High Response Rate to Donor Lymphocyte Infusion after Allogeneic Stem Cell Transplantation for Indolent Non-Hodgkin Lymphoma

Biology of Blood and Marrow Transplantation 14:50-58 (2008) Q 2008 American Society for Blood and Marrow Transplantation 1083-8791/08/1401-0001$32.00/0 doi:10.1016/j.bbmt.2007.04.013

High Response Rate to Donor Lymphocyte Infusion after Allogeneic Stem Cell Transplantation for Indolent Non-Hodgkin Lymphoma Adrian J. C. Bloor, Kirsty Thomson, Noha Chowdhry, Stephanie Verfuerth, Stuart J. Ings, Ronjon Chakraverty, David C. Linch, Anthony H. Goldstone, Karl S. Peggs, Stephen Mackinnon, MD Department of Haematology, Royal Free and University College London School of Medicine, London, United Kingdom An abstract of these data was presented at the American Society of Hematology Annual Meeting, Atlanta, 2005. Correspondence and reprint requests: Dr Adrian J.C. Bloor, Christie Hospital NHS Trust, Wilmslow Road, Manchester, M20 4BX, UK; Tel: 144 161 446 3869; Fax: 144 161 446 3940 (e-mail: [email protected]). Received September 16, 2006; accepted April 18, 2007

ABSTRACT The role of donor lymphocyte infusion (DLI) in the management of lymphoid malignancies after allogeneic stem cell transplantation (SCT) has not been clearly characterized. There is emerging evidence pointing to the effectiveness of this approach, particularly in patients with low-grade disease, although to date this has been reported only in small numbers of patients, and thus the utility of this treatment remains uncertain. A total of 28 patients with low-grade lymphoid malignancies previously treated with allogeneic SCT received a total of 68 infusions of donor lymphocytes. The diagnoses were indolent non-Hodgkin lymphoma (NHL; n 5 23) and transformed NHL (n 5 5), and the indications for DLI were progressive disease with or without mixed chimerism (MC) (n 5 17) and persistent MC alone (n 5 11). Escalating doses of cells were administered in the absence of graftversus-host disease (GVHD) or continued disease progression, until stable full donor chimerism or disease response were achieved. The cumulative response rates after DLI to treat progressive disease and persistent MC were 76.5% and 91.6%, respectively. The major toxicity resulting from the use of donor lymphocytes was GVHD. The cumulative incidence of acute grade II-IV disease was 15%, and that of extensive chronic disease was 31%; there were no deaths resulting from GVHD. Seven patients had graft-versus-lymphoma responses without significant GVHD. These data support the existence of a clinically significant graft-versus-tumor effect in indolent NHL and suggest that this is an effective treatment for progressive disease after allogeneic SCT.

Ó 2008 American Society for Blood and Marrow Transplantation

KEY WORDS Bone marrow transplantation  Donor lymphocyte  Lymphoma

INTRODUCTION Allogeneic stem cell transplantation (SCT) is a potentially curative therapy for patients with nonHodgkin lymphoma (NHL), although its role in the treatment of this group of diseases remains unclear. Several studies have demonstrated a long-term survival advantage of allogeneic SCT over autologous SCT [1,2]. Part of this benefit is derived from the use of an uncontaminated graft, supported by the reduced relapse rate observed after syngeneic transplantation compared with autologous procedures [3]. A second mechanism for this advantage is a graft-versus-tumor 50

(GVT) effect. The antitumor capacity of allogeneic T lymphocytes in recipients of allogeneic SCT has long been recognized [4], most notably in the treatment of chronic myelogenous leukemia (CML) [5]. The evidence for a clinically significant GVT effect in lymphoma is less robust, however. Comparison of the outcome of syngeneic and allogeneic SCT for patients with NHL demonstrated similar relapse rates in each group [3]. Furthermore, there is no clear association between the development of GVHD and reduced relapse rate [3,6]. These data have been interpreted as demonstrating a lack of GVT effect in NHL [3],

51

Donor Lymphocytes for Non-Hodgkin Lymphoma

although the validity of this conclusion is hampered by the relatively small numbers and heterogeneity of the patients studied [6,7]. In contrast, the response to either withdrawal of immunosuppression or DLI provides more direct evidence of a significant GVT effect, although to date this has been demonstrated only in case reports or small series [7-17]. The utility of allogeneic transplantation is limited by the procedure related toxicity and with a median age at diagnosis in the mid-60’s [18], most patients with NHL are ineligible for this treatment. The development of reduced-intensity transplantation (RIT) has allowed application of allogeneic therapies to a broader range of patients. Whereas RIT allows durable engraftment with reduced toxicity, GVHD remains a significant cause of morbidity and mortality [19]. Incorporation of in vivo T cell depletion (TCD) into conditioning protocols decreases the GVHD-associated morbidity and mortality [20-22], although it is associated with impaired immune reconstitution, leading to an increased incidence of opportunistic infections, and a decreased remission duration possibly resulting from less GVT activity [12,23,24]. The increased relapse risk after T-deplete RIT may be abrogated by administering escalating doses of DLI [25], and although emerging evidence indicates that this approach may be effective in the treatment of lymphoproliferative diseases, the current body of literature supporting this approach is small, with little consistency in the indications, timing, or dose of DLI [7-17]. Here we retrospectively report the results of administration of dose-escalated DLI to 28 patients with indolent lymphoid malignancies after allogeneic SCT. PATIENTS AND METHODS Patients

A total of 81 consecutive patients underwent allogeneic SCT at a single institution between 1997 and 2004 for indolent lymphoid malignancies; 28 subsequently received DLI and are included in this retrospective study (Table 1). The indications for DLI were disease progression or mixed chimerism (MC) 6 months from the date of transplantation, without significant GVHD (acute grade III-IV or extensive chronic disease [aGVHD, cGVHD]). Otherwise eligible candidates for DLI who were not treated for GVHD were not included. A total of 26 patients received RIT (fludarabine 150 mg/m2 in 5 divided doses, melphalan 140 mg/m2, and alemtuzumab 100 mg in 5 divided doses in 22 patients and 60 mg in 2 divided doses in 7 patients) and an unmanipulated peripheral blood stem cell (PBSC) graft (n 5 24) or a bone marrow (BM) graft (n 5 2) from a sibling (n 5 22), a matched unrelated donor (n 5 3), or a single antigenmismatched unrelated (n 5 1) donors, with cyclosporine as GVHD prophylaxis [20]. The remaining 2

Table 1. Patient characteristics Characteristic Number Median age at transplantation, years (range) Sex Transplant conditioning and source T-replete sibling T-deplete reduced-intensity sibling T-deplete reduced-intensity unrelated donor Disease Low grade NHL (FL, 14; CLL, 6; MCL, 3) Transformed low grade NHL (tFL, 5) GVHD before DLI T-replete sibling T-deplete reduced-intensity sibling T-deplete reduced-intensity unrelated donor Indication for DLI Disease progression 1/2 MC MC

28 45 (30-64) M, 21; F, 7 2 22 4 23 5 1 6 1 17 11

FL indicates follicular lymphoma; CLL, chronic lymphocytic leukemia; MCL, mantle cell lymphoma; tFL, transformed follicular lymphoma. Of the patients treated with RIT from unrelated donors, 3 received fully HLA-matched stem cells and 1 received cells mismatched at a single HLA allele.

patients received myeloablative conditioning with total body irradiation (TBI; 12 Gy in 6 fractions) and cyclophosphamide (120 mg/kg in 2 divided doses), an unmanipulated sibling BM graft and cyclosporine plus methotrexate (MTX) as GVHD prophylaxis [26]. Eleven patients developed GVHD after transplant (aGVHD grade I in 9, aGVHD grade II in 1, and limited cGVHD in 5), although none required systemic immunosuppression at the time of the first DLI. Written informed consent was obtained before DLI. The protocol and consent form were approved by the Institutional Research Ethics Committee. Assessment of Chimerism and Disease Status

Lineage-specific chimerism of peripheral blood lymphocytes (B and T lineages) and myeloid lineage cells was performed by analysis of informative mini-satellite short tandem repeat (STR) loci using a polymerase chain reaction (PCR)-based assay (n 5 22), as described elsewhere [20], or by dual-color chromosome X-Y interphase fluorescent in situ hybridization (FISH) (n 5 6). Complete donor chimerism was defined by lack of detection of a previously determined recipient-specific peak on STR PCR in all hematopoietic lineages. MC was defined by detection of recipient-specific peaks (at any level) in 1 or more cell lineages, in addition to peaks derived from donor cells. Of the patients treated for disease progression, 10 had both clinical and radiologic evidence of relapse, 6 had only radiologic evidence of progression (computed tomography [CT] scan in 2 and positron emission tomography [PET] scanning in 4), and 1 patient had progressive disease diagnosed after a BM biopsy; histological

52

confirmation of disease relapse was obtained in 8 patients before DLI. Disease response was assessed on the basis of clinical, radiologic (CT), and pathological (BM) criteria according to the site of relapse and graded according to standard disease-specific criteria, [27,28] at 2-3 months after each DLI and then 6-12 months after remission was achieved. PET scanning (where performed) was undertaken at 3, 6, 9, 15, and 24 months posttransplantation. DLI Administration and Additional Treatments

In the absence of GVHD, escalating doses of CD31 cells were administered at 3-month intervals (1 106/kg, 3  106/kg, 1  107/kg, 3  107/kg, and 1 108/kg) in patients with persistent MC or no evidence of disease response. Immunosuppression had been discontinued in all patients before the first lymphocyte infusion. Twenty-three patients received an initial dose of 1  106/kg at a median of 273 days posttransplantation (range, 181-728 days); 5 patients with progressive disease were treated with using a higher initial dose. Four patients received 1  107/kg cells at a median of 1064 days posttransplantation (range, 215-2674 days), and 1 patient received 6  107/kg cells. Seventeen patients received DLI for disease progression, classified as relapsed disease (previous complete remission [CR]) or progressive disease (previous partial remission [PR]). Patients were considered evaluable for follow-up if more than 100 days had elapsed since their last DLI or if they had evidence of GVHD, disease response, or disease progression before this time. GVHD was graded according to standard criteria [29]. Patients with rapidly progressive or bulky disease (. 5 cm diameter) were also treated with 3 or 4 weekly infusions of rituximab (375 mg/m2) before or shortly after DLI. Those who failed to respond to DLI were eligible for treatment with salvage chemoradiotherapy. Statistical Methods

Fisher’s exact test was used for analysis of 2  2 tables of cross-categorized frequency data. Survival analysis (Kaplan-Meier method) and cumulative incidence analysis (using death as a competing risk) were performed using the survival/reliability module of the NCSS software package (NCSS, Kaysville, UT). RESULTS Disease Response

A total of 68 doses of DLI were administered, with a median of 2 infusions per patient (range, 1-5). Seventeen patients were treated for disease progression (relapse in 8 and progressive disease in 9; Table 2); 14 of these patients also had MC. Three patients had nodal relapse in the context of peripheral blood full donor chimerism, reflecting the relative insensitivity of peripheral blood STR analysis as a marker of disease

A. J. C. Bloor et al.

progression elsewhere. One patient died before the response to DLI could be assessed (patient 6; Table 2), and 3 patients were refractory to treatment (patients 1, 3, and 10; Table 2). Thirteen patients demonstrated disease response to donor lymphocytes (Table 2), with a cumulative response rate of 76.4% (Figure 1A; 95% confidence interval [CI] 5 55.8%-99.5%). The median time to response was 12 months. All 13 responding patients achieved CR; in 9 of these patients, this is ongoing, with a median duration of 967 days from last DLI (range, 402-1769 days). Four patients demonstrated disease progression after attaining an initial CR (patients 7, 8, 18, and 23; Table 2), although all responded to additional lymphocyte infusions (CR in patients 7, 8, and 23; patient 18 is currently receiving further escalating DLI). Of the 17 patients treated for disease progression, the projected 5-year overall survival (OS) and progression-free survival (PFS) after the last treatment with DLI are 87.8% (95% CI 5 72.0%-100%) and 76.2% (95%CI 5 55.5%-96.6%), respectively (Figure 2). PFS includes all patients in a stable remission at the time the data were evaluated. Disease Response with Additional Treatment before DLI

Of the patients treated for disease progression, 8 received additional treatment before or shortly after DLI. Five patients were treated with rituximab in combination with DLI (patients 14, 15, 18, 19, and 22; Table 2). One patient is currently undergoing continued treatment, and 4 patients have evaluable follow-up. Of the 4 evaluable patients, all achieved CR after combination treatment using rituximab and DLI, with a median remission duration of 776 days (range, 412-1357 days) from their last DLI. One patient received radiotherapy to a single lymph node field (patient 14; Table 2), but exhibited evidence of disease response outside the radiation field indicating a response to DLI. Two patients received combination chemoradiotherapy after failing to respond to DLI (patients 1 and 10; Table 2). Chimerism Response

A total of 25 patients received DLI for persistent MC. Eleven had MC alone, and 14 also had progressive disease (Tables 2 and 3); 2 patients died before their response to DLI could be assessed (patients 3 and 20; Table 2 and 3). The cumulative response to DLI for MC was 92.0% (95% CI 5 82%-100%; Figure 1A). All of the responding patients converted to stable full donor chimerism, and the median time to response was 6.7 months. GVHD

Three patients died before they could be assessed for the development of GVHD, leaving 25 evaluable for follow-up. Fifteen of these 25 developed GVHD (all

Best response

Current status

Diagnosis

Transplant Type

Treatment before DLI

Maximum dose DLI  106/kg

Disease status at first DLI

Chimerism at first DLI (method)

Disease

Chimerism

GVHD

Disease

1 5 6 7 9 10 14 15 21 22 23

CLL FL CLL CLL FL MCL FL FL FL FL MCL

Sibling RI mMUD RI MUD RI sibling RI sibling RI sibling RI sibling RI sibling RI sibling RI sibling RI sibling

Chemo Chemo, DXT Rituximab, DXT Rituximab Rituximab -

10 10 3 100 30 100 100 60 1 10 100

PD R PD PD PD R PD PD PD PD R

MC (all) MC (FISH) FD MC (T) MC (T) FD MC (all) MC (all) MC (T) MC (T) MC (T)

NR CR NE CR CR NR CR CR CR CR CR

FD FD FD FD FD FD FD FD FD

CR* CR Dead (infection) CR CR PR* CR CR CR CR CR

FD FD FD FD FD FD FD FD FD FD

28

MCL

RI MUD

R

FD

CR

-

CR

MC*

3 8 13 18 19

tFL tFL tFL tFL tFL

RI sibling RI sibling RI sibling RI sibling RI sibling

Rituximab Rituximab

Acute grade I Extensive chronic NE Acute grade I Acute grade I Extensive chronic Extensive chronic Extensive chronic Acute grade I / limited chronic -

PD R PD R R

MC (FISH) MC (B) MC (all) MC (FISH) MC (T)

NR CR CR CR CR

NE FD FD FD FD

NE Extensive chronic Acute grade II / extensive chronic

Dead (disease) CR CR R* CR

FD FD FD FD

Number

3 60 100 3 100 30

Chimerism

Donor Lymphocytes for Non-Hodgkin Lymphoma

Table 2. Response to treatment in patients treated for disease progression with or without MC

Chemo indicates combination chemotherapy; PD, progressive disease; NR, no response; FD, full donor chimerism; mMUD, (mis)matched unrelated donor; R, relapse; FD, full donor; PD, progressive disease; NE, not evaluable; DXT, radiotherapy; PR, partial remission; FL, follicular lymphoma; CLL, chronic lymphocytic leukemia; MCL, mantle cell lymphoma; tFL, transformed follicular lymphoma. The method used for chimerism analysis is indicated in brackets for patients with MC. All, T, B, and M refer to MC in all lineages, T lymphocytes, B lymphocytes, and myeloid cells, respectively, using STRPCR analysis. *Indicates patients undergoing continued donor lymphocyte dose escalation treatment.

53

54

A. J. C. Bloor et al.

Cumulative Response / %

Probability of current survival / %

100

A

Mixed chimerism

90 80

Disease progression

70 60 50 40 30 20 10 0 0

6

12

18

24

30

36

42

Mixed chimerism 25

13

8

7

3

2

2

2

Disease progression 17

11

7

2

0

0

0

0

48

100 Overall survival

90 80 70

Progression free survival

60 50 40 30 20 10 0

Number at risk

0

6

12

18

24

30

36

42

48

54

17

13

10

7

6

5

3

3

2

1

60

Time since last DLI / months

B Cumulative Incidence / %

100 90 80 70 60 50 40

Extensive chronic

30 20 10

Acute grade II-IV

0 0 Extensive Chronic 28

6 20

12 15

18 9

Acute grade II-IV 28

18

15

9

24 9

30 8

36 6

42 6

48 3

54 2

9

8

6

6

3

2

60

Time / months Figure 1. Cumulative response to DLI and incidence of GVHD. A, Time taken to maximal response (CR or full donor chimerism) after DLI administered for progressive disease (solid line) or MC (dashed line). B, Cumulative incidence of extensive chronic (solid line) and acute grade II-IV GVHD. The numbers below the figures indicate the number of patients at risk at each time point.

grades), 8 of whom required systemic immunosuppression (Tables 2 and 3). The cumulative incidence of aGVHD grade II-IV was 14.7% (95% CI 5 5.9%-36.4%), and that of extensive cGVHD was 31.4% (95% CI 5

Figure 2. Survival after DLI in patients treated for relapsed/progressive disease; overall (- - - -) and progression-free (——) survival after the most recent DLI given for disease progression. Progression-free survival includes all patients in stable CR at the time the data were evaluated. This figure should be interpreted together with Figure 3, which indicates the timing and dose of DLI in individual patients.

17.4%-56.4%) (Figure 1B). One patient developed acute grade III hepatic aGVHD (patient 24; Table 3), although he responded to treatment with immunosuppression. A total of 63 doses of DLI were administered with evaluable follow-up for GVHD; 50 were given in the presence of MC, and 13 were given in the presence of full donor chimerism (Figure 3). No difference in the incidence of GVHD (aGVHD grade II-IV or extensive cGVHD) was seen between the 2 groups (8 of 50 mixed chimeras vs 3 of 13 full donor chimeras; P 5 .68). Figure 4 shows the occurrence of GVHD by dose and timing of DLI. There was a possible excess of cases of GVHD (aGVHD grade II-IV or extensive cGVHD) after administration of DLI less than 1 year after transplantation compared with doses given after this time:

Table 3. Response to treatment in patients treated for MC alone

Diagnosis

Transplant type

Maximum DLI dose  106/kg

Chimerism method

Best response

2 4 11 12 16 17 20 24

FL FL FL CLL FL FL FL CLL

RI sibling RI sibling Sibling RI sibling RI sibling RI sibling RI sibling RI sibling

30 30 100 1 1 1 1 1

FISH, STR (T) FISH, STR (all) FISH STR (T) STR (M, T) STR (T) STR (all) STR (T)

FD FD FD FD FD FD NE FD

25 26

FL FL

RI MUD RI sibling

1 1

STR (T) STR (T)

FD FD

27

CLL

RI sibling

1

STR (T)

FD

Number

GVHD

Current status

Limited chronic NE Acute grade III/ extensive chronic Acute grade II/extensive chronic Acute grade II

FD FD FD FD FD FD Dead (infection) FD FD FD Dead (infection)

FD, indicates full donor chimerism; NE, not evaluable; DXT, radiotherapy; FL, follicular lymphoma; CLL, chronic lymphocytic leukemia. The method used for chimerism analysis is indicated in brackets for patients with MC. All, T, B, and M refer to MC in all lineages, T lymphocytes, B lymphocytes, and myeloid cells, respectively, using STR-PCR analysis.

55

Donor Lymphocytes for Non-Hodgkin Lymphoma

1

*

10

2

1

3

60

1

3

10

30

1

3

6

1

3

7

1

3 10

8

1

9

10

30

100 100

10

10

3

12

30

30100

*

0

19

1 3 10 30

1

36

48

60

72

84

96

100

*

30100

1

1

1

1

28

30 100

30

(infection)

10

25

100

10

10

26

24

3

1

27

3 10

12

1

24

1 3

1

18

22

100

1

14

1

23

10

13

1

21

100

30

1

16

20

(infection)

1 10 30

11

1 30 60

17

(disease)

4

5

3 10 30

15

(infection)

1

0

3

12

* 24

36

48

Time / months Complete remission Full donor chimera

Partial remission Mixed chimera

Progressive disease Died (cause)

1

*

DLI x106/kg

Ongoing DLI

Figure 3. Timing of DLI and response to treatment by patient. The horizontal bars represent the time elapsed since transplantation for each patient, colored to indicate the response to DLI by indication (MC or disease progression). Abbreviations are explained in Table 2.

6 of 20 doses (\1 year) versus 5 of 43 doses (. 1 year). However, the variation between both the number of doses administered to individual patients and endpoints to continued dose escalation (GVHD, response, or death) makes interpretation of the significance of this finding uncertain. Fifteen patients treated for disease progression who responded to DLI were evaluable for both response and GVHD. Of these, 7 responded without significant GVHD (none in 5 and cutaneous grade I aGVHD in 2). Two patients developed grade I skin aGVHD with no significant disease response (patients 1 and 10; Table 2). DISCUSSION The advent of RIT protocols over the last decade has significantly expanded the age range over which al-

logeneic SCT may be applied, although the associated procedure related morbidity and mortality, particularly from GVHD, remains significant. Most of the patients in the present study were treated with RIT and in vivo TCD using Campath-1H. As we have reported previously this is effective in treating patients with NHL and results in a low incidence of GVHD, although with a significant rate of disease progression and residual recipient chimerism after transplantation [12]. The results of this study demonstrate a significant response to DLI for patients treated for indolent lymphomas with disease progression post-SCT, resulting in a cumulative CR rate of . 75%. In most of those treated, the remission was durable, with a median duration of almost 3 years, moreover, each of the 4 patients who subsequently relapsed attained a further remission with repeat lymphocyte infusions. These data add to the emerging body of evidence supporting

56

A. J. C. Bloor et al.

84

Time post transplant / months

72 60 48

24 18 12 6 0 1 n=22

3 n=7

10 n =14

30 n=13

60-100 n=7

Dose of DLI / x106/kg Figure 4. Relationship between DLI dose and incidence of GVHD. Each circle represents the administration of a single dose of donor lymphocytes. Black circles indicate the occurrence of acute grade II-IV or extensive chronic GVHD; open circles indicate that GVHD did not occur. Five doses of donor lymphocytes were not evaluable for GVHD (not shown).

the use of DLI to treat indolent lymphoid malignancies after allogeneic SCT [7,8]. A number of patients in this study received DLI for disease progression diagnosed using CL-PET scaning, based on the results of a previously published pilot study describing the utility of this imaging modality to guide the use of DLI after allogeneic SCT [30]. One potential drawback of this approach is a lack of histological confirmation of relapse. But this may not be required in patients with a pattern of fluorodeoxyglucose avidity that is highly suspicious for lymphoma relapse [30], although we would recommend that biopsy be done, if possible, in all patients with lesions at unexpected sites or if the clinical context suggests an alternative explanation (particularly infection). A biopsy is also recommended in patients with previous highgrade transformation given the uncertainty of the efficacy of DLI for the treatment of relapsed high-grade disease [9,12,13]. In this series, 4 of the 5 patients with previously transformed disease responded to DLI. These data suggest that DLI may be effective for treating patients with previous high-grade transformation, although interpretation of the significance of these results is hampered by the lack of confirmation of disease histology (high grade vs low grade) before DLI in 3 of these 5 cases. Determining the response to DLI may be more difficult in the 8 patients treated with radiotherapy or chemotherapy shortly before or after DLI. One of these patients received local radiotherapy for an apparently localized relapse but subsequently developed

more widespread disease progression and responded to treatment with DLI outside of the radiation field, indicating a response to donor lymphocytes. Two other patients received chemoradiotherapy after having failed to respond to donor lymphocytes and were clearly refractory to DLI. Five patients with rapidly progressive or bulky disease received 3 or 4 weekly infusions of rituximab shortly before DLI. Of the 4 patients with evaluable follow-up, all achieved a durable CR of . 2 years (median, 776 days). These data compare favorably with previous studies using rituximab monotherapy for relapsed or refractory lymphoma that typically reported CR rates of \ 10% and a median time to progression of 6-12 months [31-33]. The results obtained in this study suggest that the DLI may have resulted in a response (both duration and quality) beyond what would be expected when using rituximab as a single agent, and that including these patients in the response analysis is valid. The balance between donor and recipient hemopoiesis is associated with several determinants of transplantation outcome. Persistent MC after allogeneic SCT is a marker of bidirectional immune tolerance, although whether or not this translates into an increased risk of disease relapse is uncertain, and the use of DLI in this context is controversial. Stable recipient hemopoiesis may persist after myeloablative conditioning, and although some reports have suggested this may be associated with an increased relapse rate [34,35], other series have not confirmed this finding [36,37]. There is emerging evidence indicating that after RIT, persistent recipient hemopoiesis correlates with an increased risk of disease progression [38,39]. Given the increased incidence of MC associated with TCD, these data suggest that after alemtuzumab-based conditioning, patients with persistent recipient hematopoiesis may not achieve long-term disease control without DLI to achieve full donor chimerism. But there is little consensus concerning what degree of recipient hematopoiesis is significant, and levels of MC as low as 3% have been shown to be associated with an increased rate of disease progression [38]. However, despite the fact that STR-PCR chimerism analysis is sufficiently sensitive to reliably detect recipient peaks assays of 1-5%, the quantitative accuracy of the assay becomes less reliable at levels \ 5% [40]. The patients in this series all had low levels of stable MC (rather than more overt graft failure) that was typically below the level of reliable quantification, and thus the detection of any level of recipient hematopoiesis was considered significant. Chimerism status also may influence the response to DLI and the occurrence of GVHD. In mouse models, GVT effects are dependent in part on the presence of host antigen-presenting cells, with a greater GVT effect in mixed chimeras after DLI [41], although the relevance of this observation in

Donor Lymphocytes for Non-Hodgkin Lymphoma

human transplant recipients is uncertain. In this study, most of the DLIs administered for disease progression were given in the context of MC (expected given the Tcell deplete strategy used in most patients); however, the response rate in full donor chimeras was not significantly different. The relationship between chimerism status and the development of GVHD is inconsistent. Although donor T cell chimerism soon after transplantation has been associated with the development of aGVHD [42-44], most cases of aGVHD develop in mixed chimeras [42,45]. Chimerism status at the time of DLI does not appear to correlate with the development of GVHD [13,25], and consistent with this, the incidence of GVHD in this study observed in mixed versus full donor chimeras, was not significantly different. The major toxicity observed in this study after DLI was GVHD, with a similar incidence to that described in previous studies describing the use of DLI for a range of hematologic malignancies [8,13]. However, in contrast to those previous reports, in which disease response was strongly correlated with the occurrence of GVHD, almost half of the patients achieving disease remission did so without developing significant GVHD. The incidence of GVHD after DLI is somewhat unpredictably related to the dose infused and the interval after transplantation and therefore the initial dose of DLI was deferred until 6 months posttransplantation [25]. In this study, there was a trend toward increased incidence of GVHD in patients treated with DLI less than a year after transplantation, with 5 patients requiring treatment with systemic after the lowest dose of DLI (1  106/kg) at 6-12 months posttransplantation. Two of the 5 received DLI for disease progression, and the other 3 received it for MC. Given the uncertainties regarding the significance of MC after RIT, it is unclear whether DLI for this indication should be delayed longer than 6 months beyond transplantation or if lower doses should be considered in this context. The results of this study demonstrate that DLI is an effective and, in some patients, nontoxic intervention for the treatment of relapsed indolent lymphoproliferative disorders post–allogeneic SCT. The data support the existence of a meaningful graft-versuslymphoma effect, and although the response to DLI is often associated with significant GVHD, in this study a significant number of patients responded with no graft-versus-host effect, suggesting that GVT and GVHD in lymphoma may be separable. REFERENCES 1. Schimmer AD, Jamal S, Messner H, et al. Allogeneic or autologous bone marrow transplantation (BMT) for non-Hodgkin’s lymphoma (NHL): results of a provincial strategy. Ontario BMT Network, Canada. Bone Marrow Transplant. 2000;26:859-864.

57

2. Peniket AJ, Ruiz de Elvira MC, Taghipour G, et al. An EBMT registry–matched study of allogeneic stem cell transplants for lymphoma: allogeneic transplantation is associated with a lower relapse rate but a higher procedure-related mortality rate than autologous transplantation. Bone Marrow Transplant. 2003;31: 667-678. 3. Bierman PJ, Sweetenham JW, Loberiza FR Jr., et al. Syngeneic hematopoietic stem cell transplantation for non-Hodgkin’s lymphoma: a comparison with allogeneic and autologous transplantation. The Lymphoma Working Committee of the International Bone Marrow Transplant Registry and the European Group for Blood and Marrow Transplantation. J Clin Oncol. 2003;21: 3744-3753. 4. Weiden PL, Flournoy N, Thomas ED, et al. Antileukemic effect of graft-versus-host disease in human recipients of allogeneic marrow grafts. N Engl J Med. 1979;300:1068-1073. 5. Kolb HJ, Mittermuller J, Clemm C, et al. Donor leukocyte transfusions for treatment of recurrent chronic myelogenous leukemia in marrow transplant patients. Blood. 1990;15: 2462-2465. 6. van Besien K, Loberiza FR Jr., Bajorunaite R, et al. Comparison of autologous and allogeneic hematopoietic stem cell transplantation for follicular lymphoma. Blood. 2003;102:3521-3529. 7. Butcher BW, Collins RH Jr. The graft-versus-lymphoma effect: clinical review and future opportunities. Bone Marrow Transplant. 2005;36:1-17. 8. Peggs KS, Mackinnon S, Linch DC. The role of allogeneic transplantation in non-Hodgkin’s lymphoma. Br J Haematol. 2005;128:153-168. 9. Russell NH, Byrne JL, Faulkner RD, et al. Donor lymphocyte infusions can result in sustained remissions in patients with residual or relapsed lymphoid malignancy after allogeneic haemopoietic stem cell transplantation. Bone Marrow Transplant. 2005; 36:437-441. 10. Grigg A, Ritchie D. Graft-versus-lymphoma effects: clinical review, policy proposals, and immunobiology. Biol Blood Marrow Transplant. 2004;10:579-590. 11. Gribben JG, Zahrieh D, Stephans K, et al. Autologous and allogeneic stem cell transplantation for poor-risk chronic lymphocytic leukemia. Blood. 2005;106:4389-4996. 12. Morris EC, Thomson K, Craddock C, et al. Outcomes after alemtuzumab-containing reduced-intensity allogeneic transplantation regimen for relapsed and refractory non-Hodgkin lymphoma. Blood. 2004;104:3865-3871. 13. Marks DI, Lush R, Cavenagh J, et al. The toxicity and efficacy of donor lymphocyte infusions given after reduced-intensity conditioning allogeneic stem cell transplantation. Blood. 2002;100: 3108-3114. 14. Bethge WA, Hegenbart U, Stuart MJ, et al. Adoptive immunotherapy with donor lymphocyte infusions after allogeneic hematopoietic cell transplantation after nonmyeloablative conditioning. Blood. 2004;103:790-795. 15. Khouri IF, Lee MS, Saliba RM, et al. Nonablative allogeneic stem cell transplantation for chronic lymphocytic leukemia: impact of rituximab on immunomodulation and survival. Exp Hematol. 2004;32:28-35. 16. Dreger P, Brand R, Hansz J, et al. Treatment-related mortality and graft-versus-leukemia activity after allogeneic stem cell transplantation for chronic lymphocytic leukemia using reduced-intensity conditioning. Leukemia. 2003;17:841-848. 17. Mandingers CM, Verdonck LF, Meijerink JP, et al. Graft-versus-lymphoma effect of donor lymphocyte infusion in indolent

58

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31.

A. J. C. Bloor et al.

lymphomas relapsed after allogeneic stem cell transplantation. Bone Marrow Transplant. 2003;32:1159-1163. Ries LAG, Eisner MP, Kosary CL, et al. SEER Cancer Statistics Review 1975-2002. Bethesda, MD: National Cancer Institute; 2005. Mielcarek M, Martin PJ, Leisenring W, et al. Graft-versus-host disease after nonmyeloablative versus conventional hematopoietic stem cell transplantation. Blood. 2003;102:756-762. Kottardis PD, Milligan DW, Chopra R, et al. In vivo CAMPATH-1 H prevents graft-versus-host disease after nonmyeloablative stem cell transplantation. Blood. 2000;96:2419-2425. Chakraverty R, Peggs KS, Chopra R, et al. Limiting transplantation-related mortality after unrelated donor stem cell transplantation by using a nonmyeloablative conditioning regimen. Blood. 2002;99:1071-1078. Mohty M, Bay JO, Faucher C, et al. Graft-versus-host disease after allogeneic transplantation from HLA-identical sibling with antithymocyte globulin–based reduced-intensity preparative regimen. Blood. 2003;102:470-476. Perez-Sim on JA, Kottardis PD, Martino R, et al. Nonmyeloablative transplantation with or without alemtuzumab: comparison between 2 prospective studies in patients with lymphoproliferative disorders. Blood. 2002;100:3121-3127. Chakrabarti S, Mackinnon S, Chopra R, et al. High incidence of cytomegalovirus infection after nomyeloablative stem cell transplantation: potential role of Campath-1 H in delaying immune reconstitution. Blood. 2002;99:4357-4363. Peggs KS, Thomson K, Hart DP, et al. Dose-escalated donor lymphocyte infusions after reduced-intensity transplantation: toxicity, chimerism, and disease responses. Blood. 2004;103: 1548-1556. Storb R, Deeg HJ, Whitehead J, et al. Methotrexate and cyclosporine compared with cyclosporine alone for prophylaxis of acute graft-versus-host disease after marrow transplantation for leukemia. N Engl J Med. 1986;314:729-735. Cheson BD, Bennett JM, Grever M, et al. National Cancer Institute–sponsored Working Group guidelines for chronic lymphocytic leukemia: revised guidelines for diagnosis and treatment. Blood. 1996;87:4990-4997. Cheson BD, Horning SJ, Coiffier B, et al. Report of an international workshop to standardize response criteria for non-Hodgkin’s lymphomas. NCI-Sponsored International Working Group. J Clin Oncol. 1999;17:1244-1253. Przepiorka D, Weisdorf D, Martin P, et al. 1994 Consensus Conference on Acute GVHD Grading. Bone Marrow Transplant. 1995;15:825-828. Hart DP, Avivi I, Thomson KJ, et al. Use of 18F-FDG positron emission tomography after allogeneic transplantation to guide adoptive immunotherapy with donor lymphocyte infusions. Br J Haematol. 2005;128:1065-1069. Maloney DG, Grillo-Lopez AJ, White CA, et al. IDEC-C2B8 (rituximab) anti-CD20 monoclonal antibody therapy in patients with relapsed low-grade non-Hodgkin’s lymphoma. Blood. 1997; 90:2188-2195.

32. Maloney DG, Grillo-Lopez AJ, Bodkin DJ, et al. IDEC-C2B8: results of a phase I multiple-dose trial in patients with relapsed non-Hodgkin’s lymphoma. J Clin Oncol. 1997;15:3166-3274. 33. McLoughlin P, Grillo-Lopez AJ, Link BK, et al. Rituximab chimeric anti-patients respond to a four-dose treatment program. J Clin Oncol. 1998;16:2825-2833. 34. Huss R, Deeg HJ, Gooley T, et al. Effect of MC on graft-versushost disease, disease recurrence and survival after HLA-identical marrow transplantation for aplastic anemia or chronic myelogenous leukemia. Bone Marrow Transplant. 1996;18:767-776. 35. Walker H, Singer CR, Patterson J, et al. The significance of host haemopoietic cells detected by cytogenetic analysis of bone marrow from recipients of bone marrow transplants. Br J Haematol. 1986;62:385-391. 36. Petz LD, Yam P, Wallace RB, et al. Mixed haematopoietic chimerism after bone marrow transplantation for hematologic malignancies. Blood. 1987;70:1331-1337. 37. Schattenberg A, De Witte T, Salden M, et al. Mixed hematopoietic chimerism after allogeneic transplantation with lymphocyte-depleted bone marrow is not associated with a higher incidence of relapse. Blood. 1989;73:1367-1373. 38. Perez-Sim on JA, Caballero D, Diaz-Campello M, et al. Chimerism and minimal residual disease monitoring after reducedintensity conditioning (RIC) allogeneic transplantation. Leukemia. 2002;16:1423-1431. 39. Baron F, Maris MB, Sandmaier BM, et al. Graft-versustumor effects after allogeneic hematopoietic cell transplantation with nonmyeloablative conditioning. J Clin Oncol. 2005; 23:1993-2003. 40. Thiede C, Florek M, Bornha¨user M, et al. Rapid quantification of MC using multiplex amplification of short-tandem repeat markers and fluorescence detection. Bone Marrow Transplant. 1999;23:1055-1060. 41. Mapara MY, Kim Y-M, Wang S-P, et al. Donor lymphocyte infusions mediate superior graft-versus-leukemia effects in mixed compared to fully allogeneic chimeras: a critical role for host antigen-presenting cells. Blood. 2002;100:1903-1909. 42. Baron F, Little MT, Storb R. Kinetics of engraftment after allogeneic hematopoietic cell transplantation with reduced-intensity or nonmyeloablative conditioning. Blood Rev. 2005;19:153-164. 43. Childs R, Clave E, Contentin N, et al. Engraftment kinetics after nonmyeloablative allogeneic peripheral blood stem cell transplantation: full donor T-cell chimerism precedes alloimmune responses. Blood. 1999;94:3234-3241. 44. Petersen SL, Madsen HO, Ryder LP, et al. Chimerism studies in HLA-identical nonmyeloablative hematopoietic stem cell transplantation point to the donor CD8(1) T-cell count on day 114 as a predictor of acute graft-versus-host disease. Biol Blood Marrow Transplant. 2004;10:337-346. 45. Mattsson J, Uzunel M, Brune M, et al. Mixed chimaerism is common at the time of acute graft-versus-host disease and disease response in patients receiving non-myeloablative conditioning and allogeneic stem cell transplantation. Br J Haematol. 2001;115:935-944.