Low transplant-related mortality in patients receiving ... - Nature

Bone Marrow Transplantation, (1999) 23, 753–758  1999 Stockton Press All rights reserved 0268–3369/99 $12.00 http://www.stockton-press.co.uk/bmt

Low transplant-related mortality in patients receiving unrelated donor marrow grafts for leukemia P Kalhs1, S Brugger1, E Reiter1, F Keil1, G Fischer2, A Schulenburg1, W Rabitsch1, A Rosenmayr2, K Dieckmann3, M Kurz4, I Schwarzinger5, B Volc-Platzer6, C Mannhalter5, K Lechner7 and HT Greinix1 Departments of 1Medicine I, Bone Marrow Transplantation Unit; 2Blood Group Serology; 3Radiotherapy and Radiobiology; 4 Transfusion Medicine; 5Laboratory Medicine; 6Division of Immunology, Allergy and Infectious Diseases, Department of Dermatology; and 7Department of Medicine I, Division of Hematology and Hemostaseology, University of Vienna, Austria

Summary: Transplantation with unrelated donor (UD) marrow has been shown to potentially cure patients with leukemia. Between January 1991 and April 1998, 54 patients with leukemia have received an UD BMT at our institution. Five patients received their UD BMT as a second transplant after a preceding autologous or syngeneic BMT and were excluded from further analysis. Forty-nine patients with leukemia (acute leukemia n ⴝ 26; CML n ⴝ 23) and a median age of 36 years (range 19–51) were analyzed. For conditioning, all patients received a combination of fractionated TBI and CY. GVHD prophylaxis consisted of MTX and CsA in all patients. As of 30 April 1998, 27 of 49 (55%) patients survive after a median observation time of 18 months. The probability of overall survival for standard risk and high risk patients is 54% and 31% (P ⴝ 0.05). Probability of transplant-related mortality (TRM) is 27%, 24% in standard risk and 31% in high risk patients (P ⴝ 0.44). Patients younger than 40 years (n ⴝ 33) had a similar TRM as patients 40 years and older (n ⴝ 16). The probability of relapse is 41% for the whole group, 29% for standard risk and 55% for high risk pts (P ⬍ 0.05). Our data confirm that UD BMT is an effective treatment for patients with leukemia. TRM is almost similar to related sibling BMT, most probably due to improvements in HLA typing technology, conditioning regimen and supportive patient care. Keywords: UD BMT; transplant-related mortality; leukemia

Allogeneic BMT is an established treatment modality for a variety of hematological malignancies and aplastic anemia.1–5 However, an HLA-matched related donor is only available for 25–30% of potential recipients. For patients lacking related donors, the use of an unrelated donor (UD) has become a suitable alternative. Due to increased efforts Correspondence: Dr P Kalhs, BMT Unit, I Med Dept, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria Received 14 July 1998; accepted 20 November 1998

of worldwide registries the probability of finding an HLAA, HLA-B, HLA-DR matched UD has increased from less than 10% in 1987 to 64% in 1995 within the National Marrow Donor Program.6 Compared with HLA genotypically identical related BMT, unrelated BMT has been associated with a higher mortality rate,7–11 mostly due to an increased incidence and severity of GVHD and associated infectious complications. Total body irradiation (TBI) is included in the vast majority of conditioning regimens published to be used in UD transplants, but there are also reports suggesting that chemotherapy-only regimens may be used with success.12–14 Here, we report the clinical outcome of 49 consecutive patients with leukemia given UD marrow grafts at our institution between January 1991 and March 1998. Our data confirm the high efficacy of UD BMT in these patients with a transplant-related mortality rate almost identical to related sibling transplants, most probably due to improvements in donor typing methods, conditioning regimen and supportive patient care.

Patients and methods Patients Between January 1991 and March 1998, 54 patients with leukemia received a UD transplant at our center. Five patients received their UD transplant as a second BMT after a preceding autologous or syngeneic BMT and were excluded from further analysis. Patient and donor characteristics of the 49 patients analyzed are shown in Table 1. Patients were categorized as standard risk if they had AML in CR, ALL in CR or CML in first chronic phase. They were categorized as high risk if they had AML or ALL in relapse or primary disease refractory to standard chemotherapy, CML in second or later chronic phase, accelerated phase or blast crisis. Data on patients with acute leukemia (AL) have in part been published previously.15 Written informed consent was obtained from all patients. Data were analyzed as of 30 April 1998.

Low transplant-related mortality after URD BMT P Kalhs et al

754

Table 1

Patient characteristics

Number of patients Median age (range), years Sex (female/male) Disease/Stage AML CR2 relapse refractory ALL CR2 or later relapse refractory CML CP1 ⬎CP1 AP BC Conditioning regimen fTBI (13.2 Gy) ⫹ CY fTBI (12 Gy) ⫹ CY GVHD prophylaxis MTX ⫹ CsA MP ⫹ CsA Marrow donors Serology and MLC match Serology and RFLP match Serology and LBT match Serology and LBT mismatch Donor/Recipient mismatch HLA-A n ⫽ 2 -B n ⫽ 1 -C n ⫽ 5 -DRB1 n ⫽ 1 -DRB3 n ⫽ 3 -DQ n ⫽ 1 ABO incompatibility Sex mismatch Donor sex (F/M)

49 36 (19–51) 20/29 8 1 9 4 1 3 14 3 5 1 45 4 48 1 3 1 32 13

(n ⫽ 15); Swedish National Registry, Stockholm, Sweden (n ⫽ 2); Anthony Nolan Bone Marrow Trust, London, UK (n ⫽ 9); Italian Bone Marrow Donor Registry, Genova, Italy (n ⫽ 2); Belgium Marrow Donor Program, Brussels, Belgium (n ⫽ 2); Australian Bone Marrow Donor Registry, Sydney, Australia (n ⫽ 1); and Austrian Bone Marrow Donor Registry, Vienna, Austria (n ⫽ 5). HLA typing for all patients and donors was confirmed by the University Hospital of Vienna Department of Blood Group Serology. The median time between initiation of the donor search and identification of a compatible donor was 4 months. Transplantation procedure Patients transplanted up to December 1993 received TBI (total dose 12 Gy, given in eight fractions over 4 days) plus CY 60 mg/kg body weight for 2 consecutive days (total dose 120 mg/kg). Patients transplanted after 1993 received TBI to a total dose of 13.2 Gy given in eight fractions over 4 days plus CY as described. Until December 1996 all patients received central nervous system (CNS) prophylaxis with 12 mg MTX intrathecally on day ⫺6. Thereafter, only patients who had a history of CNS leukemia received intrathecal MTX.19 Patients with ALL (n ⫽ 8) received recombinant human G-CSF (Neupogen, 5 ␮g/kg body weight) starting 1 day after BMT until hematopoietic engraftment. Engraftment

30/49 (61%) 17/49 (37%) 20/29

CP ⫽ chronic phase; AP ⫽ accelerated phase; BC ⫽ blast crisis; MP ⫽ methylprednisolone; LBT ⫽ ligation-based typing.

HLA typing and donor selection Histocompatibility studies for class I antigens consisted of serological typing according to a standard two-stage microtoxicity assay,16 and antigens were assigned as defined by the World Health Organization HLA nomenclature committee effective at the time of transplantation.17 For class II antigens, between 1991 and 1993 HLA typing was performed by restriction fragment length polymorphism (RFLP) and mixed leukocyte culture (MLC). Since 1994, ligation based typing of HLA-DRB1, HLA-DRB3, HLA-DRB4, HLA-DRB5 and HLA-DQB1 alleles was performed as described elsewhere.18 In addition, nucleotide sequencing analysis of HLA-DRB1 and HLA-DQB1 alleles was performed.18 Donor and recipient were considered matched if they were identical at HLA-A, HLA-B, HLAC, HLA-DR and HLA-DQ loci. Donors were accepted if they were either fully matched or if there was a one-antigen mismatch. Unrelated donor marrow was provided by donor centers associated with the Austrian Bone Marrow Donor Registry: National Marrow Donor Program, Minneapolis, USA (n ⫽ 11), Europdonor Foundation, Leiden, The Netherlands (n ⫽ 4), Swiss National Registry, Bern, Switzerland (n ⫽ 3), German National Registry, Ulm, Germany

Peripheral blood (PB) and reticulocyte counts were performed on a daily basis starting 7 days before BMT until hematopoietic engraftment. Hemograms were obtained with the Sysmex NE-8000 (Toa Medical Electronics, Kobe, Japan). Microscopic white blood cell differential counts were performed from PB smears stained according to a modified Wright technique. Absolute neutrophil counts (ANC) were calculated from leukocyte and differential counts. Bone marrow (BM) aspirates were performed on days 28, 100 and 365 after BMT. Engraftment was defined as the first of 3 consecutive days with an ANC of ⬎0.5 ⫻ 109/l, selfsustaining platelet counts ⬎20 ⫻ 109/l and independence of red blood cell (RBC) transfusions. Engraftment of donor cells was further documented by cytogenetic analyses of recipient marrow cells before and after BMT and amplification of the variable number of tandem repeats (VNTR) region within intron 40 of the von Willebrand factor gene by polymerase chain reaction (PCR), as described.20 GVHD prophylaxis, supportive care All patients received a combination of CsA 1.5 mg/kg every 12 h starting on day ⫺1 together with a short course of MTX i.v. (15 mg/m2 day ⫹1, 10 mg/m2 day 3, 6 and 11) according to the Seattle protocol.21 Day 11 MTX was given to all patients. The clinical diagnosis of GVHD was confirmed by appropriate biopsies and clinically graded 0 to IV by the criteria reported for acute GVHD, and as ‘none’, ‘limited’ or ‘extensive’ for chronic GVHD.22,23 Patients with acute GVHD II or more were treated with corticosteroids (2 mg/kg/day), increasing doses of CsA and, if no response to corticosteroids (2 mg/kg) and CsA occurred,


with high-dose corticosteroids (10 mg/kg). Treatment of extensive chronic GVHD was with CsA and corticosteroids according to a modified protocol published by the Seattle group.24 Patients not responding to this regimen received second-line treatment with either azathioprine, thalidomide or extracorporeal photochemotherapy. Patients were hospitalized in laminar air-flow rooms. They received antimicrobial prophylaxis with nonabsorbable antibiotics and Pneumocystis carinii prophylaxis with cotrimoxazole. For CMV prophylaxis, patients received acyclovir as described.25 In addition, all patients received CMV-negative blood products. Packed RBC were given to maintain hemoglobin concentrations above 80 g/l, and platelet transfusions to keep the platelet count above 20 ⫻ 109/l. No special prophylaxis for veno-occlusive disease of the liver was given. In the outpatient setting, CMV screening (virus excretion, antigen detection in blood) was performed weekly during the first 100 days after BMT and in the event of virus detection ganciclovir therapy was started. Patients with chronic GVHD received cotrimoxazole for Pneumocystis carinii prophylaxis and oral penicillin for pneumococcal prophylaxis. They received immunoglobulin therapy if their serum IgG levels were below normal. Patients who required readmission after initial discharge following BMT were treated in single bed rooms in our nonsterile BMT ward by the same team of physicians and nurses who had performed their transplant. Transplantrelated mortality (TRM) was defined as any nonleukemic cause of death related to the transplant procedure at any time point after BMT. The Karnofsky performance scale was used to assess the functional capacity of surviving patients. Statistics Probabilities of overall survival, relapse and transplantrelated mortality were estimated by the method of Kaplan and Meier including 95% confidence limits. Comparisons were based on the generalized Wilcoxon test and the logrank test.

Results

Table 2

Cause of death

VOD/MOF Sepsis/MOF GVHD Posthepatitic liver failure CNS aspergillosis Total (%)

All (n ⫽ 49)

Standard risk (n ⫽ 26)

High risk (n ⫽ 23)

6 3 2 1 1

1 1 2 1 0

5 2 0 0 1

13/49 (27)

5/26 (19)

8/23 (35)

VOD ⫽ veno-occlusive disease; MOF ⫽ multi-organ failure; CNS ⫽ central nervous system.

27%, 24% in standard risk and 31% in high risk patients (P ⫽ 0.44, Figure 1; lower and upper confidence limits in standard risk patients at 2 months: 0.07–0.40, in high risk patients: 0.12–0.5). All transplant-related deaths occurred within the first 100 days after transplantation. Patients younger than 40 years at transplant had a similar probability of TRM (28%, n ⫽ 33) compared to patients older than 40 years (26%, n ⫽ 16; P ⫽ 0.83). In patients with AL there was no difference between standard and high risk patients regarding probability of TRM (25% vs 24%, P ⫽ 0.95). In CML patients, there was a trend towards a lower probability of TRM in standard risk vs high risk patients (23% vs 44%); however, this difference did not reach statistical significance (P ⫽ 0.16). Graft-versus-host disease Acute GVHD grade II–IV occurred in 25 of 47 (53%) evaluable patients; 18 of 47 patients (38%) developed acute GVHD grade III–IV. Out of 30 patients at risk, 22 (73%) showed signs of chronic GVHD; in 13 of the 30 patients (43%) extensive chronic GVHD was observed. Patients with acute GVHD grade III–IV had a probability of TRM (29%) which was not significantly different compared to grade 0–II patients (21%, P ⫽ 0.75). There was also no difference between the two groups regarding the probability of overall survival (49% grade III–IV vs 43% grade 0–II, P ⫽ 0.78). Acute GVHD grade III–IV was observed in

Engraftment

100

80

Probability

The median number of nucleated cells transplanted was 2.7 ⫻ 108/kg (range 0.5–11). Three of 49 patients died before day 28 and were thus not evaluable for engraftment. All of the remaining 46 patients showed durable engraftment. The median time to achieve an ANC greater than 0.5 ⫻ 109/l was 21 days (range 15–40). In patients who had received recombinant human G-CSF after BMT, the respective time point was 16 (range 11–22) days.

755

Transplant-related mortality

60

40

High risk (n = 23)

P = 0.44 20

Standard risk (n = 26)

Transplant-related mortality (TRM) 0

Causes of death of the 13 patients who died from transplant-related causes are listed in Table 2. All four patients transplanted up to 1993 died of severe veno-occlusive disease (VOD). The probability of TRM in all patients was

0

10

20 30 40 Time after BMT (months)

50

Figure 1 Probability of transplant-related mortality after unrelated donor BMT for leukemia.


756

100

80

Probability

Standard risk (n = 12) 60

P = 0.48 High risk (n = 14)

40

20

0 0

10

20 30 40 Time after BMT (months)

50

Figure 2 Probability of overall survival after unrelated donor BMT for acute leukemia.

Leukemic relapse was observed in nine of 49 (18%) patients after a median time of 8 months (2–27 months) from BMT and was ultimately fatal in all patients. Relapse occurred in two of 26 (8%) standard risk and in seven of 23 (30%) high risk patients. The probability of relapse was 41% for the whole group of patients, 29% for standard risk patients and 55% for high risk patients (P ⫽ 0.04, Figure 4; lower and upper confidence limits in standard risk patients at 12 and 24 months: 0.00–0.16; in high risk patients at 12 months: 0.43–0.91, at 24 months: 0.34–0.85). There was no difference in the probabilty of relapse between standard and high risk patients with acute leukemia (56% vs 51%, P ⫽ 0.3). In CML patients, none of 14 standard risk patients have relapsed to date compared to two of nine high risk patients (0% vs 60%, P ⫽ 0.13). Of the 14 CML patients alive, 11 (79%) are BCR-ABL PCR negative after a median observation time of 18 months (range 2–40).

6/13 (46%) mismatched donor/recipient pairs compared to 12/36 (33%) in matched pairs (P ⫽ NS). Discussion Overall survival, relapse As of 30 April, 1998, 27 of 49 (55%) patients survive after a median observation time of 18 months (2–48). Twentyfive of the 27 patients (93%) had a Karnofsky performance scale of 90–100, in 2/27 patients (7%) this was 70 and 80, respectively. The probability of overall survival for the whole group of patients is 43%; standard risk and high risk patients had a probability of survival of 54% and 31% (P ⫽ 0.05), respectively. In patients with AL, there was no difference regarding the probability of overall survival between standard risk and high risk patients (33% and 37%, P ⫽ 0.48, Figure 2; lower and upper confidence limits in standard risk patients at 12 and 24 months: 0.38–0.93 and 0.04–0.83; in high risk patients: 0.09–0.65 and 0.10–0.65). In CML patients, standard risk patients had a significantly better survival compared to high risk patients (77% vs 22%, P ⫽ 0.05, Figure 3; standard risk patients: lower and upper confidence limits at 12 and 24 months: 0.58–1.00; high risk patients: 0.12–0.77). There was no significant difference in overall survival between patients younger than 40 years and 40 years or older at transplant (50% vs 25%, P ⫽ 0.70).

Marrow transplantation from UD has recently been shown to be an effective form of treatment for patients with hematological malignancies.11,26,27 However, TRM rates have been reported to be between 40 and 60%, mostly due to GVHD and associated infectious complications. TRM in our 49 consecutive unrelated donor marrow recipients is 27%, being 24% in standard risk and 31% in high risk patients. These results compare favorably with TRM rates reported recently.11,27 From this study, it is difficult to explain the reasons for the low TRM rate. One of the important factors for the outcome of a UD BMT is the degree of donor/recipient histocompatibility. Tiercy et al28 showed that 56% of donor/recipient pairs who appeared to be HLA-identical serologically were disparate at the molecular level. Recent reports show that high resolution HLA matching between unrelated donors and recipients is associated with decreased mortality after UD BMT.11,29,30 The typing technology used in our patients allows a high resolution of class II antigens within a short time period that makes it possible to perform UD transplants in patients with acute leukemia primarily refractory to chemotherapy.

100 100 Standard risk (n = 14) 80

60 High risk (n = 9)

P = 0.05

Probability

Probability

80

40

High risk (n = 23)

60

P = 0.04 40 Standard risk (n = 26)

20 20 0 0

10

20 30 Time after BMT (months)

40

Figure 3 Probability of overall survival after unrelated donor BMT for chronic myeloid leukemia.

0 0

10

20 30 Time after BMT (months)

40

50

Figure 4 Probability of relapse after unrelated donor BMT for leukemia.


In our study the probability of TRM did not differ significantly between patients younger than 40 years and 40 years or older at transplant. This accords with the finding of Hansen et al,26 who found that the overall survival of patients 21 to 36 years of age and 37 to 50 years of age was very similiar. These findings suggest that eligibility for UD transplantation for leukemia might be considered up to the age of 45–50 years. Graft failure has been reported to be associated with HLA-C disparity after UD BMT.30 We have performed five HLA-C-mismatched UD transplants and did not observe graft failure. However, the number of patients in our series is too small to draw any conclusion regarding the influence of HLA-C disparity on graft failure. The combination of CY and TBI is an effective regimen for allogeneic transplants both in sibling donor and unrelated donor BMT. However, the total dose and schedule of TBI has varied among studies. Geller et al31 increased the dose of TBI to 14 Gy and observed a doubling of the baseline serum creatinine in 61% of their patients. However, when they reduced the FK506 dose in their patients, renal function improved. We have increased the total TBI dose from 12 Gy to 13.2 Gy in an attempt to increase immunosuppression and avoid graft rejection. We have not observed graft rejection to date and we did not observe an increase in liver or renal toxicity compared to patients receiving 12 Gy. All of our 13 transplant-related deaths occurred within the first 100 days after BMT. To date after a median observation time of 18 months, we have not observed a patient dying of transplant-related causes after day 100 post-transplant. Patient care in a separate ward consisting of seven single-bed rooms where transplant recipients are treated by the same team performing the transplant, may be one factor responsible for this low TRM in our patients. Acute and chronic GVHD remain the major problems after UD BMT. The incidence of acute GVHD grade III– IV (38%) observed in our series is high but within the published range for UD BMT recipients. There was no significant difference regarding acute GVHD III–IV between HLA mismatched (n ⫽ 13) and fully matched (n ⫽ 36) donor/recipient pairs. The probability of overall survival was not different between patients with acute GVHD grade 0–II (43%) and grade III–IV (49%, P ⫽ 0.78) in our series. However, this may be due to the small patient number. Improvements in GVHD prophylaxis and treatment are mandatory. The high incidence of extensive chronic GVHD (43% in our series) is a major problem, especially because skin and mucosal changes decrease the quality of life in these patients and severe infections are frequent. As many patients are refractory to standard treatment protocols, new treatment modalities such as extracorporeal photochemotherapy32 and new immunosuppressive drugs should be investigated. Relapse remains the most frequent cause of death after UD BMT in our series. However, keeping in mind that 47% of our patients are high risk patients with nine AL patients who were absolute refractory to chemotherapy, a 52% probability of relapse for these patients is not surprising. To date, none of our standard risk CML patients has relapsed; two advanced disease CML patients relapsed 9 and 18 months after BMT. Both of them received donor buffy coat

cells but eventually died 6 and 9 months after relapse, respectively. In summary, the implementation of a new transplant regimen for UD BMT in leukemia consisting of high resolution molecular HLA typing of donors and recipients, a total dose of 13.2 Gy TBI and improvements in supportive care have led to a probability of transplant-related mortality of 27% (24% in standard risk, 31% in high risk patients). Although a substantial proportion of UD marrow recipients with leukemia may be cured, incidence and treatment of extensive chronic GVHD remain a clinical challenge in long-term survivors and new therapeutic modalities should be investigated in these patients. Acknowledgements We thank the dedicated nurses of our stem cell transplant program, our fellows, the medical technicians, and the physicians who referred patients to our unit. We are indebted to the staff of the blood bank for technical assistance in support of blood products. We thank the staff of the Austrian Bone Marrow Donor Registry for excellent cooperation in finding suitable marrow donors for our patients.

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