Hannah Hunter

Coexistence of LMPP-like and GMP-like Leukemia Stem Cells in Acute Myeloid Leukemia

The relationships between normal and leukemic stem/progenitor cells are unclear. We show that in ∼80% of primary human CD34+ acute myeloid leukemia (AML), two expanded populations with hemopoietic progenitor immunophenotype coexist in most patients. Both populations have leukemic stem cell (LSC) activity and are hierarchically ordered; one LSC population gives rise to the other. Global gene expression profiling shows the LSC populations are molecularly distinct and resemble normal progenitors but not stem cells. The more mature LSC population most closely mirrors normal granulocyte-macrophage progenitors (GMP) and the immature LSC population a previously uncharacterized progenitor functionally similar to lymphoid-primed multipotential progenitors (LMPPs). This suggests that in most cases primary CD34+ AML is a progenitor disease where LSCs acquire abnormal self-renewal potential.

Weekly versus twice weekly bortezomib given in conjunction with rituximab, in patients with recurrent follicular lymphoma, mantle cell lymphoma and Waldenström macroglobulinaemia

The combination of bortezomib and rituximab was evaluated in patients with mantle cell lymphoma (MCL), follicular lymphoma (FL) and Waldenström macroglobulinaemia (WM), in a Phase I and later, a randomized Phase II study. In the randomized study, 42 patients with recurrent/refractory disease received either: bortezomib 1·3 mg/m2 on days 1, 4, 8 and 11 of a 3‐week cycle with rituximab 375 mg/m2 on day 1 (21 patients) or: bortezomib 1·6 mg/m2 and rituximab on days 1, 8, 15 and 22 of a 5‐week cycle (with rituximab being given only in cycles 1 and 4).Twenty‐eight patients were withdrawn (toxicity 16, progression 7, and ‘patient choice’ 5). The main toxicities were neurological, gastro‐intestinal and haematological. The overall response rate was 28/42(67%) and by histology: MCL 11/19, FL 8/15, and WM 9/10. Ten of 28 responding patients remained progression‐free at 1–3·5 years. Toxicity and efficacy were equivalent between the two groups. The combination has significant toxicity but is effective, particularly in patients with WM.

The effect of salvage autologous stem-cell transplantation on overall survival in patients with relapsed multiple myeloma (final results from BSBMT/UKMF Myeloma X Relapse [Intensive]): a randomised, open-label, phase 3 trial

BACKGROUND The Myeloma X trial previously reported improved durability of response (time to disease progression) in patients with relapsed multiple myeloma with salvage autologous stem-cell transplantation (ASCT) compared with oral cyclophosphamide in patients with multiple myeloma relapsing after a first ASCT. We report the final overall survival results of the trial. METHODS BSBMT/UKMF Myeloma X was a multicentre, randomised, open-label, phase 3 trial done at 51 centres in the UK. Eligible patients with multiple myeloma relapsing after a previous ASCT were re-induced with intravenous bortezomib (1·3 mg/m(2) on days 1, 4, 8, 11), intravenous doxorubicin (9 mg/m(2) per day on days 1-4), and oral dexamethasone (40 mg/day on days 1-4, 8-11, and 15-18 during cycle 1 and days 1-4 during cycles 2-4), with supportive care as per local institutional protocols before randomisation in a 1:1 ratio to either high-dose melphalan (200 mg/m(2)) and salvage ASCT or weekly oral cyclophosphamide (400 mg/m(2) per week for 12 weeks). Randomisation was by permuted blocks stratified by length of first remission and response to re-induction treatment. The primary endpoint was time to disease progression; the study was also powered to detect a difference in the secondary endpoint, overall survival. Further secondary endpoints were the proportion of patients achieving an objective response, progression-free survival, overall survival, toxic effects and safety, pain, and quality of life. Prespecified exploratory endpoints included time to second objective disease progression (PFS2). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00747877, and the European Clinical Trials Database, number 2006-005890-24, and is now in long-term follow-up. FINDINGS Between April 16, 2008, and Nov 19, 2012, 297 patients were registered into the study and 174 were randomly assigned to receive either high-dose melphalan and salvage ASCT (n=89) or oral weekly cyclophosphamide (n=85). 173 (58%) of 297 patients relapsed after more than 24 months from first ASCT. 75 (43%) of 174 randomised patients had died at follow-up: salvage ASCT (n=31 [35%]) versus oral weekly cyclophosphamide (n=44 [52%]). Updated time to disease progression shows continued advantage in the salvage ASCT group compared with the weekly cyclophosphamide group (19 months [95% CI 16-26] vs 11 months [9-12]; hazard ratio [HR] 0·45 [95% CI 0·31-0·64] log-rank p<0·0001). Median overall survival was superior in the salvage ASCT group compared with weekly cyclophosphamide group (67 months [95% CI 55-not estimable] vs 52 months [42-60]; log-rank p=0·022; HR 0·56 [0·35-0·90], p=0·0169). Time to second objective disease progression was superior in the salvage ASCT group compared with the weekly cyclophosphamide group (67 months [52-not estimable] vs 35 months [31-43]; HR 0·37 [0·24-0·57], log-rank p<0·0001). During extended follow-up, no further treatment-related or treatment-unrelated adverse events were reported. 15 second primary malignancies were reported in 12 patients (salvage ASCT [n=7] vs oral weekly cyclophosphamide [n=5]). The cumulative incidence of second primary malignancies at 60 months after trial entry was 5·2% (2·1-8·2). INTERPRETATION Salvage ASCT increases overall survival during consolidation of re-induction treatment in patients with multiple myeloma at first relapse after a first ASCT. The delay of salvage ASCT to third-line treatment or later might not confer the same degree of advantage as seen with salvage ASCT at first relapse. FUNDING Cancer Research UK, Janssen-Cilag, and Chugai Pharma UK.

Genetically distinct leukemic stem cells in human CD34- acute myeloid leukemia are arrested at a hemopoietic precursor-like stage.

Quek and colleagues identify human leukemic stem cells (LSCs) present in CD34− AML. In-depth characterization of the functional and clonal aspects of CD34− LSCs indicates that most are similar to myeloid precursors.

Updated Outcomes and Impact of Age With Lenalidomide and Low-Dose Dexamethasone or Melphalan, Prednisone, and Thalidomide in the Randomized, Phase III FIRST Trial.

Purpose This analysis of the FIRST trial in patients with newly diagnosed multiple myeloma (MM) ineligible for stem-cell transplantation examined updated outcomes and impact of patient age. Patients and Methods Patients with untreated symptomatic MM were randomly assigned at a one-to-one-to-one ratio to lenalidomide plus low-dose dexamethasone until disease progression (Rd continuous), Rd for 72 weeks (18 cycles; Rd18), or melphalan, prednisone, and thalidomide (MPT; 72 weeks), stratified by age (≤ 75 v > 75 years), disease stage (International Staging System stage I/II v III), and country. The primary end point was progression-free survival. Rd continuous and MPT were primary comparators. Results Between August 21, 2008, and March 7, 2011, 1,623 patients were enrolled (Rd continuous, n = 535; Rd18, n = 541; MPT, n = 547), including 567 (35%) age older than 75 years. Higher rates of advanced-stage disease and renal impairment were observed in patients older than 75 versus 75 years of age or younger. Rd continuous reduced the risk of progression or death compared with MPT by 31% (hazard ratio [HR], 0.69; 95% CI, 0.59 to 0.80; P < .001) overall, 36% (HR, 0.64; 95% CI, 0.53 to 0.77; P < .001) in patients age 75 years or younger, and 20% (HR, 0.80; 95% CI, 0.62 to 1.03; P = .084) in those age older than 75 years. Median overall survival was longer with Rd continuous than with MPT, including a 14-month difference in patients age older than 75 years. Progression-free survival with Rd18 was similar to that with MPT, and overall survival with Rd18 was marginally inferior to that with Rd continuous. Rates of grade 3 to 4 treatment-emergent adverse events were similar for Rd continuous-treated patients age 75 years or older and those age older than 75 years; however, older patients had more frequent lenalidomide dose reductions. Conclusion Results support Rd continuous treatment as a new standard of care for stem-cell transplantation-ineligible patients with newly diagnosed MM of all ages.

Stem cell harvesting after bortezomib-based re-induction for myeloma relapsing after autologous transplant: results from the BSBMT/UKMF Myeloma X (Intensive) trial.

The phase III British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X trial (MMX) demonstrated prospectively, for the first time, superiority of salvage autologous stem cell transplantation over chemotherapy maintenance for multiple myeloma (MM) in first relapse after previous ASCT. However, many patients have stored insufficient stem cells (PBSC) for second ASCT and robust evidence for remobilization after first ASCT is lacking. We report the feasibility, safety, and efficacy of remobilization after bortezomib-doxorubicin-dexamethasone reinduction in MMX and outcomes of second ASCT with these cells. One hundred ten patients underwent ≥1 remobilization with 32 and 4, undergoing second and third attempts, respectively. Toxicities of remobilization were similar to those seen in first-line mobilization. After all attempts, 52% of those with insufficient previously stored PBSC had harvested a sufficient quantity to proceed to second ASCT. Median PBSC doses infused, neutrophil engraftment, and time to discharge after second ASCT were similar regardless of stem cell source, as were the toxicities of second ASCT. No significant differences between PBSC sources were noted in depth of response to ASCT or time to progression. Harvesting after bortezomib-doxorubicin-dexamethasone reinduction for MM at first relapse is safe and feasible and yields a reliable cell product for second ASCT. The study is registered with ClinicalTrials.gov (NCT00747877) and EudraCT (2006-005890-24).

Stem Cell Harvesting after Bortezomib-Based Reinduction for Myeloma Relapsing after Autologous Transplantation: Results from the British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X (Intensive) Trial

The phase III British Society of Blood and Marrow Transplantation/United Kingdom Myeloma Forum Myeloma X trial (MMX) demonstrated prospectively, for the first time, superiority of salvage autologous stem cell transplantation over chemotherapy maintenance for multiple myeloma (MM) in first relapse after previous ASCT. However, many patients have stored insufficient stem cells (PBSC) for second ASCT and robust evidence for remobilization after first ASCT is lacking. We report the feasibility, safety, and efficacy of remobilization after bortezomib-doxorubicin-dexamethasone reinduction in MMX and outcomes of second ASCT with these cells. One hundred ten patients underwent ≥1 remobilization with 32 and 4, undergoing second and third attempts, respectively. Toxicities of remobilization were similar to those seen in first-line mobilization. After all attempts, 52% of those with insufficient previously stored PBSC had harvested a sufficient quantity to proceed to second ASCT. Median PBSC doses infused, neutrophil engraftment, and time to discharge after second ASCT were similar regardless of stem cell source, as were the toxicities of second ASCT. No significant differences between PBSC sources were noted in depth of response to ASCT or time to progression. Harvesting after bortezomib-doxorubicin-dexamethasone reinduction for MM at first relapse is safe and feasible and yields a reliable cell product for second ASCT. The study is registered with ClinicalTrials.gov (NCT00747877) and EudraCT (2006-005890-24).

UK consensus statement on the use of plerixafor to facilitate autologous Peripheral Blood Stem Cell collection to support high‐dose chemoradiotherapy for patients with malignancy

Plerixafor is a CXC chemokine receptor (CXCR4) antagonist that mobilizes stem cells in the peripheral blood. It is indicated (in combination with granulocyte‐colony stimulating factor [G‐CSF]) to enhance the harvest of adequate quantities of cluster differentiation (CD) 34+ cells for autologous transplantation in patients with lymphoma or multiple myeloma whose cells mobilize poorly. Strategies for use include delayed re‐mobilization after a failed mobilization attempt with G‐CSF, and rescue or pre‐emptive mobilization in patients in whom mobilization with G‐CSF is likely to fail. Pre‐emptive use has the advantage that it avoids the need to re‐schedule the transplant procedure, with its attendant inconvenience, quality‐of‐life issues for the patient and cost of additional admissions to the transplant unit. UK experience from 2 major centers suggests that pre‐emptive plerixafor is associated with an incremental drug cost of less than £2000 when averaged over all patients undergoing peripheral blood stem cell (PBSC) transplant. A CD34+ cell count of <15 µl−1 at the time of recovery after chemomobilization or after four days of G‐CSF treatment, or an apheresis yield of <1 × 106 CD34+ cells/kg on the first day of apheresis, could be used to predict the need for pre‐emptive plerixafor.

The use of Bruton's tyrosine kinase inhibition as a bridging strategy to successful allogeneic stem cell transplant in relapsed mantle cell lymphoma

The Bruton’s tyrosine kinase (BTK) inhibitors have been reported to deliver high response rates without significant toxicity in relapsed mantle cell lymphoma (MCL). The lead compound, ibrutinib, has demonstrated activity in MCL in patients with multiply-relapsed disease irrespective of baseline risk characteristics. This raises the question of where in the overall treatment schema to best employ these agents. In view of their modest side effect profile and ability to deliver responses in the majority of patients this would suggest one clinical scenario for which they would be ideally placed would be as a bridging therapy to allogeneic stem cell transplant, although there are no reports as yet of these agents being used in this setting. We report the case of a 51-year-old male patient diagnosed with mantle cell non-Hodgkin lymphoma (NHL) in August 2011. He presented with shortness of breath and subsequent investigations revealed a right-sided 13-cm lung mass. A biopsy of this confirmed a diagnosis of cyclin D1-positive classical MCL with a Ki-67 of  30%. By conventional staging criteria he had stage IV disease with a calculated mantle cell prognostic index (MIPI) of low risk. The patient was previously fit and on no prescription medications. He was treated initially with six cycles of R-CHOP chemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone) with a good clinical response. However as he had only achieved a partial remission his treatment continued with ESHAP (etoposide, cytarabine, cisplatin and methylprednisolone) for two cycles achieving a complete remission which was consolidated with a BEAM autograft (carmustine, cytarabine, etoposide and melphalan). He did not receive any maintenance therapy and post therapy imaging showed ongoing complete remission. A PET scan was not performed. Six weeks following his autograft the patient developed a recurrence of his presenting respiratory symptoms and imaging confirmed a relapse with further lung masses and a pleural effusion. Apart from his mild shortness of breath the patient was well with no B symptoms, a normal WCC, and no marrow involvement. His care was then transferred to our centre and he was included in a clinical trial with the oral BTK inhibitor, ONO-4059 (clinical trials.gov identifier: NCT01659255). The drug was given at a dose of 160 mg daily continuously using monthly cycles. The medication was well tolerated, with no toxicity and very rapid resolution of the lymphoma-related symptoms. After two cycles of therapy, imaging demonstrated resolution of the lung masses and pleural effusion. After seven cycles of therapy a PET-CT demonstrated a complete metabolic remission. The patient had an Human Leukocyte Antigen (HLA) identical sibling and it was decided to consolidate this response with an allogeneic transplant procedure. He continued on the BTK inhibitor for a total of 12 cycles, with no significant side effects although he was diagnosed with mild type 2 diabetes. The BTK inhibitor was stopped on day  8 prior to a reduced intensity sibling allogeneic stem cell transplant. Lymphocyte count at this time was 1.1  10^6/L Conditioning chemotherapy consisted of fludarabine 30 mg/m2, melphalan 140 mg/m2 and campath 30 mg with 5 mg/kg cyclosporine as graft-versus-host disease (GVHD) prophylaxis. He received a graft of 4.5  106 CD34  stem cells. His post-allograft recovery was uneventful aside from the development of a pulmonary embolus for which he was anticoagulated. Engraftment of neutrophils ( 0.5  106/L) occurred on day  13 with platelet engraftment to  20 by day  10 and to  50 by day  11. Lymphocyte count  1 was achieved on day  17. The BTK inhibitor was not re-started. At 7 months post transplant the patient was well with no evidence of graft versus host disease and complete donor chimerism. Bruton’s tyrosine kinase is involved in the signal regulation of a pathway of the B cell receptor, which is critical for normal B cell maturation and functioning [1]. Maintenance of the viability of malignant B cells of varied NHL subtypes is dependent on effective signaling from the B cell receptor [2,3]. The clinical success of inhibitors of BTK have been clearly demonstrated in relapsed and refractory mantle cell Leukemia & Lymphoma, February 2016; 57(2): 461–462

Detection of hepatitis b virus DNA in the blood of a stem cell donor after granulocyte colony‐stimulating factor treatment

Occult hepatitis B virus (HBV) infections have gained much attention in terms of transmissibility and reactivation. Here, we report the case of a healthy stem cell donor with serological evidence of a resolved HBV infection who became temporarily HBV DNA–positive in the blood after stimulation with granulocyte colony-stimulating factor (G-CSF). A 51-year-old man from the German Bone Marrow Donor Center was identified as human leukocyte antigen matching (10/10) stem cell donor for a 44-year-old female patient diagnosed with precursor B-cell acute lymphoblastic leukemia in the United Kingdom. This donor was a well-known blood donor since 2009 and was previously tested positive for antibody to hepatitis B core antigen, antibody to hepatitis B e antigen, and antibody to hepatitis B surface antigen (anti-HBs). During the diagnostic workup the serological findings could be confirmed and HBV DNA was not detected. Thus, in accordance with German regulations, this donor was considered eligible for stem cell donation. The donor started G-CSF treatment, and at day 5 cluster of differentiation 34 (CD34)–positive stem and progenitor cells were collected. At this time HBV DNA (pooled tested, detection limit 257 IU/mL) tested negative. The product was shipped from the German apheresis center to the UK transplantation center and infused after myeloablative conditioning of the patient had been completed. Six days after transplantation, testing of the product at the transplantation center revealed the presence of 26 IU/mL HBV DNA, which could be confirmed by testing backup samples (product and blood) (Table 1; Supporting Information). Therefore, the stem cell recipient immediately started lamivudine treatment and has tested negative for HBV DNA (last test day 1130) ever since. AntiHBs of the recipient was negative before transplantation but temporarily positive after transplantation (Supporting Information). HBV DNA testing of the donor was again negative at day 16 after apheresis. Anti-HBs titration and neutralizing experiments using hepatitis B surface antigen (HBsAg) from different genotypes specified the presence 3,300 IU/L anti-HBs in the blood of the donor highly capable of neutralizing HBsAg from different genotypes. Parts of the HBV DNA detected in the