after 8 weeks of
`treatment and one patient showed disease progression and was
`withdrawn from treatment after 10 weeks. Thus, 47 patients
`were evaluable for a response to treatment with the combination
`of G-CSF and epo.
`The absolute majority of the patients managed to self-
`administer, while the rest needed support either with dosing or
`with dosing plus the injections.
`
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`

`

`70
`
`HELLSTRO¨ M-LINDBERG ET AL
`
`Table 1. Baseline Characteristics in 50 Evaluable Patients
`
`Variable
`
`Age (yr)
`Sex (M/F)
`RA
`RARS
`RAEB
`IPSS (low/Int 1/Int 2/high)†
`Disease duration (mos)
`Prior RBC transfusions (yes/no)
`RBC transf. units/mo‡
`Hemoglobin level (g/dL)
`ANC count ⫻ 109/L
`Platelet count ⫻ 109/L
`Bone marrow cellularity (%)
`Bone marrow blasts (%)
`Karyotype (normal/abnormal)
`Serum erythropoietin (U/L)§
`S. transferrin receptor (ng/mL)
`
`Arm A n ⫽ 24
`
`69 ⫾ 10
`8/16
`4
`8
`12
`4/10/7/2
`11.6 ⫾ 11.7
`17/7
`2.5 ⫾ 1.1
`87.0 ⫾ 10.8
`2.2 ⫾ 1.9
`210 ⫾ 141
`70 ⫾ 24
`7.0 ⫾ 5.9
`13/10
`216 (6-4979)
`6,983 ⫾ 5,631
`
`Arm B n ⫽ 26
`
`69 ⫾ 9
`18/8
`6
`5
`15
`7/9/7/0
`8.1 ⫾ 8.1
`18/8
`2.9 ⫾ 1.6
`86.3 ⫾ 12.8
`2.1 ⫾ 1.7
`216 ⫾ 193
`78 ⫾ 20
`6.2 ⫾ 3.9
`9/14
`237 (20-4128)
`6,480 ⫾ 5,987
`
`All Patients n ⫽ 50
`
`PValue
`
`69 ⫾ 9
`26/24
`10
`13
`27
`11/19/14/2
`9.3 ⫾ 9.8
`35/15
`2.7 ⫾ 1.4
`86.4 ⫾ 11.7
`2.2 ⫾ 1.8
`213 ⫾ 168
`74 ⫾ 22
`6.6 ⫾ 4.9
`22/24
`216
`6,714 ⫾ 5,763
`
`.92
`.01
`
`.5*
`
`.4
`.23
`.90
`.45
`.85
`.88
`.75
`.23
`.58
`.5
`.61
`.77
`
`*Step-wise ANOVA.
`†IPSS, International prognostic scoring system.2 Low, low risk; int-1, intermediate 1 risk; int-2, intermediate 2 risk; high, high risk.
`‡Transfusion needed from 35 patients with pretreatment RBC transfusions.
`§Mann-Whitney U test.
`
`treatment. Eighteen of the 47 fully
`Clinical results of
`evaluable patients (38%) showed an erythroid response to
`treatment. Ten patients had a CR and eight a PR (Table 2). All
`nonresponders were exposed to the highest epo dose. Responses
`were not correlated to dose/body weight (P ⬎ .5). Figure 1
`shows hemoglobin levels during treatment in patients with a
`CR. The response rates in the different subgroups of MDS were
`20%, 46%, and 37% for RA, RARS, and RAEB, respectively.
`The overall difference in response rate between subgroups was
`not statistically significant (Table 2). Only one response was
`observed in seven patients with 5q-. Forty-eight percent of the
`patients showed a complete neutrophil response to treatment
`(increase in absolute neutrophil count [ANC] to ⱖ6 ⫻ 109/L)
`and 6% and 15%, respectively, showed partial and minor
`reponses. Thirty-one percent of the patients were by definition
`nonresponders to G-CSF; 9% showed a decrease in neutrophil
`counts after treatment and 22% an increase less than 1 ⫻ 109/L.
`Responses were not correlated to dose/body weight (P ⬎ .5).
`All evaluable patients who were nonresponders to G-CSF
`received the highest dose. There were two patients with a minor
`response to G-CSF (ANC after treatment ⬍3 ⫻ 109/L) who
`received only the low and intermediate G-CSF doses, respec-
`tively. Both of these patients showed increased thrombocytope-
`
`Table 2. Erythroid Response to Treatment in 50 Evaluable Patients
`
`MDS Subtype
`
`No.
`
`RA
`RARS
`RAEB
`All patients
`
`10
`13
`27
`50
`
`NR
`
`8
`7
`17
`32
`
`PR
`
`1
`1
`6
`8
`
`CR
`
`1
`5
`4
`10
`
`All R
`
`2
`6
`10
`18
`
`% R
`
`20*
`46*
`37*
`38
`
`Note that three patients (all nonresponders) only were evaluable to
`treatment with epo alone.
`Abbreviations: NR, no response; PR, partial response; CR, complete
`response.
`*No statistically significant differences in response rate (␹2 analysis,
`P⫽ .43).
`
`nia during treatment, as well as an increase of bone marrow
`blasts at the final evaluation. No erythroid responses were seen
`in the group with decreased neutrophil counts after treatment,
`but otherwise the change in ANC was not associated with an
`erythroid response to treatment. Thirteen of 18 patients with an
`erythroid response to treatment received 70,000 U of epo per
`week and five 35,000 U/week. One patient had a PR on the
`lower dose, but improved to a CR when the epo dose was
`increased after the study period. There was no correlation
`between the G-CSF dose and response to treatment; seven,
`three, and eight patients received the low, middle, and high
`dose, respectively.
`There was no significant differences between the two random-
`ization arms, apart from a significantly higher proportion of
`male patients in arm B (Table 1). The response rate was
`identical in the two arms. Nine of 24 patients (38%) responded
`in arm A (6 CR, 3 PR) and 9 of 23 (39%) in arm B (4 CR, 5 PR).
`There was clear evidence of in vivo synergy between G-CSF
`and epo in a proportion of the patients. Only 3 of the 9
`responders in arm B showed any response to epo alone (1 CR, 2
`
`Fig 1. Hemoglobin levels in patients with a CR to treatment.
`Before, before start of treatment; after, at the end of the study period
`(16 weeks in arm A and 18 weeks in arm B); Max, maximum
`hemoglobin level during the maintenance phase.
`
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`

`

`TREATMENT OF ANEMIA IN MDS WITH G-CSF ⫹ EPO
`
`71
`
`PR). An erythroid response induced by the addition of G-CSF
`was thus seen in 6 patients. Time from start of combination
`treatment to response did not differ between the two arms, but
`the study was not designed to analyze signs of early response.
`Morphologic and laboratory parameters. All differences in
`percentages are given as percentage points. Treatment induced
`increase in bone marrow cellularity (⫹7% in
`an overall
`nonresponders (P ⫽ .06) and ⫹9% in responding patients (P ⫽
`.06). The percentage of erythropoietic cells was generally
`reduced, ⫺9% in nonresponding and ⫺10% in responding
`patients (P ⫽ .0009 and .001, respectively). The percentage of
`bone marrow blasts was unchanged in both groups of patients
`(⫺1.3% in responders, P ⫽ .25 and ⫹0.4% in nonresponders,
`P ⫽ .8, Fig 1). Serum ferritin was significantly increased in
`nonresponders (⫹582 µg/L, P ⫽ .0001), but slightly increased
`also in the responding patients (⫹214 µg/L, P ⫽ 0.10). Serum
`epo was increased after treatment in all patients (responders
`⫹1,135 U/L, P ⫽ .22 and nonresponders ⫹867 U/L, P ⫽ .05).
`Mean corpuscular volume (MCV) was slightly increased in
`responding patients (⫹4.2 fL, P ⫽ .07), while no change was
`seen in nonresponding patients (P ⫽ .53). Patients with RARS
`had higher serum soluble transferrin receptor levels (tfr) than
`the other subgroups (P ⫽ .09 with ANOVA for all three groups
`and P ⫽ .05 with t-test comparing RA and RARS). There was
`also a weak inverse correlation (P ⫽ .049) between serum epo
`and serum tfr. Tfr levels were reduced in nonresponding
`patients (⫺936 µg/L, P ⫽ .3), while it was increased in the
`responding population (⫹2,582 µg/L). However, because there
`was a large heterogeneity in the tfr response, this difference was
`not significant (P ⫽ .34). Clonal evolution during treatment was
`observed in three patients in whom posttreatment karyotypic
`analyses were performed. Two patients with normal karyotype
`pretreatment showed 6p deletion and add 18p in a small
`proportion of the cells after treatment. One patient with 5q-
`before treatment showed, in addition, ⫹8 in a few cells after
`treatment.
`Adverse events. General side effects were few. Eight of the
`patients experienced minor flu-like side effects, which in the
`majority of cases, diminished after a couple of weeks. Irritation
`at local injection sites was observed in a few patients. Two
`patients developed increased splenomegaly. One of these had a
`long history of RARS with previous massive transfusion need
`and secondary hemochromatosis. The other had also RARS,
`and in addition to this, alcohol-induced liver cirrhosis and
`secondary splenomegaly. There was no general tendency of
`
`disease progression in the patient group, but three patients
`developed a significant increase in their bone marrow blasts
`(Fig 2).
`The most important side effect was an overall decrease in
`platelet counts (Fig 3). This decrease was most pronounced in
`nonresponding patients (-32 ⫻ 109/L, P ⫽ .004) and was a
`problem in patients with preexisting thrombocytopenia. Four-
`teen of 17 patients with pretreatment platelet counts of ⬍ 100 ⫻
`109/L showed a further decrease in their values after treatment.
`A reduction in platelet counts was also observed in the
`responding group (Fig 3), but this was mainly due to a decrease
`in patients with supranormal platelet levels before treatment.
`Variables associated with a response to treatment. Table 3
`shows continuous variables and Table 4 category variables in
`responding and nonresponding patients. Serum epo showed the
`strongest association with a response to treatment. A cut-off
`level of 500 U/L was more informative than 100 U/L. The
`degree of RBC transfusion need was significantly associated
`with a response to treatment. The response rate in patients with
`ⱖ2 U of RBC transfusions per month was 21.7% compared
`with 50% in those with less than 2 U/month. Three variables
`showed borderline significance; pretreatment platelet counts,
`MCV, and soluble transferrin receptor levels were higher in
`responding patients. The IPSS score showed no correlation with
`response rate. The response rates in the low, intermediate-1, and
`intermediate-2 risk groups were 45%, 32%, and 43%, respec-
`tively. One of the two patients with a high risk score responded
`to treatment.
`Long-term follow up and duration of response. Survival
`and time to progression to acute leukemia were calculated from
`start of treatment. The median time from final diagnosis to start
`of treatment was 6.5 months (range, 1 to 79 months). This
`variable had no association at all with response to treatment
`(P ⬎ .5), response duration (P ⬎ .5), or survival (P ⬎ .5).
`However, the median time from diagnosis to treatment was
`shorter in patients developing AML during or after treatment
`(4.5 v 8.5 months, P ⫽ .03). The median survival time of the 71
`evaluable patients in both studies was 26 months. Four patients
`were not scored according to IPSS due to missing cytogenetic
`data and thus 67 patients were given an IPSS score. Patients
`with a low risk score showed a survival of 68% at 5 years, while
`the median survival of patients with intermediate-1 and interme-
`diate-2 risk score was 27 and 14 months, respectively. There
`were only two patients with a high score. Time to progression to
`AML was measured from start of treatment. Only one patient
`
`Fig 2. Bone marrow blasts (%)
`before start of treatment and at
`the end of the treatment period
`in (A) responding patients and
`(B) nonresponding patients.
`
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`

`72
`
`HELLSTRO¨ M-LINDBERG ET AL
`
`Fig 3. Platelet count (ⴛ109/L)
`before start of treatment and at
`the end of the treatment period in
`(A) responding patients and (B)
`nonresponding patients.
`
`progressed to overt AML during the treatment period, but four
`additional patients developed AML within 2 months from the
`end of the study. Altogether 19 patients (28%) progressed to
`AML during the observation period with a median time from
`start of treatment to progression of 11 months (range, 4 to 31
`months). The frequency of leukemic progression was 12% (2 of
`17) in the low-risk group, 21% (6 of 28) in the intermediate-1
`group, 45% (9 of 20) in the intermediate-2 group, and 100% (2
`of 2) in the high-risk group.
`Twenty patients of altogether 26 responders (8 in the previous
`and 18 in the present study) were given maintenance treatment.
`Three of the responding patients in the first study and three from
`the second study did not enter the maintenance phase. In the
`second study, one patient (PR) showed an increase of bone
`marrow blasts shortly after the first study period and was
`withdrawn from treatment, and two patients did not want to
`continue with the injections. The median time for duration of
`response was 24 months (range, 4 to 60 months) (Fig 4). Six of
`
`Table 3. Continuous Variables in Responding
`and Nonresponding Patients
`
`Variable
`
`Age (yr)
`Disease duration (mo)
`RBC transf. units/mo*
`Hemoglobin level (g/dL)
`MCV (fL)
`ANC count ⫻ 109/L
`Platelet count ⫻ 109/L
`Bone marrow cellularity (%)
`Bone marrow
`erythropoiesis (%)
`Bone marrow blasts (%)
`Serum ferritin (µg/L)
`Serum lactate dehydro-
`genase
`Serum erythropoietin (U/L)
`S. transferrin receptor
`(ng/mL)
`
`Responding
`Patients,
`n ⫽ 18
`
`Nonresponding
`Patients,
`n ⫽ 29
`
`PValue
`
`70 ⫾ 10
`10 ⫾ 11
`2.0 ⫾ 0.94
`88.6 ⫾ 7.1
`90.4 ⫾ 17.5
`1.9 ⫾ 1.5
`270 ⫾ 190
`68 ⫾ 21
`
`68 ⫾ 10
`9 ⫾ 10
`3.0 ⫾ 1.4
`85.5 ⫾ 13.6
`98.7 ⫾ 12
`2.3 ⫾ 1.9
`182 ⫾ 148
`78 ⫾ 22
`
`37 ⫾ 16
`6.9 ⫾ 5.6
`515 ⫾ 284
`
`31 ⫾ 20
`6.4 ⫾ 4.6
`813 ⫾ 912
`
`.6
`.74
`.05
`.37
`.09
`.46
`.07
`.13
`
`.3
`.73
`.18
`
`7.0 ⫾ 1.8
`247 ⫾ 318
`
`7.5 ⫾ 2.8
`1,293 ⫾ 1,531
`
`.56
`.008
`
`8,667 ⫾ 6,972 5,529 ⫾ 4,632
`
`.07
`
`*Transfusion need in the 35 patients with pretreatment RBC transfu-
`sions.
`
`nine patients with RARS had a response duration of ⱖ18
`months. All patients showing a response duration of ⱖ12
`months had either a low or an intermediate-1 IPSS, but there
`was no difference between these two groups.
`
`DISCUSSION
`
`Treatment of anemia in MDS has so far been relatively
`discouraging. Epo alone shows an overall response rate of 20%,
`with only around 10% responses in patients with preexisting
`transfusion need. Other treatment alternatives, such as low-dose
`cytosine arabinoside has shown an erythroid response rate of
`30% or less, but with more side effects than the cytokines.21,22
`The erythroid response rate in our study, 38%, seems to be
`relatively high in comparison with other treatment alternatives
`for anemia in MDS and deserves further consideration.
`The present study confirmed the response rate, 38%, from the
`first Scandinavian study. These results are in accordance with
`another relatively large phase II study17 using the same drugs
`and also with a study using G-CSF and epo in combination with
`all-trans–retinoic acid (ATRA).23 The reason why two smaller
`studies have failed to show similar results is not clear, but might
`be due to the lower epo dose used in these two studies and
`maybe also the very high G-CSF dose used in the Japanese
`study.24,25
`The second aim of the study was to investigate whether
`G-CSF treatment was needed as a primer before the addition of
`epo to obtain an optimal erythroid effect. This was appearantly
`not the case, as response rates in the two randomization arms
`were identical. The consequence of this result is that treatment
`with G-CSF and epo are started simultaneously in the ongoing
`third Scandinavian trial.
`Third, the study aimed at showing evidence for in vivo
`synergy between G-CSF and epo. The response pattern in arm
`B, starting with epo, showed that six of nine responders to
`combination treatment did not show any response to epo alone.
`Most responses to epo have been reported to occur within the
`first 8 weeks of treatment,11,26,27 and it is therefore not likely that
`all of these six patients would have developed a late response to
`epo as monotherapy. Moreover, some patients who maintained
`their transfusion need during the epo phase developed a
`pronounced increase in hemoglobin (hemoglobin ⱖ150 g/L)
`
`DR. REDDY’S LABS., INC. EX. 1033 PAGE 5
`
`

`

`TREATMENT OF ANEMIA IN MDS WITH G-CSF ⫹ EPO
`
`73
`
`Table 4. Category Variables in Responding and Nonresponding Patients
`
`Variable
`
`Favorable Group
`
`Response Rate (%)
`
`Unfavorable Group
`
`Response Rate (%)
`
`PValue
`
`Sex (M/F)*
`Karyotype (N/A)†
`Pretreatment transfusions (yes/no)
`Pretreatment transfusions U/month
`Serum epo ⬍500 U/L or ⱖ500 U/L
`Serum epo ⬍100 U/L or ⱖ100 U/L
`
`*Male/female.
`†Normal karyotype/abnormal karyotype.
`
`Female
`A
`no
`⬍2
`⬍500
`⬍100
`
`after the addition of G-CSF (Fig 1). Another argument for a true
`synergistic effect of the drugs was the high response rate, 46%,
`in patients with RARS, as this MDS subgroup has shown a poor
`response to epo alone.12 Recently, additional evidence for a
`synergistic effect was published. Approximately 50% of the
`responders to G-CSF ⫹ epo in the American study17 lost their
`erythroid response when G-CSF was withdrawn. In our study,
`the synergistic effect seemed to be most pronounced in patients
`with RARS, even if patients with RAEB also seemed to respond
`relatively well to the combination (37%). The response in
`patients with RA was not as good, (20%), but the size of the RA
`group (10 patients) was too small to allow conclusions about the
`effect of the combination compared with epo alone. Only one of
`the seven patients with 5q- aberration showed a response to
`treatment. Four of these patients were found in the RA
`subgroup, which might explain the response rate in this group.
`The reason for the poor response rate in the 5q- group is unclear.
`Serum epo levels and pretreatment
`transfusion need were
`comparable between patients with and without 5q-, which
`suggests that the poor response might be explained by the
`specific biology of this MDS subtype.
`The fourth aim of the trial was to study clinical outcome and
`long-term efficacy. The median response duration of 24 months
`was comparable and even better than that described in the
`American study.17 Again,
`the most pronounced long-term
`efficacy was found in the RARS group with six of nine patients
`responding for more than 18 months. The observation that there
`are responses with a duration of more than 5 years is promising.
`Unfortunately, there are no data on long-term efficacy with epo
`alone, so that comparison can at present not be done. All
`patients, except one (data not shown), needed continuous
`maintenance treatment to maintain their response. It was also
`
`Fig 4. Duration of response in the 20 patients with primary
`response who entered maintenance phase. Median duration of
`response 24 months.
`
`38
`41
`53.3
`50
`48.3
`50
`
`Male
`N
`yes
`ⱖ2
`ⱖ500
`ⱖ100
`
`35
`38
`28.6
`21.7
`15.8
`29.4
`
`.93
`.81
`.09
`.04
`.02
`.18
`
`found that a relatively high epo dose (ⱖ50,000 U/wk) was
`needed for the majority of the responding patients, but also that
`a minority of the responders managed to lower their epo dose to
`30,000 U/wk. However, dose reduction and titration of minimal
`effective doses were not a part of the protocol, but is included in
`the ongoing Scandinavian trial.
`A recently published joint study by the Scandinavian and
`American Study Groups28 used multivariate analysis to study
`predictors of response in a larger patient sample (including 34
`of the patients in the present study). Multivariate analysis was
`not repeated in the present study, but it was evident that the two
`predictors of response observed in the joint study, pretreatment
`serum epo levels and transfusion need, were significant univari-
`ate variables also in the present study. The most interesting
`additional finding was probably the higher median MCV value
`in responding patients and the fact that MCV actually increased
`during treatment
`in these patients. Macrocytosis has been
`defined as a dysplastic sign in MDS29 and the reason for an
`increase in responding patients is unclear. A previous study has
`shown that an erythroid response to G-CSF ⫹ epo is paralleled
`by both a reduced number of erythroid cells and a reduced
`number of apoptotic cells in the bone marrow, but how this is
`linked to the MCV findings remains to be investigated.30
`Another finding was that pretreatment soluble serum tr