Tisagenlecleucel utilisation and outcomes across refractory, first relapse and multiply relapsed B-cell acute lymphoblastic leukemia: a retrospective analysis of real-world patterns

Background

Tisagenlecleucel was approved by the Food and Drug Administration (FDA) in 2017 for refractory B-cell acute lymphoblastic leukemia (B-ALL) and B-ALL in ≥2nd relapse. Outcomes of patients receiving commercial tisagenlecleucel upon 1st relapse have yet to be established. We aimed to report real-world tisagenlecleucel utilisation patterns and outcomes across indications, specifically including patients treated in 1st relapse, an indication omitted from formal FDA approval.

Methods

We conducted a retrospective analysis of real-world tisagenlecleucel utilisation patterns across 185 children and young adults treated between August 30, 2017 and March 6, 2020 from centres participating in the Pediatric Real-World CAR Consortium (PRWCC), within the United States. We described definitions of refractory B-ALL used in the real-world setting and categorised patients by reported Chimeric Antigen Receptor (CAR) T-cell indication, including refractory, 1st relapse and ≥2nd relapse B-ALL. We analysed baseline patient characteristics and post-tisagenlecleucel outcomes across defined cohorts.

Findings

Thirty-six percent (n = 67) of our cohort received tisagenlecleucel following 1st relapse. Of 66 evaluable patients, 56 (85%, 95% CI 74-92%) achieved morphologic complete response. Overall-survival (OS) and event-free survival (EFS) at 1-year were 69%, (95% CI 58-82%) and 49%, (95% CI 37-64%), respectively, with survival outcomes statistically comparable to remaining patients (OS; p = 0.14, EFS; p = 0.39). Notably, toxicity was increased in this cohort, warranting further study. Interestingly, of 30 patients treated for upfront refractory disease, 23 (77%, 95% CI 58-90%) had flow cytometry and/or next-generation sequencing (NGS) minimum residual disease (MRD)-only disease at the end of induction, not meeting the historic morphologic definition of refractory.

Interpretation

Our findings suggested that tisagenlecleucel response and survival rates overlap across patients treated with upfront refractory B-ALL, B-ALL ≥2nd relapse and B-ALL in 1st relapse. We additionally highlighted that definitions of refractory B-ALL are evolving beyond morphologic measures of residual disease.

Funding

St. Baldrick's/Stand Up 2 Cancer, Parker Institute for Cancer Immunotherapy, Virginia and D.K. Ludwig Fund for Cancer Research.

Prospective PTCTC trial of myeloablative haplo-BMT with posttransplant cyclophosphamide for pediatric acute leukemias

Promising results have been reported for adult patients with high-risk hematologic malignancies undergoing haploidentical bone marrow transplant (haploBMT) with posttransplant cyclophosphamide (PTCy). To our knowledge, we report results from the first multicenter trial for pediatric and young adult patients with high-risk acute leukemias and myelodysplastic syndrome (MDS) in the Pediatric Transplantation and Cellular Therapy Consortium. Nine centers performed transplants in 32 patients having acute leukemias or MDS, with myeloablative conditioning (MAC), haploBMT with PTCy, mycophenolate mofetil, and tacrolimus. The median patient age was 12 years. Diagnoses included AML (15), ALL (11), mixed-lineage leukemia (1), and MDS (5). Transplant-related mortality (TRM) at 180 days was 0%. The cumulative incidence (CuI) of grade 2 acute graft-versus-host disease (aGVHD) on day 100 was 13%. No patients developed grades 3-4 aGVHD. The CuI of moderate-to-severe chronic GVHD (cGVHD) at 1 year was 4%. Donor engraftment occurred in 27 patients (84%). Primary graft failures included 3 patients who received suboptimal bone marrow grafts; all successfully engrafted after second transplants. The CuI of relapse at 1 year was 32%, with more relapse among patients MRD positive pre-BMT vs MRD negative. Overall survival rates at 1 and 2 years were 77% and 73%, and event-free survival rate at 1 and 2 years were 68% and 64%. There was no TRM or severe aGVHD, low cGVHD, and favorable relapse and survival rates. This successful pilot trial has led to a phase 3 trial comparing MAC haploBMT vs HLA-matched unrelated donor BMT in the Children's Oncology Group. This trial was registered at www.clinicaltrials.gov as #NCT02120157.

Immune Reconstitution Profiling Suggests Antiviral Protection After Transplantation with Omidubicel: a Phase 3 Substudy

BACKGROUND

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative treatment for hematological malignancies and non-malignant disorders. Rapid immune reconstitution (IR) following allogeneic HCT has been shown to be associated with improved clinical outcomes and lower infection rates. A global phase 3 trial (NCT02730299) of omidubicel, an advanced cell therapy manufactured from an appropriately human leukocyte antigen-matched single umbilical cord blood (UCB) unit, showed faster hematopoietic recovery, reduced rates of infection, and shorter hospitalizations in patients randomized to omidubicel compared with those randomized to standard UCB.

OBJECTIVE

This optional, prospective substudy of the phase 3 trial characterized the IR kinetics following HCT with omidubicel compared with UCB in a systematic and detailed manner.

STUDY DESIGN

In this substudy, 37 patients from 14 global sites were included (omidubicel: n=17, UCB: n=20). Peripheral blood samples were collected over 10 predefined time points from 7 to 365 days post-HCT. Flow cytometry immunophenotyping, T cell receptor excision circle quantification, and T cell receptor sequencing were employed to evaluate the longitudinal IR kinetics post-transplant and their association with clinical outcomes.

RESULTS

Patient characteristics in the two comparator cohorts were overall statistically similar, except for age and total body irradiation (TBI) based conditioning regimens. The median age (range) for patients who received omidubicel or UCB was 30 (13-62) years and 43 (19-55) years, respectively. The percentages of patients receiving TBI based conditioning regimens were 47% and 70% for omidubicel and UCB recipients, respectively. Graft characteristics differed in their cellular composition. Omidubicel recipients received a 33-fold higher median dose of CD34+ stem cells, while receiving one third of the median CD3+ lymphocyte dose infused to UCB transplanted patients. Compared with UCB, omidubicel recipients exhibited faster IR of all measured lymphoid and myelomonocytic subpopulations, predominantly in the first 14 days post-transplant. This effect involved circulating natural killer (NK) cells, helper T cells, monocytes, and dendritic cells, with superior long-term B cell recovery from Day 28. One-week post-HCT, omidubicel recipients exhibited 4.1 and 7.7 -fold increases in the median helper T and NK cell counts respectively, compared to their UCB transplanted counterparts. By three weeks post-HCT, omidubicel transplanted patients were 3-fold more likely to achieve clinically relevant helper T and NK cell counts of 100 cells/ µL or above. Similar to UCB, omidubicel yielded a balanced cellular subpopulation composition and diverse T cell receptor repertoire in the short to long term. Omidubicel's CD34+ cell content correlated with faster IR by Day 7 post-HCT, which in turn coincided with earlier hematopoietic recovery. Lastly, early NK and helper T cell reconstitution correlated with a decreased rate of post-HCT viral infections, suggesting a plausible explanation for this phenomenon among omidubicel recipients in the phase 3 study.

CONCLUSIONS

Our findings suggest that omidubicel efficiently promotes IR across multiple immune cells, including CD4+ T cells, B cells, NK cells, and dendritic cell subtypes as early as 7 days post-transplant, potentially endowing recipients of omidubicel with early protective immunity.

Introducing intersex wellbeing and rights and the INIA programme

Background

Intersex people are exposed to human rights violations all over the world. Ongoing practices of sex-normalising surgery and other medical interventions on minors too young to give informed consent encroach on their bodily autonomy. Little is known about the public health implications of bodies with variations of sex characteristics (VSC). What key issues do VSCs raise?

Methods

In 2020 the INIA international consortium began work on a large research programme to address intersex people's wellbeing and human rights from a variety of new and innovative perspectives. The programme will train a cohort of 10 early-stage researchers working collaboratively to develop knowledge that will inform policy making and practice across a range of key sectors. Drawing on critical intersex studies, the research projects are relevant to stakeholders who are concerned with supporting the wellbeing and rights of intersex people through knowledge sharing and development. The project received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 859869. Please see https://www.intersexnew.co.uk/.

Results

Indicative findings show that VSC could be an important area of public health work concerning diversity and equality. Early-stage results show a dearth of intersex visibility in key areas including social policy, education, and elder care. Intersex people and those with VSC face major health challenges and discrimination. There is a pressing need for appropriate healthcare.

Conclusions

The interdisciplinary INIA programme surfaces multiple discourses about intersex people and those with variations of sex characteristics. Projects of particular interest to public health practitioners and policy makers include those concerning multi-disciplinary healthcare, ethics, social policy, education, aging, and service user participation.

Real-world evidence of tisagenlecleucel for pediatric acute lymphoblastic leukemia and non-Hodgkin lymphoma

Tisagenlecleucel is a CD19 chimeric antigen receptor (CAR) T-cell therapy approved for treatment of pediatric and young adult patients with relapsed/refractory acute lymphoblastic leukemia (ALL) and adults with non-Hodgkin lymphoma (NHL). The initial experience with tisagenlecleucel in a real-world setting from a cellular therapy registry is presented here. As of January 2020, 511 patients were enrolled from 73 centers, and 410 patients had follow-up data reported (ALL, n = 255; NHL, n = 155), with a median follow-up of 13.4 and 11.9 months for ALL and NHL, respectively. Among patients with ALL, the initial complete remission (CR) rate was 85.5%. Twelve-month duration of response (DOR), event-free survival, and overall survival (OS) rates were 60.9%, 52.4%, and 77.2%, respectively. Among adults with NHL, the best overall response rate was 61.8%, including an initial CR rate of 39.5%. Six-month DOR, progression-free survival, and OS rates were 55.3%, 38.7%, and 70.7%, respectively. Grade ≥3 cytokine release syndrome and neurotoxicity were reported in 11.6% and 7.5% of all patients, respectively. Similar outcomes were observed in patients with in-specification and out-of-specification products as a result of viability <80% (range, 61% to 79%). This first report of tisagenlecleucel in the real-world setting demonstrates outcomes with similar efficacy and improved safety compared with those seen in the pivotal trials.

Accuracy of Stated Calorie and Sodium Counts of Menu Items at Popular Chain Restaurants

Objectives

The objective of this study was to evaluate the accuracy of stated calorie and sodium content of various menu items from 13 fast food/fast casual restaurants.

Methods

Three samples of four different menu items (52 total menu items) were collected from 13 popular fast food/fast casual restaurant chains (n = 152) in NY, NJ and CT. Each sample was weighed to obtain the serving size in grams. Sodium content was determined and a proximate analysis was performed to estimate total calories. Analytical test data per 100g was calculated based on actual serving size weights. For each menu item, samples were averaged and compared to the restaurant's stated calorie and sodium counts.

Results

Of the 152 samples analyzed, 15% (n = 23) were 20% or more of the declared calories and 26% (39 of 152) were 20% or more than the declared sodium content. The highest average overage for a menu item was 31% for calories and more than twice the declared amount for sodium. Among the 52 menu items, on average, three were approximately 26 to 31% higher, or about 150 to 200 calories more than declared. Fourteen of the 52 menu items (27%) had average analytical sodium amounts greater than 20% of the declared sodium. This translates to about 150 to 500 mg more sodium than expected. Sodium was less than 20% of the declared sodium for 31 models (60%), with more than half within 100 mg of the declared sodium values.

Conclusions

Across 52 menu items representing 13 fast food/fast casual chains, the amount of calories provided by restaurants were more consistent with stated amounts as compared to sodium content. If stated calorie or sodium content inaccuracies are widespread, this could hamper the consumer's ability to self-monitor their dietary intake. It also impacts the ability of researchers to accurately estimate the contribution of these nutrients to dining outside the home.

Funding Sources

Performed as part of my role at Consumer Reports.

Outcomes of Measurable Residual Disease in Pediatric Acute Myeloid Leukemia before and after Hematopoietic Stem Cell Transplant: Validation of Difference from Normal Flow Cytometry with Chimerism Studies and Wilms Tumor 1 Gene Expression

We enrolled 150 patients in a prospective multicenter study of children with acute myeloid leukemia undergoing hematopoietic stem cell transplantation (HSCT) to compare the detection of measurable residual disease (MRD) by a "difference from normal" flow cytometry (ΔN) approach with assessment of Wilms tumor 1 (WT1) gene expression without access to the diagnostic specimen. Prospective analysis of the specimens using this approach showed that 23% of patients screened for HSCT had detectable residual disease by ΔN (.04% to 53%). Of those patients who proceeded to transplant as being in morphologic remission, 10 had detectable disease (.04% to 14%) by ΔN. The disease-free survival of this group was 10% (0 to 35%) compared with 55% (46% to 64%, P < .001) for those without disease. The ΔN assay was validated using the post-HSCT specimen by sorting abnormal or suspicious cells to confirm recipient or donor origin by chimerism studies. All 15 patients who had confirmation of tumor detection relapsed, whereas the 2 patients with suspicious phenotype cells lacking this confirmation did not. The phenotype of the relapse specimen was then used retrospectively to assess the pre-HSCT specimen, allowing identification of additional samples with low levels of MRD involvement that were previously undetected. Quantitative assessment of WT1 gene expression was not predictive of relapse or other outcomes in either pre- or post-transplant specimens. MRD detected by ΔN was highly specific, but did not identify most relapsing patients. The application of the assay was limited by poor quality among one-third of the specimens and lack of a diagnostic phenotype for comparison.

Targeting MUC1-C suppresses BCL2A1 in triple-negative breast cancer

B-cell lymphoma 2-related protein A1 (BCL2A1) is a member of the BCL-2 family of anti-apoptotic proteins that confers resistance to treatment with anti-cancer drugs; however, there are presently no agents that target BCL2A1. The MUC1-C oncoprotein is aberrantly expressed in triple-negative breast cancer (TNBC) cells, induces the epithelial-mesenchymal transition (EMT) and promotes anti-cancer drug resistance. The present study demonstrates that targeting MUC1-C genetically and pharmacologically in TNBC cells results in the downregulation of BCL2A1 expression. The results show that MUC1-C activates the BCL2A1 gene by an NF-κB p65-mediated mechanism, linking this pathway with the induction of EMT. The MCL-1 anti-apoptotic protein is also of importance for the survival of TNBC cells and is an attractive target for drug development. We found that inhibiting MCL-1 with the highly specific MS1 peptide results in the activation of the MUC1-C→NF-κB→BCL2A1 pathway. In addition, selection of TNBC cells for resistance to ABT-737, which inhibits BCL-2, BCL-xL and BCL-W but not MCL-1 or BCL2A1, is associated with the upregulation of MUC1-C and BCL2A1 expression. Targeting MUC1-C in ABT-737-resistant TNBC cells suppresses BCL2A1 and induces death, which is of potential therapeutic importance. These findings indicate that MUC1-C is a target for the treatment of TNBCs unresponsive to agents that inhibit anti-apoptotic members of the BCL-2 family.

Blood Stem Cell Collection: Factors Influencing the Recovery of Granulocyte-Macrophage Colony Forming Cells

We evaluated data from all blood cell (BC) collections performed in our institution between 1989 and 1995 to determine factors influencing the outcome of collection. One hundred and thirty-three collections were performed on 106 patients. Malignant diagnoses were: non-Hodgkins lymphoma (NHL) in 35%, multiple myeloma in 31%, breast cancer in 26%, and Hodgkin's disease in 8%. Collections were obtained routinely in myeloma and breast cancer and due to bone marrow involvement with malignancy or inaspirable bone marrow in lymphoma patients. Collections were obtained on a Cobe Spectra or Baxter-Fenwall CS3000+. Engraftment potential was determined by methylcellulose colony assay (CFU-GM), with a target of >10 × 104 CFU-GM/kg. Apheresis nucleated cell count correlated significantly, albeit weakly (r = 0.26), with CFU-GM with a cell count of >5 × 10s/kg resulting in an adequate number of CFU-GM in 78% of patients. In univariant analysis outcome of collection was significantly influenced by the patients age (p = 0.01), malignant diagnosis (p < 0.001), reason for collection (p = 0.002), and the mobilization regimen (p = 0.01). The nature of the apheresis device used did not influence outcome. Only malignant diagnosis was significant (p < 0.001) in multivariate analysis. We conclude that the outcome of BC is most strongly influenced by patient factors such as malignant diagnosis. These factors must be considered when comparing the outcome of different mobilization regimens and when planning collection strategies.

Bone Marrow Mononuclear Cell Count does not Predict Neutrophil and Platelet Recovery following Autologous Bone Marrow Transplant: Value of the Colony-Forming Unit Granulocyte-Macrophage (CFU-GM) Assay

The common use of the marrow autograft mononuclear cell (MNC) count derives from positive correlative studies following allogeneic transplantation and from earlier conflicting data regarding the value of the bone marrow autograft colony-forming unit granulocyte-macrophage (CFU-GM) assay for predicting hematologic recovery after ABMT. We conducted a retrospective analysis at our institution to determine whether autograft CFU-GM levels predict engraftment of neutrophils and platelets after ABMT in heavily pretreated patients with hematologic malignancies. Between 1 January 1993 and 1 March 1995, 58 heavily pretreated patients received only marrow cells as the autograft product. Patients with Hodgkin's disease (n = 25), acute myeloid leukemia (n = 19), and non-Hodgkin's lymphoma (n = 14) underwent intensive therapy with etoposide and melphalan. Unpurged marrow containing a minimum of 1.5 × 108/kg (range: 1.5-4.8) was infused. Median time to an absolute neutrophil count ≥0.5 × 109/L was 21 days (range 10-270) and median time to a platelet count ≥20 × 109/L independent of transfusions was 44 days (range 13-317). There was no correlation between autograft MNC count and neutrophil or platelet engraftment. However, a correlation between autograft CFU-GM and both platelet and neutrophil recovery was demonstrated with a threshold CFU-GM of 3 × 104/kg; delayed neutrophil recovery was observed in 79% of patients below this threshold compared to only 9% in those with an autograft CFU-GM level of more than 3 × 104/kg (p = 0.0001). Similarly, platelet recovery was delayed in 76% of patients below, and 20% of those above this threshold (p = 0.003). We conclude that marrow autograft CFU-GM is predictive of engraftment of both platelets and neutrophils in heavily pretreated patients after ABMT for hematological malignancies.

Personalized Prognostic Risk Score for Long-Term Survival for Children with Acute Leukemia after Allogeneic Transplantation

We studied leukemia-free (LFS) and overall survival (OS) in children with acute myeloid (AML, n = 790) and acute lymphoblastic leukemia (ALL, n = 1096) who underwent transplantation between 2000 and 2010 and who survived for at least 1 year in remission after related or unrelated donor transplantation. Analysis of patient-, disease-, and transplantation characteristics and acute and chronic graft-versus-host disease (GVHD) was performed to identify factors with adverse effects on LFS and OS. These data were used to develop risk scores for survival. We did not identify any prognostic factors beyond 4 years after transplantation for AML and beyond 3 years for ALL. Risk score for survival for AML includes age, disease status at transplantation, cytogenetic risk group, and chronic GVHD. For ALL, the risk score includes age at transplantation and chronic GVHD. The 10-year probabilities of OS for AML with good (score 0, 1, or 2), intermediate (score 3), and poor risk (score 4, 5, 6, or 7) were 94%, 87%, and 68%, respectively. The 10-year probabilities of OS for ALL were 89% and 80% for good (score 0 or 1) and poor risk (score 2), respectively. Identifying children at risk for late mortality with early intervention may mitigate some excess late mortality.

Asiatic acid induces endoplasmic reticulum stress and apoptotic death in glioblastoma multiforme cells both in vitro and in vivo

Glioblastoma multiforme (GBM) is an untreatable malignancy. Existing therapeutic options are insufficient, and adversely affect functional and non-cancerous cells in the brain impairing different functions of the body. Therefore, there is an urgent need for additional preventive and therapeutic non-toxic drugs against GBM. Asiatic acid (AsA; 2,3,23-trihydroxy-12-ursen-28-oic acid, C30 H48 O5 ) is a natural small molecule widely used to treat various neurological disorders, and the present research investigates AsA's efficacy against GBM both in vitro and in vivo. Results showed that AsA treatment (10-100 µM) decreased the human GBM cell (LN18, U87MG, and U118MG) viability, with better efficacy than temozolomide at equimolar doses. Orally administered AsA (30 mg/kg/d) strongly decreased tumor volume in mice when administered immediately after ectopic U87MG xenograft implantation (54% decrease, P ≤ 0.05) or in mice with established xenografts (48% decrease, P ≤ 0.05) without any apparent toxicity. Importantly, AsA feeding (30 mg/kg/twice a day) also decreased the orthotopic U87MG xenografts growth in nude mice as measured by magnetic resonance imaging. Using LC/MS-MS methods, AsA was detected in mice plasma and brain tissue, confirming that AsA crosses blood-brain barrier. Mechanistic studies showed that AsA induces apoptotic death by modulating the protein expression of several apoptosis regulators (caspases, Bcl2 family members, and survivin) in GBM cells. Furthermore, AsA induced ER stress (increased GRP78 and Calpain, and decreased Calnexin and IRE1α expression), enhanced free intra-cellular calcium, and damaged cellular organization in GBM cells. These experimental results demonstrate that AsA is effective against GBM, and advocate further pre-clinical and clinical evaluations of AsA against GBM.

A phase I/II study of sepantronium bromide (YM155, survivin suppressor) with paclitaxel and carboplatin in patients with advanced non-small-cell lung cancer

BACKGROUND

This phase I/II study examined the safety and efficacy of Sepantronium Bromide (S), a small-molecule selective survivin suppressant, administered in combination with carboplatin (C) and paclitaxel (P).

PATIENTS AND METHODS

Forty-one patients were treated on study. Twenty-two patients received escalating doses of S (3.6-12 mg/m(2)) and 19 with untreated stage IV non-small-cell lung cancer (NSCLC) were treated with the maximum tolerated dose of 10 mg/m(2) in combination with standard doses of C (AUC6) and P (200 mg/m(2)) for six cycles. S was administered as a continuous intravenous infusion (CIVI) over 72 h in 21-day treatment cycles. Study end points included safety and toxic effect, response rate, progression-free and overall survival (PFS and OS), as well as exploratory pharmacodynamic correlates.

RESULTS

Treatment with S was well tolerated, and toxic effects were mostly hematological in the phase II study. Two (11%) partial responses were observed with a median PFS of 5.7 months and median OS 16.1 months. Pharmacodynamic analysis did not demonstrate an association with response.

CONCLUSION

The combination of S (10 mg/m(2)/day 72-h CIVI) administered with C and P every 3 weeks exhibited a favorable safety profile but failed to demonstrate an improvement in response rate in advanced NSCLC.

CLINICAL TRIAL NUMBER

NCT01100931.

Late effects of total body irradiation and hematopoietic stem cell transplant in children under 3 years of age

BACKGROUND

Total body irradiation (TBI) is an important component of hematopoietic stem cell transplant (SCT) for pediatric malignancies. With increasing survival rates, late effects of SCT become more important. Younger children may be at particular risk of late effects of radiation and SCT.

METHODS

We retrospectively reviewed outcomes of children less than 3 years of age who received TBI as part of their preparative regimen for SCT at Children's Hospital Colorado. Clinical information including the date of last follow-up, most recent lab values, and physiologic tests were extracted from the medical record.

RESULTS

Of 81 patients who underwent SCT, 19 received TBI and of those, 15 were long-term survivors available for review. Late effects occurring in greater than 50% of the children included abnormalities involving endocrine, metabolic, renal, cataracts, and neurocognitive systems. Other organs involved less commonly included liver, skeletal, and cardiac abnormalities. Solid tumors were a rare finding with only one patient developing a benign osteochondroma and no identified secondary malignancies.

CONCLUSIONS

TBI has been shown to be an important part of the preparative regimen for patients undergoing SCT. Our results, similar to other studies, suggest TBI in patients less than 3 years of age will likely result in multi-organ dysfunction including endocrine, metabolic, renal, eye, and neurocognitive abnormalities. A longitudinal study with standardized testing of these systems would further clarify the late effects concerns in this patient population.

Modeling the effects of low-LET cosmic rays on electronic components

The effects of cosmic radiation in single cells, organic tissues and electronics are a major concern for space exploration and manned missions. Standard heavy ions radiation tests employ ion cocktails with energy of the order of 10 MeV per nucleon and with a linear energy transfer ranging from a few MeV cm(2) mg(-1) to hundreds of MeV cm(2) mg(-1). In space, cosmic rays show significant fluxes at energies up to the order of GeV per nucleon. The present work aims at investigating single event damage due to low-, high- and very-high-energy ions. The European Space Agency reference single event upset monitor data are used to support the discussion. Finally, the effect of ionization induced directly by primary particles and ionization induced by recoils produced in an electronic device is investigated for different types of devices.

Intrathecal transplantation of stem cells by lumbar puncture for thoracic spinal cord injury in the rat

STUDY DESIGN

Experimental investigation of intrathecal transplantation of stem cells by lumbar puncture (LP) in a rat model that simulates human thoracic spinal cord injury (SCI).

OBJECTIVES

To examine the distribution and phenotype of spinal cord-derived neural stem/progenitor cells (NSPCs) and bone marrow-derived mesenchymal stromal cells (BMSCs) following LP transplantation in SCI rats.

SETTING

Toronto Western Research Institute, Toronto, Ontario, Canada.

METHODS

NSPCs or BMSCs were transplanted via LP at level L3-5 1 week after compression SCI at T8. Rats were killed at 3, 17 and 27 days after LP transplantation and the relative distribution of cells at C4, T8 and L3-5 was quantitated. The phenotype of the NSPC and BMSC was assessed with immunocytochemistry in vitro and following LP transplantation.

RESULTS

By 4 weeks, more NSPC migrated to the lesion site relative to BMSC and uninjured animals. However, there was no preferential homing of either of these types of cells into the parenchyma of the injury site, and most of the transplanted cells remained in the intrathecal space. In vitro, spinal cord-derived NSPC proliferated and expressed nestin, but after LP transplantation, NSPC became post-mitotic and primarily expressed oligodendrocyte markers. In contrast, BMSC did not express any neural antigens in vivo.

CONCLUSION

LP is a minimally invasive method of cell transplantation that produces wide dissemination of cells in the subarachnoid space of the spinal cord. This is the first study to report and quantify the phenotype and spatial distribution of LP transplanted NSPC and BMSC in the intact and injured spinal cord.

High-dose chemotherapy and auto-SCT in elderly patients with Hodgkin's lymphoma

Our purpose was to assess efficacy and toxicity of high-dose chemotherapy (HDCT) and ASCT in patients with relapsed and refractory Hodgkin's lymphoma (HL) aged 60 years and older and compare the results with a group of younger HL patients treated in a similar manner. We identified 15 consecutive patients, with HL aged 60 years and older who underwent HDCT (etoposide 60 mg/kg+ melphalan 160 mg/m(2)) and ASCT at our institution from May 2001 to March 2008. The results were compared with a cohort of 157 younger HL patients treated in a similar manner from January 1999 to December 2006. After a median follow-up of 2.5 years, PFS at 3 years after ASCT was 73% (95% confidence interval (CI) 37-90) for the older group and 56% (95% CI 46-64) for the younger group (P=0.45); OS after ASCT was 88% (95% CI 39-98) for the older group and 84% (95% CI 75-90) for the younger group (P=0.80). No transplant-related deaths were seen. Our study suggests that ASCT is feasible for selected elderly patients with HL, giving similar results to younger patients in terms of survival and toxicity.

Subdural Hematomas during CML Therapy with Imatinib Mesylate

Seven of one hundred twenty-one patients with chronic myeloid leukemia (CML) treated with imatinib mesylate developed subdural hematomas. All had advanced disease and were treated initially at a dose of 600 mg per day. Three patients had thrombocytopenia (platelet < 10 x 10(9)/l), one had leukocytosis (white blood cell count > 150 x 10(9)/l) and three had neither around the time of diagnosis of the subdural hematomas. Four patients required surgical evacuation. One patient, in blast crisis, died as a consequence of the subdural hematoma. Three patients survived but died of progressive CML. The remaining three patients having recommenced imatinib, are alive and well, and one has achieved a major cytogenetic response. Subdural hematomas must be considered even in mildly symptomatic patients receiving imatinib regardless of their peripheral blood counts. Patients who survive can be cautiously restarted on imatinib. Further studies are required to study the potential relationship between imatinib mesylate and subdural hematomas.

Irradiated KHYG-1 retains cytotoxicity: Potential for adoptive immunotherapy with a natural killer cell line

PURPOSE

To evaluate gamma-irradiation on KHYG-1, a highly cytotoxic natural killer (NK) cell line and potential candidate for cancer immunotherapy.

METHODS AND MATERIALS

The NK cell line KHYG-1 was irradiated at 1 gray (Gy) to 50 Gy with gamma-irradiation, and evaluated for cell proliferation, cell survival, and cytotoxicity against tumor targets.

RESULTS

We showed that a dose of at least 10 Gy was sufficient to inhibit proliferation of KHYG-1 within the first day but not its cytolytic activity. While 50 Gy had an apoptotic effect in the first hours after irradiation, the killing of K562 and HL60 targets was not different from non-irradiated cells but was reduced for the Ph + myeloid leukemia lines, EM-2 and EM-3.

CONCLUSIONS

gamma-irradiation (at least 10 Gy) of KHYG-1 inhibits cell proliferation but does not diminish its enhanced cytolytic activity against several tumor targets. This study suggests that KHYG-1 may be a feasible immunotherapeutic agent in the treatment of cancers.

Utility of subsequent conventional dose chemotherapy in relapsed/refractory transplant-eligible patients with diffuse large B-cell lymphoma failing platinum-based salvage chemotherapy

Up to 60% of patients with relapsed/refractory diffuse large B-cell lymphoma (DLBCL) do not respond to second-line (salvage) chemotherapy and hence are not offered autologous hematopoietic cell transplantation (AHCT). The utility of further salvage chemotherapy in an attempt to proceed with AHCT remains undefined. The authors reviewed 201 patients with DLBCL relapsed/refractory to anthracycline-based chemotherapy who received first-line salvage chemotherapy containing cis-platinum. Of the 120 non-responders to first-line platinum-based salvage chemotherapy, 73 received second-line salvage chemotherapy. The response rate to second-line salvage chemotherapy was 14%. Factors predicting lack of response were progression on primary therapy (p = 0.007), abnormal lactate dehydrogenase findings (p = 0.0027) and tumor bulk (p = 0.013) at second progression. Eight patients who responded received AHCT and appeared to have comparable survival to those transplanted after one salvage regimen. The authors conclude that the utility of second-line salvage chemotherapy is low, and that it is best reserved for patients demonstrating initial anthracycline sensitivity and low tumor burden.

The relationship between absolute lymphocyte count with PFS in patients with Hodgkin's lymphoma undergoing autologous hematopoietic cell transplant

Previous reports in Hodgkin's lymphoma (HL) patients undergoing autologous hematopoietic cell transplantation (AHCT) have demonstrated a significant association between the absolute lymphocyte count at day 15 (ALC-15) with survival. To evaluate this finding further, we analyzed 146 patients with relapsed/refractory HL who underwent AHCT to evaluate the relationship between lymphocyte counts at apheresis and at two time points (days 15 and 90) after AHCT with PFS. We found no association between the ALC-15 and the ALC-90 with PFS. We found lymphocyte counts at apheresis and disease sensitive to salvage chemotherapy were predictive of PFS. In conclusion, our study does provide some support for the theory that the immune system may be important in disease control but further and more detailed studies in this area are required.

Bone marrow-derived mesenchymal stromal cells for the repair of central nervous system injury

Transplantation of bone marrow-derived mesenchymal stromal cells (MSCs) into the injured brain or spinal cord may provide therapeutic benefit. Several models of central nervous system (CNS) injury have been examined, including that of ischemic stroke, traumatic brain injury and traumatic spinal cord injury in rodent, primate and, more recently, human trials. Although it has been suggested that differentiation of MSCs into cells of neural lineage may occur both in vitro and in vivo, this is unlikely to be a major factor in functional recovery after brain or spinal cord injury. Other mechanisms of recovery that may play a role include neuroprotection, creation of a favorable environment for regeneration, expression of growth factors or cytokines, vascular effects or remyelination. These mechanisms are not mutually exclusive, and it is likely that more than one contribute to functional recovery. In light of the uncertainty surrounding the fate and mechanism of action of MSCs transplanted into the CNS, further preclinical studies with appropriate animal models are urgently needed to better inform the design of new clinical trials.

Outcome following multiple lines of salvage chemotherapy prior to autologous stem cell transplant for relapsed or refractory diffuse large B-cell lymphoma (DLBCL)

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Background: The standard of care for chemosensitive relapsed or refractory DLBCL is autologous stem cell transplant (ASCT). There is no standard approach for patients (pts) whose disease fails to respond to platinum-based salvage chemotherapy (pSC) although pts who undergo further salvage chemotherapy to demonstrate chemosensitivity may benefit from ASCT (Chen, et al, BMT 2002). We analyzed the overall response rate (ORR) to each line of salvage therapy for pts with relapsed or refractory DLBCL and the impact of the number of salvage regimens necessary to demonstrate chemosensitivity on overall and progression-free survival (OS and PFS) post-ASCT. Methods: We retrospectively reviewed our computerized database and charts between Jan 1/99 - Dec 31/05 and identified 203 pts relapsed after or refractory to anthracycline-based chemo treated with pSC. Pts typically received 2–3 cycles of pSC to assess chemotherapy sensitivity. Responding patients received etoposide 60 mg/kg and melphalan 160 mg/m2 supported by autologous PBSCs. Pts with stable or progressive disease following first line salvage chemotherapy (SC1) were offered alternate non-cross resistant second-line salvage chemotherapy (SC2) and proceeded to ASCT if chemosensitive. Results: Pt characteristics: Median age at time of salvage chemotherapy: 52 years (range 21–65); primary refractory: 48%; advanced stage disease at salvage: 50%; prior rituximab: 17%; prior radiation 26%. 119/203 pts did not respond to SC1, 81 pts received SC2 and 10 pts received 3 salvage regimens (SC3). ORRs to salvage were: SC1: 40%, SC2: 14%, SC3: 10%. Pts able to proceed to ASCT were: SC1: 37%, SC2: 14%, SC3: 0. With a median follow-up of 1.8 years, the 2-year OS post ASCT for the SC1 and SC2 groups was 69% and 56% respectively. The 2-year PFS post ASCT for the SC1 and SC2 groups were 58% and 40%. Conclusions: The ORR to platinum-based SC is low in this cohort of primary refractory/relapsed patients (40%), and only 14% of pts who received SC2 after pSC responded. Although some have prolonged PFS following SC2 and ASCT, additional strategies should be investigated in these patients.

No significant financial relationships to disclose.