Allogeneic hematopoietic cell transplantation is equally effective in secondary acute lymphoblastic leukemia (ALL) compared to de-novo ALL-a report from the EBMT registry.

Secondary acute lymphoblastic leukemia (s-ALL) comprises up to 10% of ALL patients. However, data regarding s-ALL outcomes is limited. To answer what is the role of allogeneic hematopoietic cell transplantation (HCT) in s-ALL, a matched-pair analysis in a 1:2 ratio was conducted to compare outcomes between s-ALL and de novo ALL (dn-ALL) patients reported between 2000-2021 to the European Society for Blood and Marrow Transplantation registry. Among 9720 ALL patients, 351 (3.6%) were s-ALL, of which 80 were in first complete remission (CR1) with a known precedent primary diagnosis 58.8% solid tumor (ST), 41.2% hematological diseases (HD). The estimated 2-year relapse incidence (RI) was 19.1% (95%CI: 11-28.9), leukemia-free survival (LFS) 52.1% (95%CI: 39.6-63.2), non-relapse mortality (NRM) 28.8% (95%CI: 18.4-40), GvHD-free, relapse-free survival (GRFS) 39.4% (95%CI: 27.8-50.7), and overall survival (OS) 60.8% (95%CI: 47.9-71.4), and did not differ between ST and HD patients. In a matched-pair analysis, there was no difference in RI, GRFS, NRM, LFS, or OS between s-ALL and dn-ALL except for a higher incidence of chronic GvHD (51.9% vs. 31.4%) in s-ALL. To conclude, patients with s-ALL who received HCT in CR1 have comparable outcomes to patients with dn-ALL.

The predictive role of interim PET after the first chemotherapy cycle and sequential evaluation of response to ABVD in Hodgkin's lymphoma patients-the Polish Lymphoma Research Group (PLRG) Observational Study.

BACKGROUND: Interim PET after two ABVD cycles (iPET2) predicts treatment outcome in classical Hodgkin's lymphoma. To test whether an earlier assessment of chemosensitivity would improve the prediction accuracy, we launched a prospective, multicenter observational study aimed at assessing the predictive value of iPET after one ABVD (iPET1) and the kinetics of response assessed by sequential PET scanning. PATIENTS AND METHODS: Consecutive patients with newly diagnosed classical Hodgkin's lymphoma underwent interim PET scan after one ABVD course (iPET1). PETs were interpreted according to the Deauville score (DS) as negative (-) (DS 1-3) and positive (+) (DS 4, 5). Patients with iPET1 DS 3-5 underwent iPET2. RESULTS: About 106 early (I-IIA) and 204 advanced (IIB-IV) patients were enrolled between January 2008 and October 2014. iPET1 was (-) in 87/106 (82%) or (+) in 19/106 (18%) of early, and (-) in 133/204 (65%) or (+) in 71/204 (35%) of advanced stage patients, respectively. Twenty-four patients were excluded from response analysis due to treatment escalation. After a median follow-up of 38.2 (3.2-90.2) months, 9/102 (9%) early and 43/184 (23%) advanced patients experienced a progression-free survival event. At 36 months, negative and positive predictive value for iPET1 were 94% and 41% (early) and 84% and 43% (advanced), respectively. The kinetics of PET response was assessed in 198 patients with both iPETs. All 116 patients with iPET1(-) remained iPET2(-) (fast responders), 41/82 with IPET1(+) became iPET2(-) (slow responders), and the remaining 41 stayed iPET2(+) (non-responders); progression-free survival at 36 months for fast, slow and non-responders was 0.88, 0.79 and 0.34, respectively. CONCLUSION: The optimal tool to predict ABVD outcome in HL remains iPET2 because it distinguishes responders, whatever their time to response, from non-responders. However, iPET1 identified fast responders with the best outcome and might guide early treatment de-escalation in both early and advanced-stage HL.

Efficacy and safety of lenalidomide treatment in multiple myeloma (MM) patients--Report of the Polish Myeloma Group.

UNLABELLED: The aim of the multi-centre retrospective study was to evaluate the efficacy and safety of lenalidomide (LEN) therapy in patients with resistant or relapsed multiple myeloma (MM) as well as in patients with stable disease (LEN used due to neurological complications). The primary endpoint of this study was an overall response rate (ORR). The secondary endpoints were as follows: time to progression (TTP), overall survival (OS) and the safety of drug use. Data were collected in 19 centres of the Polish Multiple Myeloma Study Group. The study group consisted of 306 subjects: 153 females and 153 males. In 115 patients (38.8%, group A), a resistant myeloma was diagnosed; in 135 (44.1%, group B) a relapse, and in 56 (18.3%, group C) a stable disease were stated. In 92.8% of patients, LEN+DEX combination was used; in remaining group, LEN monotherapy or a combination therapy LEN+bortezomib or LEN+bendamustine and other were used. In the entire study group, ORR was 75.5% (including 12.4% patients achieving complete remission [CR] or stringent CR [sCR]). Median time to progression (TTP) was 20 months. Median overall survival (OS) was 33.3 months. The regression model for "treatment response" was on the borderline of statistical significance (p=0.07), however the number of LEN treatment cycles ≥ 6 (R(2)=17.2%), baseline LDH level (R(2)=1.1%) and no ASCT use (R(2)=1.7%) where the factors most affecting treatment response achievement. The regression model for dependant variable--"overall survival"--was statistically significant (p=0.0000004). Factors with the most impact on OS were as follows: number of LEN cycles treatment ≥ 6 (R(2)=16.7%), treatment response achievement (R(2)=6.9%), ß-2-microglobulin (ß-2-M) level (R(2)=4.8%), renal function (R(2)=3.0%) and lack of 3/4 grade adverse events (R(2)=1.4%). SUMMARY: LEN is an effective and safe therapeutic option, even in intensively treated resistant and relapsed MM patients, as well as in patients with stable disease and previous treatment-induced neurological complications. In particular, the number of LEN treatment cycles ≥ 6 was the factor which affected treatment response achievement the most, together with an important impact on OS.

International prognostic index, type of transplant and response to rituximab are key parameters to tailor treatment in adults with CD20-positive B cell PTLD: clues from the PTLD-1 trial.

Tailoring treatment by patient strata based on the risk of disease progression and treatment toxicity might improve outcomes of patients with posttransplant lymphoproliferative disorder (PTLD). We analysed the cohort of 70 patients treated in the international, multicenter phase II PTLD-1 trial (NCT01458548) to identify such factors. Of the previously published scoring systems in PTLD, the international prognostic index (IPI), the PTLD prognostic index and the Ghobrial score were predictive for overall survival. None of the scoring systems had a considerable effect on the risk for disease progression. Age and ECOG performance status were the baseline variables with the highest prognostic impact in the different scoring systems. Baseline variables not included in the scoring systems that had an impact on overall survival and disease progression were the type of transplant and the response to rituximab at interim staging. Thoracic organ transplant recipients who did not respond to rituximab monotherapy were at particularly high risk for death from disease progression with subsequent CHOP-based chemotherapy. Patients in complete remission after four courses of rituximab and patients in partial remission with low-risk IPI had a low risk of disease progression. We speculate that chemotherapy might not be necessary in this patient cohort.

Imatinib-associated neutropenia may not be overcome by filgrastim treatment in patients with blastic phase of chronic myeloid leukaemia.

Imatinib mesylate is a very effective treatment in patients with Philadelphia (Ph)-positive chronic myeloid leukaemia (CML). However, in patients with advanced phase CML, it is still unclear whether, in the presence of myelosuppression, therapy with imatinib should be continued. It has been reported that intermittent filgrastim treatment may overcome imatinib-associated neutropenia and allow improved delivery of imatinib. Such combined sequential treatment is theoretically attractive as it may lead to better disease response. Here, we report a patient with blastic phase CML who developed severe and prolonged myelosuppression during imatinib treatment. Despite cessation of imatinib and 2 months of filgrastim therapy neither recurrence of Ph-positive or Ph-negative cells occurred. We conclude that filgrastim treatment may not always reverse imatinib-associated neutropenia therefore the decision of continued imatinib therapy in patients with advanced CML should be taken with caution.

Imatinib therapy prior to myeloablative allogeneic stem cell transplantation.

It is unknown whether imatinib prior to myeloablative haematopoietic stem cell transplantation (HSCT) increases transplant-related toxicity. Among the side effects induced by imatinib, myelosuppression and liver injury might worsen HSCT outcomes. We retrospectively analysed engraftment, liver toxicity, acute graft-versus-host disease (aGVHD) incidence and 100-day mortality in 30 patients with BCR/ABL-positive leukaemias who received imatinib before HSCT and compared results of 48 age-matched controls who did not receive preceding imatinib. Both neutrophil and platelet engraftment occurred more rapidly among imatinib patients but the differences adjusted for Gratwohl scale were not statistically significant (P = 0.18 and 0.22, respectively). The adjusted hazards of having liver function tests (LFTs) >1.5 normal increased and the adjusted durations of elevated LFTs were not significantly different. The estimated adjusted difference in mean peak bilirubin values was also not significantly different (P = 0.48). However, the adjusted hazard of increased creatinine >1.5 normal was significantly higher in the imatinib group (HR = 4.09, P = 0.02). The adjusted odds of grades II-IV aGVHD were similar in both groups (OR = 0.86, P = 0.78), and while the adjusted odds of 100-day mortality were lower among imatinib patients, the difference was not significant (OR = 0.65, P = 0.60). These data do not provide any evidence that imatinib preceding HSCT increases acute transplant-related toxicities.

Multiple red cell alloantibodies, including anti-Dib, after allogeneic ABO-matched peripheral blood progenitor cell transplantation.

BACKGROUND: Data on red blood cell (RBC) alloantibody appearance after hematopoietic progenitor cell transplantation (HPCT) from an ABO-matched donor are limited. CASE REPORT: A 32-year-old Caucasian man with chronic myeloid leukemia, never transfused, conditioned with BuCy120, received granulocyte-colony-stimulating factor-mobilized peripheral blood progenitor cells from his HLA-identical sister. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A and methotrexate. The patient engrafted showing complete donor chimerism and developed Grade 3 acute GVHD and subsequently extensive chronic GVHD. He received 2 units of RBCs on Days 13 and 14 without clinical signs of hemolysis. RESULTS: Patient was 0 Rh-K-JK(a-) and donor was 0 Rh+K-JK(a-). Pretransplant alloantibody screening was negative in the patient. In the donor, anti-E was detected before donation, together with anti-Jka and anti-Dib 4, 9, and 12 months after donation, likely triggered by RBC transfusion 2 months before cell harvest. In the patient, anti-Jka was detected on Day +25 and later anti-E and anti-Dib as well. In both, a Dia/Dia genotype was identified. Both parents were Di(a+b+). CONCLUSIONS: Three kinds of non-ABO alloantibodies were detected, including anti-Dib described for the first time after HPCT. The rapid development of antibodies in the recipient despite intensive immunosuppression suggests their production by the donor cells primed by the RBC transfusion before HPC harvest. Their production by the residual host cells cannot be unequivocally excluded, however.

IL-2 does not enhance the conversion to complete donor chimerism following nonmyeloablative hematopoietic cell transplantation in dogs.

A dog model of stable mixed hematopoietic chimerism was established in which leukocyte-antigen-identical littermates receive nonmyeloablative total body irradiation before hematopoietic cell transplantation and postgrafting immunosuppression with mycophenolate mofetil and cyclosporine. Unmodified donor lymphocyte infusion (DLI) into stable mixed chimeras failed to increase donor chimerism, while DLI from donors sensitized to recipient minor-histocompatibility antigens promptly converted all recipients to complete donor chimerism. This established a model for studying approaches to enhance the graft-versus-host (GVH)-effect, a potential surrogate for graft-versus-leukemia activity. We asked if interleukin-2 (IL-2) given after unmodified DLI could result in reliable conversion to complete donor chimerism. IL-2, 4 x 10(5) IU/kg/day, was administered to six mixed chimeric dogs for 14 days. Four dogs received unmodified DLI with IL-2. At 20-40 weeks after DLI, all dogs remained mixed chimeras. For the two recipients of IL-2 only, mixed chimerism also remained unchanged. These results show that IL-2 given with DLI after nonmyeloablative transplantation in dogs is not effective in reliably converting mixed to complete donor chimerism.

Adoptive immunotherapy against kidney targets in dog-leukocyte antigen-identical mixed hematopoietic canine chimeras.

BACKGROUND: Stable mixed-donor-host-hematopoietic chimerism can serve as a platform for adoptive immunotherapy. Infusions of donor lymphocytes (DLI) sensitized against hematopoietic cells converted mixed hematopoietic into full-donor chimerism in dog-leukocyte antigen (DLA)-identical littermates. Whether sensitization against tissue of solid organs leads to organ-specific immunity that can be transferred by DLI was unknown and was investigated in these experiments using the kidney as target. METHODS: DLA-identical recipients with established stable mixed-donor-host-hematopoietic chimerism were used. In five pairs, hematopoietic stem-cell transplant (HSCT) donors were sensitized by kidney transplantation from the respective chimeras. In a second group, five HSCT donors received vaccinations that were generated from kidney cells of the respective mixed chimeras. Twenty-eight days after sensitization, DLI were administered to the mixed-hematopoietic chimeras. RESULTS: All HSCT donors rejected their kidney grafts from their mixed-chimeric recipients within 22 to 45 days. DLI caused no sustained graft-versus-kidney effects in the mixed-chimeric recipients. However, DLI donors sensitized by kidney transplantation converted 4 of 5 mixed chimeras into virtually complete (>95%) donor-type chimeras, compared with 1 of 5 mixed chimeras given DLI by vaccination from sensitized donors. CONCLUSION: Although DLA-identical kidney grafts from mixed-hematopoietic chimeras were readily rejected by their HSCT donors, subsequent transfusions of sensitized-donor lymphocytes into mixed chimeras converted mixed to all-donor chimerism but failed to induce graft-versus-kidney effects. Vaccination strategies in lieu of kidney grafts failed to convert mixed chimerism.

Engraftment of early erythroid progenitors is not delayed after non-myeloablative major ABO-incompatible haematopoietic stem cell transplantation.

We hypothesized that patients undergoing major ABO-incompatible non-myeloablative haematopoietic stem cell transplantation (nm-HSCT) might experience prolonged haemolysis after transplant due to the delayed disappearance of host plasma cells producing anti-donor isohaemagglutinins (HAs). To address this question, we analysed data from 107 consecutive patients transplanted with allogeneic peripheral blood stem cells from human leucocyte antigen-matched (related, n = 84; unrelated, n = 23) donors after non-myeloablative conditioning (200 cGy total body irradiation +/- fludarabine). In total, 23 out of the 107 patients received major or major/minor ABO-incompatible transplants. Red blood cell (RBC) transfusion requirements during the first 120 d post transplant were higher in major ABO-mismatched than in ABO-matched recipients (0.12 vs 0.03 median units RBC concentrate/d, P = 0.04). Two patients developed transient pure red cell aplasia, which had resolved spontaneously by 9 months after transplant. Major ABO incompatibility did not influence rates of engraftment. Patients with sustained engraftment experienced gradual declines of anti-donor HAs, and the estimated median time to reaching IgM and IgG titres of < 1:1 was at least 133 d in evaluable patients, approximately twice longer than reported after myeloablative conditioning. There was a strong correlation between degrees of donor chimaerism in erythroid burst-forming units, granulocyte macrophage colony-forming units and granulocytes, indicating that donor erythroid engraftment, defined by early erythroid progenitors, was as prompt as myeloid engraftment. In conclusion, our data suggest that major ABO-incompatibility is not a barrier to successful non-myeloablative HSCT.

CD34 cell dose in granulocyte colony-stimulating factor-mobilized peripheral blood mononuclear cell grafts affects engraftment kinetics and development of extensive chronic graft-versus-host disease after human leukocyte antigen-identical sibling transplantation.

A retrospective analysis of granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cell (G-PBMC) products harvested from healthy donors indicates significant variability in both the absolute number and relative proportion of CD34, CD3, and CD14 cells obtained. This report examined whether variations in the cellular composition of G-PBMC products correlated with clinical outcomes after myeloablative allogeneic transplantation. The numbers of CD34, CD3, and CD14 cells infused into 181 human leukocyte antigen (HLA)-identical sibling recipients were analyzed with respect to tempo of engraftment, acute graft-versus-host-disease (GVHD), clinical extensive chronic GVHD, overall survival, and disease relapse. Neither acute GVHD, overall survival, nor disease relapse was statistically significantly associated with CD34, CD3, or CD14 cell doses or the CD14 to CD3 ratio. CD3 and CD14 cell doses and CD14 to CD3 ratios did not correlate with the tempo of neutrophil and platelet engraftment. However, increasing CD34 cell numbers were significantly associated with accelerated neutrophil (P =.03) and platelet (P =.01) engraftment. Higher doses of CD34 cells (> 8.0 x 10(6)/kg) were also associated with a significantly increased hazard of clinical extensive chronic GVHD (HR = 2.3, 95% confidence interval [CI] 1.4-3.7, P =.001), but neither CD3 nor CD14 doses were statistically significantly associated with chronic GVHD. It was concluded that CD34 cell dose in G-PBMC grafts appears to affect both the engraftment kinetics and the development of clinical extensive chronic GVHD in HLA-identical sibling recipients but without a demonstrable impact on survival, relapse, and acute GVHD. Given the morbidity associated with extensive chronic GVHD, efforts to further accelerate engraftment in HLA-matched sibling transplants by increasing CD34 cell number in G-PBMC products may be counterproductive.

Engraftment of DLA-haploidentical marrow with ex vivo expanded, retrovirally transduced cytotoxic T lymphocytes.

Genetically modified donor T cells with an inducible "suicide" gene have the potential to improve the safety and availability of allogeneic hematopoietic stem cell transplantation by enhancing engraftment and permitting control of graft-versus-host disease (GVHD). However, several clinical studies of gene-modified T cells have shown limited to no in vivo function of the ex vivo expanded T cells. Using the well-established dog model of allogeneic marrow transplantation, the question was asked if retrovirally transduced, donor derived, ex vivo expanded cytotoxic T lymphocytes (CTLs) that are recipient specific could enhance engraftment of dog leukocyte antigen (DLA)-haploidentical marrow following a single dose of 9.2 Gy total body irradiation and no postgrafting immunosuppression. In this setting, only 4 of 11 control recipients of DLA-haploidentical marrow without added CTLs engrafted. CTLs did not enhance engraftment of CD34(+) selected peripheral blood stem cells. However, recipient-specific CTLs enhanced engraftment of DLA-haploidentical marrow in 9 of 11 evaluable recipients (P =.049). All dogs that engrafted developed multiorgan GVHD. To facilitate in vivo tracking, 8 dogs received CTLs transduced with a retroviral vector encoding green fluorescent protein (GFP) and neomycin phosphotransferase (neo). Recipients that engrafted had sharp increases in the numbers of circulating GFP(+) CTLs on days +5 to +6 after transplantation. GFP(+) CTLs isolated from blood were capable of recipient-specific lysis. At necropsy, up to 7.1% of CD3(+) cells in tissues were GFP(+) and polymerase chain reaction in situ hybridization for neo showed infiltration of transduced CTLs in GVHD-affected organs. These results show that ex vivo expanded, transduced T cells maintained in vivo function and enhanced marrow engraftment.

Effects of extending the duration of postgrafting immunosuppression and substituting granulocyte-colony-stimulating factor-mobilized peripheral blood mononuclear cells for marrow in allogeneic engraftment in a nonmyeloablative canine transplantation model.

Stable mixed donor/host hematopoietic chimerism was uniformly achieved in dogs given 200 cGy total body irradiation (TBI) before and immunosuppression with mycophenolate mofetil (MMF) for 28 days and cyclosporine (CSP) for 35 days after transplantation of marrow from dog leukocyte antigen-identical littermates. When the TBI dose was lowered to 100 cGy, donor marrow engraftment in 6 dogs was only transient, lasting 3 to 12 weeks. In this study, we asked whether stable engraftment in this model could be achieved: (1) by substituting recombinant canine granulocyte-colony-stimulating factor-mobilized peripheral blood mononuclear cells (G-PBMCs) for marrow and (2) by extending CSP administration from 35 to 100 days. Eighteen dogs were given G-PBMC grafts and MMF for 28 days. Eight of the 18 dogs received CSP for 35 days and 10 for 100 days. We found that substituting G-PBMCs for marrow did not increase the incidence of stable allogeneic engraftment (P = .11). However, increasing the duration of posttransplantation immunosuppression with CSP from 35 to 100 days favorably influenced stable donor engraftment (P = .06).

Nonmyeloablative hematopoietic stem cell transplantation: transplantation for the 21st century.

Conventional approaches to allogeneic stem cell transplantation have used toxic high-dose conditioning therapy to achieve allogeneic engraftment and control of underlying disease. For engraftment purposes, preclinical studies and clinical observations have shown that conditioning regimens can be markedly reduced in intensity, resulting in reduced treatment toxicities. Preclinical canine studies demonstrated that the use of potent pre- and postgrafting immunosuppression allows for reduction in conditioning regimens while facilitating development of stable mixed chimerism. If attenuated conditioning regimens can be successfully translated to human stem cell transplantation, an improved safety profile will allow potentially curative treatment to a more representative patient profile not currently offered such therapy. Mixed chimerism could prove curative of disease phenotype of various nonmalignant disturbances of the hematopoietic and immune systems. For patients with hematopoietic malignancy, spontaneous conversion to full donor hematopoeisis after stem cell transplant may prove curative by virtue of graft versus host reactions directed against the malignancy, however infusion of additional donor lymphocytes may be needed to treat persistent disease.

Hematopoietic responses to stress conditions in young dogs compared with elderly dogs.

Clinical observations show that older patients do not tolerate high-dose chemoradiotherapy as well as younger patients. It is unclear whether this is due to age-related differences in their responses to hematopoietic injury or to differential toxicities to other organs. In the present study, 6 young (0.5 years) and 6 elderly (8 years) dogs were challenged with 7 repeated nonlethal doses of 50 or 100 cGy total body irradiation (TBI) each (total 550 cGy), and 21 days of recombinant canine granulocyte-colony stimulating factor (rcG-CSF) after the last TBI dose. Recoveries of absolute neutrophil, platelet, and lymphocyte counts after each TBI dose, responses to rcG-CSF treatment, and telomere lengths in neutrophils were compared before and after the study. No differences were found in recoveries of neutrophils, platelets, or in responses to rcG-CSF among young and old dogs. In contrast, recoveries were suggestively worse in younger dogs. After rcG-CSF, platelet recoveries were poor in both groups compared with previous platelet recoveries (P <.01). Consequently, 2 old and 3 young dogs were euthanized because of persistent thrombocytopenia and bleeding. At the study's completion, marrow cellularities and peripheral blood counts of the remaining young and elderly dogs were equivalent. The telomere lengths in both groups were significantly reduced after the study versus beforehand (P =.03), but the median attritions of telomeres were not different. It was concluded that aging does not appear to affect hematopoietic cell recoveries after repeated low-dose TBI, suggesting that poor tolerance of radiochemotherapy regimens in older patients may be due to nonhematopoietic organ toxicities rather than age-related changes in hematopoietic stem cells reserves.