Haematopoietic stem cell transplantation for treatment of relapsing-remitting multiple sclerosis in Sweden: an observational cohort study.

BACKGROUND: A growing evidence base supports the use of autologous haematopoietic stem cell transplantation (aHSCT) for treatment of relapsing-remitting multiple sclerosis (RRMS), but it has not yet been integrated into most national clinical guidelines. The objective of this study was to assess efficacy and safety when aHSCT is implemented in routine healthcare. METHODS: We assessed 231 patients and the final analysis included 174 RRMS patients who were treated with aHSCT in Sweden before 1 January 2020. Efficacy was evaluated by performing a retrospective analysis of prospectively collected data from the Swedish MS registry. Procedure-related safety was assessed by analysing data from electronic patient records covering a period of 100 days following aHSCT. RESULTS: With a median follow-up time of 5.5 (IQR: 3.4-7.5) years, the Kaplan-Meier estimate for no evidence of disease activity was 73% (95% CI 66% to 81%) at 5 years and 65% (95% CI 57% to 75%) at 10 years. Out of the 149 patients with baseline disability, 80 (54%) improved, 55 (37%) were stable and 14 (9%) deteriorated. The mean number of adverse events per patient was 1.7 (±SD: 1.5) for grade 3 events and 0.06 (±SD: 0.3) for grade 4 events. Febrile neutropenia was the most common adverse event, affecting 68% of patients. There was no treatment-related mortality. CONCLUSIONS: Treatment with aHSCT for RRMS is associated with freedom from disease activity in a majority of patients, with acceptable adverse events. This procedure should be considered a standard of care for patients with highly active RRMS.

Carfilzomib and dexamethasone maintenance following salvage ASCT in multiple myeloma: A randomised phase 2 trial by the Nordic Myeloma Study Group.

OBJECTIVE: We investigated the efficacy and safety of carfilzomib-containing induction before salvage high-dose melphalan with autologous stem-cell transplantation (salvage ASCT) and maintenance with carfilzomib and dexamethasone after salvage ASCT in multiple myeloma. METHODS: This randomised, open-label, phase 2 trial included patients with first relapse of multiple myeloma after upfront ASCT who were re-induced with four cycles of carfilzomib, cyclophosphamide and dexamethasone. Two months after salvage, ASCT patients were randomised to either observation or maintenance therapy with iv carfilzomib 27 â†’ 56 mg/sqm and p.o. dexamethasone 20 mg every second week. The study enrolled 200 patients of which 168 were randomised to either maintenance with carfilzomib and dexamethasone (n = 82) or observation (n = 86). RESULTS: Median time to progression (TTP) after randomisation was 25.1 months (22.5-NR) in the carfilzomib-dexamethasone maintenance group and 16.7 months (14.4-21.8) in the control group (HR 0.46, 95% CI 0.30-0.71; P = .0004). The most common adverse events during maintenance were thrombocytopenia, anaemia, hypertension, dyspnoea and bacterial infections. CONCLUSION: In summary, maintenance therapy with carfilzomib and dexamethasone after salvage ASCT prolonged TTP with 8 months. The maintenance treatment was in general well-tolerated with manageable toxicity.

Autologous haematopoietic stem cell transplantation compared with alemtuzumab for relapsing-remitting multiple sclerosis: an observational study.

OBJECTIVE: To compare outcomes after treatment with autologous haematopoietic stem cell transplantation (AHSCT) and alemtuzumab (ALZ) in patients with relapsing-remitting multiple sclerosis. METHODS: Patients treated with AHSCT (n=69) received a conditioning regimen of cyclophosphamide (200 mg/kg) and rabbit anti-thymocyte globulinerG (6.0 mg/kg). Patients treated with ALZ (n=75) received a dose of 60 mg over 5 days, a repeated dose of 36 mg over 3 days after 1 year and then as needed. Follow-up visits with assessment of the expanded disability status scale score, adverse events and MR investigations were made at least yearly. RESULTS: The Kaplan-Meier estimates of the primary outcome measure 'no evidence of disease activity' was 88% for AHSCT and 37% for ALZ at 3 years, p<0.0001. The secondary endpoint of annualised relapse rate was 0.04 for AHSCT and 0.1 for ALZ, p=0.03. At last follow-up, the proportions of patients who improved, were stable or worsened were 57%/41%/1% (AHSCT) and 45%/43%/12% (ALZ), p=0.06 Adverse events grade three or higher were present in 48/69 patients treated with AHSCT and 0/75 treated with ALZ in the first 100 days after treatment initiation. The most common long-term adverse event was thyroid disease with Kaplan-Meier estimates at 3 years of 21% for AHSCT and 46% for ALZ, p=0.005. CONCLUSIONS: In this observational cohort study, treatment with AHSCT was associated with a higher likelihood of maintaining 'no evidence of disease activity'. Adverse events were more frequent with AHSCT in the first 100 days, but thereafter more common in patients treated with ALZ.

Intrathecal immunoglobulins and neurofilament light after autologous haematopoietic stem cell transplantation for multiple sclerosis.

BACKGROUND: Oligoclonal bands (OCB) are widely believed to be stable over time and rarely affected by disease-modifying treatment in MS. It is presently unknown how intrathecal immunoglobulin production and other cerebrospinal fluid (CSF) biomarkers are impacted by a highly efficacious procedure such as autologous haematopoietic stem cell transplantation (aHSCT). OBJECTIVE: To describe the evolution of intrathecal immunoglobulin and neurofilament light (NFL) over time in MS patients treated with aHSCT. METHODS: In this retrospective study, available data from previously made CSF investigations in 46 patients treated with aHSCT were analysed. RESULTS: After a median follow-up time of 745 days, immunoglobulin G (IgG) OCB remained detectable in 74% of patients, the proportion of patients with a pathological IgG index went down from 70% to 46%, and the proportion of patients with a pathological NFL went down from 72% to 24%. In patients with follow-up time >1500 days, IgG OCB were detectable in 50% of patients, 14% had a pathological IgG index and none a pathological NFL. CONCLUSIONS: Intrathecal immunoglobulin production and NFL were lower after treatment with aHSCT, decreased over time and were normalised in a significant portion of patients. This challenges the notion that OCB are unaffected by therapeutic intervention in MS.

Outcome and characteristics of non-measurable myeloma: A cohort study with population-based data from the Swedish Myeloma Registry.

OBJECTIVE: We describe survival in patients with oligo- and non-secretory multiple myeloma (MM). We refer to the whole group as non-measurable MM and compare it with secretory MM. METHODS: Oligo-secretory MM was defined as M protein in serum <10 g/L and M protein in urine <200 measured as mg/day, mg/liter or mg/mmol creatinine. If patients had no M protein, they were defined as non-secretory. The groups were also subdivided by Free Light Chains (SFLC) level and ratio. RESULTS: Out of 4325 patients with symptomatic MM in the Swedish Myeloma Registry during 2008-2016 eligible for the study, 389 patients (9%) had non-measurable MM. Out of these, 253 patients (6%) had oligo-secretory and 136 (3%) had non-secretory MM. Median survival for secretory MM was 42.7 months, non-measurable MM 40.2 months, oligo-secretory MM 38.6 months, and non-secretory MM 44.6 months. Difference in overall observed survival was non-significant for all groups when compared with secretory MM. Within non-secretory MM, stem cell transplantation (SCT), 95% being auto-SCT, was significant for superior survival in multivariate analysis (HR 0.048. P = .0015). CONCLUSION: In this population-based study, we found no difference in survival between oligo- or non-secretory MM when compared with secretory MM. SCT appears to be important also for patients with non-secretory disease.

Quantification of 11C-PIB kinetics in cardiac amyloidosis.

BACKGROUND: The purpose of this work was to determine the optimal tracer kinetic model of 11C-PIB and to validate the use of the simplified methods retention index (RI) and standardized uptake value (SUV) for quantification of cardiac 11C-PIB uptake in amyloidosis. METHODS AND RESULTS: Single-tissue, reversible and irreversible two-tissue models were fitted to data from seven cardiac amyloidosis patients who underwent 11C-PIB PET scans and arterial blood sampling for measurement of blood radioactivity and metabolites. The irreversible two-tissue model (2Tirr) best described cardiac 11C-PIB uptake. RI and SUV showed high correlation with the rate of irreversible binding (Ki) from the 2Tirr model (r2 =0.95 and r2 =0.94). Retrospective data from 10 amyloidosis patients and 5 healthy controls were analyzed using RI, SUV, as well as compartment modelling with a population-average metabolite correction. All measures were higher in amyloidosis patients than in healthy controls (p=.001), but with an overlap between groups for Ki. CONCLUSION: An irreversible two-tissue model best describes the 11C-PIB uptake in cardiac amyloidosis. RI and SUV correlate well with Ki from the 2Tirr model. RI and SUV discriminate better between amyloidosis patients and controls than Ki based on population-average metabolite correction.

High Graft-versus-Host Disease-Free, Relapse/Rejection-Free Survival and Similar Outcome of Related and Unrelated Allogeneic Stem Cell Transplantation for Aplastic Anemia: A Nationwide Swedish Cohort Study.

Allogeneic stem cell transplantation (SCT) as primary treatment for aplastic anemia (AA) is being increasingly used. Yet, age, stem cell source, and donor type are important outcome factors. We have recently performed a nationwide cohort study of all patients with AA in Sweden diagnosed from 2000 to 2011 and now present outcome data on SCT patients. In total, 68 patients underwent SCT, and 63% of them had failed immunosuppressive therapy. We found that, with a median follow-up of 109 months (range, 35 to 192 months), 5-year overall survival (OS) for all patients was 86.8%, whereas graft-versus-host disease-free, relapse/rejection-free survival (GRFS) at 5 years was 69.1%. There was no survival impact regarding the donor type or stem cell source. Patients aged ≥40 years had a higher transplant-related mortality (29.4% versus 7.8%; P = .023), which translated into a lower 5-year OS: 70.6% versus 92.2% (P = .022) and a trend of lower GRFS (52.9% versus 74.5%; P = .069). In conclusion, we found in this real-world setting that both OS and GRFS were high, but SCT for patients with AA aged ≥40 years is problematic, and clinical trials addressing this issue are warranted.

Family Mismatched Allogeneic Stem Cell Transplantation for Myelofibrosis: Report from the Chronic Malignancies Working Party of European Society for Blood and Marrow Transplantation.

This analysis included 56 myelofibrosis (MF) patients transplanted from family mismatched donor between 2009 and 2015 enrolled in the European Society for Blood and Marrow Transplantation database. The median age was 57years (range, 38 to 72); 75% had primary MF and 25% had secondary MF. JAK2 V617F was mutated in 61%. Donors were HLA mismatched at 2 or more loci. Stem cells were sourced from bone marrow in 66% and peripheral blood in 34%. The median CD34+ cell dose was 4.8 × 106/kg (range, 1.7 to 22.9; n = 43). Conditioning was predominantly myeloablative in 70% and reduced intensity in the remainder. Regimens were heterogeneous with thiotepa, busulfan, fludarabine, and post-transplant cyclophosphamide used in 59%. The incidence of neutrophil engraftment by 28days was 82% (range, 70% to 93%), at a median of 21days (range, 19 to 23). At 2years the cumulative incidence of primary graft failure was 9% (95% CI 1% to 16%) and secondary graft failure was 13% (95% CI 4% to 22%). The cumulative incidence of acute graft-versus-host disease (GVHD) grades II to IV and III to IV was 28% (95% CI 16% to 40%) and 9% (95% CI 2% to 17%) at 100days. The cumulative incidence of chronic GVHD at 1 year was 45% (95% CI 32% to 58%), but the cumulative incidence of death without chronic GVHD by 1 year was 20% (95% CI 10% to 31%). With a median follow-up of 32 months, the 1- and 2-year overall survival was 61% (95% CI 48% to 74%) and 56% (95% CI 41% to 70%), respectively. The 1- and 2- year progression-free survival was 58% (95% CI 45% to 71%) and 43% (95% CI 28% to 58%), respectively, with a 2-year cumulative incidence of relapse of 19% (95% CI 7% to 31%). The 2-year nonrelapse mortality was 38% (95% CI 24% to 51%). This retrospective study of MF allo-SCT using family mismatched donors demonstrated feasibility of the approach, timely neutrophil engraftment in over 80% of cases, and acceptable overall and progression-free survival rates with relapse rates not dissimilar to the unrelated donor setting. However, strategies to minimize the risk of graft failure and the relatively high nonrelapse mortality need to be used, ideally in a multicenter prospective fashion.

Sustained remission in multiple sclerosis after hematopoietic stem cell transplantation.

OBJECTIVES: To determine whether treatment with autologous hematopoietic stem cell transplantation (HSCT) can induce sustained complete remission in patients with multiple sclerosis (MS). MATERIAL AND METHODS: Case series of patients with relapsing-remitting MS (n = 10) treated at a single center between 2004 and 2007 and followed up for 10 years. The patients were treated with a BEAM/ATG conditioning regimen (n = 9) or a cyclophosphamide/ATG conditioning regimen (n = 1) followed by infusion of unmanipulated autologous hematopoietic stem cells. The primary endpoint was sustained complete remission. Sustained complete remission was defined as "no evidence of disease activity-4," sustained for a period of at least 5 years without any ongoing disease-modifying treatment. Furthermore, MS was considered as "resolved" if intrathecal IgG production and cerebrospinal fluid neurofilament light levels were normalized as well. RESULTS: Five out of 10 patients were in sustained complete remission at the end of the study. In three of them, MS was resolved. CONCLUSIONS: Our data demonstrate that sustained complete remission after autologous HSCT for MS is possible.

Effect of Nonmyeloablative Hematopoietic Stem Cell Transplantation vs Continued Disease-Modifying Therapy on Disease Progression in Patients With Relapsing-Remitting Multiple Sclerosis: A Randomized Clinical Trial.

Importance: Hematopoietic stem cell transplantation (HSCT) represents a potentially useful approach to slow or prevent progressive disability in relapsing-remitting multiple sclerosis (MS). Objective: To compare the effect of nonmyeloablative HSCT vs disease-modifying therapy (DMT) on disease progression. Design, Setting, and Participants: Between September 20, 2005, and July 7, 2016, a total of 110 patients with relapsing-remitting MS, at least 2 relapses while receiving DMT in the prior year, and an Expanded Disability Status Scale (EDSS; score range, 0-10 [10 = worst neurologic disability]) score of 2.0 to 6.0 were randomized at 4 US, European, and South American centers. Final follow-up occurred in January 2018 and database lock in February 2018. Interventions: Patients were randomized to receive HSCT along with cyclophosphamide (200 mg/kg) and antithymocyte globulin (6 mg/kg) (n = 55) or DMT of higher efficacy or a different class than DMT taken during the previous year (n = 55). Main Outcomes and Measures: The primary end point was disease progression, defined as an EDSS score increase after at least 1 year of 1.0 point or more (minimal clinically important difference, 0.5) on 2 evaluations 6 months apart, with differences in time to progression estimated as hazard ratios. Results: Among 110 randomized patients (73 [66%] women; mean age, 36 [SD, 8.6] years), 103 remained in the trial, with 98 evaluated at 1 year and 23 evaluated yearly for 5 years (median follow-up, 2 years; mean, 2.8 years). Disease progression occurred in 3 patients in the HSCT group and 34 patients in the DMT group. Median time to progression could not be calculated in the HSCT group because of too few events; it was 24 months (interquartile range, 18-48 months) in the DMT group (hazard ratio, 0.07; 95% CI, 0.02-0.24; P < .001). During the first year, mean EDSS scores decreased (improved) from 3.38 to 2.36 in the HSCT group and increased (worsened) from 3.31 to 3.98 in the DMT group (between-group mean difference, -1.7; 95% CI, -2.03 to -1.29; P < .001). There were no deaths and no patients who received HSCT developed nonhematopoietic grade 4 toxicities (such as myocardial infarction, sepsis, or other disabling or potential life-threatening events). Conclusions and Relevance: In this preliminary study of patients with relapsing-remitting MS, nonmyeloablative HSCT, compared with DMT, resulted in prolonged time to disease progression. Further research is needed to replicate these findings and to assess long-term outcomes and safety. Trial Registration: ClinicalTrials.gov Identifier: NCT00273364.

Outcome of patients with Myelofibrosis relapsing after allogeneic stem cell transplant: a retrospective study by the Chronic Malignancies Working Party of EBMT.

Allogeneic Haematopoietic Stem Cell Transplant (allo-HSCT) remains the only curative approach for Myelofibrosis (MF). Scarce information exists in the literature on the outcome and, indeed, management of those MF patients who relapse following transplant. We hereby report on the management and outcome of 202 patients who relapsed post allo-HSCT for MF.

Outcome and survival of myeloma patients diagnosed 2008-2015. Real-world data on 4904 patients from the Swedish Myeloma Registry.

Epidemiology and outcome of myeloma are mainly reported from large university centers and collaborative groups, and do not represent 'real-world' patients. The Swedish Myeloma Registry is a prospective population-based registry documenting characteristics, treatment and outcome in newly diagnosed myeloma, including asymptomatic and localized forms, with the purpose of improving disease management and outcome. This report presents information on patients diagnosed between 2008 and 2015, including data on first-line treatment in patients diagnosed up to 2014, with a follow up until December 2016. We present age-adjusted incidence, patients' characteristics at baseline, treatment, response, and survival. Baseline data were available with a 97% coverage in 4904 patients (median age 71 years, males 70 years, females 73 years; 72% were 65 years or older), and at 1-year follow up in 3558 patients with symptomatic disease (92% of patients initially reported). The age-adjusted incidence was 6.8 myeloma cases per 100,000 inhabitants per year. Among initially symptomatic patients (n=3988), 77% had osteolytic lesions or compression fractures, 49% had anemia, 18% impaired kidney function, and 13% hypercalcemia. High-dose therapy with autologous stem cell transplantation was given to 77% of patients aged up to 66 years, and to 22% of patients aged 66-70 years. In the study period, 68% received bortezomib, thalidomide, and/or lenalidomide as part of the first-line treatment, rising from 31% in 2008 to 81% in 2014. In active myeloma, the median relative survival of patients aged 65 years or under was 7.7 years, and 3.4 years in patients aged 66 years and over. Patients diagnosed with myeloma in more recent years were associated with significantly higher rates of complete or very good partial remission (P<0.05), and with a significantly higher survival, with a Hazard Ratio (HR) of 0.84 (95%CI: 0.77-0.92; P<0.05). There was a small, but significant survival benefit in patients treated at university hospitals (HR 0.93; 95%CI: 0.87-0.99; P<0.05). We report here on a near complete 'real-world' population of myeloma patients during an 8-year period; a period in which newer drugs were implemented into standard practice. The overall incidence and median age were both higher than in most previous studies, indicating a more complete coverage of older patients. Myeloma survival in Sweden is comparable to other large registry studies, and responses and survival improved during the study period.

Low response rate to ATG-based immunosuppressive therapy in very severe aplastic anaemia - A Swedish nationwide cohort study.

OBJECTIVES: Antithymocyte globulin (ATG)-based immunosuppression remains a cornerstone in aplastic anaemia (AA) treatment. However, most ATG studies are not population-based and knowledge about real-world results concerning response and outcome could offer important information for treating physicians. METHODS: We have recently performed a nationwide retrospective cohort study on all AA patients diagnosed in Sweden in 2000-2011 and now present treatment and outcome data on patients receiving first-line ATG. In total, 158 patients showed a 47.0% response rate which was similar in all age groups (range 41.5%-51.7%) with no difference regarding ATG formulation. The response was significantly associated with severity grade-especially at time of treatment initiation: very severe (VSAA) 22.7%; severe (SAA) 54.5% (P < .001); and non-severe 88.5% (P < .001). A logistic regression-based predictive model indicated that VSAA patients with an absolute reticulocyte count <25 × 109 /L had only a 19% probability of response. In a multivariable analysis, age and VSAA at the time of treatment were the independent factors for inferior survival. CONCLUSIONS: Real-world VSAA patients respond poorly to ATG which indicates the need for a different treatment approach. Our findings suggest that age alone should not be a discriminating factor for administering ATG treatment.

Incidence and outcome of acquired aplastic anemia: real-world data from patients diagnosed in Sweden from 2000-2011.

A plastic anemia is a rare life-threatening disease. However, since the introduction of immunosuppressive therapy and allogeneic stem cell transplantation, the outcome has improved considerably, and the 5-year survival is reported to be 70-80% in selected patient cohorts. Yet, contemporary population-based data on incidence and survival are lacking. We performed a national retrospective study to determine the incidence, treatment, and survival of patients with aplastic anemia diagnosed in Sweden from 2000-2011. Patients were included via the National Patient Registry, and diagnosed according to the Camitta criteria. In total, 257 confirmed cases were identified, with an overall incidence of 2.35 (95% CI: 2.06-2.64) cases per million inhabitants per year. Median age was 60 years (range: 2-92), and median follow up was 76 (0-193) months. Primary treatments included immunosuppressive therapy (63%), allogenic stem cell transplantation (10%), or single-agent cyclosporine/no specific therapy (27%). The 5-year survival was 90.7% in patients aged 0-18 years, 90.5% in patients aged 19-39 years, 70.7% in patients aged 40-59 years, and 38.1% in patients aged ≥60 years. Multivariate analysis showed that age (both 40-59 and ≥60 age groups), very severe aplastic anemia and single-agent cyclosporine/no specific therapy were independent risk factors for inferior survival. In conclusion, younger aplastic anemia patients experience a very good long-term survival, while that of patients ≥60 years in particular remains poor. Apparently, the challenge today is to improve the management of older aplastic anemia patients, and prospective studies to address this medical need are warranted.

Incidence, characteristics, and outcome of solitary plasmacytoma and plasma cell leukemia. Population-based data from the Swedish Myeloma Register.

Solitary plasmacytoma (SP) and plasma cell leukemia (PCL) are uncommon (3-6%) types of plasma cell disease. The risk of progression to symptomatic multiple myeloma (MM) is probably important for the outcome of SP. PCL is rare and has a dismal outcome. In this study, we report on incidence and survival in PCL/SP, and progression to MM in SP, using the prospective observational Swedish Multiple Myeloma Register designed to document all newly diagnosed plasma cell diseases in Sweden since 2008. Both solitary bone plasmacytoma (SBP) (n=124) and extramedullary plasmacytoma (EMP) (n=67) have better overall survival (OS) than MM (n=3549). Progression to MM was higher in SBP than in EMP (35% and 7% at 2 years, respectively), but this did not translate into better survival in EMP. In spite of treatment developments, the OS of primary PCL is still dismal (median of 11 months, 0% at 5 years). Hence, there is a great need for diagnostic and treatment guidelines as well as prospective studies addressing the role for alternative treatment options, such as allogeneic stem cell transplantation and monoclonal antibodies in the treatment of PCL.

Second allogeneic stem cell transplant for aplastic anaemia: a retrospective study by the Severe Aplastic Anaemia Working Party of the European Society for Blood and Marrow Transplantation.

We analysed the outcome of a second allogeneic haematopoietic stem cell transplant (alloHSCT) in 162 patients reported to the European Society for Blood and Marrow Transplantation between 1998 and 2009. Donor origin was a sibling in 110 and an unrelated donor in 52 transplants, respectively. The stem cell source was bone marrow in 31% and peripheral blood in 69% of transplants. The same donor as for the first alloHSCT was used in 81% of transplants whereas a change in the choice of stem cell source was reported in 56% of patients, mainly from bone marrow to peripheral blood. Neutrophil and platelet engraftment occurred in 85% and 72% of patients, after a median time of 15 and 17 days, respectively. Grade II-IV acute graft-versus-host disease (GVHD) and chronic GVHD occurred in 21% and 37% of patients, respectively. Graft failure (GF) occurred in 42 patients (26%). After a median follow-up of 3·5 years, the 5-year overall survival (OS) was 60·7%. In multivariate analysis, the only factor significantly associated with a better outcome was a Karnofsky/Lansky score ≥80 (higher OS). We conclude that a second alloHSCT is feasible rescue option for GF in SAA, with a successful outcome in 60% of cases.

Optimizing production of Fc-amidated peptides by Chinese hamster ovary cells.

BACKGROUND: Amidation of the carboxyl terminal of many peptides is essential for full biological potency, often increasing receptor binding and stability. The single enzyme responsible for this reaction is peptidylglycine α-amidating monooxygenase (PAM: EC 1.14.17.3), a copper- and ascorbate-dependent Type I membrane protein. METHODS: To make large amounts of high molecular weight amidated product, Chinese hamster ovary (CHO) cells were engineered to express exogenous PAM. To vary access of the enzyme to its substrate, exogenous PAM was targeted to the endoplasmic reticulum, trans-Golgi network, endosomes and lysosomes or to the lumen of the secretory pathway. RESULTS: PAM was equally active when targeted to each intracellular location and assayed in homogenates. Immunocytochemical analyses of CHO cells and a pituitary cell line demonstrated that targeting of exogenous PAM was partially successful. PAM substrates generated by expressing peptidylglycine substrates (glucagon-like peptide 1-Gly, peptide YY-Gly and neuromedin U-Gly) fused to the C-terminus of immunoglobulin Fc in CHO cell lines producing targeted PAM. The extent of amidation of the Fc-peptides was determined by mass spectrometry and amidation-specific enzyme immunoassays. Amidation was inhibited by copper chelation, but was not enhanced by the addition of additional copper or ascorbate. CONCLUSIONS: Peptide amidation was increased over endogenous levels by exogenous PAM, and targeting PAM to the endoplasmic reticulum or trans-Golgi network increased peptide amidation compared to endogenous CHO PAM.

Secretion of Fc-amidated peptide fusion proteins by Chinese hamster ovary cells.

BACKGROUND: The therapeutic use of α-amidated peptides (e.g. calcitonin, glucagon-like peptide) has increased dramatically, but there are major impediments to wider use of such peptides. Larger peptides are expensive to synthesize, and short plasma half-lives frequently limit the clinical circumstances in which the peptides would be useful. Both problems are potentially solved by producing peptides as fusions with the Fc region of human immunoglobulin. METHODS: Glucagon-like peptide 1 (GLP1), peptide YY (PYY) and neuromedin U (NMU) were expressed and purified from stable CHO lines; since the α-amide group is essential for full biological potency of many peptides, Fc-fusion peptides were expressed in CHO lines stably expressing the α-amidating enzyme, peptidylglycine α-amidating monooxygenase (PAM: EC 1.14.17.3). Purified fusion proteins were analyzed intact and after HRV3C rhinovirus protease cleavage, at a site in the linker separating the Fc region from the peptide, by mass spectrometry and amide-specific immunoassays. RESULTS: The Fc fusions were expressed at 1-2.5 µg/mg cell protein and secreted at 5-20% of cell content per hour, in a peptide-specific manner. CHO cells express measurable endogenous PAM activity, amidating 25% of Fc-PYY and almost 90% of Fc-GLP1. Expression of exogenous PAM increased the level of peptide amidation to 50% of Fc-PYY and 95 % of Fc-NMU. The Fc-GLP1 fusions were 10,000-fold less active than synthetic GLP1 in a cell-receptor cyclic AMP-based assay, as expected since the amino terminal of GLP1 is essential for full biological activity. The Fc-PYY fusions were 100-fold less active than PYY-NH2 but 10-fold more active than non-amidated PYY-Gly. CONCLUSIONS: This type of approach can be used for the production of stabilized α-amidated peptides aimed at clinical trials.

Autologous stem cell transplantation for enteropathy-associated T-cell lymphoma: a retrospective study by the EBMT.

Enteropathy-associated T-cell lymphoma (EATL) is a rare subtype of peripheral T-cell lymphomas with a poor prognosis. Autologous stem cell transplantation (ASCT) was retrospectively evaluated as a consolidation or salvage strategy for EATL. The analysis included 44 patients who received ASCT for EATL between 2000 and 2010. Thirty-one patients (70%) were in first complete or partial remission at the time of the ASCT. With a median follow-up of 46 months, relapse incidence, progression-free survival, and overall survival were 39%, 54%, and 59% at 4 years, respectively, with only one relapse occurring beyond 18 months posttransplant. There was a trend for better survival in patients transplanted in first complete or partial remission at 4 years (66% vs 36%; P = .062). ASCT is feasible in selected patients with EATL and can yield durable disease control in a significant proportion of the patients.