Sickle cell disease Hydroxyurea treatment for sickle cell disease - Nature

Bone Marrow Transplantation (2004) 33, 799–803 & 2004 Nature Publishing Group All rights reserved 0268-3369/04 $25.00

www.nature.com/bmt

Sickle cell disease Hydroxyurea treatment for sickle cell disease: impact on haematopoietic stem cell transplantation’s outcome C Brachet1, N Azzi1, A Demulder2, C Devalck1, A Gourdin1, B Gulbis3, A Klein1, PQ Le1, M Loop1, E Sariban1 and A Ferster1 1 Haemato-Oncology Unit, Hoˆpital Universitaire des Enfants – ULB, Brussels, Belgium; 2Laboratory of Haematology, Hoˆpital Universitaire Brugmann – ULB, Brussels, Belgium; and 3Laboratory of Chemistry, Hoˆpital Universitaire Erasme – ULB, Brussels, Belgium

Summary: Since 1988, 24 children have undergone haematopoietic stem cell transplantation (HSCT) for severe sickle cell disease (SCD) in our unit, 13 being grafted after having been exposed to hydroxyurea (HU) to control SCDrelated complications. Different pre-transplant conditioning regimens were given over time: Bu14/Cy200 in six patients (group 1), Bu16/Cy200/antithymocyte globulin (ATG) in five (group 2) and Bu16/Cy200/ATG with HU prior to HSCT in 13 (group 3). The aim of this study is to compare the outcome after HSCT of these groups of patients, which differ according to pre-transplant drug exposure. Overall, 20 of the 24 transplanted children had stable engraftment and have remained free of SCDrelated symptoms after HSCT; 19 of them are currently alive and cured of SCD. In group 1 (HU, ATG), we observed one unexplainable late death, one absent engraftment, one late rejection and one mixed stable chimerism. In group 2 (HU, ATG þ ), we observed the absence of engraftment in two patients and one early rejection. In group 3 (HU þ , ATG þ ), we observed no cases of either absent engraftment, mixed stable chimerism or late rejection. In our experience, pre-transplant treatment with HU seems to be associated with a lower incidence of rejection/absent engraftment in severe SCD patients. These results need to be confirmed with a larger number of patients. Bone Marrow Transplantation (2004) 33, 799–803. doi:10.1038/sj.bmt.1704443 Published online 9 February 2004 Keywords: sickle cell disease; transplantation; hydroxyurea Sickle cell disease (SCD) patients are at risk of high mortality and premature death. Although their life expectancy has increased in countries where adequate

Correspondence: Dr A Ferster, Hoˆpital Universitaire des Enfants, Haemato-Oncology Unit, Av. J.J. Crocq, 15, Brussels 1020, Belgium; E-mail: [email protected] Received 29 July 2003; accepted 3 November 2003 Published online 9 February 2004

support is routinely available,1 some patients with SCD still have a poor quality of life and/or develop complications associated with an increased risk of chronic organ damage.2–4 Bone marrow transplantation (BMT) for SCD was successfully developed in the middle of the 1980s5 and remains the only curative approach available so far. Despite increasing expertise, haematopoietic stem cell transplantation (HSCT) remains a procedure that carries the risks of graft-versus-host disease (GVHD), impaired fertility and transplant-related mortality. Up to now, only a limited number of series of HSCT in SCD patients have been published,6–8 and new transplantation approaches are currently being developed such as non-myeloablative conditioning9–12 or cord blood transplantation.13 Although hydroxyurea (HU) treatment for SCD children and young adults gives overall encouraging results14–23 and reduces mortality in adults with frequent painful episodes,24 we have pursued our HSCT programme for selected patients with a suitable family donor. We review here the outcome of 24 consecutive HSCT for SCD carried out in our unit (the Haemato-Oncology Unit of the Hoˆpital Universitaire des Enfants, Brussels) since 1988. The aim of this study is to assess retrospectively the results of the transplant according to the pre-transplant SCD complications, the pre-transplant management and the conditioning regimen. Starting 1994, symptomatic SCD patients were exposed to HU. Thus, it was also of interest to compare the outcome of grafted patients on the basis of prior HU exposure.

Patients, donors and methods In all, 24 children with SCD have received a HSCT in our unit between 1988 and 2002 (23 SCA, 1SDPunjab). Informed consent was obtained from the patients and/or their parents. All patients and transplant details were retrospectively collected from case notes.

Patients’ clinical characteristics All patients were transplanted because of the severity of the disease: 17 patients had been admitted to hospital for vasoocclusive crises (VOC) more than twice a year, six had had

Transplantation for sickle cell disease C Brachet et al

800

at least one episode of acute chest syndrome, five had had at least one stroke/seizure, four had alloimmunization secondary to blood transfusions. The countries of origin were the Democratic Republic of Congo (19 patients), Angola (one patient), Cameroon (one patient), Central African Republic (one patient), Nigeria (one patient) and Morocco (one patient). Age at the time of transplant ranged from 2.25 to 14.16 years (median 7.20 years). There were nine females and 15 males. Follow-up period ranges from 1 to 15 years (median 8.7 years). The pre-HSCT neurological work-up included EEG, CNS imaging by either CT-SCAN or MRI and, since 2000, transcranial doppler echography (TCD). Five patients had a pre-HSCT history of seizures or strokes and five additional patients had abnormalities in their pre-HSCT neurological work-up defined as MRI/magnetic resonance angiography showing small vessel or large vessel stroke or as blood velocity in the median cerebral artery 4200 cm/s at TCD.

Pre-HSCT SCD management Before HSCT, eight patients had received more than three blood transfusions and 13 patients had been treated with HU for a period of time ranging from 0.6 to 4 years (median 2.16 years). Hydryoxyurea (20–35 mg/kg/day) was given until the start of conditioning regimen.

Conditioning regimen The conditioning regimen consisted of the standard combination of busulphan (14 mg/kg) and cyclophosphamide (200 mg/kg) (Bu14/Cy200) in the first six patients; Bu16/Cy200/antithymocyte globulins (ATGs) (Fresenius) 80 mg/kg in the nine next patients (since November 1991) and Bu16/Cy200/ATG (Merieux) 12–20 mg/kg in the last nine patients (since July 2000). We divided the patients into three groups according to their pre-HSCT management and conditioning regimen. The clinical characteristics of the three groups are shown in Table 1. Six patients received neither ATG during conditioning nor HU prior to HSCT (HU, ATG, group 1). Five patients received ATG in the conditioning regimen but no HU prior to HSCT (HU, ATG þ , group 2). In all, 13 patients with ATG in the conditioning regimen received HU (HU þ , ATG þ , group 3).

thereafter) together with a short course of methotrexate (MTX, 12 mg/m2/day1, 10 mg/m2/day 3 and 6). Acute GVHD was treated with steroids as first-line therapy. Chronic GVHD was treated with steroids and azathioprine.

Anticonvulsant prophylaxis Following the observation of a high incidence of convulsive episodes post transplantation,25 the last 10 patients received clonazepam as an anticonvulsant prophylaxis from –12 to þ 100 days post transplant. Two patients received the same prophylaxis but for a shorter period (8 and 50 days post transplant). In addition, special care was taken to maintain the platelet count above 50 000/ml, the blood pressure, the plasma CsA and magnesium levels inside the normal ranges.

Antimicrobial prophylaxis Prophylaxis of infections consisted in gut decontamination, acyclovir as well as trimethoprim/sulphamethoxazol (after PMN recovery) and immunoglobulin infusions (every 3 weeks) for 6 months post transplantation. Broad-spectrum antibiotics were given in the event of fever (along with amphotericin if fever persisted or if there was a suggested fungal infection). All patients were nursed in air-filtered rooms with reverse barrier nursing. After immune reconstitution, active immunizations with pertussis, polio, diphtheria, tetanus, influenza, pneumococcus vaccines were carried out.

Chimerism studies Chimerism studies were performed by at least one of the following methods: (1) cytogenetics when there was a sex discrepancy between donor and receiver, (2) residual HbS levels when the donor had a A/A Hb genotype and (3) studies of variable numbers of tandem repeats in DNA for the others.

Statistical analysis The Mann–Whitney U-test was used to compare groups. All cited P-values are two-sided.

Results Donors and HSC source Donors were siblings aged 0.66–27 years (median 8.75 years) at the time of transplant. In nine cases, donors and receivers were matched for sex. All but one patient received HLA-genoidentical transplant; one patient received a one antigen mismatched transplant (1Ag MMBMT). The source of stem cells consisted of bone marrow for 23 patients and peripheral blood (PBSCT) for one patient.

GVHD prophylaxis To prevent GVHD, all the patients received cyclosporin A (CsA, 5 mg/kg/day for 6 months and progressively reduced Bone Marrow Transplantation

Before HSCT, the severity of SCD was similar in the three groups except for the lower number of blood transfusions in group 3, probably as a result of chronic HU treatment that was proven to reduce the need of transfusion in children and adults14,15 (Table 1). Group 3 patients had significant lower preconditioning absolute neutrophil count (ANC) than groups 1 and 2 (Po0.05), which again could result from chronic HU treatment. Mean age at HSCT is 7 years (range 1.8–14.2) in groups 1 and 2 and 7.4 years (3.8– 12.3) in group 3. Engraftment was observed in 21 patients, whereas three patients never presented any sign of engraftment. After engraftment, we observed one early rejection (31 days)


801 Table 1 Clinical and BMT-related characteristics of 24 SCD children who underwent HSCT from HLA-identical related donors in our unit from 1988 to 2002 Group 1

Group 2

Group 3

Total

Number of patients Median follow-up (years) (range)

6 13.2 (12–15)

5 10.1 (9–11)

13 3 (1–9)

24 8.7 (1–15)

Country of origin Democratic Republic of Congo Other African countries

4 2

5 0

Age (years) (median) Receiver Donor

5.5 10

11 11.8

7.4 6

7.2 8.8

Sex Receiver (R) M:F Donor (D) M:F Sex matching D/R

3:3 4:2 3

2:3 3:2 2

10:3 6:7 4

15:9 13:11 9

Severity of SCD 42 VOC/year Seizures/strokes Acute chest syndrome Alloimmunization

4 1 1 1

3 3 2 2

10 1 3 1

17 5 6 4

3 0 12.9 (4.0–17.4)

3 0 6.7 (4.3–8.7)

Conditioning regimen Bu14/Cy200 Bu16/Cy200/ATG

6 0

0 5

0 13

6 18

HSC source HLA genoidentical 1 Ag mismatch Bone marrow Peripheral blood

5 1 6 0

5 0 5 0

13 0 12 1

23 1 23 1

Clonazepam prophylaxis

0

0

12

12

Pre-HSCT SCD management 43 blood transfusions HU mean duration (years) ANC before conditioning ( 109/l) (median) (range)

10 3

2 2.16 4.3 (1.8–8.8)

19 5

8 — 5.9 (1.8–17.4)

Group 1 – patients received neither HU prior to HSCT nor ATG during the conditioning (HU, ATG). Group 2 – patients have not been treated with HU prior to HSCT but received ATG during the conditioning (HU, ATG +). Group 3 – patients received both HU prior to HSCT and ATG during the conditioning (HU+, ATG+).

rescued by a donor leucocyte infusion, one late rejection (14 months) and one stable mixed chimerism. One patient unexplainably died at home 6 years post transplant at the age of 16 years. He had a complete donor chimerism with a normal level of Hb and full immune reconstitution, had recovered from cGVHD and was without any medical treatment at the time of his death. Unfortunately, post-mortem examination and analysis could not reveal the cause of his death. Overall, 23 of the 24 SCD children who received HSCT in our unit are currently alive. We observed grade III acute GVHD in three patients, grade II aGVHD in three patients and chronic nonextensive GVHD in seven patients (two de novo). cGVHD required 2 years of immunosuppressive therapy in four children, which has now been stopped in all but one patient. Seizures occurred in eight patients from 10 days to 13 months post HSCT: three early seizures and five late seizures. After 1994 (introduction of prophylactic

clonazepam), no seizure complicated the early post HSCT period (o100 days post HSCT) but late seizures occurred (6–13 months) while still on CsA. All the three patients with early seizures had CNS infarcts on brain imaging prior to HSCT. Among the five patients with late seizures, one had an abnormal MRI and EEG, one a preHSCT seizure history and two an abnormal pre-HSCT TCD. Fever occurred in all patients in the early post HSCT period (within 100 day post HSCT). In 11 of these febrile episodes, we documented an infection (six Gram-positive sepsis, two Escherichia coli urinary tract infections, three enteritis, one CMV reactivation with interstitial lung disease). Seven girls and four boys are assessable for gonadal function. All but one of the girls have ovarian insufficiency with very high levels of circulating gonadotrophins. The boys have moderately elevated circulating gonadotrophins and moderately low levels of circulating testosterone. Their final height is in the normal range. Bone Marrow Transplantation


802

As seen in Table 2, we assessed the outcome of HSCT according to pre-HSCT management with groups 1–3 being described above. In group 1 (HU, ATG), we observed one unexplainable late death, one absent engraftment, one late rejection 14 months post HSCT when CsA had been discontinued for 2 months and one mixed stable chimerism 15 months post HSCT. In group 2 (HU, ATG þ ), we observed the absence of engraftment in two patients and one early rejection 31 days post HSCT that was controlled by steroids and donor lymphocytes infusion (DLI). In group 3 (HU þ , ATG þ ), we observed no cases of either absent engraftment, mixed stable chimerism or late rejection. With respect to the complications of HSCT according to pre-HSCT management, group 1 included one de novo cGVHD and one early seizure; group 2, one aGVHD followed by cGVHD and one de novo cGVHD; group 3, five aGVHD, four cGVHD cases were observed and five late seizures were observed. There is a statistically significant association between engraftment and (1) HSCT performed after 1995 and (2) HU treatment prior to HSCT. With respect to GVHD occurrence, donors’ age is the only statistically significant associated factor: a lower cGVHD occurrence is seen with young donors (o10 years old). ANC before conditioning were different (Po0.05) between groups 1 and 2 and group 3. (Table 1). Overall, 20 of 24 transplanted children have had stable engraftment and have remained free of SCD-related symptoms after HSCT. Of these, 19 of them are alive and cured of SCD with normal activity and attendance to school or work. Of these, three patients have required immunosuppression for chronic GVHD (nonextensive) for 2 years post HSCT.

Discussion and conclusion Chronic treatment with HU reduces the frequency/severity of VOC, ACS and strokes in some SCD patients14,16,19 and Table 2 Survival, engraftment and complications in 24 SCD children who underwent HSCT from HLA-identical related donors in our unit from 1988 to 2002 Group 1 Group 2 Group 3 Number of patients Stable engraftment Absent engraftment Early rejection Late rejection Death

6 4a 1 0 1 1

5 3 2 1b 0 0

13 13 0 0 0 0

Seizures Early Late aGVHD

1 0 0

2 0 1

0 5 5

CGVHD Total Require immunosuppression (p2years) Current immunosuppression

1 1 0

2 0 0

4 3 1

a

One patient with stable mixed chimerism. Full donor chimerism after DLI.

b

Bone Marrow Transplantation

has recently been shown to reduce mortality in adult patients.24 Along with the benefits of HU treatment, accurate data on the outcome of HSCT is necessary to enable patients with an HLA-identical sib and their caregivers to decide whether to perform HSCT or not.26 We therefore analysed the data of 24 allogeneic HSCT performed in SCD children in our institution. The overall survival is 96% and 19 of the 23 survivors remain free of SCD-related symptoms and should be regarded as cured from SCD after a median follow-up of 8.7 years. Of interest, our results clearly have improved with time since neither death nor graft rejection occurred since 1995. Given the relatively small number and heterogeneity of the patients, the factors that influence the results are probably multiple. Nevertheless, we do not think that the improvement of the results derives from patient selection bias as both SCD-related complications and median age at HSCT are similar between the transplantation periods considered (1988–1995, 1995–2002). Our criteria for eligibility for transplantation have been unchanged since 1988: (1) recurrent ACS and/or (2) stroke and/or (3) more than 2 VOC/year and/or (4) alloimmunization and/or (5) osteonecrosis, with a suitable family donor. Retrospectively all our patients but one fulfilled the Paediatric Haematology Forum Criteria.27 Patients free of SCD-related symptoms while on HU but fulfilling inclusion criteria before starting HU remain eligible for HSCT in our institution. This attitude is based on the facts that the very long-term benefits and hazards of HU are unknown, that transplantation gives better results in younger patients and that the increasing age of donors is associated with an increase in GVHD occurrence. The conditioning regimen has also changed over time but in our single centre experience, the increase of busulphan dose and the introduction of immunotherapy have not improved the results (group 1 compared to group 2). This contrasts with the experience of the French Group, which did not experience graft rejection after conditioning with ATG.6 The improvement of our results coincides with the start of chronic HU treatment of SCD. This observation could be accounted for by the myelosuppressive effect of HU as attested by lower ANC before the start of conditioning. It is well known that patients with chronic haemolytic anaemia such as SCD have myeloid and erythroid hyperplasia, which could in turn hinder engraftment. In thalassaemia, the results of HSCT after conventional conditioning in class 3 patients and the results of second HSCT after graft failure are poor, whereas preconditioning with cytoreductive-immunosuppressive drugs including HU seems to improve engraftment rate.28 The need for an optimal control of medullary hypercellularity is also illustrated by the disappointing results of the nonmyeloablative conditioning protocols in SCD patients, suggesting that it remains of importance to ‘create space in the marrow’ for stable engraftment to take place in this kind of patient.11 In conclusion, we provide here a review of our single centre experience of HSCT for SCD in 24 children. Furthermore, our data are the first to suggest a possible positive impact of chronic HU treatment prior to HSCT for


803

SCD on stable engraftment and persistence of full donor chimerism. These preliminary results should be confirmed using a larger cohort of patients. Finally, HSCT has the advantage of a clear improvement in the quality of life despite the occurrence of chronic GVHD that was not, in our experience, debilitating as immunosuppression could be stopped after 2 years in all patients. As a whole, these results constitute an important element for consideration when patients, parents and careproviders need to make an informed choice between conservative treatment and HSCT in patients with a suitable family donor.

Acknowledgements This work was supported by grants from the Fonds National des Recherches Scientifiques (FNRS) no. 7.4525.98; no. 7.4503.00; no. 7.4501.02.

References 1 Platt OS, Brambilla DJ, Rosse WF et al. Mortality in sickle cell disease: life expectancy and risk factors for early death. N Engl J Med 1994; 330: 1639–1644. 2 Ohene-Frempong K, Weiner SJ, Sleeper LA et al. Cerebrovascular accidents in sickle cell disease: rates and risk factors. Blood 1998; 91: 288–294. 3 Platt OS, Thorington BD, Brambilla DJ et al. Pain in sickle cell disease: rates and risk factors for early death. N Engl J Med 1991; 325: 11–16. 4 Vichinsky EP, Neumayr LD, Earles AN et al. Causes and outcomes of the acute chest syndrome in sickle cell disease. N Engl J Med 2000; 342: 1855–1865. 5 Vermylen C, Fernandez-Robles E, Ninane J, Cornu G. Bone marrow transplantation in five children with sickle cell anaemia. Lancet 1988; i: 1427–1428. 6 Bernaudin F, Vernant JP, Vilmer E et al. Results of myeloblative allogenic stem cell transplant (SCT) for severe sickle cell disease (SCD) in France. Blood 2002; 11 (Suppl. 1a): 5a (abstr. 4). 7 Vermylen C, Cornu G, Ferster A et al. Haematopoı¨ etic stem cell transplantation for sickle cell anaemia: the first 50 patients transplanted in Belgium. Bone Marrow Transplant 1998; 22: 1–6. 8 Walters MC, Storb R, Patience M et al. Impact of bone marrow transplantation for symptomatic sickle cell disease: an interim report. Multicenter investigation of bone marrow transplantation for sickle cell disease. Blood 2000; 15: 1918–1924. 9 Amado RG, Schiller GJ. Nonmyeloablative approaches to the treatment of sickle hemoglobinopathies. Semin Oncol 2000; 27: 82–89. 10 Fixler J, Vichinsky E, Walters MC. Stem cell transplantation for sickle cell disease: can we reduce the toxicity? Pediatr Pathol Mol Med 2001; 20: 73–86.

11 Iannone F, Casella JF, Fuchs EJ et al. Failure of a minimally toxic non-myeloblative regimen to establish stable donor engraftment after transplantation for sickle cell anemia and b-thalassemia. Blood 2002; 11 (Suppl. 1a): 46a (abstr. 161). 12 Walters MC, Nienhuis AW, Vichinsky E. Novel therapeutic approaches in sickle cell disease. Hematology 2002; 1: 10–34. 13 Locatelli F, Rocha V, Reed W et al. Related umbilical cord blood transplantation in patients with thalassemia and sickle cell disease. Blood 2003; 15: 2137–2143. 14 Charache S, Terrin ML, Moore RD et al. Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. N Engl J Med 1995; 332: 1317–1322. 15 Charache S, Barton FB, Moore et al. Hydroxyurea in sickle cell anemia: clinical utility of a myelosuppressive ‘switching’ agent. Medicine 1996; 75: 300–326. 16 De Montalambert M, Belloy M, Bernaudin F et al. Three year follow-up of hydroxyurea treatment in severely ill children with sickle cell disease. The French Study Group on Sickle Cell Disease. J Pediatr Hematol Oncol 1997; 19: 313–318. 17 De Montalembert M, Begue P, Bernaudin F et al. Preliminary report of a toxicity study of hydroxyurea in sickle cell disease. French Study Group on Sickle Cell disease. Arch Dis Child 1999; 81: 437–439. 18 Ferster A, Vermylen C, Cornu G et al. Hydroxyurea for treatment of severe sickle cell anemia: a pediatric clinical trial. Blood 1996; 88: 1960–1964. 19 Ferster A, Tahriri P, Vermylen C et al. Five years of experience with hydroxyurea in children and young adults with sickle cell disease. Blood 2001; 97: 3628–3632. 20 Hoppe C, Vichinsky E, Quirolo K et al. Use of hydroxyurea in children ages 2–5 years with sickle cell disease. J Pediatr Hematol Oncol 2000; 22: 330–334. 21 Jayabose S, Tugal O, Sandoval C et al. Clinical and hematologic effects of hydroxyurea in children with sickle cell anemia. J Pediatr 1996; 129: 559–565. 22 Kinney TR, Helms RW, O’Branski EE et al. Safety of hydroxyurea in children with sickle cell anemia: results of the HUG-KIDS study, a phase I/II trial. Pediatric Hydroxyrea Group. Blood 1999; 94: 1550–1554. 23 Ohene-Frempong K, Smith-Whitley K. Use of hydroxyurea in children with sickle cell disease: what comes next? Semin Hematol 1997; 34 (Suppl. 3): 30–41. 24 Steinberg MH, Barton F, Castro O et al. Effect of hydroxyurea on mortality and morbidity in adult sickle cell anemia. JAMA 2003; 289: 1645–1651. 25 Van Besien K, Koshy M, Anderson-Shaw L et al. Allogeneic stem cell transplantation for sickle cell disease. A study of patients’ decisions. Blood 2001; 28: 545–549. 26 Walters MC, Sullivan KM, Bernaudin F et al. Neurologic complications after allogeneic marrow transplantation for sickle cell anemia. Blood 1995; 85: 879–884. 27 Davies SC. Bone marrow transplant for sickle cell disease – the dilemma [review]. Blood 1993; 7: 4–9. 28 Gaziev D, Polchi P, Lucarelli G et al. Second marrow transplants for graft failure in patients with thalassemia. Bone Marrow Transplant 1999; 24: 1299–1306.

Bone Marrow Transplantation