Thomas R. Klumpp

Selective modulation of human natural killer cells in vivo after prolonged infusion of low dose recombinant interleukin 2.

The immunologic consequences of prolonged infusions of rIL-2 in doses that produce physiologic serum concentrations of this cytokine were investigated. rIL-2 in doses of 0.5-6.0 x 10(6) U/m2 per d (3.3-40 micrograms/m2 per d) was administered by continuous intravenous infusion for 90 consecutive days to patients with advanced cancer. IL-2 concentrations (25 +/- 25 and 77 +/- 64 pM, respectively) that selectively saturate high-affinity IL-2 receptors (IL-2R) were achieved in the serum of patients receiving rIL-2 infusions of 10 micrograms/m2 per d and 30 micrograms/m2 per d. A gradual, progressive expansion of natural killer (NK) cells was seen in the peripheral blood of these patients with no evidence of a plateau effect during the 3 mo of therapy. A preferential expansion of CD56bright NK cells was consistently evident. NK cytotoxicity against tumor targets was only slightly enhanced at these dose levels. However, brief incubation of these expanded NK cells with IL-2 in vitro induced potent lysis of NK-sensitive, NK-resistant, and antibody-coated targets. Infusions of rIL-2 at 40 micrograms/m2 per d produced serum IL-2 levels (345 +/- 381 pM) sufficient to engage intermediate affinity IL-2R p75, which is constitutively expressed by human NK cells. This did not result in greater NK cell expansion compared to the lower dose levels, but did produce in vivo activation of NK cytotoxicity, as evidenced by lysis of NK-resistant targets. There was no consistent change in the numbers of CD56- CD3+ T cells, CD56+ CD3+ MHC-unrestricted T cells, or B cells during infusions of rIL-2 at any of the dosages used. This study demonstrates that prolonged infusions of rIL-2 in doses that saturate only high affinity IL-2R can selectively expand human NK cells for an extended period of time with only minimal toxicity. Further activation of NK cytolytic activity can also be achieved in vivo, but it requires concentrations of IL-2 that bind intermediate affinity IL-2R p75. Clinical trials are underway attempting to exploit the differing effects of various concentrations of IL-2 on human NK cells in vivo.

Granulocyte colony-stimulating factor accelerates neutrophil engraftment following peripheral-blood stem-cell transplantation: a prospective, randomized trial.

PURPOSE It is well-established that the infusion of hematopoietic growth factors (HGF) accelerates neutrophil recovery in patients undergoing high-dose therapy followed by autologous bone marrow infusion. In addition, there is evidence that the infusion of autologous peripheral-blood stem cells (PBSC) accelerates engraftment in comparison to patients who receive bone marrow alone. However, few data are available regarding the ability of HGF to accelerate engraftment further in patients who receive PBSC following high-dose therapy. PATIENTS AND METHODS Forty-one patients undergoing high-dose therapy followed by infusion of autologous PBSC with or without bone marrow were randomized to receive granulocyte colony-stimulating factor (G-CSF) 5 micrograms/kg/d beginning on day + 1 following transplant or standard posttransplant supportive care without HGF. RESULTS The median time to a neutrophil count > or = 500/microL was 10.5 days in the G-CSF group versus 16 days in the control group (P = .0001). G-CSF was associated with statistically significant reductions in the time to neutrophil engraftment among patients who received PBSC alone (11 v 17 days, P = .0003) and in patients who received PBSC in conjunction with bone marrow (10 v 14 days, P = .02). The median duration of posttransplant hospitalization (18 v 24 days, P = .002) and the median number of days on nonprophylactic antibiotics (11 v 15, P = .03) were also significantly reduced. CONCLUSION Administration of G-CSF in the posttransplant period accelerates the rate of neutrophil engraftment, shortens the duration of hospitalization, and reduces the number of days on nonprophylactic antibiotics in patients who receive autologous PBSC with or without autologous bone marrow following high-dose therapy.

The outcome of full-intensity and reduced-intensity conditioning matched sibling or unrelated donor transplantation in adults with Philadelphia chromosome–negative acute lymphoblastic leukemia in first and second complete remission

We examined the efficacy of reduced-intensity conditioning (RIC) and compared outcomes of 93 patients older than 16 years after RIC with 1428 patients receiving full-intensity conditioning for allografts using sibling and unrelated donors for Philadelphia-negative acute lymphoblastic leukemia (ALL) in first or second complete remission. RIC conditioning included busulfan 9 mg/kg or less (27), melphalan 150 mg/m(2) or less (23), low-dose total body irradiation (TBI; 36), and others (7). The RIC group was older (median 45 vs 28 years, P < .001) and more received peripheral blood grafts (73% vs 43%, P < .001) but had similar other prognostic factors. The RIC versus full-intensity conditioning groups had slightly, but not significantly, less acute grade II-IV graft-versus-host disease (39% vs 46%) and chronic graft-versus-host disease (34% vs 42%), yet similar transplantation-related mortality. RIC led to slightly more relapse (35% vs 26%, P = .08) yet similar age-adjusted survival (38% vs 43%, P = .39). Multivariate analysis showed that conditioning intensity did not affect transplantation-related mortality (P = .92) or relapse risk (P = .14). Multivariate analysis demonstrated significantly improved overall survival with: Karnofsky performance status more than 80, first complete remission, lower white blood count, well-matched unrelated or sibling donors, transplantation since 2001, age younger than 30 years, and conditioning with TBI, but no independent impact of conditioning intensity. RIC merits further investigation in prospective trials of adult ALL.

Comparable survival after HLA–well-matched unrelated or matched sibling donor transplantation for acute myeloid leukemia in first remission with unfavorable cytogenetics at diagnosis

We compared the outcomes of unrelated donor (URD, n = 358) with human leukocyte antigen (HLA)-matched sibling donor (MSD, n = 226) transplantations in patients with acute myeloid leukemia (AML) in first complete remission (CR1) having unfavorable cytogenetics at diagnosis. Unfavorable cytogenetic abnormalities were: complex (≥ 3 abnormalities), 32%; and noncomplex involving chromosome 7, 25%; chromosome 5, 9%; 11q or MLL rearrangements, 18%; t(6;9), 5%; and other noncomplex, 10%. URDs were HLA-well-matched (n = 254; 71%) or partially-matched (n = 104; 29%). Three-year leukemia-free survival (LFS) for MSD was 42% (95% confidence interval [CI], 35%-48%) compared with 34% (95% CI, 28%-41%) for HLA-well-matched URD and 29% (95% CI, 20%-39%) for partially-matched URD (P = .08). In multivariate analysis, HLA-well-matched URD and MSD yielded similar LFS (relative risk [RR] = 1.1, 95% CI, 0.86-1.40, P = .44) and overall survival (OS; RR = 1.06, 95% CI, 0.83-1.37, P = .63). LFS and OS were significantly inferior for HLA-partially-matched URD recipients, those with prior myelodysplastic syndrome, and those older than 50 years. All cytogenetic cohorts had similar outcomes. Patients with chronic graft-versus-host disease had a significantly lower risk of relapse (RR = 0.68, 95% CI, 0.47-0.99, P = .05). Hematopoietic cell transplantation (HCT) using HLA-well-matched URD and MSD resulted in similar LFS and OS in AML patients in CR1 with unfavorable cytogenetics. Outcomes of HCT from HLA-partially- matched URD were inferior.

Clinical consequences of alterations in platelet transfusion dose: a prospective, randomized, double‐blind trial

BACKGROUND: The dose‐response relationship for platelet transfusion has become increasingly important as the use of platelet transfusion has grown.

Extended continuous infusion low-dose recombinant interleukin-2 in advanced cancer: prolonged immunomodulation without significant toxicity.

In previous clinical trials, recombinant interleukin-2 (rIL-2) has been infused at high doses over short periods of time to generate lymphokine-activated killer (LAK) cells in vivo. These trials have been limited by severe toxicities, and the immunologic effects of rIL-2 have been transient. The present study was designed to assess the toxicity and immunologic effects of prolonged administration of low doses of rIL-2. In this phase I study, patients with advanced cancer were scheduled to receive intravenous (IV) infusion of rIL-2 without interruption for 3 months in an outpatient setting. Twenty-one patients received rIL-2 at doses ranging from 0.5 x 10(5) to 6.0 x 10(5) U/m2/d. Treatment was extremely well tolerated, and no patient experienced grade 3 or grade 4 toxicity. The lowest dose level (0.5 x 10(5) U/m2/d) did not have demonstrable immunologic activity. At doses of 1.5 x 10(5) and 4.5 x 10(5) U/m2/d, rIL-2 infusion resulted in the specific expansion of natural-killer (NK) cells (sixfold and ninefold increases, respectively, at these two dose levels) without any changes in B cells, T cells, neutrophils, or monocytes. Grade 2 toxicity was observed at the dose of 6.0 x 10(5) U/m2/d, as three patients required interruption of therapy and two patients who completed therapy developed transient hypothyroidism. In patients with increased NK cells, enhancement of non-major histocompatibility complex (MHC)-restricted cytotoxicity and increased generation of LAK cells in vitro were also demonstrated. Therapy with low-dose rIL-2 can be given safely in an uninterrupted fashion for prolonged periods of time in an outpatient setting. This results in selective expansion of NK cells in vivo with minimal toxicity. Further investigation of this schedule for immunomodulation in vivo should be pursued in phase II studies of both malignant and immunodeficient disease states.

Increasing Incidence of Chronic Graft-versus-Host Disease in Allogeneic Transplantation: A Report from the Center for International Blood and Marrow Transplant Research

Although transplant practices have changed over the last decades, no information is available on trends in incidence and outcome of chronic graft-versus-host disease (cGVHD) over time. This study used the central database of the Center for International Blood and Marrow Transplant Research (CIBMTR) to describe time trends for cGVHD incidence, nonrelapse mortality, and risk factors for cGVHD. The 12-year period was divided into 3 intervals, 1995 to 1999, 2000 to 2003, and 2004 to 2007, and included 26,563 patients with acute leukemia, chronic myeloid leukemia, and myelodysplastic syndrome. Multivariate analysis showed an increased incidence of cGVHD in more recent years (odds ratio = 1.19, P < .0001), and this trend was still seen when adjusting for donor type, graft type, or conditioning intensity. In patients with cGVHD, nonrelapse mortality has decreased over time, but at 5 years there were no significant differences among different time periods. Risk factors for cGVHD were in line with previous studies. This is the first comprehensive characterization of the trends in cGVHD incidence and underscores the mounting need for addressing this major late complication of transplantation in future research.

Chronic GVHD risk score: a Center for International Blood and Marrow Transplant Research analysis.

Several risk factors are associated with increased mortality in patients with chronic graft-versus-host disease (cGVHD), but there is considerable variability in the reported factors. Therefore, we evaluated patient, transplantation, and cGVHD characteristics to develop a risk score in 5343 patients with cGVHD. Ten variables were identified as being significant in multivariate analysis of overall survival and nonrelapse mortality (NRM): age, prior acute GVHD, time from transplantation to cGVHD, donor type, disease status at transplantation, GVHD prophylaxis, gender mismatch, serum bilirubin, Karnofsky score, and platelet count. These 10 variables were used to build a cGVHD risk score, and 6 risk groups (RGs) were identified. The 5-year NRM was 5% (1%-9%) in RG1, 20% (19%-23%) in RG2, 33% (29%-37%) in RG3, 43% (40%-46%) in RG4, 63% (53%-74%) in RG5, and 72% (59%-85%) in RG6. The 5-year overall survival was highest at 91% (95% confidence interval [CI]:85%-97%) in RG1, followed by 67% (65%-69%) in RG2, 51% (46%-55%) in RG3, 40% (37%-43%) in RG4, 21% (12%-30%) in RG5, and 4% (0%-9%) in RG6 (all P < .01). This analysis demonstrates the usefulness of data from a large registry to develop risk-score categories for major transplantation outcomes. Validation of this cGVHD risk score is needed in a different population to ensure its broad applicability.

Unrelated donor transplants in adults with Philadelphia-negative acute lymphoblastic leukemia in first complete remission

We report the retrospective outcomes of unrelated donor (URD) transplants in 169 patients with acute lymphoblastic leukemia (ALL) in first complete remission (CR1) who received transplants between 1995 and 2004. Median age was 33 years (range, 16-59 years). A total of 50% had a white blood cell count (WBC) more than 30 x 10(9)/L, 18% extramedullary disease, 42% achieved CR more than 8 weeks from diagnosis, 25% had adverse cytogenetics, and 19% had T-cell leukemia. A total of 41% were HLA well-matched, 41% partially matched with their donors, and 18% were HLA-mismatched. At 54-month median follow-up, incidences of acute grade 2-IV, III to IV, and chronic graft-versus-host disease were 50%, 25%, and 43%, respectively. Five-year treatment-related mortality (TRM), relapse, and overall survival were 42%, 20%, and 39%, respectively. In multivariate analyses, TRM was significantly higher with HLA-mismatched donors and T-cell depletion. Relapse risk was higher if the diagnostic WBC was more than 100 x 10(9)/L. Factors associated with poorer survival included WBC more than 100 x 10(9)/L, more than 8 weeks to CR1, cytomegalovirus seropositivity, HLA mismatching, and T-cell depletion. Nearly 40% of adults with ALL in CR1 survive 5 years after URD transplantation. Relapse risks were modest; TRM is the major cause of treatment failure. Selecting closely HLA-matched URD and reducing TRM should improve results.

A COMPARISON OF HLA-IDENTICAL SIBLING ALLOGENEIC VERSUS AUTOLOGOUS TRANSPLANTATION FOR DIFFUSE LARGE B-CELL LYMPHOMA: A REPORT FROM THE CIBMTR

We compared outcomes of 916 diffuse large B cell lymphoma (DLBCL) patients aged >or=18 years undergoing first autologous (n = 837) or myeloablative (MA) allogeneic hematopoietic cell transplant (HCT) (n = 79) between 1995 and 2003 reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). Median follow-up was 81 months for allogeneic HCT versus 60 months for autologous HCT. Allogeneic HCT recipients were more likely to have high-risk disease features including higher stage, more prior chemotherapy regimens, and resistant disease. Allogeneic HCT was associated with a higher 1 year treatment-related mortality (TRM) (relative risk [RR] 4.88, 95% confidence interval [CI], 3.21-7.40, P < .001), treatment failure (RR 2.06, 95% CI, 1.54-2.75, P < .001), and mortality (RR 2.75, 95% CI, 2.03-3.72, P < .001). Risk of disease progression was similar in the 2 groups (RR 1.12, 95% CI, 0.73-1.72, P = .59). In fact, for 1-year survivors, no significant differences were observed for TRM, progression, progression-free (PFS) or overall survival (OS). Increased risks of TRM and mortality were associated with older age (>50 years), lower performance score, chemoresistance, and earlier year of transplant. In a cohort of mainly high-risk DLBCL patients, upfront MA allogeneic HCT, although associated with increased early mortality, was associated with a similar risk of disease progression compared to lower risk patients receiving autologous HCT.