ALBERT

Description: Multiple myeloma (MM) is the second most common hematologic malignancy. Presently, the majority of suitable MM patients who undergo high-dose melphalan therapy followed by autologous peripheral blood stem cell transplantation (PBSCT) fail to achieve a complete response (CR). This suggests that treatment options following autologous transplantation are needed. Moreover, there is a need to determine the optimal role of maintenance therapy following PBSCT in MM. Over time, Bortezomib (B) has been shown to be an active agent in the treatment of newly diagnosed, and relapsed or refractory MM. Therefore, the primary objective of this study was to determine the efficacy of B treatment after high-dose melphalan therapy followed by PBSCT in MM. Fifty patients (pts) were enrolled between March 2004 and November 2007, and 47 were evaluable (2 pts ineligible and 1 pt data pending). Pts received B 1.3 mg/m2 IV on Days 1, 4, 8, and 11 of each 21-day cycle. Pts were treated for 4 cycles or until evidence of disease progression or intolerable toxicity. If an improvement in response was noted after Cycle 4, pts could receive up to 4 additional cycles. To reduce the incidence of varicella zoster infection, antiviral prophylaxis (acyclovir 400 mg PO BID) was taken for the duration of the study. The median patient age was 56 years (range, 39–74), 82% were white, and 68% were male. The majority of pts (64%) had ECOG PS 0, 44% were Durie-Salmon Stage IIIA prior to induction therapy. Forty percent had symptomatic IgG-kappa multiple myeloma. Of all pts, 74% had a single transplant, while 24% had tandem transplants (2% [n=1 pt] data pending). Sixty-eight percent of pts had a PR and 18% had a MR following their transplant(s). While on study, pts received a median of 4 cycles (range, 2–8) of therapy with B. Efficacy results for the evaluable population are: CR 4%, unconfirmed (u) CR 4%, PR 21%, uPR 17%, MR 11%, and No Change 36%. Median time-to-treatment failure was 5.8 months (mos) (range, 0.2–19.4). There were 2 on-study deaths (sepsis and PD). Grade 3–4 treatment-related toxicities reported in 〉1 pt were thrombocytopenia (15%), asthenia (10%), neutropenia or neuropathy (8% each), peripheral neuritis (6%), and nausea (4%). Twenty patients discontinued study treatment due to toxicity (22%), pt request (6%), disease progression, ineligibility, and intercurrent illness/protocol deviation (4% each). 26 pts (52%) completed the study; 4 pts are still on study (8%). Sixteen pts started new treatment; median time from start of study treatment to the start of new treatment was 5.2 mos (range, 1.5–17.6 mos). The study was closed earlier than the planned due to the widespread availability of B, and the inability to find B-naïve patients. Bortezomib given after high-dose melphalan therapy and autologous PBSCT was well-tolerated with manageable adverse events. Updated cytogenetic analysis will be available for presentation.

Description: INTRODUCTION: Perifosine (peri) is an oral, novel synthetic alkylphospholipid, with multiple effects on signal transduction pathways, including inhibition of Akt and activation of JNK. In vitro studies showed that peri induces cytotoxicity in both MM cell lines and patient (pt) MM cells resistant to conventional therapies, and augments dexamethasone (dex) and bortezomib-induced MM cell cytotoxicity (Hideshima T. et. al. BLOOD 2006). In vivo studies showed antitumor activity in a human plasmacytoma mouse model. Here we report the results of a phase II trial of peri, alone and + dex, in pts with relapsed or relapsed / refractory MM. METHODS: Pts received 150 mg of peri daily for a 21 day (d) cycle, and were assessed every cycle by serum- and/or urine-electrophoresis. Eligible pts had symptomatic relapsed or relapsed / refractory MM. Pts were permitted to receive bisphosphonate treatment. Concomitant steroids (prednisone 〉 10 mg/d), creatinine of 〉 3.0 mg/dL, and hemoglobin 〈 8.0 g/dL within 14 d of enrollment were exclusion criteria. Progressing pts, documented on 2 occasions at least one week apart, had dex 20 mg twice per week added to peri. Toxicities were assessed by NCI-CTCAE, v3.0. RESULTS: 64 pts (35 M/ 29 F, median age 62, range 38–79) have been treated to date. Median lines of prior treatment was 4 (range 1–11); 32 (50%) pts had relapsed and refractory MM. Prior therapy included dex (95%), thalidomide (89%), bortezomib (73%), lenalidomide (30%) and ASCT (61%). Among 48 pts currently evaluable for response, best response (EBMT criteria) to single agent peri after ≥ 2 cycles was MR in 1 pt, stable disease (〈 25% reduction in M-protein) in 22 pts (46%). Dex was added in 37 pts with PD, with 31 pts evaluable for response on the combination as follows: Peri + Dex N (%) Duration (wks) PR 4 (13%) 17, 24, 44+, 46+ MR 8 (25%) 3+, 12+, 19, 21, 25, 30, 32, 55+ Stable Disease 15 (47%) 6+ − 46 (median 12)* *4 pts ongoing at 6, 9, 11 and 24 wks Most common adverse events included nausea (74%, 8% G3); vomiting (61%, 5% G3); diarrhea (65%, 2% G3); fatigue (31%, 2% G3), increased creatinine (51%, 7% G3/4 in the context of PD and light chain nephropathy but reversible) and anemia (63%, 5% G3). 10 pts had G3/4 neutropenia which resolved. Dose reduction was required to 100 mg/d (n=16) or to 50 mg/d (n=4). 9 pts discontinued treatment due to side effects. Attributable toxicities otherwise proved manageable with supportive care and no peripheral neuropathy or DVT seen. CONCLUSION: Perifosine as monotherapy has modest activity, but in combination with dex showed significant activity in pts with relapsed/refractory MM, achieving PR + MR in 38%, and/or stabilization of disease in 47% of evaluable pts to date. It was generally well tolerated, although caution in pts with renal dysfunction is warranted. PK, IHC and gene array studies are ongoing. Other novel studies with peri in combination with bortezomib and with lenalidomide +/−dex are underway.

Description: Paroxysmal Nocturnal Hemoglobinuria (PNH) is an acquired clonal stem cell disease, characterised by intravascular hemolysis, bone marrow failure and lifethreatening thromboses. The median survival is 10–15 years, with the average age of presentation being in the 30’s. Symptoms include hemoglobinuria, fatigue, anemia, venous and arterial thromboses, recurrent pain, renal impairment, erectile dysfunction and pulmonary hypertension. The care of a patient with PNH is complex and challenging, as many experience chronic symptoms with periods of acute exacerbations. Historically the management of PNH included bone marrow transplant, blood transfusion and administration of additional supportive therapies, all necessitating regular visits to the hospital. Eculizumab, a monoclonal antibody that binds to the C5 complement component inhibiting the activity of terminal complement and thus preventing the destruction of red blood cells has dramatically altered the management of hemolytic PNH. Clinical trials of eculizumab demonstrated the resolution of the majority of symptoms and complications of PNH and resulted in its approval in the UK in June 2007. Eculizumab is administered as a 30 minute intravenous infusion every 14 days, and under the terms of its current EU licence, must be administered by a healthcare professional. In view of the rarity of PNH there are relatively few specialist Centres for the disease resulting in, patients travelling long distances for review and treatment. In view of the dramatic improvement in symptoms on eculizumab many patients are able to return to a near normal lifestyle. In the UK, Leeds Teaching Hospitals with Healthcare at Home have developed a home infusion programme that ensures safe administration of eculizumab in the patient’s home at a time convenient to them, leading to enhanced treatment-associated convenience for patients and their families. Patients then only attend the PNH Centre every 3 months to ensure appropriate monitoring and patient education. A recent survey of patients reports a reduction in treatment-associated burden for PNH patients and their families when receiving infusions at home. 46 patients responded to the survey with just over half receiving eculizumab. Of the 21 patients at the time receiving home infusions 19 found this more convenient than the hospital. Home treatment allows flexibility and for some, the return to full-time employment, with the associated financial benefits and improvement in psychological well-being. Of the 21 patients on home care 7 stated there ability to work was transformed with a further 10 having great improvement. Whilst the purpose of the survey was not to address financial burden, the home infusion programme has anecdotally reduced the financial burden on the patient and their family by eliminating the need for time off work, allowing return to full-time employment, and eliminating the cost of travel to and from the hospital for treatments. No patients reporting negative impact, including effect on social life and family relationships, whilst 15 experienced improvement or complete transformation in both areas. The patients reported confidence in the homecare programme, knowing that a very close working relationship existed between the expert hospital and homecare teams. This innovative programme of medication delivery by a dedicated home nursing team allows patients who have previously struggled to cope with their illness to lead a near normal life with an associated enhancement in quality of life. Patients are able to carry on with activities of daily life, including work, recreational activities and holidays, whilst at the same time ensuring compliance with treatment and therefore allowing maximum therapeutic benefit.

Description: The RUNX1 (AML1) gene is a transcription factor that regulates expression of genes involved in hematopoietic cell differentiation. It is a gene located on chromosome 21 at q22. Genetic alterations of RUNX1 whether through loss-of-function point mutations, translocation or amplification are known to impact myeloid differentiation and trigger leukemic transformation in particular with respect to myelodysplasia and acute myeloid leukemia. However, while there are many articles describing the impact of these types of RUNX1 genetic alterations, there is a paucity of information regarding loss of the entire RUNX1 gene. The case in this abstract highlights the significance of understanding loss of the RUNX1 gene. An 87 year old patient presented for evaluation for anemia and leukopenia. Flow cytometric evaluation revealed 26% myeloid blasts and confirmed a diagnosis of acute myeloid leukemia (AML). The cytogenetic findings demonstrated a translocation between chromosomes 17 and 21 −t(17;21)(q11.2;q22). The dilemma then was to determine if this was a variant of the traditional t(15;17) associated with acute promyelocytic leukemia or a variant of the t(8;21) associated with the M2 subtype of AML. FISH studies determined that there was no involvement of the RARA gene and no evidence of a RUNX1/ETO rearrangement. However, there was a complete loss of RUNX1 on the abnormal chromosome 21. Thus, what appeared to be a balanced translocation included a cryptic loss of RUNX1. While this may be an interesting case presentation the more pertinent question is what is the impact of the RUNX1 loss? This case prompted a review of the data on complete loss of the RUNX1 gene which while limited suggests that RUNX1 loss on its own is not leukemogenic. This poster presents the data and implication of complete loss of RUNX1, the role of this loss in leukemogenesis and patient management.

Description: Human B lymphocyte-induced maturation protein-1 (BLIMP-1) was originally described as a repressor of the interferon-beta response to viral infection. Subsequently, the murine orthologue was identified as a regulator of plasma cell differentiation. The involvement of BLIMP-1 in hemopoietic differentiation is not restricted to the B-cell lineage as BLIMP-1 is induced during differentiation of myeloid progenitors. During in vitro macrophage and plasma cell differentiation the expression of BLIMP-1 is cytokine driven. However, the BLIMP-1 response to virus infection can be reproduced by transfection with double-stranded RNA (dsRNA), indicating that BLIMP-1 is a target of dsRNA responsive signaling pathways. A central regulator of the intracellular response to viral infection is the interferon-inducible double-stranded RNA activated kinase, PKR. PKR belongs to a family of kinases that phosphorylate the eukaryotic translation initiation factor 2-alpha (eIF2α) and activate common downstream signaling pathways. PERK, the endoplasmic reticulum (ER) PKR-homologue is activated during the unfolded protein response (UPR), a stress response involved in both macrophage activation and terminal B-cell differentiation. This suggested the hypothesis that BLIMP-1 may represent a shared target of signaling pathways in the response to cellular stresses such as virus infection and the UPR. In this study we demonstrate that BLIMP-1 is rapidly upregulated during the UPR in human myeloid and B-cell lines. This response is conserved in primary murine macrophages, in which mimics of physiological stress and classical activation stimuli also induce Blimp-1. During the UPR, BLIMP-1 mRNA is induced at the level of transcription, with enhanced recruitment of RNA polymerase II to the BLIMP-1 promoter. Furthermore the stress response is limited to induction of BLIMP-1α mRNA and does not affect levels of an alternate transcript encoding a truncated protein, BLIMP-1β. The common induction of BLIMP-1 mRNA by stimuli which trigger the UPR supports the hypothesis that BLIMP-1 is a target of the eIF2α kinase family. To test this hypothesis directly, we employed a dominant negative mutant PERK. Our data demonstrate that the BLIMP-1 response to UPR stress is dependent on an intact PERK signaling pathway. Collectively our results provide evidence for a novel link between cellular stress, the eIF2α kinase family and a regulator of differentiation in macrophages and B-cells.

Description: Activation of haemostasis in sepsis may lead to microvascular thrombosis and progression to multiorgan failure (MOF). Almost all critically ill patients with sepsis have abnormal coagulation screens but these are unlikely to adequately represent the state of a patient’s haemostatic system and global assays may be more useful. Normal controls (n=32) and critically ill patients with sepsis (n=39) were recruited. Coagulation factors, antithrombin (AT) and protein C (PC) were measured. Thrombin generation was measured using the calibrated automated thrombogram (CAT) in platelet rich (PRP) and poor (PPP) plasma. Low dose tissue factor (6pM) activated whole blood Rotem® was measured and the first derivative of the trace gave a velocity of clot firmness. Haemostatic changes in sepsis compared to normal controls Controls Controls mean (SD) Sepsis mean (SD) P Apparent effect of change PT (s) 11.7 (0.5) 19.7 (5.9) 0.001 Anticoagulant aPTT (s) 27 (3.4) 44.1 (18.2) 0.001 Anticoagulant Fibrinogen g/l 2.8 (0.57) 5.3 (2.1) 0.001 Prothrombotic FII IU/dl 100 (12.1) 64 (32.2) 0.001 Anticoagulant FV IU/dl 116 (22.9) 96 (55.2) 0.03 Anticoagulant FVII IU/dl 130 (31.1) 58 (33.5) 0.001 Anticoagulant FVIII IU/dl 107 (31.5) 242 (96) 0.001 Prothrombotic FIX IU/dl 101 (16.5) 112 (51.3) NS Neutral FX IU/dl 123 (16.6) 75 (42.1) 0.001 Anticoagulant FXI IU/dl 116 (15.7) 80 (41) 0.001 Anticoagulant FXII IU/dl 125 (27.8) 56 (29.4) 0.001 Neutral PC % 127 (20) 66 (37) 0.001 Prothrombotic AT IU/dl 103 (8) 64 (29) 0.001 Prothrombotic CAT in PRP Lag time (min) 17 (8) 30 (23) 0.02 Delayed ETP (nM.min) 1395 (488) 1270 (573) NS Neutral Peak thrombin (nM) 76 (40) 55 (31) 0.02 Anticoagulant Time to peak (min) 32 (12) 50 (29) 0.001 Delayed CAT in PPP Lag time (min) 2.4 (0.9) 5.1 (5.4) 0.001 Delayed ETP (nM.min) 1681 (281) 1645 (442) NS Neutral Peak thrombin (nM) 454 (100) 343 (146) 0.001 Anticoagulant Time to peak (min) 4.2 (1.2) 6.8 (6.6) 0.001 Delayed Low dose tissue factor Rotem Clot time (s) 818 (271) 1170 (766) 0.04 Delayed Alpha angle (°) 51 (12) 67 (17) 0.005 Prothrombotic MCF (mm) 51 (12) 67 (17) 0.001 Prothrombotic Max vel (mm/s) 6.5 (3.0) 10.9 (7.4) 0.005 Prothrombotic Time to Vmax (s) 1040 (334) 1079 (650) NS Neutral AUC 51 (12) 62 (24) 0.001 Prothrombotic The results show that despite decreased levels of factors II, V, VII, XI and XII (correlation with decreased albumin, P

Description: CD33 is a sialoglycan protein expressed on the vast majority of myeloid malignancies as well as normal myeloid and monocytic progenitors. SGN-33 is a humanized antibody that specifically binds CD33, inducing antibody-dependent cellular cytotoxicity, complement-dependent cytotoxicity, and antibody-dependent cellular phagocytosis. In prior clinical testing at lower dose levels, this antibody elicited antitumor activity and objective responses in patients with relapsed and refractory acute myeloid leukemia (AML) without dose-limiting toxicity. To further characterize a dose-response relationship, a phase I single-arm dose-escalation trial was performed at 5 trial sites to assess the safety, immunogenicity, pharmacokinetics, and antileukemic activity of SGN-33. Entry criteria included CD33 expression on 〉50% of marrow blasts as determined by flow cytometry. Cohorts of 3–6 patients with advanced myeloid malignancies received intravenous SGN-33 at weekly doses of 1.5 to 8 mg/kg for 5 weeks as outpatients. Clinical response was assessed by bone marrow morphology and hematologic improvement. Patients demonstrating clinical benefit were eligible for additional every other week outpatient infusions. A total of 31 patients [AML (18), MDS (10), and CMML (3)] with a median age of 75 years (range: 52 to 89) were treated with escalating doses of SGN-33. Among AML patients, 6 had antecedent hematologic disorder. Dosing cohorts included 1.5 (6), 2.5 (4), 4 (4), and 8 mg/kg (17). Dose limiting toxicity has not been observed; the most common drug-related adverse event was chills associated with the first infusion (11/31 patients). Infusion reactions were uncommon during subsequent doses. Among adverse events considered related to antibody, none were Grade 4 and two were Grade 3: tumor lysis syndrome documented at 4 mg/kg that resolved swiftly with hydration, and febrile neutropenia observed at 8 mg/kg dose level. No anti-SGN-33 immune responses were detected among the first 15 patients tested. Exposure (AUC) to SGN-33 increased relative to dose and accumulation was documented with repeat dosing. The median time on study was 33 days (range 1–407) and 9 patients have received treatment for more than 56 days. Among 18 patients with AML, 4 have achieved CR and 1 CR with incomplete platelet recovery. To date, stable disease has been observed in 6 MDS patients. In summary, SGN-33 has been well tolerated at doses up to 8 mg/kg/wk, achieving serum SGN-33 exposures approximately twenty times higher than in prior studies. Complete remissions were observed in older patients with AML who were not candidates for intensive therapies. Given the responses observed in the context of an excellent tolerability profile, SGN-33 holds promise, as single agent or as part of combination therapy, for the treatment of patients with myeloid malignancy who are ineligible for aggressive therapy.

Description: CD33 is a sialoglycan protein expressed on normal myeloid and monocytic cells as well as the vast majority of myeloid malignancies. A humanized antibody (HuM195) has been developed that specifically recognizes CD33 and induces potent effector function (ADCC, CDC, ADCP). In prior clinical testing, this antibody led to antitumor activity and objective responses in patients with relapsed and refractory AML. To further characterize a dose-response relationship and because a maximum tolerated dose for SGN-33 has never been identified, a phase I single-arm dose escalation trial was initiated at multiple sites to assess safety, immunogenicity, PK, and activity of SGN-33 at substantially increased dose intensity and in a patient (pt) population not previously tested, including untreated AML and MDS. Entry criteria included CD33 expression on 〉50% of the marrow blasts to ensure that adequate target antigen was present. Cohorts of 3–6 pts with advanced myeloid malignancies were planned to receive IV SGN-33 at weekly doses of 1.5 to 8 mg/kg for 5 weeks. Response was assessed by marrow morphology and hematologic improvement. Pts demonstrating clinical benefit were eligible for additional infusions. To date, 12 pts have been treated at a maximum weekly dose of 1.5 mg/kg (N=6), 2.5 mg/kg (N=4), or 4 mg/kg (N=2). The median age was 74.5 years (range 52–88), and the majority of pts were previously untreated. Eight pts had a diagnosis of AML and four had MDS. SGN-33 has been well tolerated; drug-related AEs so far include mild to moderate infusion reactions (Day 1 only) and mild rash. One pt experienced tumor lysis syndrome after the first week of treatment; laboratory abnormalities returned to baseline after hydration. There has been no dose-limiting toxicity or related adverse events 〉 grade 3. No anti-SGN-33 immune responses were detected among the first 8 pts tested. CD33 saturation of the marrow blasts after two infusions for Cohorts I and II averaged 55.4% and 89.0%, respectively. Three pts did not complete 1 cycle (ie five weeks) of treatment due to: disease progression (1), thrombocytopenia refractory to transfusion (1), and pt withdrawal after a Grade 2 infusion reaction (1). Six of the seven pts that completed Cycle 1 received additional infusions after demonstrating one or more of the following: improved blood counts, decreased transfusion requirements, or decreased blasts. There was no unresolved toxicity after the first cycle of therapy and no evidence of cumulative toxicity during Cycle 2. Two pts demonstrated a marked decrease in the percentage of blasts in the marrow at the end of Cycle 1 compared to baseline. In summary, SGN-33 has been well tolerated at a dose intensity substantially higher than previously achieved, and antitumor activity was observed in elderly pts with untreated AML and MDS. SGN-33 holds promise as single-agent therapy and/or in combination with other non-myeloablative therapies for the treatment of pts with myeloid malignancy who are ineligible for aggressive therapy.

Description: BLIMP-1 initiates plasma cell differentiation by inhibiting the expression of a limited set of transcription factor genes. BLIMP-1 mediates repression of its targets by promoter occupancy and recruitment of the Groucho corepressor, histone deacetylase and the G9a lysine methyltransferase. The relative contribution of these mechanisms to the stable silencing of BLIMP-1 target genes in plasma cells is not known. Epigenetic changes initiated by BLIMP-1 could be maintained by independent factors or alternatively may be dependent on continuous occupancy of the promoter by BLIMP-1. The aim of this study was to investigate the mechanisms operating at two well-defined BLIMP-1 target genes, MHC2TA and PAX-5. Repression of PAX-5 is essential for extinction of the B-cell phenotype, while repression of MHC2TA mediates the loss of MHC class-II expression characteristic of plasma cell differentiation. PAX-5 is silenced in virtually all cases of myeloma, whereas MHC class-II continues to be expressed in a subset of primary myeloma cells and many myeloma cell lines. Using chromatin immunoprecipitation we demonstrate that BLIMP-1 constitutively binds MHC2TA promoter-3 and is present equally in MHC2TA expressing and non-expressing myeloma cell lines. In expressing cells MHC2TA promoter-3 is associated with acetylation of histone H3 lysine-9, a marker of open chromatin, whereas histone H3 lysine-9 is neither acetylated nor methylated in non-expressing cells. In contrast the PAX-5 promoter is associated with trimethylation of histone H3 lysine-9, a marker of repressed heterochromatin, in all the cell lines examined, but constitutive BLIMP-1 occupancy is not detectable. Although BLIMP-1 does not silence MHC2TA expression in the MHC class-II positive U266 cell line, it is mediating transcriptional repression, since siRNA knockdown of BLIMP-1 is associated with elevated MHC2TA mRNA and MHC class-II surface expression. In contrast PAX-5 mRNA and its target CD19 continue to be repressed. MHC class-II re-expression was associated with loss of CD138 and the entry of the majority of cells into apoptosis. Our data demonstrate that MHC class-II expression in myeloma cell lines is associated with defective silencing of MHC2TA despite BLIMP-1 occupancy, and reveal differences in the contribution of epigenetic modifications and promoter occupancy in the maintenance of target gene silencing by BLIMP-1. Loss of BLIMP-1 results in a partial reversion of plasma cell phenotype that is associated with induction of apoptosis. As continual high levels of BLIMP-1 expression appear to be critical for plasma cell survival, suppression of BLIMP-1 represents a potential therapeutic pathway.

Description: In mucopolysaccharidosis-I (MPS-I), α-L-iduronidase deficiency leads to progressive heparan sulfate (HS) and dermatan sulfate (DS) glycosaminoglycan (GAG) accumulation. The functional consequences of these accumulated molecules are unknown. HS critically influences tissue morphogenesis by binding to and modulating the activity of several cytokines (eg, fibroblast growth factors [FGFs]) involved in developmental patterning. We recently isolated a multipotent progenitor cell from postnatal human bone marrow, which differentiates into cells of all 3 embryonic lineages. The availability of multipotent progenitor cells from healthy volunteers and patients with MPS-I (Hurler syndrome) provides a unique opportunity to directly examine the functional effects of abnormal HS on cytokine-mediated stem-cell proliferation and survival. We demonstrate here that abnormally sulfated HS in Hurler multipotent progenitor cells perturb critical FGF-2–FGFR1-HS interactions, resulting in defective FGF-2–induced proliferation and survival of Hurler multipotent progenitor cells. Both the mitogenic and survival-promoting activities of FGF-2 were restored by substitution of Hurler HS by normal HS. This perturbation of critical HS–cytokine receptor interactions may represent a mechanism by which accumulated HS contributes to the developmental pathophysiology of Hurler syndrome. Similar mechanisms may operate in the pathogenesis of other diseases where structurally abnormal GAGs accumulate.