A Phase II Study of PXD101 in Advanced Multiple Myeloma.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3583-3583 ◽  
Author(s):  
Daniel Sullivan ◽  
Seema Singhal ◽  
Michael Schuster ◽  
James Berenson ◽  
Peter Gimsing ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Stable Disease ◽  
Progressive Disease ◽  
Synergistic Effects ◽  
Objective Response ◽  
Study Drug ◽  
Primary Objective

Abstract Background: PXD101 is a small molecule HDAC inhibitor of the hydroxamate class, which demonstrates broad anti-neoplastic activity in vitro and in vivo. PXD101 has antiproliferative activity on multiple myeloma cell lines, and shows additive/synergistic effects with standard agents used in myeloma, against these cell lines. PXD101 is being tested as monotherapy and in combination with standard agents for treatment of multiple myeloma. Methods: The primary objective of this study was to assess the activity of PXD101 alone or with dexamethasone, in multiple myeloma patients (pts) who have failed at least 2 prior therapies. Response was measured using the Blade criteria. PXD101 was administered as a 30-min IV infusion on Days 1–5 of a 3-wk cycle, at a dose of 1000 mg/m2/d (900 mg/m2/d in earlier patients). Patients are initially treated with PXD101 alone for two cycles. At the end of cycle two and every cycle thereafter, pts are evaluated for tumor response and continue on the study as follows: pts with objective response or stable disease continue on PXD101 monotherapy, while pts who have progressive disease (PD) are treated with a combination of PXD101 + dexamethasone (Dex). Dex was given orally 40 mg daily on Days 2–5 and 10–13 of the treatment cycle. Results: To date, 24 pts have been enrolled, 19 for which data are currently available. These pts have received a median of 5 (range 2–10) prior therapies. Seventeen pts are evaluable, 12 of whom are evaluable for ≥ 2 cycles, and 5 evaluable for 1 cycle only; 2 pts are unevaluable due to inconsistent baseline that prevented response assessment. Of the 5 pts evaluable for 1 cycle only, 4 discontinued due to PD and one withdrew from study. The 12 pts evaluable for ≥ 2 cycles received a median of 4 treatment cycles (range 2–12); 6 of these patients went on to receive PXD101+Dex. In these 12 pts, duration of PXD101 monotherapy was for 2–4 cycles, with almost all pts (10) receiving only 2 cycles. PXD101+Dex treatment in 6 pts was for 1–10 cycles (10, 6, 4, 4, 3, and 1). In 12 pts on monotherapy for ≥ 2 cycles, there were 6 SD (duration 6–12 wks) and 6 PD. The short duration of SD in PXD101 monotherapy was attributed to patient withdrawal or moving to Dex addition in spite of disease stabilization. All 6 pts receiving PXD101+Dex had previously received at least 2 Dex-containing regimens. One pt had MR (duration 6 wks), and 5 pts had SD. One pt has had SD for 35 wks, with 90% decrease in serum M-component sustained in the last 12 wks; another pt has had SD for 15 wks. In 69 cycles of treatment there were 7 Grade 3/4 adverse events assessed by the investigator as potentially related to study drug. These include anemia (2), infection, respiratory distress, hyperglycemia, thrombocytopenia, and fatigue. Conclusions: PXD101 treatment has resulted in stabilization of advanced and progressive disease, providing clinical benefit to patients. PXD101 combination with dexamethasone led to an MR as well as long duration of stable disease in patients who have previously received multiple Dex regimens. These observations support the continued exploration of PXD101 in combination with other agents for treatment of multiple myeloma.

A Multicenter Phase II Study of Combination Treatment with Melphalan, Arsenic Trioxide and Vitamin C (MAC) for Patients with Relapsed or Refractory Multiple Myeloma.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2564-2564 ◽  
Author(s):  
James Berenson ◽  
Ralph Boccia ◽  
David Siegel ◽  
Marek Bozdech ◽  
Alberto Bessudo ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Ascorbic Acid ◽  
Vitamin C ◽  
Arsenic Trioxide ◽  
Phase Ii ◽  
Stable Disease ◽  
Objective Response ◽  
In Vivo Studies

Abstract Background: Despite the recent increase in treatment options for patients with multiple myeloma (MM), the disease remains largely incurable. Both arsenic trioxide (ATO) and melphalan have shown clinical activity in MM. Recent in vitro and in vivo studies in our laboratory have shown that arsenic trioxide sensitizes chemoresistant MM cells to melphalan-induced cytotoxicity; the addition of ascorbic acid (AA) further improves this effect. We conducted a multi-center clinical trial to evaluate the safety and efficacy of this steroid-free combination, melphalan, ATO and vitamin C (MAC), for patients with relapsed/refractory MM. Methods: MM pts who relapsed after responding to 1st-line therapy and/or were refractory to prior treatment were enrolled. During week 1 of each 6-week cycle, pts received ATO, 0.25 mg/kg IV, followed by ascorbic acid (AA), 1 g IV, days 1–4. ATO followed by AA was given twice-weekly for the next 4 weeks of each cycle. Low-dose melphalan (0.10 mg/kg) was administered orally for the first 4 days of each cycle. Pts received a maximum of 6 cycles followed by weekly maintenance treatment with ATO and AA. The primary objectives of this study were to determine response rate and safety and tolerability of MAC therapy. Results: 65 patients have been enrolled and 51 are currently evaluable for response. 26 (1 CR, 10 PR, 15 MR) of the 51 evaluable patients (51%) had an objective response and an additional 14 patients achieved stable disease, resulting in a total of 40 patients (78%) with disease control. Among patients with elevated serum creatinine levels at baseline, renal function improved for those with responsive or stable disease. 20 of the 26 responding patients had failed ≥ 2 prior therapies: 19 pts had received prior thalidomide or lenalidomide therapy and 8 pts had received prior bortezomib. The regimen was well-tolerated with few significant side effects reported. Mild cytopenias occurred infrequently and were reversible. Conclusions: The results from this large multi-center phase II trial show that the MAC regimen is active in a group of MM patients who had either relapsed or were refractory to standard and/or investigational MM treatments. The regimen was well-tolerated even in this heavily pre-treated patient population. These findings are consistent with preclinical studies that showed the efficacy of this combination from both in vitro and in vivo studies.

A Phase IB, Multicenter, Open-Label, Dose-Escalation Study of Oral Panobinostat (LBH589) and I.V. Bortezomib in Patients with Relapsed Multiple Myeloma

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2781-2781 ◽  
Author(s):  
Davi d Siegel ◽  
Orhan Sezer ◽  
Jesus F. San Miguel ◽  
Maria-Victoria Mateos ◽  
Ian Prosser ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Dose Escalation ◽  
Maximum Tolerated Dose ◽  
Primary Objective ◽  
Lower Grade ◽  
Open Label ◽  
Dose Escalation Study

Abstract Panobinostat (LBH589) is a pan-deacetylase inhibitor (pan-DACi), targeting epigenetic and multiple oncogenic pathways. Beyond numerous hematological cell lines being highly sensitive in vitro, panobinostat has shown to induce cytotoxicity at low nanomolar concentrations in multiple myeloma (MM) cell lines resistant to dexamethasone, melphalan, and doxorubicin. Additional in vitro and in vivo experiments have demonstrated potent synergistic MM cytotoxicity of panobinostat and bortezomib associated with blocking of aggresome and proteosome degradation of ubiquinated protein. Collectively, these data provide a strong rationale for the first clinical trial of this combination in MM patients. The primary objective of this Phase I study is to establish the maximum-tolerated dose (MTD) of panobinostat with bortezomib in a second-line setting. Safety, tolerability, pharmacokinetic/pharmacodynamic profiles, and preliminary efficacy of the combination will be assessed as secondary endpoints.. Patients with relapsed MM, who have received at least 1 prior line of therapy, are to be enrolled, if they are suitable for bortezomib therapy and have no primary refractory MM prior exposure to an HDACi, impaired cardiac function, or QTc prolongation. Dose-escalation started at 10 mg of panobinostat (po thrice weekly) in combination with 1 mg/m2 of bortezomib (i.v on Days 1, 4, 8 and 11) over a 21 day cycle. In any cohort, dexamethasone can be added after Cycle 1, in case of worsening disease. A 6-parameter, adaptive Bayesian logistic regression model guides the escalation to MTD with each dose-combination being studied in cohorts of at least 6 patients. At the confirmed MTD, additional patients will be enrolled to obtain further safety and tolerability information. As of 21 July 2008, a total of 14 patients have been enrolled in 2 cohorts: Cohort 1 (10 mg panobinostat + 1.0 mg/m2 bortezomib, n=7,), and Cohort 2 (20 mg panobinostat + 1.0 mg/m2 bortezomib, n=7). Patients are 10 males and 4 females, with median age of 57 (range 46–78). Median number of prior therapies is 3 (range 1–7). All patients had at least one prior auto-SCT, and bortezomib was listed among prior therapies in 8 pts. Disease status included 9/14 pts refractory at entry, defined as progressing within 60 days of last therapy. 1 patient (Cohort 2) with a borderline entry ANC value experienced an early Grade 4 afebrile neutropenia, which met DLT criteria. Grade 3/4 hematological AEs were the most frequent and included anemia in 2 pts, thrombocytopenia in 11 pts, and neutropenia in 3 pts. G-CSF treatment was required by 2 patients. Non-hematological AEs have included lower grade diarrhea and fatigue. To date, with a total of 44 complete cycles received by 14 patients, 1 immunofixation negative (IF-) CR, 1 VGPR, and 3 PR were seen with dexamethasone added at 2nd cycle in 3 of these 5 pts (CR + 2 PR). The IF-CR response in a patient of Cohort 2, in relapse after Auto-SCT and observed after 3 cycles, was determined by negative IF and normalized serum-free light chain ratio (bone marrow evaluation refused by the patient). VGPR was observed in 1 patient in relapse after auto-SCT, after 7 cycles (Cohort 1); therapy was discontinued in Cycle 10 due to Grade 2 weight loss. PR was observed in 3 patients (1 in Cohort 1; 2 in Cohort 2), occurring early on after one to two cycles. 2 of these patients had received prior bortezomib, 1 had been treated with 4 prior lines of therapy, and the other received 6 prior lines of therapy, including autologous and allogeneic SCT, donor lymphocyte infusion, cyclophosphamide/thalidomide, and lenalidomide. These responses, observed at early/low dose levels of the trial drugs, show a potential activity of panobinostat in combination to bortezomib in patients who had not responded to bortezomib. The combination of panobinostat and bortezomib shows promising activity and a good safety profile. Enrollment into Cohort 3 (20 mg panobinostat + 1.3mg/mg/m2 bortezomib) is currently underway. Updated follow-up, as well as new patient data, will be presented.

scholarly journals In Vitro Investigation of the Cytotoxic Activity of Emodin 35 Derivative on Multiple Myeloma Cell Lines

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jing Zheng ◽  
Yingyu Chen ◽  
Zhihong Zheng ◽  
Yanxin Chen ◽  
Yujuan Chai ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Synergistic Effects ◽  
Annexin V ◽  
Myeloma Cell ◽  
In Vitro Investigation ◽  
Cellular Apoptosis

Background. Bortezomib is used for treating multiple myeloma (MM); however, it has considerable adverse effects. Emodin has been reported to exhibit inhibitory effects on MM cell lines. We investigated the efficacy of emodin 35 (E35), an emodin derivative, using U266 and MM1s cell lines in treating MM and the efficacy of combining bortezomib and E35. Methods. MTT assays were used to observe the effects of E35 on MM cell growth. The effects on cellular apoptosis were then observed using Annexin V/propidium iodide (PI) staining assay. The expression of apoptosis-related genes, including the caspase family, was examined. The efficacy of combining bortezomib and E35 was investigated by examining the expression of the Akt/mTOR/4EBP1 signaling pathway-related proteins. Results. We report that E35 inhibited the growth of U266 and MM1s cells by inducing cellular apoptosis. Moreover, E35 downregulated the expression of apoptosis-related genes and suppressed the phosphorylation of Akt/mTOR/4EBP1 signaling pathway-related genes, thus exhibiting synergistic effects with bortezomib. All observed effects were dose-dependent. Conclusion. The results showed that E35 exhibited cytotoxic effects in MM cell lines in protein levels. Thus, E35, particularly in combination with bortezomib, may be considered as a promising treatment for MM; however, this requires further investigation in vivo.

A Phase I/II Multicenter, Safety and Efficacy Study of Combination Treatment with Melphalan, Arsenic Trioxide and Vitamin C (MAC) in Patients with Relapsed or Refractory Multiple Myeloma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2398-2398 ◽  
Author(s):  
James R. Berenson
Keyword(s):  
Multiple Myeloma ◽  
Ascorbic Acid ◽  
Arsenic Trioxide ◽  
Stable Disease ◽  
Low Dose ◽  
Objective Response ◽  
Multicenter Trial ◽  
In Vivo Studies

Abstract Background: An urgent need exists for new treatments to overcome chemoresistance in MM patients. Recent in vitro and In vivo studies in our laboratory show that arsenic trioxide (ATO) can sensitize chemoresistant MM cells to melphalan-induced cytotoxic effects. Pre-clinical studies also show the most profound anti-MM effects when ATO, ascorbic acid and melphalan are used in combination compared with the effects observed when the drugs are used alone or combinations of any two of these agents. Based on encouraging results from a pilot study1, a larger, multicenter trial was recently started. Methods: MM patients who showed relapse after responding to first-line chemotherapy and/or having proved to be refractory to chemotherapy are enrolled. Patients received a loading dose of ATO at 0.25 mg/kg IV followed by ascorbic acid 1 g IV days 1–4 of week 1 of each six-week cycle. ATO/ascorbic acid was given twice-weekly for the next 4 weeks of each cycle. Low-dose melphalan (0.10 mg/kg) was administered orally for the first 4 days of each cycle. Patients received a maximum of 6 cycles followed by weekly maintenance treatment with weekly ATO followed by ascorbic acid. The primary objectives of this study are to determine response rate and safety and tolerability of MAC therapy. Results: Twenty patients have received at least one treatment cycle. Preliminary data show that eight (4 PR, 4 MR) of the 14 evaluable patients (57%) had an objective response, an additional three patients achieved stable disease, resulting in a total of 11 patients (79%) with disease control. Since responses were seen after 2 to 5 treatment cycles, it is possible that some patients with stable disease may experience additional disease response. Seven of the eight responding patients had failed two or more treatments: five patients had received prior thalidomide therapy, two had received melphalan and bortezomib, and two patients had undergone autologous peripheral stem cell transplantation. Of the six patients who have now completed the maximal numbers of cycles, four achieved PR, one MR, and one SD. The regimen was well tolerated with few significant side effects reported; mild cytopenias were reported as reversible. Conclusions: These preliminary results in this treatment group of heavily pre-treated MM patients who had either relapsed or were refractory to standard and/or investigational multiple myeloma treatments suggests that the MAC treatment regimen (1) shows efficacy using a low dose of melphalan supporting the preclinical evidence that ATO can sensitize tumors to chemotherapy; (2) is well tolerated; (3) may require multiple cycles before response.

scholarly journals In Vitro Investigation of The Cytotoxic Activity of E35 on Multiple Myeloma Cell Lines

2020 ◽  
Author(s):  
Jing Zheng ◽  
Yingyu Chen ◽  
Zhihong Zheng ◽  
Yanxin Chen ◽  
Yujuan Chai ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Synergistic Effects ◽  
Annexin V ◽  
Myeloma Cell ◽  
In Vitro Investigation ◽  
Cellular Apoptosis

Abstract Background: Bortezomib is used for the treatment of multiple myeloma (MM); however, it has significant adverse effects. Emodin has been reported to exhibit inhibitory effects on MM cell lines. Here, we investigated the efficacy of E35, an emodin derivative, using U266 and MM1s cell lines in the treatment of MM and the efficacy of the combination of bortezomib and E35. Methods: MTT assays were used to observe the effects of E35 on MM cell growth. The effects on cellular apoptosis were observed using the Annexin V/propidium iodide (PI) staining assay. The expression of apoptosis-related genes, including the caspase family, was also examined. The efficacy of the combination of bortezomib and E35 was investigated by examining the expression of the Akt/mTOR/4EBP1 signaling pathway-related proteins. Results: We found that E35 inhibited the growth of the U266 and MM1s cells by inducing cellular apoptosis. E35 also downregulated the expression of the apoptosis-related genes and suppressed the phosphorylation of the Akt/mTOR/4EBP1 signaling pathway-related genes, exhibiting synergistic effects with bortezomib. All the observed effects were dose-dependent. Conclusion: The results of this study showed that E35 exhibited cytotoxic effects in MM cell lines. Thus, E35, especially in combination with bortezomib, may be considered as a promising treatment for MM. However, this requires further investigation in vivo.

CDK12 inhibition mediates DNA damage and is synergistic with sorafenib treatment in hepatocellular carcinoma

Gut ◽  
2019 ◽  
Vol 69 (4) ◽  
pp. 727-736 ◽  
Author(s):  
Cun Wang ◽  
Hui Wang ◽  
Cor Lieftink ◽  
Aimee du Chatinier ◽  
Dongmei Gao ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Dna Damage ◽  
Cell Lines ◽  
Synergistic Effects ◽  
Loss Of Function ◽  
Bioinformatics Analyses ◽  
Sorafenib Treatment ◽  
Hcc Cells

ObjectivesHepatocellular carcinoma (HCC) is one of the most frequent malignancies and a major leading cause of cancer-related deaths worldwide. Several therapeutic options like sorafenib and regorafenib provide only modest survival benefit to patients with HCC. This study aims to identify novel druggable candidate genes for patients with HCC.DesignA non-biased CRISPR (clustered regularly interspaced short palindromic repeats) loss-of-function genetic screen targeting all known human kinases was performed to identify vulnerabilities of HCC cells. Whole-transcriptome sequencing (RNA-Seq) and bioinformatics analyses were performed to explore the mechanisms of the action of a cyclin-dependent kinase 12 (CDK12) inhibitor in HCC cells. Multiple in vitro and in vivo assays were used to study the synergistic effects of the combination of CDK12 inhibition and sorafenib.ResultsWe identify CDK12 as critically required for most HCC cell lines. Suppression of CDK12 using short hairpin RNAs (shRNAs) or its inhibition by the covalent small molecule inhibitor THZ531 leads to robust proliferation inhibition. THZ531 preferentially suppresses the expression of DNA repair-related genes and induces strong DNA damage response in HCC cell lines. The combination of THZ531 and sorafenib shows striking synergy by inducing apoptosis or senescence in HCC cells. The synergy between THZ531 and sorafenib may derive from the notion that THZ531 impairs the adaptive responses of HCC cells induced by sorafenib treatment.ConclusionOur data highlight the potential of CDK12 as a drug target for patients with HCC. The striking synergy of THZ531 and sorafenib suggests a potential combination therapy for this difficult to treat cancer.

CHIR258, a Novel Multi-Targeted Tyrosine Kinase Inhibitor, for the Treatment of t(4;14) Multiple Myeloma.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 641-641 ◽  
Author(s):  
Suzanne Trudel ◽  
Zhi Hua Li ◽  
Ellen Wei ◽  
Marion Wiesmann ◽  
Katherine Rendahl ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Mouse Model ◽  
Tyrosine Kinase ◽  
Cell Lines ◽  
Small Molecule ◽  
Kinase Inhibitor ◽  
Wild Type ◽  
Myeloma Cells

Abstract The t(4;14) translocation that occurs uniquely in a subset (15%) of multiple myeloma (MM) patients results in the ectopic expression of the receptor tyrosine kinase, Fibroblast Growth Factor Receptor3 (FGFR3). Wild-type FGFR3 induces proliferative signals in myeloma cells and appears to be weakly transforming in a hematopoeitic mouse model. The subsequent acquisition of FGFR3 activating mutations in some MM is associated with disease progression and is strongly transforming in several experimental models. The clinical impact of t(4;14) translocations has been demonstrated in several retrospective studies each reporting a marked reduction in overall survival. We have previously shown that inhibition of activated FGFR3 causes morphologic differentiation followed by apoptosis of FGFR3 expressing MM cell lines, validating activated FGFR3 as a therapeutic target in t(4;14) MM and encouraging the clinical development of FGFR3 inhibitors for the treatment of these poor-prognosis patients. CHIR258 is a small molecule kinase inhibitor that targets Class III–V RTKs and inhibits FGFR3 with an IC50 of 5 nM in an in vitro kinase assay. Potent anti-tumor and anti-angiogenic activity has been demonstrated in vitro and in vivo. We employed the IL-6 dependent cell line, B9 that has been engineered to express wild-type FGFR3 or active mutants of FGFR3 (Y373C, K650E, G384D and 807C), to screen CHIR258 for activity against FGFR3. CHIR258 differentially inhibited FGF-mediated growth of B9 expressing wild-type and mutant receptors found in MM, with an IC50 of 25 nM and 80 nM respectively as determined by MTT proliferation assay. Growth of these cells could be rescued by IL-6 demonstrating selectivity of CHIR258 for FGFR3. We then confirmed the activity of CHIR258 against FGFR3 expressing myeloma cells. CHIR258 inhibited the viability of FGFR3 expressing KMS11 (Y373C), KMS18 (G384D) and OPM-2 (K650E) cell lines with an IC50 of 100 nM, 250 nM and 80 nM, respectively. Importantly, inhibition with CHIR258 was still observed in the presence of IL-6, a potent growth factors for MM cells. U266 cells, which lack FGFR3 expression, displayed minimal growth inhibition demonstrating that at effective concentrations, CHIR258 exhibits minimal nonspecific cytotoxicity on MM cells. Further characterization of this finding demonstrated that inhibition of cell growth corresponded to G0/G1 cell cycle arrest and dose-dependent inhibition of downstream ERK phosphorylation. In responsive cell lines, CHIR258 induced apoptosis via caspase 3. In vitro combination analysis of CHIR258 and dexamethasone applied simultaneously to KMS11 cells indicated a synergistic interaction. In vivo studies demonstrated that CHIR258 induced tumor regression and inhibited growth of FGFR3 tumors in a plasmacytoma xenograft mouse model. Finally, CHIR258 produced cytotoxic responses in 4/5 primary myeloma samples derived from patients harboring a t(4;14) translocation. These data indicate that the small molecule inhibitor, CHIR258 potently inhibits FGFR3 and has activity against human MM cells setting the stage for a Phase I clinical trial of this compound in t(4;14) myeloma.

Improved Therapy of Multiple Myeloma by Combining Milatuzumab (Anti-CD74 Humanized mAb) and Bortezomib: In Vitro and In Vivo Results.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1176-1176
Author(s):  
Rhona Stein ◽  
David M. Goldenberg
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Leukemic Cells ◽  
Tumor Type ◽  
Term Survival ◽  
Significant Difference ◽  
Highly Effective ◽  
Ic50 Values

Abstract Background: The humanized anti-CD74 monoclonal antibody, milatuzumab (hLL1, or IMMU-115; Immunomedics, Inc, Morris Plains, NJ), is in clinical evaluation for therapy of multiple myeloma (MM) after preclinical evidence of activity in this tumor type (Stein et al, Blood2004;104:3705). Here we examine the ability of milatuzumab to increase the efficacy of drugs in MM cell lines. Methods: MTT cytotoxicity assays were performed on a panel of MM cell lines, including CAG, KMS11, KMS12-PE, and MC/CAR, to examine the effects of bortezomib, doxorubicin (dox), and dexamethasone (dex) alone and combined with milatuzumab or milatuzumab + crosslinking 2nd Ab (goat anti-human IgG, GAH). In vivo studies used a CAG-SCID mouse model of disseminated disease. Results: Without drugs, crosslinked milatuzumab, but not milatuzumab alone, yielded significant anti-proliferative effects on the four MM cell lines. In combination studies, crosslinked milatuzumab produced significant reductions in the IC50 values of the anti-MM drugs. For example, in CAG, milatuzumab+GAH decreased the IC50 values 58%, 78%, and 98% for bortezomib, dox, and dex, respectively (P=0.0034, 0.0073, and 0.078, respectively). In vivo, milatuzumab at 100 μg/injection, 2x weekly for 4 weeks, starting 1 day after injection of CAG cells, more than doubled the median survival time (MST) from 42 days in untreated CAG-bearing SCID mice to 103 days. Combination therapy with milatuzumab and bortezomib or dox was compared to milatuzumab alone, with treatments initiated 5 days after injection of CAG cells. Bortezomib alone (1.0 mg/kg) increased MST from 33 to 44 days (P=0.0021 vs. untreated). Treatment with milatuzumab alone (100 μg/mouse) increased the MST to 73 days (P<0.0001 vs. untreated). When bortezomib and milatuzumab treatments were combined, the MST increased to 93 days (P=0.0441 vs. milatuzumab and P=0.0065 vs. bortezomib). Thus, the combination of milatuzumab and bortezomib increased survival significantly compared to either single treatment. Given alone, dox yielded little or no effect on survival compared with untreated animals, and there was no significant difference between milatuzumab monotherapy and milatuzumab plus doxorubicin in this model. In contrast, a milatuzumabdox immunoconjugate was found to be a highly effective therapeutic agent, with all mice achieving long-term survival. The inhibition of the NF-κB survival pathway of B-leukemic cells by milatuzumab supports its complementary effects when combined with drugs having different mechanisms of action, such as bortezomib. Conclusions: The therapeutic efficacies of bortezomib, dox, and dex are enhanced in vitro in MM cell lines when given in combination with milatuzumab. In vivo, milatuzumab alone or especially in combination with bortezomib is highly effective in MM. (Supported in part by USPHS grant P01CA103985 from the NCI, and grants from the Thomas and Agnes Carvel Foundation and the Walter and Louise Sutcliffe Foundation.)

A Humanized Anti-Ganglioside GM2 Antibody, BIW-8962, Exhibits ADCC/CDC Activity against Multiple Myeloma Cells and Potent Anti- Tumor Activity in Mouse Xenograft Models.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1718-1718 ◽  
Author(s):  
Toshihiko Ishii ◽  
Asher Alban Chanan-Khan ◽  
Jazur Jafferjee ◽  
Noreen Ersing ◽  
Takeshi Takahashi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Phase 1 ◽  
Xenograft Model ◽  
Surface Expression ◽  
Scid Mice ◽  
Subcutaneous Xenograft ◽  
Anti Tumor Activity

Abstract BIW-8962 is a humanized anti-ganglioside GM2 (GM2) monoclonal antibody, produced by Poteligent technology to enhance ADCC activity. GM2 is expressed on many cancer cells including multiple myeloma (MM), small cell lung cancer and glioma cells. In this study, we evaluated the anti-myeloma activity of BIW-8962 in preclinical myeloma models both in vitro and in vivo. Expression of GM2 was analyzed in 15 human MM cell lines by FCM. Eleven out of 15 MM cell lines had positive surface expression of GM2. GM2 as a potential target was then verified in primary MM samples obtained from patients. Eleven out of 15 samples were positive for GM2. We then used two GM2 positive MM cell lines (U266B1 and KMS-11) and evaluated ADCC and CDC activity of BIW-8962 in vitro. BIW-8962 exhibited a potent ADCC and less potent CDC activity. In vivo anti-tumor activity of BIW-8962 was then examined using the standard subcutaneous xenograft model; KMS-11 was inoculated in the flank of SCID mice. BIW-8962 (intravenously administered biweekly for 3 weeks) exhibited a potent anti-tumor activity from as low a dose level as 0.1 mg/kg. Furthermore, in a more clinically relevant model, in which OPM-2/GFP (GM2 positive MM cell line) cells were intravenously inoculated into SCID mice with preferentially tumor growth within the bone marrow microenvironment, BIW-8962 (intravenously administered biweekly for 4 weeks, 10 mg/kg) suppressed OPM-2/GFP cell growth and serum M protein elevation, demonstrating in vivo anti-myeloma effect of BIW-8962. Our preclinical investigations rationalize clinical evaluation of BIW-8962 in patients with MM. Currently BIW-8962 is being investigated in a Phase 1 study in patients with multiple myeloma.

The Monoclonal Antibody nBT062 Conjugated to Cytotoxic Maytansinoids Has Potent and Selective Cytotoxicity against CD138 Positive Multiple Myeloma Cells in Vitro and in Vivo.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1716-1716 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Teru Hideshima ◽  
Robert J. Lutz ◽  
Sonia Vallet ◽  
Samantha Pozzi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Monoclonal Antibody ◽  
Tumor Cells ◽  
Cell Lines ◽  
Xenograft Model ◽  
Growth Delay ◽  
Selective Cytotoxicity ◽  
Bystander Killing

Abstract CD138 is expressed on differentiated plasma cells and is involved in the development and/or proliferation of multiple myeloma (MM), for which it is a primary diagnostic marker. In this study, we report that immunoconjugates comprised of the murine/human chimeric CD138-specific monoclonal antibody nBT062 conjugated with highly cytotoxic maytansinoid derivatives (nBT062-SMCC-DM1, nBT062-SPDB-DM4 and nBT062-SPP-DM1) showed cytotoxic activity against CD138-positive MM cells both in vitro and in vivo. These agents demonstrated cytotoxicity against OPM1 and RPMI8226 (CD138-positive MM cell lines) in a dose and time-dependent fashion and were also cytotoxic against primary tumor cells from MM patients. Minimal cytotoxicity was noted in CD138-negative cell lines and no activity was observed against peripheral blood mononuclear cells from healthy volunteers, suggesting that CD138-targeting is important for immunoconjugate-mediated cytotoxicity. Examination of the mechanism of action whereby these immunoconjugates induced cytotoxicity in MM cells demonstrated that treatment triggered G2/M cell cycle arrest, followed by apoptosis associated with cleavage of PARP and caspase-3, -8 and -9. Neither interleukin-6 nor insulin-like growth factor-I could overcome the apoptotic effect of these agents. The level of soluble (s)CD138 in the BM plasma from 15 MM patients was evaluated to determine the potential impact of sCD138 on immunoconjugate function. The sCD138 level in BM plasma was found to be significantly lower than that present in MM cell culture supernatants where potent in vitro cytotoxicity was observed, suggesting that sCD138 levels in MM patient BM plasma would not interfere with immunoconjugate activity. Because adhesion to bone marrow stromal cells (BMSCs) triggers cell adhesion mediated drug resistance to conventional therapies, we next examined the effects of the conjugates on MM cell growth in the context of BMSC. Co-culture of MM cells with BMSCs, which protects against dexamethasoneinduced death, had no impact on the cytotoxicity of the immunoconjugates. The in vivo efficacy of these immunoconjugates was also evaluated in SCID mice bearing established CD138-positive MM xenografts and in a SCID-human bone xenograft model of myeloma. Significant tumor growth delay or regressions were observed at immunoconjugate concentrations that were well tolerated in all models tested. The ability of these agents to mediate bystander killing of proximal CD138-negative cells was also evaluated. While nBT062-SPDB-DM4 was inactive against CD138-negative Namalwa cells cultured alone, significant killing of these CD138-negative cells by nBT062-SPDB-DM4 was observed when mixed with CD138-positive OPM2 cells. This bystander killing may contribute to the eradication of MM tumors by disrupting the tumor microenvironment and/or killing CD138-negative MM tumor cells, such as the putative CD138 negative myeloma stem cells. These studies demonstrate strong evidence of in vitro and in vivo selective cytotoxicity of these immunoconjugates and provide the preclinical framework supporting evaluation of nBT062-based immunoconjugates in clinical trials to improve patient outcome in MM.

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