Roberto Crocchiolo

Infusion of suicide-gene-engineered donor lymphocytes after family haploidentical haemopoietic stem-cell transplantation for leukaemia (the TK007 trial): a non-randomised phase I–II study

BACKGROUND Procedures to prevent severe graft-versus-host disease (GVHD) delay immune reconstitution secondary to transplants of haploidentical haemopoietic stem cells for the treatment of leukaemia, leading to high rates of late infectious mortality. We aimed to systematically add back genetically engineered donor lymphocytes to facilitate immune reconstitution and prevent late mortality. METHODS In a phase I-II, multicentre, non-randomised trial of haploidentical stem-cell transplantation, we infused donor lymphocytes expressing herpes-simplex thymidine kinase suicide gene (TK-cells) after transplantation. The primary study endpoint was immune reconstitution defined as circulating CD3+ count of 100 cells per muL or more for two consecutive observations. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00423124. FINDINGS From Aug 13, 2002, to March 26, 2008, 50 patients (median age 51 years, range 17-66) received haploidentical stem-cell transplants for high-risk leukaemia. Immune reconstitution was not recorded before infusion of TK-cells. 28 patients received TK-cells starting 28 days after transplantation; 22 patients obtained immune reconstitution at median 75 days (range 34-127) from transplantation and 23 days (13-42) from infusion. Ten patients developed acute GVHD (grade I-IV) and one developed chronic GVHD, which were controlled by induction of the suicide gene. Overall survival at 3 years was 49% (95% CI 25-73) for 19 patients who were in remission from primary leukaemia at the time of stem-cell transplantation. After TK-cell infusion, the last death due to infection was at 166 days, this was the only infectious death at more than 100 days. No acute or chronic adverse events were related to the gene-transfer procedure. INTERPRETATION Infusion of TK-cells might be effective in accelerating immune reconstitution, while controlling GVHD and protecting patients from late mortality in those who are candidates for haploidentical stem-cell transplantation. FUNDING MolMed SpA, Italian Association for Cancer Research.

Temporal, quantitative, and functional characteristics of single-KIR-positive alloreactive natural killer cell recovery account for impaired graft-versus-leukemia activity after haploidentical hematopoietic stem cell transplantation

In this study, we have characterized reconstitution of the natural killer (NK) cell repertoire after haploidentical CD34(+) selected hematopoietic stem cell transplantation (HSCT) for high-risk hematologic malignancies. Analysis focused on alloreactive single-KIR(+) NK cells, which reportedly are potent antileukemic effectors. One month after HSCT, CD56(bright)/CD56(dim) NK-cell subsets showed inverted ratio and phenotypic features. CD25 and CD117 down-regulation on CD56(bright), and NKG2A and CD62L up-regulation on CD56(dim), suggest sequential CD56(bright)-to-CD56(dim) NK-cell maturation in vivo. Consistently, the functional potential of these maturation intermediates against leukemic blasts was impaired. Mature receptor repertoire reconstitution took at least 3 months. Importantly, at this time point, supposedly alloreactive, single-KIR(+) NK cells were not yet fully functional. Frequency of these cells was highly variable, independently from predicted NK alloreactivity, and below 1% of NK cells in 3 of 6 alloreactive patients studied. In line with these observations, no clinical benefit of predicted NK alloreactivity was observed in the total cohort of 56 patients. Our findings unravel the kinetics, and limits, of NK-cell differentiation from purified haploidentical hematopoietic stem cells in vivo, and suggest that NK-cell antileukemic potential could be best exploited by infusion of mature single-KIR(+) NK cells selected from an alloreactive donor.

Nonpermissive HLA-DPB1 disparity is a significant independent risk factor for mortality after unrelated hematopoietic stem cell transplantation

The importance of donor-recipient human leukocyte antigen (HLA)-DPB1 matching for the clinical outcome of unrelated hematopoietic stem cell transplantation (HSCT) is controversial. We have previously described an algorithm for nonpermissive HLA-DPB1 disparities involving HLA-DPB1*0901,*1001,*1701,*0301,*1401,*4501, based on T-cell alloreactivity patterns. By revisiting the immunogenicity of HLA-DPB1*02, a modified algorithm was developed and retrospectively tested in 621 unrelated HSCTs facilitated through the Italian Registry for oncohematologic adult patients. The modified algorithm proved to be markedly more predictive of outcome than the original one, with significantly higher Kaplan-Meier probabilities of 2-year survival in permissive compared with nonpermissive transplantations (55% vs 39%, P = .005). This was the result of increased adjusted hazards of nonrelapse mortality (hazard ratio [HR] = 1.74; confidence interval [CI], 1.19-2.53; P = .004) but not of relapse (HR = 1.02; CI, 0.73-1.42; P = .92). The increase in the hazards of overall mortality by nonpermissive HLA-DPB1 disparity was similar in 10 of 10 (HR = 2.12; CI, 1.23-3.64; P = .006) and 9 of 10 allele-matched transplantations (HR = 2.21; CI, 1.28-3.80; P = .004), both in early-stage and in advanced-stage disease. These data call for revisiting current HLA matching strategies for unrelated HSCT, suggesting that searches should be directed up-front toward identification of HLA-DPB1 permissive, 10 of 10 or 9 of 10 matched donors.

Bone Marrow Compared with Peripheral Blood Stem Cells for Haploidentical Transplantation with a Nonmyeloablative Conditioning Regimen and Post-transplantation Cyclophosphamide

Recently, the administration of high-dose cyclophosphamide (Cy) after T cell-replete haploidentical stem cell infusion has been reported to be feasible and effective. In the original study, bone marrow (BM) was used as the source of stem cells. Here, we retrospectively analyzed the use of BM versus peripheral blood stem cells (PBSCs) in a cohort of patients receiving haploidentical T cell-replete transplantation after a nonmyeloablative conditioning regimen with postinfusion Cy. In the PBSC versus BM groups, the incidence of acute graft-versus-host disease (GVHD) was 33% versus 25%, respectively, and the incidence of chronic GVHD was 13% versus 13%, respectively. The median time to achieve a safe and unsupported absolute neutrophil and platelet count was 20 versus 21 days and 27 versus 29 days, respectively. The incidence of engraftment was also similar in the 2 cohorts. The 1-year nonrelapse mortality rate was 12% versus 22%, respectively (P = .96). Finally, nonsignificant differences in survival were observed. In conclusion, the use of PBSCs instead of BM after T cell-replete haploidentical transplantation did not appear to be detrimental in terms of either GVHD or engraftment rate. PBSCs could be a valid alternative to BM after transplantation from a haploidentical donor using postinfusion Cy.

Sirolimus-based graft-versus-host disease prophylaxis promotes the in vivo expansion of regulatory T cells and permits peripheral blood stem cell transplantation from haploidentical donors

Hematopoietic stem cell transplantation (HSCT) from human leukocyte antigen (HLA) haploidentical family donors is a promising therapeutic option for high-risk hematologic malignancies. Here we explored in 121 patients, mostly with advanced stage diseases, a sirolimus-based, calcineurin-inhibitor-free prophylaxis of graft-versus-host disease (GvHD) to allow the infusion of unmanipulated peripheral blood stem cell (PBSC) grafts from partially HLA-matched family donors (TrRaMM study, Eudract 2007-5477-54). Conditioning regimen was based on treosulfan and fludarabine, and GvHD prophylaxis on antithymocyte globulin Fresenius (ATG-F), rituximab and oral administration of sirolimus and mycophenolate. Neutrophil and platelet engraftment occurred in median at 17 and 19 days after HSCT, respectively, and full donor chimerism was documented in patients’ bone marrow since the first post-transplant evaluation. T-cell immune reconstitution was rapid, and high frequencies of circulating functional T-regulatory cells (Treg) were documented during sirolimus prophylaxis. Incidence of acute GvHD grade II–IV was 35%, and occurrence and severity correlated negatively with Treg frequency. Chronic GvHD incidence was 47%. At 3 years after HSCT, transpant-related mortality was 31%, relapse incidence 48% and overall survival 25%. In conclusion, GvHD prophylaxis with sirolimus–mycophenolate–ATG-F–rituximab promotes a rapid immune reconstitution skewed toward Tregs, allowing the infusion of unmanipulated haploidentical PBSC grafts.

Haploidentical T Cell-Replete Transplantation with Post-Transplantation Cyclophosphamide for Patients in or above the Sixth Decade of Age Compared with Allogeneic Hematopoietic Stem Cell Transplantation from an Human Leukocyte Antigen-Matched Related or Unrelated Donor.

It has recently been shown that a T cell-replete allogeneic (allo) hematopoietic stem cell transplantation (HSCT) from a haploidentical donor (haplo-ID) could be a valid treatment for hematological malignancies. However, little data exist concerning older populations. We provided transplantation to 31 patients over the age of 55 years from a haplo-ID and compared their outcomes with patients of the same ages who underwent transplantation from a matched related (MRD) or an unrelated donor (UD). All 3 groups were comparable, except for their conditioning. Patients in haplo-ID group received 2 days of post-transplantation high-dose cyclophosphamide followed by cyclosporine A and mycophenolate mofetil, whereas patients in other groups received pretransplantation antithymocyte globulin, cyclosporine A, and additional mycophenolate mofetil in case of 1-antigen mismatch. All patients but 1 in the haplo-ID group engrafted. The incidence of grades 2 to 4 acute graft-versus-host disease (GVHD) was not statistically different between recipients from haplo-ID (cumulative incidence, 23%) and MRD (cumulative incidence, 21%) transplantations but it was lower than after UD HSCT (cumulative incidence, 44%). No patient in the haplo-ID group developed severe chronic GVHD, compared with cumulative incidences of 16% and 14% after MRD (P = .02) and UD (P = .03) grafts, respectively. The cumulative incidences of relapse were similar in the 3 groups, whereas nonrelapse mortality after UD HSCT was 3-fold higher than after haplo-ID or MRD HSCT. Overall, 2-year overall survival (70%), progression-free survival (67%), and progression and severe chronic GVHD-free survival (67%) probabilities after haplo-ID did not statistically differ from MRD transplantation (78%, 64%, and 51%, respectively), although they were higher than after UD transplantation (51% [P = .08], 38% [P = .02], and 31% [P = .007]). We conclude that T cell-replete haplo-ID HSCT followed by post-transplantation high-dose- cyclophosphamide in patients over 55 years is associated with promising results, similar to MRD HSCT, and is deserving prospective evaluation.

Six-month oral clarithromycin regimen is safe and active in extranodal marginal zone B-cell lymphomas: final results of a single-centre phase II trial.

Antibiotics could be included in the long list of anticancer candidates by virtue of their good tolerability and direct proapoptotic effect on tumour cells. This effect is achieved by means of multiple antiproliferative mechanisms that deserve to be better explored. Among others, macrolides have been proposed as potential antineoplastic and immunomodulatory agents. They enhance the antitumour activity of macrophages, natural killerand CD8 cytotoxic T-cells, reduce neutrophil production of interleukin-8, and inhibit tumour necrosis factor-a and vascular endothelial growth factor activity (Aoki et al, 2005). Clarithromycin is a substrate of P-glycoprotein, induces apoptotic changes in tumour cells and exhibits antitumour activity in different murine cancer models (Wakasugi et al, 1998; Hamada et al, 2000). These preclinical data constitute the rationale for prospective clinical trials addressing the antineoplastic activity of macrolides. In particular, the combination of clarithromycin with other immunomodulatory agents has been associated with encouraging results in prospective trials on multiple myeloma and Waldenström macroglobulinemia (Niesvizky et al, 2008). Additionally, anecdotal case reports suggest an antineoplastic effect of clarithromycin in patients with marginal zone B-cell lymphoma (MZL) of the gastrointestinal tract (Arima & Tsudo, 2003; Matsumoto & Iida, 2005). Given its indolent behaviour, extranodal MZL (EMZL) is a suitable candidate to test the potential direct anticancer effect of macrolides. On this basis, we designed a pilot phase II trial to address the feasibility and activity of a 6-month oral clarithromycin regimen as exclusive treatment in patients with relapsed/refractory EMZL. The trial conformed to the tenets of the Declaration of Helsinki, and was approved by the Institutional Review Board of the San Raffaele Scientific Institute. From June 2006 to May 2008, 13 patients (median age 57 years, range 36–80 years; seven males) with relapsed/ refractory EMZL, Eastern Cooperative Oncology Group (ECOG) performance status (PS) £3 and at least one measurable or parametrable lesion were registered. Baseline assessment included physical examination, haemogram and biochemical profile, human immunodeficiency virus, hepatitis C virus (HCV) and hepatitis B virus serology, total body computed tomography scan, gastroscopy, and bone marrow biopsy. All patients were tested for Helicobacter pylori (Hp)

Central nervous system dissemination in immunocompetent patients with aggressive lymphomas: incidence, risk factors and therapeutic options

Central nervous system (CNS) dissemination is a rare (4–5%) but usually fatal complication of aggressive lymphomas. Prophylaxis modalities to prevent CNS dissemination in aggressive lymphomas cannot be widely applied to every lymphoma patient since it is associated with increased risk of neurotoxicity. Therefore, identification of high‐risk patients as the best candidates to receive CNS prophylaxis constitutes a major endpoint in the management of these malignancies. Various risk factors and models for CNS recurrence have been described. Parameters reflecting the extent and proliferation of the disease, like elevated serum lactate dehydrogenase levels, involvement of multiple extranodal sites, advanced stage and high age‐adjusted International Prognostic Index (IPI) score, as well as the involvement of specific anatomic sites, like testes, orbit, paranasal sinuses, have been identified and confirmed as important to predict CNS dissemination. Management of this complication in aggressive lymphomas with conventional‐dose chemotherapy is associated with disappointing results, while some preliminary but encouraging experiences suggest a potential role of high‐dose chemotherapy and stem cell transplantation. The analysis of recent clinical studies could lead to advancement in the prognosis of aggressive lymphomas, but several questions regarding the optimum chemotherapy combination, the best conditioning regimen and the role of radiation therapy and intrathecal chemotherapy remain still unanswered. The purposes of the present review are to critically analyse current data on the risk of CNS dissemination in aggressive lymphomas, the clinical presentation of secondary CNS lymphomas and the efficacy of CNS prophylaxis as well as to discuss the available therapeutic options for this devastating event. Copyright

Role of naïve-derived T memory stem cells in T cell reconstitution following allogeneic transplantation

Early T-cell reconstitution following allogeneic transplantation depends on the persistence and function of T cells that are adoptively transferred with the graft. Posttransplant cyclophosphamide (pt-Cy) effectively prevents alloreactive responses from unmanipulated grafts, but its effect on subsequent immune reconstitution remains undetermined. Here, we show that T memory stem cells (TSCM), which demonstrated superior reconstitution capacity in preclinical models, are the most abundant circulating T-cell population in the early days following haploidentical transplantation combined with pt-Cy and precede the expansion of effector cells. Transferred naive, but not TSCM or conventional memory cells preferentially survive cyclophosphamide, thus suggesting that posttransplant TSCM originate from naive precursors. Moreover, donor naive T cells specific for exogenous and self/tumor antigens persist in the host and contribute to peripheral reconstitution by differentiating into effectors. Similarly, pathogen-specific memory T cells generate detectable recall responses, but only in the presence of the cognate antigen. We thus define the cellular basis of T-cell reconstitution following pt-Cy at the antigen-specific level and propose to explore naive-derived TSCM in the clinical setting to overcome immunodeficiency. These trials were registered at www.clinicaltrials.gov as #NCT02049424 and #NCT02049580.

The increase from 2.5 to 5 mg/kg of rabbit anti-thymocyte-globulin dose in reduced intensity conditioning reduces acute and chronic GVHD for patients with myeloid malignancies undergoing allo-SCT

We previously reported that reduced intensity conditioning (RIC) regimen with fludarabine, BU and 2.5 mg/kg of rabbit anti-thymocyte globulin (r-ATG) was effective but associated with a high rate of acute and chronic GVHD. Therefore, we increased the dose of r-ATG to 5 mg/kg. In this report, we analyzed 87 patients with AML or myelodysplastic syndrome (MDS) undergoing allo-SCT from an HLA-identical sibling donor from 2000 to 2010. RIC consisted of fludarabine, BU and r-ATG 2.5 mg/kg on 1 day (r-ATG1; n=53) or 2.5 mg/kg per day over 2 days (r-ATG2; n=22). Grade 2–4 acute GVHD incidence at day 100 was 30.2% and 8.8% in the r-ATG1 and r-ATG2 groups, respectively (P=0.038). Extensive chronic GVHD incidence was 60.4% and 12% in the r-ATG1 and r-ATG2 groups, respectively (P<0.001). The relapse incidences (RI) at 24 months were 18.9% and 28.5% in r-ATG1 and r-ATG2 groups, respectively (P=0.640). Overall and PFS were not different between the r-ATG1 and r-ATG2 groups. r-ATG dose at 5 mg/kg in the setting of RIC seems a good balance allowing GVHD prevention and antitumor effect with a remarkable reduction of GVHD incidence without an identical level of increased relapse rate.