Pramila Krishnamurthy

TP53 mutations in myelodysplastic syndrome are strongly correlated with aberrations of chromosome 5, and correlate with adverse prognosis

This study aimed to determine the incidence/prognostic impact of TP53 mutation in 318 myelodysplastic syndrome (MDS) patients, and to correlate the changes to cytogenetics, single nucleotide polymorphism array karyotyping and clinical outcome. The median age was 65 years (17–89 years) and median follow‐up was 45 months [95% confidence interval (CI) 27–62 months]. TP53 mutations occurred in 30 (9·4%) patients, exclusively in isolated del5q (19%) and complex karyotype (CK) with ‐5/5q‐(72%), correlated with International Prognostic Scoring System intermediate‐2/high, TP53 protein expression, higher blast count and leukaemic progression. Patients with mutant TP53 had a paucity of mutations in other genes implicated in myeloid malignancies. Median overall survival of patients with TP53 mutation was shorter than wild‐type (9 versus 66 months, P < 0·001) and it retained significance in multivariable model (Hazard Ratio 3·8, 95%CI 2·3–6·3,P < 0·001). None of the sequentially analysed samples showed a disappearance of the mutant clone or emergence of new clones, suggesting an early occurrence of TP53 mutations. A reduction in mutant clone correlated with response to 5‐azacitidine, however clones increased in non‐responders and persisted at relapse. The adverse impact of TP53 persists after adjustment for cytogenetic risk and is of practical importance in evaluating prognosis. The relatively common occurrence of these mutations in two different prognostic spectrums of MDS, i.e. isolated 5q‐ and CK with ‐5/5q‐, possibly implies two different mechanistic roles for TP53 protein.

Allogeneic haematopoietic SCT for chronic myelomonocytic leukaemia: a single-centre experience.

Haematopoietic SCT (HSCT) offers the only potentially curative option in chronic myelomonocytic leukaemia (CMML). In this study, we report on single-centre results of 18 patients with CMML who have undergone allogeneic HSCT. The median age of patients was 54 years. Seven patients had AML, which had transformed from CMML. Overall, 11 patients received stem cells from an unrelated donor. A total of 15 patients received a T-cell-depleted fludarabine/BU-based reduced-intensity conditioning HSCT. The actuarial 3-year OS, non-relapse mortality (NRM) and relapse incidence for the cohort was 31±11%, 31±14% and 47±13%, respectively. Patients with favourable cytogenetics had a 3-year disease-free survival of 65±17%, whereas none of the seven patients with intermediate or poor risk cytogenetics survived beyond 2 years (P<0.01). No patients with favourable risk cytogenetics died from NRM causes, while the 2-year NRM for the intermediate/poor risk cytogenetics subgroup was 71±22% (P<0.02). In terms of disease status at transplantation, patients who had <5% BM blasts had a 3-year disease-free survival of 46.9±19% compared with those with >5% blasts at the time of transplantation (that is, 20.0±13%). Recipient age, type of conditioning regimen or stem cell dose did not have a significant impact on overall outcomes. Our data support existing evidence that allogeneic HSCT is a feasible therapeutic option for CMML, with the ability to attain long-term remission among patient subgroups.

Long-Term Outcomes of Alemtuzumab-Based Reduced-Intensity Conditioned Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndrome and Acute Myelogenous Leukemia Secondary to Myelodysplastic Syndrome

Allogeneic hematopoietic stem cell transplantation (HSCT) with reduced-intensity conditioning (RIC) offers a potential cure for patients with myelodysplastic syndrome (MDS) who are ineligible for standard-intensity regimens. Previously published data from our institution suggest excellent outcomes at 1 yr using a uniform fludarabine, busulfan, and alemtuzumab-based regimen. Here we report long-term follow-up of 192 patients with MDS and acute myelogenous leukemia (AML) secondary to MDS (MDS-AML) transplanted with this protocol, using sibling (n = 45) or matched unrelated (n = 147) donors. The median age of the cohort was 57 yr (range, 21 to 72 yr), and median follow-up was 4.5 yr (range, 0.1 to 10.6 yr). The 5-yr overall survival (OS), event-free survival, and nonrelapse mortality were 44%, 33%, and 26% respectively. The incidence of de novo chronic graft-versus-host disease (GVHD) was low at 19%, illustrating the efficacy of alemtuzumab for GVHD prophylaxis. Conversely, the 5-yr relapse rate was 51%. For younger patients (age <50 yr), the 5-yr OS and relapse rates were 58% and 39%, respectively. On multivariate analysis, advanced age predicted significantly worse outcomes, with patients age >60 yr having a 5-yr OS of 15% and relapse rate of 66%. Patients receiving preemptive donor lymphocyte infusions had an impressive 5-yr OS of 67%, suggesting that this protocol may lend itself to the incorporation of immunotherapeutic strategies. Overall, these data demonstrate good 5-yr OS for patients with MDS and MDS-AML undergoing alemtuzumab-based RIC-HSCT. The low rate of chronic GVHD is encouraging, and comparative studies with other RIC protocols are warranted.

BCSH/BSBMT/UK clinical virology network guideline: diagnosis and management of common respiratory viral infections in patients undergoing treatment for haematological malignancies or stem cell transplantation.

A joint working group established by the Haemato‐oncology subgroup of the British Committee for Standards in Haematology, the British Society for Bone Marrow Transplantation and the UK Clinical Virology Network has reviewed the available literature and made recommendations for the diagnosis and management of respiratory viral infections in patients with haematological malignancies or those undergoing haematopoietic stem cell transplantation. This guideline includes recommendations for the diagnosis, prevention and treatment of respiratory viral infections in adults and children. The suggestions and recommendations are primarily intended for physicians practising in the United Kingdom.

The combined molecular adjuvant CASAC enhances the CD8+ T cell response to a tumor-associated self-antigen in aged, immunosenescent mice

BackgroundIneffective induction of T cell mediated immunity in older individuals remains a persistent challenge for vaccine development. Thus, there is a need for more efficient and sophisticated adjuvants that will complement novel vaccine strategies for the elderly. To this end, we have investigated a previously optimized, combined molecular adjuvant, CASAC (Combined Adjuvant for Synergistic Activation of Cellular immunity), incorporating two complementary Toll-like receptor agonists, CpG and polyI:C, a class-II epitope, and interferon (IFN)-γ in aged mice.FindingsIn aged mice with typical features of immunosenescence, antigen specific CD8+ T cell responses were stimulated after serial vaccinations with CASAC or Complete/Incomplete Freund’s Adjuvant (CFA/IFA) and a class I epitope, deriving either from ovalbumin (SIINFEKL, SIL) or the melanoma-associated self-antigen, tyrosinase-related protein-2 (SVYDFFVWL, SVL). Pentamer analysis revealed that aged, CASAC/SIL-vaccinated animals had substantially higher frequencies of H-2Kb/SIL-specific CD8+ T cells compared to the CFA/IFA-vaccinated groups. Similarly, higher frequencies of H-2Kb/SVL-pentamer+ and IFN-γ+ CD8+ T cells were detected in the aged, CASAC + SVL-vaccinated mice than in their CFA/IFA-vaccinated counterparts. In both antigen settings, CASAC promoted significantly better functional CD8+ T cell activity.ConclusionThese studies demonstrate that functional CD8+ T cells, specific for both foreign and tumour-associated self-antigens, can be effectively induced in aged immunosenescent mice using the novel multi-factorial adjuvant CASAC.

Alemtuzumab based reduced intensity conditioning allogeneic haematopoietic stem cell transplantation for myelofibrosis.

We report the results of 11 patients myelofibrosis, who have received a uniform alemtuzumab-based RIC HSCT. The median recipient age was 51 years. Stem cells were obtained from 8 full HLA-matched and 3 HLA-mismatched donors. The 2-year OS and TRM at 2-years was 46% and 54% with no disease relapse observed. For patients with a full HLA-matched donor, the 2-year TRM and OS was 37.5% and 62.5%. All 4 JAK2 V617F mutant positive patients achieved molecular remission after a median of 90 days post-transplant, and the median time to regression of bone marrow fibrosis was 180 days.

Abstract B124: Immunotherapy of acute myeloid leukemia using Vg9Vd2 T-cells

Disease remission is successfully induced in the majority of patients with acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS), but is generally not sustained without stem cell transplantation. Adoptive immunotherapy offers an attractive option to consolidate AML remission. Here, we hypothesized that ex-vivo expanded Vg9Vd2 T-cells will mediate a therapeutically beneficial graft versus leukemia (GvL) effect in this disease. Peripheral blood mononuclear cells from healthy donors and from patients with AML were activated in-vitro using zoledronic acid and a cytokine cocktail, containing IL-2. As a result, we observed an average 200-fold expansion of Vg9Vd2 T-cells from AML patients, over 15 days. Such expansion was only observed in patients without circulating AML blasts. Expanded patient-derived Vg9Vd2 T-cells exhibited a less differentiated phenotype than cells from healthy donors, indicated by higher expression of CD62L, CCR7 and CD27. A four hour Annexin V cytotoxicity assay using KG-1 and U937 leukemic cells showed that these Vg9Vd2 T-cells were cytotoxic and produced nanogram amounts of interferon-g; (IFN-g). In a parallel approach, we investigated feasibility of developing a universal allogeneic Vg9Vd2 T-cell therapy. Feasibility of this approach has been demonstrated in a small trial in which haploidentical donor-derived Vg9Vd2 T-cells were safely infused and achieved an efficacy signal in patients with advanced haematological diseases. We have recently developed a novel method to expand Vg9Vd2 T-cells from healthy donors ex-vivo (“Method 2 (M2)” cells – patent protected), which improves their expansion over 2 weeks to 1700 fold. Cytotoxicity data shows that M2 cells destroy luciferase-expressing U937 and KG-1 target cells at 2-3 fold enhanced efficiency, accompanied by 2-3.5-fold increased IFN-g; release when compared to cells expanded using conventional approaches. Furthermore, M2 cells can achieve serial killing of AML cell lines through up to 4 cycles of re-stimulation. Treatment of SCID-Beige mice with an established U937 leukemic burden is also more effective using M2 expanded Vg9Vd2 T-cells, particularly when combined with zoledronic acid. Together these data highlight the promise of Vg9Vd2 T-cell immunotherapy of AML. Citation Format: Ana C. Parente-Pereira, Lynsey M. Whilding, Pramila Krishnamurthy, Richard Beatson, Tomasz Zabinski, Linda Barber, Farzin Farzaneh, Ghulam Mufti, John Maher. Immunotherapy of acute myeloid leukemia using Vg9Vd2 T-cells. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr B124.