The Acidic Region of Factor VIII Light Chain Contains the Thrombin-Binding Site(s) Responsible for the Cleavage at Arg1689

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2270-2270
Author(s):  
Hiroaki Minami ◽  
Keiji Nogami ◽  
Midori Shima

Abstract Thrombin-catalyzed activation of factor (F)VIII by cleavages at Arg372, Arg740, and Arg1689 is essential for the propagation phase of blood coagulation cascade. Activated FVIII (FVIIIa) forms the tenase complex and markedly amplifies the activation of FX as a cofactor of FIX. We had already demonstrated that thrombin interacts with FVIII through the residues 392-394 and 484-509 in the A2 domain and the C2 domain, and each association regulates cleavage at Arg740, Arg372, and Arg1689, respectively (Nogami K, JBC 2000, 2005; BJH 2008), and recently reported that the A1 acidic clustered region 340-350 involving the sulfated tyrosine regulate the cleavage of Arg372 (Minami et al. 55th ASH). On the other hand, Fay and colleague suggested that recombinant FVIII lacking the C2 domain retains greater than 50% cofactor activity (JBC 2010), supporting the presence of other thrombin-binding region responsible for cleavage at Arg1689 of the light chain. In this study, we attempted to identify this thrombin-binding site(s). We focused on the acidic residues 1659-1669 and 1675-1685 within the light chain, which had similar sequence to the A1 residues 340-350 in terms of involving the clustered acidic residues and sulfated tyrosine as well as hirugen residues 54-65. We prepared four of synthetic peptides corresponding to the residues 1659-1669 and 1675-1685 with sulfated tyrosine, P(1659-69s) and P(1675-85s), and with non-sulfated tyrosine, P(1659-69) and P(1675-85). The inhibitory effect on the thrombin-catalyzed FVIII activation by each peptide was evaluated in a one-stage clotting assay. Each peptide showed a dose-dependent inhibition on thrombin-catalyzed activation. These inhibitory effects were greater in order of P1675-85s, P1659-69s, P1675-85, P1659-69, and the IC50 were 25, 67, 71 and 225 µM, respectively. The peptides with sulfated tyrosine had approximately 3-fold greater inhibition of the FVIII activation by thrombin than with non-sulfated tyrosine. The IC50 in the presence of mixture of P1675-85s and P1659-69s was 30.4 µM, suggesting that these peptides had no an additive effect. The impacts of P1659-69s and P1675-85s on the thrombin-catalyzed cleavage at Arg1689 were examined by SDS-PAGE/western blotting. These peptides blocked the cleavage at Arg1689 in dose-dependent fashions. In timed-course assay, the presence of P1659-69s and P1675-85s decreased the cleavage rate of Arg1689 by 61.3 % and 81.8 %, respectively compared to its absence. The direct binding of P1659-69s and P1675-85s to thrombin was examined by surface resonance plasmon (SPR)-based assay and by the zero-length cross-linking reagent EDC. In SPR-based assay using a Biacore T200TM, thrombin bound to immobilized P1659-69s and P1675-85s directly with high affinity. The Kd values adjusted to 1:1 binding model of global fitting were 203 nM and 94 nM, respectively. EDC cross-linking in fluid-phase assay revealed that formation of EDC cross-linking products between biotinylated P1659-69s or P1675-85s and thrombin were observed in dose-dependent fashions. The products between the biotinylated peptides (800 nM) and thrombin were competitively reduced by the addition of non-biotinylated peptides. Moreover, N-terminal sequence analysis of cross-linking products between both peptides-thrombin indicated that thrombin bound to the residues 1664-1669 and 1683-1684. Taken together, we demonstrated that the A3 residues 1659-1669 (QEEIDYDDTIS) and residues 1675-1685 (EDFDIYDEDEN) contained the thrombin binding-sites responsible for proteolytic cleavage at Arg1689 of the A3 domain. Disclosures Nogami: Bayer, NovoNordisk, Baxalta, Chugai, Kaketsuken, Pfizer, Biogen: Honoraria; Chugai: Membership on an entity's Board of Directors or advisory committees; Bayer, Novo Nordisk, Baxalta. Biogen: Research Funding. Shima:Chugai Pharmaceutical Co., Ltd. and F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding.

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3763-3763
Author(s):  
Furukawa Shoko ◽  
Masahiro Takeyama ◽  
Midori Shima ◽  
Keiji Nogami

Abstract Factor (F)VIII functions as a cofactor in the tenase complex responsible for phospholipid (PL) surface-dependent conversion of FX to FXa by FIXa. On the other hand, protein S (PS) functions as a cofactor of activated protein C that inactivates FVIII(a) and FV(a). We have reported a new regulatory mechanism on coagulation that PS directly impaired the FXase complex by competing the FIXa-FVIIIa interaction (Takeyama, Br J Haematol. 2008;143:409), and identified the PS-interactive site on the FVIII A2 domain (Takeyama, Thromb Haemost. 2009;102:645). However, the contribution of FVIII light chain (LC) to PS-binding has not been determined. In this study, several approaches were employed to assess a PS-FVIII LC interaction. The binding of FVIII LC to active site-modified FIXa (EGR-FIXa) was inhibited by PS dose-dependently (Ki; 4.6 nM) on ELISA. Because FVIII C2 domain has a binding site for FIXa, we examined whether FVIII C2 domain bound to PS. PS bound to FVIII C2 domain (Kdapp; 283 nM) by the ELISA. A SPR-based assay also revealed that FVIII C2 domain bound to PS (Kd; 62 nM). We have reported that a FIXa-interactive site exits on FVIII C2 domain (residues 2228-2240) (Soeda, J Biol Chem. 2009;284:3379). Therefore, we assessed the interaction of the synthetic peptide spanning the residues (2228-2240) with PS. ELISA showed that the peptide bound to PS (Kdapp; 104 µM). SPR-based assay also revealed that the peptide bound to PS (Kd; 31.4 µM), although scrambled peptide failed to bind to PS. Covalent cross-linking was observed between the biotynated 2228-2240 peptide and PS following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) using SDS-PAGE. This cross-linking formation was blocked by the addition of the unlabeled peptide. Furthermore, N-terminal sequence analysis of the peptide-PS product showed that one basic residue (K2239) could not be detected, supporting that this residue participates in cross-link formation. These results indicate that the 2228-2240 residues in the FVIII C2 domain, in particular K2239, may contribute to a PS-interactive site. To inquire further into the interactive region of FVIII C2 domain to PS, we prepared a stably expressed recombinant B-domainless FVIII mutants (E2228A, D2233A, K2236A, and K2239A), which were polar amino acids in the 2228-2240 residues, subsequently compared interaction with PS of the mutants with B-domainless FVIII wild type. To evaluate the binding affinity to PS, we performed SPR-based assay with the wild type FVIII and the FVIII mutants. The assay showed K2239A bound to PS with ~1.9-fold higher Kd value (28.1 nM) than that of wild type (Kd; 14.7 nM), although E2228A, D2233A, or K2236A bound to PS (Kd; 12.7, 16.3, and 10.3 nM, respectively) with no significant difference compared with wild type. In addition, to evaluate the effect of mutants for FXa generation, we assessed FXa generation assay with wild type or K2239A in the presence or absence PS, because K2239 might contribute to a PS interaction of FVIII. After each FVIII (1 nM) was reacted with various concentrations of PS in the presence of PL (20 µM) for 30 minutes, FVIII was activated by thrombin (30 nM), followed by the reaction with FIXa (40 nM) and FX (300 nM) for 1 minute. Although generated FXa with both wild type and K2239A were reduced in the presence of PS dose-dependently, compared with its absence, the inhibition ratio of K2239A was less than that of wild type (18.2% and 31%, respectively in the presence of 500 nM PS). On the other hand, the Km value on FXa generation of K2239A for various concentrations of FIXa was ~1.8-fold higher than that of wild type (5.5±0.9 and 3.1±0.2 nM, respectively), suggesting that K2239 residue, involved in the FIXa-interactive site, might contribute to the inhibition of FVIII function by PS. In conclusion, FVIII C2 domain, in particular K2239, was possible to play an important role of the inhibitory mechanism to FVIII function by PS, due to the binding to PS. Disclosures Shima: Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding. Nogami:Sysmex Corporation: Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding.


Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1514-1514 ◽  
Author(s):  
Pradyumna D. Phatak ◽  
Pierre Brissot ◽  
Herbert Bonkovsky ◽  
Mark Wurster ◽  
Lawrie Powell ◽  
...  

Abstract Abstract 1514 Poster Board I-537 Background and aims Hereditary hemochromatosis (HH) is an autosomal recessive disorder characterized by progressive iron overload through increased intestinal absorption. Phlebotomy treatment is the standard of care, but compliance is variable and some patients are poor candidates due to underlying medical disorders and/or poor venous access. An oral iron chelator such as deferasirox (Exjade®) may provide an alternative treatment option for HH patients. Methods This is an inter-patient dose-escalation study of deferasirox (5, 10, 15 and 20 mg/kg) administered daily for 24 weeks to C282Y HFE homozygous HH patients with a pre-treatment serum ferritin (SF) value of 300–2000 ng/mL, transferrin saturation ≥45% and no known history of cirrhosis. A 6-month extension of this trial has recently been completed. The primary endpoint is the incidence and severity of adverse events (AEs). Secondary endpoints include change in SF, time to SF normalization (<100 ng/mL), longitudinal course of SF, and pharmacokinetics of deferasirox. Results 49 patients were enrolled and 48 patients were treated (33 men, 16 women; mean age 50.6 years; mean of 3.1 years since HH diagnosis) with deferasirox 5 (n=11), 10 (n=15) or 15 mg/kg/day (n=23) for at least 24 weeks. 37 (75.5%) patients completed the study (10 [90.9%], 11 [73.3%]; 16 [69.6%] patients in the 5, 10 and 15 mg/kg/day groups, respectively. The most common reasons for discontinuation were AEs in 3 (20.0%) patients and 4 (17.4%) patients in the 10 and 15 mg/kg/day groups, respectively. Bayesian analysis and medical review were performed between dose escalations. Meaningful reductions in SF were observed across the first three dose groups (median decrease -31.1%, -52.8% and -55.4% in the 3 groups respectively), and escalation to 20 mg/kg/day was not undertaken. Time course of the SF decline was dose-dependent (Figure). AEs in the core were dose dependent and consistent with the known safety profile of deferasirox. The most common drug-related AEs (≥10% in all patients) reported were diarrhea in 1 (9%), 4 (27%) and 9 (39%) patients, nausea in 0 (0%), 2 (13%) and 4 (17%) patients and abdominal pain in 0 (0%), 2 (13%), 3 (13%) patients in the 5, 10 and 15 mg/kg/day groups, respectively. One patient had ALT >5X upper limit of normal, and 11 patients had serum creatinine ≥33% over baseline and upper limit of normal on two consecutive occasions. All resolved with dose cessation or modification. Conclusions The results from the CORE trial suggest that deferasirox doses of 5, 10 and 15 mg/kg/day are effective at reducing iron burden in HH patients. Based on the safety profile, only the 5 and 10 mg/kg/day doses are being considered for further study in this population. The results of the 24 week extension phase will be available at the time of the meeting. Larger studies are required to define the appropriate treatment regimen in HH. Disclosures Phatak: Novartis: Honoraria, Speakers Bureau. Brissot:Novartis: Honoraria, Research Funding. Bonkovsky:Boehringer-Ingelheim: Consultancy, Membership on an entity's Board of Directors or advisory committees; Clinuvel: Consultancy; Lundbeck: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Myers Squibb: Research Funding; Merck: Research Funding; Roche: Research Funding; Vertex: Research Funding. Niederau:Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau. Adams:Novartis: Honoraria. Griffel:Novartis: Employment, Equity Ownership. Lynch:Novartis Pharmaceuticals: Employment. Schoenborn-Kellenberger:Novartis Pharma AG: Employment.


Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3150-3150 ◽  
Author(s):  
Raymond L. Comenzo ◽  
Daniel E Fein ◽  
Hani Hassoun ◽  
Christina Bello ◽  
Joanne F Chou ◽  
...  

Abstract Abstract 3150 Background: AL is a plasma cell dyscrasia characterized by the pathologic production of monoclonal light chains which misfold, deposit in various organs, including the heart, and can cause early death. High dose melphalan with stem cell transplant (SCT) results in high hematologic response rates and is a standard treatment for eligible patients. Achieving a complete hematologic response (CR) to SCT results in extended event-free and overall survival (OS), up to 8 and 13 years respectively in one large series. (Blood 2011; 118:4346) We have studied the addition of novel agents as consolidation following risk-adapted SCT (RA-SCT) in order to improve hematologic response (HR) rates and therefore outcomes. (Br J Haem 2007;139:224; Amyloid 2010;17:80a) In this report we examine the long-term outcomes of patients who received initial therapy with RA-SCT followed by consolidation for hematologic response less than CR (HR < CR). Methods: We performed a retrospective study to assess the HR rates, incidence of hematologic progression and overall survival (OS) of AL patients enrolled at diagnosis on two consecutive phase II trials using RA-SCT with consolidation for HR < CR (NCT01527032 and NCT00458822). OS was calculated from date of transplant to date of death or last follow up. Median event free survival (EFS) and OS were estimated by the method of Kaplan Meier. Cumulative incidence function was used to estimate the incidence of progression and death. Results: Between 2002 and 2011, 83 patients were enrolled and underwent RA-SCT on these trials and, following RA-SCT, those with HR < CR received consolidation with thalidomide and dexamethasone (TD) in the first and bortezomib and dexamethasone (BD) in the second trial. Thirty-six patients had cardiac involvement (43%) and all patients had free light chain measurements employed to score hematologic response and progression using consensus criteria (Am J Hematol 2005;79:319; Blood 2010;116:1364a). The frequency of CR following SCT was 24% and increased to 48% with post-SCT consolidation. The CR rates increased at 1 year compared to 3 months post-SCT from 21% to 36% with TD and from 28% to 62% with BD. With a median follow up of 5.1 years, the EFS is 4.5 years (95% CI: 2.6 to not reached) and the OS of all patients has not been reached (Figure 1). Sixteen patients died prior to hematologic progression and 26 patients have progressed with a cumulative incidence of hematologic progression of 8%, 18%, and 29% at 1, 2 and 3 years, respectively (Figure 2). Thirty-one percent (8/26) of relapsed patients have not required second-line therapy while among those who have, 78% (14/18) have responded including 44% (8/18) with CR. The median OS following hematologic progression was 5 years (95% CI: 2.6–5.8). Conclusions: Half of the AL patients on initial therapy trials employing RA-SCT and consolidation for HR < CR achieved CR with 36% of pts on the TD and 62% on the BD consolidation trial in CR at 1 year post-SCT respectively. At 3 years post-SCT the cumulative incidence of relapse was 29% and a third of relapsed patients did not require therapy, likely due to the very sensitive serum free light chain assay that detects low level hematologic progression in the absence of organ progression. Almost 80% of patients requiring second-line therapy responded, over half with CR, and median OS after relapse was 5 years. These results indicate that initial therapy with RA-SCT and consolidation is an effective initial treatment strategy for patients with AL in the era of novel agents. With over 5 years of follow up the median OS has not been reached. Disclosures: Comenzo: Millennium Pharmaceuticals, Inc.: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Off Label Use: Use of the investigational agent MLN9708, an oral proteasome inhibitor, in the treatment of relapsed or refractory light-chain amyloidosis. Hassoun:Millenium: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Research Funding. Giralt:Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees, Research Funding. Landau:Millenium: Membership on an entity's Board of Directors or advisory committees, Research Funding; Onyx: Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2187-2187
Author(s):  
Surbhi Sidana ◽  
Nidhi Tandon ◽  
Angela Dispenzieri ◽  
Morie A. Gertz ◽  
Francis K Buadi ◽  
...  

Abstract Introduction: Melphalan based chemotherapy is commonly used for treatment of light chain amyloidosis (AL). Patients with AL often receive chemotherapy before autologous stem cell transplantation (ASCT) if they have high plasma cell burden or while awaiting ASCT. Melphalan is an alkylator and can affect bone marrow stem cells. Limited data is available on the effect of melphalan on stem cell mobilization in patients with amyloidosis. This study aims to identify the impact of melphalan therapy on collection of stem cells and ASCT in amyloidosis. Methods: All patients with AL seen at our institution within 90 days of diagnosis over a 10-year period (2006 to 2015) who underwent stem cell harvest were identified from an institutional database. Data pertaining to demographics, diagnosis, treatment, stem cell harvest and ASCT was extracted from the electronic medical records. Analysis was carried out by chi-square and Fisher's exact test for categorical variables and Kruskal-Wallis and Wilcoxon rank sum test for ordinal and continuous variables. Results: Three hundred and seventy two patients with AL who met the inclusion criteria were identified, of whom 10% (n=38) received melphalan based chemotherapy prior to harvesting, 28.5% (n=106) received non-melphalan based chemotherapy and 61.3% (n=228) received no chemotherapy prior to stem cell collection. Bortezomib based regimens were the most common (78%, n=83) non-melphalan based chemotherapy. All three groups were similar in terms of median age at diagnosis (59.1 years), median age at collection (59.4 years), gender distribution (59% males, n=221) and type of involved free light chain (FLC), with lambda being more common (72.2%, n=268). Patients who received melphalan-based chemotherapy had more cardiac (73.8% vs. 45.2% vs. 46.4%, p=0.005) and renal (84.2% vs. 50.9% vs. 68%, p=0.0002) involvement compared to other chemotherapy and no chemotherapy groups, respectively. In contrast, patients who received non-melphalan based chemotherapy had higher plasma cell burden (15% vs. 6% vs. 10%, p< 0.0001) and greater difference between involved and uninvolved FLC (44.2 mg/dL vs. 13.3 mg/dL vs. 13.2 mg/dL, p< 0.0001) compared to melphalan and no chemotherapy, respectively. Median duration of melphalan based chemotherapy was shorter at 54 days (34.5 to 79.5) or estimated 2 cycles compared to 101 days (60 to 135.5) or estimated 4 cycles (p=0.0019). Despite shorter duration of chemotherapy, total stem cell yield (million CD34/kg) was lower in patients who received melphalan based chemotherapy (5.54) compared to non-melphalan based chemotherapy (8.14) or no prior chemotherapy (7.94); p<0.0001. Similarly, day one stem cell yield (million CD34/kg) was the lowest in the melphalan group (2.71), followed by other chemotherapy group (3.63) and highest in no chemotherapy group (4.84); p<0.0001. This trend persisted for average stem cell yield per collection as illustrated in table 1. Filgrastrim (GCSF) alone was the most common mobilizing agent. However, patients with any chemotherapy prior to harvesting had higher utilization of plerixafor; 26.3% (n=10) in the melphalan group and 39.6% (n=42) in the non-melphalan group compared to 11.6% (n=27) if no prior chemotherapy (p<0.0001). However, no statistically significant difference was seen for melphalan vs. non-melphalan chemotherapy groups (p=0.44). In patients who underwent ASCT (85%, n=315), median stem cell dose (million CD34/kg) was different in the melphalan (3.66), non-melphalan (4.2) and no chemotherapy groups (4.44) (p=0.047), though the difference was not statistically significant amongst the 2 chemotherapy groups (p=0.34). There was also no difference in time to engraftment (table 1). Conclusions: Melphalan based chemotherapy, even if used for a short duration of time, significantly decreases both total stem cell yield and the yield on day one. It therefore has the potential to add to resource utilization with more collections needed. As much as possible, limited cycles of melphalan based chemotherapy or non-melphalan based treatment should be utilized in patients who are transplant eligible. Disclosures Dispenzieri: GSK: Membership on an entity's Board of Directors or advisory committees; Alnylam: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; Celgene: Research Funding; pfizer: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kapoor:Amgen: Research Funding; Takeda: Research Funding; Celgene: Research Funding. Kumar:Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; AbbVie: Research Funding; Glycomimetics: Consultancy; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Millennium: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Kesios: Consultancy.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 2082-2082
Author(s):  
Nidhi Tandon ◽  
Surbhi Sidana ◽  
Morie A. Gertz ◽  
Angela Dispenzieri ◽  
Martha Q. Lacy ◽  
...  

Abstract Introduction Immunoglobulin light chain amyloidosis (AL Amyloidosis) is a monoclonal plasma cell proliferative disorder that is characterized by tissue deposits of misfolded insoluble κ or λ light chain derived amyloid fibrils, leading to organ dysfunction. The prognosis of patients depends on the number and severity of organ involvement, especially cardiac involvement. Autologous stem cell transplant (ASCT), if eligible, alkylator (melphalan) and novel drugs like proteasome inhibitors (PI) and immunomodulators (IMiD) have improved the overall survival (OS) during the past decades. But still, nearly half of the patients die within a year of diagnosis. We analyzed the factors predicting early relapse / progression or death (within 12 months) after first line therapy for systemic AL amyloidosis. Methods Clinical and laboratory data of all consecutive patients with systemic AL amyloidosis seen at Mayo Clinic within 90 days of their diagnosis, between 2006 and 2015, was collected by chart review and analyzed retrospectively. Patients who died within 3 months of starting the first line treatment were excluded from analysis. Early relapse (ER) was defined as relapse / progression requiring treatment change / re-institution or death within 12 months of starting first line treatment. Patients in the cohort with ER were compared with patients with a follow up of more than 12 months who had a relapse / progression beyond 12 months or had continuing response at the time of analysis. Categorical variables were analyzed using chi - square and Fisher's exact test and continuous variables using Kruskal- Wallis test and Wilcoxon rank sum test. Multivariate analysis was done using logistic regression model. Results Seven hundred and eighty six patients with newly diagnosed systemic AL amyloidosis met the study criteria and were included in the analysis. Among these, 230 (29.3%) patients had ER within 12 months of starting initial therapy while 556 (70.7%) patients either relapsed after 1 year or had continuing response at the time of analysis. Baseline demographics, organ involvement and type of first line therapy are presented in Table1. The median estimated follow up for the entire cohort from start of initial therapy was 62.9 months (95% CI; 59.9, 67.3). The variables included in the univariate and multivariate analyses for factors predicting ER were age at diagnosis (≤ vs > 70 years ), revised mayo stage (I and II vs III and IV), bone marrow plasma cell percentage (BMPC; ≤ 10% vs > 10%), presence of any chromosomal abnormalities, trisomies or IgH translocations by fluorescence in situ hybridization (FISH), multiorgan involvement [(>1 vs 1) (heart, liver, kidney, gastrointestinal tract, autonomic neuropathy), incorporation of ASCT in initial therapy. In univariate analysis, mayo stage (p<0.0001), multiorgan involvement (p=0.0008) and inclusion of ASCT as part of initial therapy (p<0.0001) were significantly associated with ER, while age (p=0.06), BMPC(p=0.9), FISH abnormalities (p=0.2) were not. However, in multivariate analysis, only mayo stage (III + IV vs I + II; p=0.01) and non-inclusion of ASCT in first line treatment (p=0.0001) were significantly predictive of ER. Conclusions Despite the introduction of ASCT and novel drugs, the early mortality in systemic AL amyloidosis remains high. This study demonstrates that patients with ER are older with higher prevalence of cardiac involvement and multiorgan involvement and higher Mayo stage (III and IV). Incorporation of ASCT as part of the initial therapy was associated with reduced early relapse, but it is difficult to separate the influence of the eligibility for ASCT from the effect of ASCT itself. This will help us in characterizing these patients to better understand their mechanisms of resistance to therapy and gives an insight to the type of initial therapy that benefits them. Disclosures Dispenzieri: GSK: Membership on an entity's Board of Directors or advisory committees; Jannsen: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Alnylam: Research Funding; pfizer: Research Funding. Kapoor:Takeda: Research Funding; Amgen: Research Funding; Celgene: Research Funding. Kumar:Celgene: Consultancy, Research Funding; Kesios: Consultancy; BMS: Consultancy; Sanofi: Consultancy, Research Funding; Noxxon Pharma: Consultancy, Research Funding; Glycomimetics: Consultancy; Millennium: Consultancy, Research Funding; Array BioPharma: Consultancy, Research Funding; Onyx: Consultancy, Research Funding; AbbVie: Research Funding; Skyline: Honoraria, Membership on an entity's Board of Directors or advisory committees; Janssen: Consultancy, Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3760-3760
Author(s):  
Masahiro Takeyama ◽  
Keiji Nogami ◽  
Shoko Furukawa ◽  
Midori Shima

Abstract We have experienced a case of acquired hemophilia A with inhibitor recognizing only a factor (F) VIII A2 epitope, and reported the inhibitory mechanism for disappearing FVIII activity (Blood, 124, 4226, 2014). In summary, the patient's inhibitor IgG bound to FVIII A2N (residue 372-562) fragment and inhibited Arg372 cleavage in FVIII by FXa, suggesting that FX(a) bound to FVIII A2 domain. ELISA-based assay showed that FVIII A2 fragment bound to FX (Kd; 338 nM). We hypothesized that FVIII A2 residues 400-429 might be FX binding site according to the 3-D model of FVIII molecule, and prepared synthetic peptides (400-409, 409-419, and 420-429). The 400-409 peptide inhibited the FVIII A2-FX interaction, suggesting that the 400-409 region contributed to FX-interactive site. In this current study, we further performed the localization of a FX-interactive site on the 400-409 region in the A2 domain. A purified FXa generation assay demonstrated the 400-409 peptide decreased the generation of FXa in a dose-dependent manner up to 38% of 100 μM (Ki; 23 ± 9 nM). In comparison, scrambled peptide of 400-409 decreased up to 10% of 100 μM. These data demonstrated that the 400-409 peptide inhibited the generated FXa, suggesting the 400-409 region contributed to regulate the coagulation function. Covalent cross-linking was observed between the biotinylated 400-409 peptide and FX following reaction with EDC (1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide) using SDS-PAGE. This cross-linking formation was blocked by the addition of unlabeled 400-409 peptide. N-terminal sequence analysis of the peptide-FX product demonstrated that two sequential residues (Lys408 and Ser409) could not be detected, supporting that two residues participate in cross-link formation. To confirm the significance of these residues in A2 domain for FX-binding, the mutant forms of the A2 domain, converted to alanine, were expressed in BHK system and purified. Compared with wild type FVIII (Kd; 10 ± 3 nM), the binding affinity of Ser409Ala FVIII mutant for FX was no significant difference (Kd; 14 ± 1 nM) on SPR-based assay. Lys408Ala or Lys408Ala/Ser409Ala double FVIII mutant, however, decreased the binding affinity by 3.6~4.3-fold (Kd; 36 ± 7 or 43 ± 2 nM, respectively), suggesting contribution of Lys408Ala to the binding interaction. For the functional evaluation of the association with FVIII mutants to FX, a FXa generation assay was repeated. Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant reacted with varying concentrations of FX decreased by 1.2~1.6-fold (Km; 53 ± 12, 69 ± 15, or 65 ± 15 nM, respectively) compared to wild type FVIII (Km; 43 ± 9 nM), supporting a contribution of these mutants to Km and overall catalytic efficiency. Vmax values were largely unaffected by the mutations with most values within approximately 30% of the wild-type value. On the other hand, Kcat/Km value of Lys408Ala, Ser409Ala, or Lys408Ala/Ser409Ala FVIII mutant were decreased by 0.5~0.7-fold (Kcat/Km; 1.0, 1.3, or 0.9 nM-1min-1, respectively) compared to wild type FVIII (Kcat/Km; 1.8 nM-1min-1), suggesting low catalytic efficacy of Lys408Ala and Ser409Ala. These results indicate that the 400-409 region in the FVIII A2 domain, and in particular Lys408 and Ser409, may contribute to a unique FX-interactive site. Disclosures Nogami: Chugai Pharmaceutical Co., Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Honoraria, Membership on an entity's Board of Directors or advisory committees; Sysmex Corporation: Patents & Royalties, Research Funding. Shima:Sysmex Corporation: Patents & Royalties, Research Funding; Chugai Pharmaceutical Co., Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Patents & Royalties, Research Funding; F. Hoffmann-La Roche Ltd.: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 3182-3182
Author(s):  
Mohammed A Aljama ◽  
M Hasib Sidiqi ◽  
Angela Dispenzieri ◽  
Morie A. Gertz ◽  
Martha Q. Lacy ◽  
...  

Abstract Background: Cardiac involvement is integral in staging and prognosis of immunoglobulin light chain (AL) amyloidosis. The N-terminal prohormone of brain natriuretic peptide (NT proBNP) is a cardiac biomarker used in screening for cardiac involvement and staging the disease. Transthoracic echocardiogram (TTE) and cardiac magnetic resonance (CMR) are the imaging modalities recommended to determine cardiac involvement and function. Methods: We conducted a retrospective review of all patients with biopsy proven systemic AL amyloidosis seen at the mayo clinic between Jan 1, 2006 and Dec 30, 2015. The aim of the study is to identify the nature of abnormalities in cardiac biomarkers and echocardiographic features in patients with AL amyloidosis and the ability of these investigations to diagnose cardiac involvement. We first identified all patients with AL amyloidosis that underwent endomyocardial biopsy for suspicion of cardiac involvement (Cohort 1). We then analyzed a cohort (Cohort 2) which consisted of patients who had serum NT proBNP and a comprehensive echocardiographic evaluation at time of diagnosis. Results: 179 patients with AL amyloidosis underwent endomyocardial biopsy (Cohort 1) of whom 173 had evidence of amyloid deposition. In this cohort, 159 patients had NT proBNP performed at the time of the procedure. The NT proBNP was elevated (>300) in all 159 patients with a median NT proBNP of 4917 (range 355-69541). The median left ventricular ejection fraction (LVEF), interventricular septal (IVS) thickness and strain rate were 54 (range 10-77), 15 (range 8-30) and -9 (range -21 to 0) respectively. CMR findings were consistent or suggestive of light chain amyloidosis in 38/42 patients, yielding a sensitivity of 90 percent. The LVEF, IVS thickness and strain rate were abnormal in 89/168 (53%), 102/64 (61%) and 92/95 (97%) respectively. 95 patients with biopsy proven cardiac amyloidosis had complete echocardiogram data available on LVEF, IVS thickness and strain rate, with 97% (n=92) presenting with an abnormality in at least one of these variables . CMR findings were consistent or suggestive of light chain amyloidosis in 38/42 patients, yielding a sensitivity of 90 percent. Patients with a normal NT proBNP and normal echocardiogram were considered disease free (true negative), based on our initial analysis of these investigations in Cohort 1. Cohort 2 consisted of 342 consecutive patients. The median NT pro BNP was 1878 (25-48214). The median LVEF, IVS thickness and strain rate were 63 (22-90), 14 (6-25) and -13 (-25 to -3) respectively. 259 (76%) patients had a positive NT proBNP (above 300), of whom 237 (92%) had an abnormality detected on TTE. 83 patients had a negative NT proBNP, of whom 27 (33%) had an abnormality in either LVEF, IVS thickness or strain rate. 19 of these 27 patients had a borderline reduced strain rate between -17 and -18, whilst the remaining 8 patients had a strain between -14 and -15. Only 6/27 patients were considered to have possible early cardiac involvement and none have any other diagnostic or classical features of amyloidosis on TTE. Conclusion: The combination of NT proBNP and comprehensive echocardiographic evaluation provides substantial information to diagnose cardiac amyloidosis in a significant portion of patients negating the need for endomyocardial biopsy. A negative NT proBNP rules out clinically meaningful cardiac involvement and may obviate the routine use of TTE in patients with a low clinical suspicion of cardiac amyloidosis. Disclosures Dispenzieri: Celgene, Takeda, Prothena, Jannsen, Pfizer, Alnylam, GSK: Research Funding. Gertz:Research to Practice: Consultancy; Physicians Education Resource: Consultancy; Ionis: Honoraria; celgene: Consultancy; spectrum: Consultancy, Honoraria; Teva: Consultancy; Amgen: Consultancy; Medscape: Consultancy; janssen: Consultancy; Alnylam: Honoraria; Abbvie: Consultancy; annexon: Consultancy; Apellis: Consultancy; Prothena: Honoraria. Lacy:Celgene: Research Funding. Dingli:Millennium Takeda: Research Funding; Millennium Takeda: Research Funding; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.; Alexion Pharmaceuticals, Inc.: Other: Participates in the International PNH Registry (for Mayo Clinic, Rochester) for Alexion Pharmaceuticals, Inc.. Kapoor:Takeda: Research Funding; Celgene: Research Funding. Kumar:AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis: Research Funding; Roche: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Takeda: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; KITE: Membership on an entity's Board of Directors or advisory committees, Research Funding; Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5696-5696 ◽  
Author(s):  
Myo Htut ◽  
Cristina Gasparetto ◽  
Jeffrey Zonder ◽  
Thomas G. Martin ◽  
Emma C. Scott ◽  
...  

Abstract Background: The bone marrow microenvironment of many multiple myeloma (MM) patients harbors high quantities of plasmacytoid dendritic cells (pDCs), which are specialized immune cells that express the interleukin-3 receptor (CD123). These pDCs have been shown to augment MM growth and contribute to drug resistance, suggesting that targeting pDCs may offer clinical benefit for MM patients. SL-401, a novel targeted therapy directed to CD123, has previously demonstrated potent preclinical in vitro and in vivo activity against MM cell lines and primary tumor samples via both a direct anti-MM effect and an indirect effect by targeting neighboring pDCs. SL-401 has also demonstrated synergy in these systems when used in combination with traditional MM therapies including pomalidomide (POM). Clinically, SL-401 has demonstrated high levels of anti-tumor activity in patients with an aggressive CD123+ malignancy of pDC origin, namely blastic plasmacytoid dendritic cell neoplasm (BPDCN). SL-401 is currently being evaluated in combination with POM and dexamethasone (DEX) in relapsed or refractory (r/r) MM patients. Preliminary results are reported here. Methods and Results: This multicenter, single arm Phase 1/2 trial of patients with r/r MM includes a lead-in (stage 1) and expansion (stage 2). In stage 1, patients receive SL-401 as a daily IV infusion at 7, 9, or 12 ug/kg/day for days 1-5 of a 28 day cycle as a single agent for the initial run-in cycle (cycle 0) and in combination with standard doses/administration of POM+DEX in cycles 1 and beyond, in a 3x3 design. In stage 2, patients receive SL-401 in combination with POM+DEX at the dose and regimen determined in stage 1. Objectives include characterization of the safety profile of SL-401 in combination with POM+DEX, including determination of the maximum tolerated or tested dose, and detection of efficacy signals including evaluation of tumor response based on International Myeloma Working Group criteria, duration of response, progression-free survival, and translational evaluation of changes in BM microenvironmental pDCs. As of 7-25-16, 2 patients with r/r MM received SL-401 at 7 ug/kg in combination with POM+DEX. The median age was 65 years (range: 63-67 years). The most common treatment-related AEs, all grades, were thrombocytopenia (2/2, both grade 1) and hypoalbuminemia (2/2, both grade 2); there has been no DLT. Rapid onset decrease in a set of myeloma-related laboratory values from pre-SL-401 treatment was observed in both patients after the first combination cycle of SL-401 and POM+DEX. In one patient, serum M-protein decreased from 2.34 to 1.19 g/dL (cycle 1), free light chain kappa decreased from 40.1 to 8.27 mg/dL (cycle 1), and free light chain kappa/lambda ratio decreased from 58.12 to 41.35 (cycle 1). In the other patient, serum M-protein decreased from 1.88 to 0.87 (cycle 1) and then was 0.96 (cycle 3) g/dL, free light chain kappa decreased from 134 to 49.4 (cycle 1) and then was 92.5 (cycle 3) mg/dL, and free light chain kappa/lambda ratio decreased from 638.1 to 76 (cycle 1) and then was 111.45 (cycle 3). Both patients remain on study receiving ongoing SL-401 at 2+ and 4+ months. Dose escalation to 9 ug/kg is planned if a third patient clears the 7 ug/kg cohort. Conclusions:This is the first clinical study to evaluate SL-401 in combination with other agents. SL-401 thus far has been well-tolerated in combination with POM+DEX in r/r MM patients, with no unexpected AEs observed. After the first cycle of SL-401 and POM+DEX combination therapy, 2 of 2 patients experienced a rapid decrease in serum M-protein and remain on SL-401 therapy. Given CD123 expression on microenvironmental immune pDCs and the potential synergy of SL-401 with certain current MM agents including POM, SL-401 may offer a novel therapeutic approach in MM. This Phase 1/2 trial continues to enroll and updated data will be presented. Clinical trial information: NCT02661022. Disclosures Zonder: Janssen: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Bristol Myers Squibb: Consultancy, Honoraria; Prothena: Consultancy, Honoraria; Seattle Genetics: Consultancy, Honoraria; Takeda: Consultancy, Honoraria; Pharmacyclics: Other: DSMC membership. Martin:Sanofi: Research Funding; Amgen: Research Funding. Chen:Stemline Therapeutics, Inc.: Employment, Equity Ownership. Shemesh:Stemline Therapeutics: Employment, Equity Ownership. Brooks:Stemline Therapeutics, Inc.: Employment, Equity Ownership, Patents & Royalties. Chauhan:Stemline Therapeutics: Consultancy. Anderson:Oncopep: Other: Scientific Founder; Acetylon: Other: Scientific Founder; Gilead: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Sonofi Aventis: Membership on an entity's Board of Directors or advisory committees; Onyx: Membership on an entity's Board of Directors or advisory committees. Richardson:Jazz Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5452-5452
Author(s):  
Susan Bal ◽  
Allison Sigler ◽  
Alexander Chan ◽  
David J. Chung ◽  
Ahmet Dogan ◽  
...  

Background B-cell maturation antigen (BCMA) is a transmembrane protein belonging to the tumor necrosis factor (TNF) superfamily involved in the regulation of B cell proliferation and survival as well as maturation/differentiation into plasma cells. In multiple myeloma cells, overexpression of BCMA has been shown to activate mitogen activated protein kinase pathways (AKT, ERK1/2, and NF-κB) and upregulates anti-apoptotic proteins (MCL1, BCL2, BCL-xL) resulting in cellular proliferation. Immunotherapeutic strategies targeting BCMA are showing great promise in heavily pre-treated refractory multiple myeloma. Light Chain Amyloidosis (AL) is a multisystem disorder of clonal plasma cells that results in the production of an abnormal light chain which misfolds and deposits in the organs leading to disruption of tissue architecture, cellular stress, dysfunction and eventually, death. The smaller burden and lower proliferative potential of the offending clonal plasma cells in amyloidosis may potentially lend itself favorably to immunotherapeutic strategies targeting BCMA. Given the efficacy of this approach in MM, the evaluation of BCMA expression on the surface of amyloidogenic plasma cells is warranted. Methods All patients diagnosed with Light chain Amyloidosis at Memorial Sloan Kettering Cancer Center, NY between January 1, 2012, and December 31, 2018, who had unstained bone marrow samples were identified. These unstained BM biopsy samples were prospectively stained for BCMA expression using Immunohistochemistry (IHC). We utilized a clinical-grade assay (clone D6; catalog sc-390147; company Santa-Cruz; monoclonal antibody; dilution 1:400) in a CLIA compliant setting. We scored the biopsies for BCMA expression, intensity, and site of staining. We also obtained their demographic details, staging, and cytogenetic information for the patients with available samples. Results During the queried period, 28 unstained samples were available for testing from the time of disease diagnosis. The median age of the population was 63 years (range 41-73). 64% of patients were male and consistent with the literature; a majority of patients (75%) had lambda-typic clonal plasma cells. Cytogenetic abnormalities using fluorescence in situ hybridization (FISH) were reviewed, t(11;14) was seen in 36% patients, and chromosome 1q and del 13q were each seen in 32% of patients. No patient had t(4;14) or del 17p. The median clonal PC burden in BM at diagnosis was 10% (range2-80%) and 36% had > 10% plasma cells. In clonal PCs, the median BCMA expression was 80% (range 20-100%). Only one patient had a staining intensity under 50% (20%). Membranous staining was noted in 82% of patients and a Golgi pattern in 11%. The median staining intensity was 2 (range 1-3). Of the patients with baseline diagnostic samples available for testing, six patients had additional unstained bone marrow samples for staining at the time of relapse. The majority of patients (83%) who relapsed had >10% plasma cells with a higher median plasma cell burden of 35% (range 10-80). The median BCMA expression was 65% (range 50-80) with no patient having <50% expression. The staining pattern was membranous in 50%, Golgi in 17%, and Golgi-membranous in 33%. At the time of relapse, the median clonal PC burden was 13% (range 5-30). BCMA expression continued to be present at the time of relapse with a median 75% (range 50-100) with predominantly membranous staining (83%). The median staining intensity in both diagnostic and relapsed tissue within the six samples studied was 1. Conclusions Our study represents the first description of BCMA expression on the surface of amyloidogenic plasma cells to our knowledge. BCMA is uniformly expressed by pathologic PCs in AL amyloidosis both at the time of diagnosis and relapse. Given the efficacy of BCMA directed therapy in multiple myeloma, further investigation of these agents in light-chain amyloidosis are warranted and may provide an effective therapeutic strategy in this devastating disease. Figure Disclosures Dogan: Corvus Pharmaceuticals: Consultancy; Celgene: Consultancy; Seattle Genetics: Consultancy; Novartis: Consultancy; Takeda: Consultancy; Roche: Consultancy, Research Funding. Giralt:Takeda: Consultancy, Research Funding; Johnson & Johnson: Consultancy, Research Funding; Kite: Consultancy; Novartis: Consultancy; Actinium: Consultancy, Research Funding; Jazz Pharmaceuticals: Consultancy; Celgene: Consultancy, Research Funding; Amgen: Consultancy, Research Funding; Miltenyi: Research Funding; Spectrum Pharmaceuticals: Consultancy. Hassoun:Novartis: Consultancy; Janssen: Research Funding; Celgene: Research Funding. Landau:Takeda: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen: Research Funding; Prothena: Membership on an entity's Board of Directors or advisory committees; Caelum: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Janssen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Karyopharm: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees.


Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4492-4492
Author(s):  
Meletios A. Dimopoulos ◽  
Maria Roussou ◽  
Maria Gavriatopoulou ◽  
Despina Fotiou ◽  
Dimitrios Ziogas ◽  
...  

Abstract Renal failure (RF) is a common severe complication of symptomatic myeloma and may be severe enough to require extrarenal dialysis in approximately 1-5% of newly diagnosed patients. Severe RF is associated with high risk of early death and increased morbidity. Immediate effective anti-myeloma therapy and vigorous supportive care are the cornerstones of management. The use of high cutoff hemodialysis to rapidly reduce the load of nephrotoxic light chains seems to offer limited additional benefit in patients requiring dialysis when treated with bortezomib-based therapies (Cook M et al EHA 2016, Abs P270). However, outside clinical trials, there are limited data focusing on the management and outcomes of NDMM patients requiring dialysis. Thus, we analyzed the outcomes of consecutive newly diagnosed patients with RF requiring dialysis, who were managed and treated in a single center. Between 1995 and 2016, 50 patients (6.2% of 796 consecutive NDMM) who were treated in the Department of Clinical Therapeutics (Athens, Greece) presented with severe RF requiring dialysis. The analysis included all patients who received at least one dose of any therapy. All patients received similar supportive care and dialysis with regular filters. The median age of patients requiring dialysis was 69 years (37-88), 68% were >65 years of age. At presentation 92% had Hb <10 g/dl, 5 (10%) had platelet count <100x109/l, 12 (24%) had hypeprcalcemia (Ca ≥11.5 mg/dl) and 24 (48%) had elevated LDH (≥250 IU/l). All patients had elevated β2-microglobulin (median 21.7 mg/L, range 6-60 mg/l) and all were ISS stage 3. High risk cytogenetics (N=40) were present in 38% and per R-ISS, 75% were R-ISS-3 and 25% R-ISS-2. Myeloma was light chain only in 42%, IgA in 26%, IgG in 30% and IgD in 1 patient (2%); light chain was κ in 38 (64%) and λ in 18 (36%). Among patients who retained urine flow at presentation, median 24h Bence Jones proteinuria was 2.2 gr (range 0.1-8.8 gr). Among patients with available FLCs, median level of involved free light chain (iFLC) was 9080 mg/l (range 119-201000 mg/l). Treatment was bortezomib-based in 41 (82%) patients: 11 (22%) had bortezomib + dexamethasone (VD), 21 (42%) VD + cyclophosphamide (VCD), 8 (16%) VD + thalidomide (VTD), 1 (2%) VD + doxorubicin (PAD). Nine (18%) patients received non-bortezomib containing regimens: 5 (10%) thalidomide plus high dose dexamethasone and 4 (8%) VAD with high dose dexamethasone. Twenty-five (50%) patients became dialysis independent at a median time of 158 days from start of therapy (range 4-336 days). Age ≤65 years was associated with higher probability (75% vs 38%) and shorter time to dialysis independence (51 vs 336 days; p=0.027); no other baseline factors were associated with dialysis independence in univariate analysis. Among patients treated with bortezomib, three-drug combinations (n=30) vs VD alone (N=11) were associated with higher probability of dialysis independence (57% vs 27%; p=0.06). Among patients who became dialysis independent 12 received VCD, 4 VTD, one PAD, 3 VD, 2 MDT, 2 VAD and one T-VAD. Median follow up for all patients was 33 months and median survival was 29 months. Early mortality (within 2 months from start of therapy) was 16%, mostly due to infectious complications. On intent to treat, 64% achieved ≥PR (CR: 6%, VGPR: 32%, PR: 26%); among patients who survived >2 months, ≥PR was achieved by 76%. At 2-month landmark, patients who achieved ≥PR within the first 2 months had higher dialysis independence rates (68% vs 27%, p=0.004). Becoming dialysis independent was associated with a significant improvement in survival (median OS of 63 vs 22 months of patients who remained on dialysis; p=0.002), even after exclusion of early deaths. Notably, the survival of patients who discontinued dialysis was similar to that of the rest of patients (57 months). High dose melphalan (HDM) followed by autologous stem cell transplantation was performed in five patients while on dialysis. Four of them (80%) become dialysis independent approximately one month after HDM. In conclusion, about 6% of NDMM present with renal failure requiring dialysis but half of them can become dialysis independent after bortezomib-based therapy, without the use of special filters, especially if they achieve a rapid myeloma response. VD-based triplets increase the probability of renal response over VD alone and independence from dialysis is associated with a significant improvement in prognosis. Disclosures Dimopoulos: Takeda: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Genesis: Consultancy, Honoraria; Novartis: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees. Terpos:Celgene: Honoraria; Genesis: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Novartis: Honoraria; BMS: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Other: Travel expenses, Research Funding; Takeda: Consultancy, Honoraria; Janssen: Consultancy, Honoraria, Other: Travel expenses, Research Funding. Kastritis:Takeda: Consultancy, Honoraria; Genesis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria.


Sign in / Sign up

Export Citation Format

Share Document