Triple Combinations of the HDAC Inhibitor Panobinostat (LBH589) + Dexamethasone with Either Lenalidomide or Bortezomib Are Highly Effective in a Multiple Myeloma Mouse Model.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1514-1514
Author(s):  
Enrique M. Ocio ◽  
David Vilanova ◽  
Laura San-Segundo ◽  
Patricia Maiso ◽  
Mercedes Garayoa ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Median Survival ◽  
Hdac Inhibitor ◽  
Single Agent ◽  
Body Weight Loss ◽  
Control Group ◽  
Synergistic Activity ◽  
Median Volume

Abstract Introduction Panobinostat (LBH589) is a novel histone deacetylase (HDAC) inhibitor being evaluated in clinical trials in hematological and solid malignancies. In multiple myeloma (MM), investigators have demonstrated its in vitro antimyeloma effect in cell lines and patients cells. Cancer treatment is typically based on the concept of combining agents with different mechanisms of action to overcome drug resistance. This was the rationale of the present study in which the in vitro and in vivo benefit of combinations of pabinostat with conventional antimyeloma agents has been explored. Material and Methods The potential in vitro synergism of pabinostat with 6 antimyeloma agents (melphalan, doxorubicin, dexamethasone, thalidomide, lenalidomide, bortezomib) was analyzed in MM1S cell line. The two most favorable combinations were tested in 120 NOD/SCID mice implanted with a human subcutaneous plasmocytoma. Mice were randomized into 12 treatment groups. Drugs were given ip, 5 days/week × 7 weeks. Doses were: pabinostat: 10 mg/Kg × 3 weeks and 5 mg/Kg afterwards; dexamethasone (D): 1 mg/Kg; bortezomib (B): 0.1 mg/Kg; and lenalidomide (L): 15 mg/Kg. Tumor volumes clinical features and weight were monitored three times a week. Mice were sacrificed when their tumors reached 2 cm. Immunohistochemistry was performed in selected tumors. Results Three agents potentiated the effect of pabinostat in vitro: bortezomib, dexamethasone and, to a lesser extent, lenalidomide. Moreover, the triple combination of pabinostat+L+D and pabinostat+B+D resulted in high synergistic activity. These studies provided the rationale for testing these combinations in vivo: Single agent pabinostat at a dose of 10 mg/Kg completely abrogated the growth of plasmocytomas without significant toxicity. In fact, after three weeks of treatment, the median volume of tumors in the pabinostat group was 163±75 mm3 as compared to 1891±1182 mm3 in the control group (p=0.001). Immunohistochemistry of pabinostat treated tumors revealed a decrease in BrdU uptake, an increase in histone acetylation and phosphorylation of H2AX suggesting DNA damage. This antiproliferative action was associated with survival advantage: median survival 70±1.8 vs 30±2.1 days (p<0.001) for the pabinostat and vehicle treated groups respectively. Subsequently the dose of pabinostat was decreased by 50% in order to gain further insights into the potential advantage of the combinations. Interestingly, the addition of D and suboptimal doses of either B or L significantly improved the antimyeloma effect of pabinostat. In this sense, median survival increased up to 86±2.6 days in pabinostat+D+B (p<0.001) and 88±1.2 days for pabinostat+D+L (p<0.001). The efficacy of these triple combinations was significantly higher than any of the respective double combinations (pabinostat+D; pabinostat+B; pabinostat+L; B+D; L+D). Some of these combinations (including or not pabinostat) initially induced a slight toxicity (5%–15% body weight loss) which spontaneously recovered after the third week of treatment. Conclusion Combinations of pabinostat + dexamethasone with either bortezomib or lenalidomide are safe and display promising antimyeloma efficacy. This study provides the rationale for the clinical development of triple combinations of these drugs to improve the outcome of MM patients.

The Novel Aurora Kinase Inhibitor ENMD-2076 Has Potent Single Agent Activity against Multiple Myeloma (MM) in Vitro and in Vivo, and Shows Synergistic Activity in Combination with Lenalidomide

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3660-3660 ◽  
Author(s):  
Xiaojing Wang ◽  
Anthony L. Sinn ◽  
Attaya Suvannasankha ◽  
Colin D. Crean ◽  
Li Chen ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Caspase 3 ◽  
Kinase Inhibitor ◽  
Single Agent ◽  
Synergistic Activity ◽  
Significant Activity ◽  
Aurora A Kinase ◽  
Free Base

Abstract ENMD-2076 is a novel, orally-active molecule that has been shown to have significant activity against Aurora A kinase as well as multiple receptor tyrosine kinases (RTK). We investigated the single agent activity of ENMD-2076 against MM cells in vitro and in vivo, and in combination with lenalidomide. ENMD-2076 free base showed significant cytotoxicity against MM cells with a mean LC50 of 3.84±0.86 μM at 48 hours in vitro. Cytotoxicity was associated with cleavage of caspase 3, 8, 9 and PARP, and loss of mitochondrial membrane potential as early as 6 hours. ENMD-2076 free base inhibited c-kit, FGFR-1, 3 and VEGFR1 and subsequently inhibition of downstream targets phosphorylated (p)-BAD, p-Foxo1a and p-GSK-3β was observed at 6 hours. NOD/SCID mice implanted with H929 human plasmacytoma xenografts and treated for 30 days with 50, 100, 200mg/kg/d ENMD-2076 showed a dose-dependent inhibition of tumor growth (Figure 1), with minimal toxicity as assessed by the stable weight of treated animals. Immunohistochemical staining of tumors from sacrificed animals showed significant reduction in Ki67 at all dose levels of treatment compared to control tumors. An increase in cleaved caspase-3 was observed on Western blot from the lysates of H929 tumors obtained from treated animals. ENMD-2076 free base also showed synergistic cytotoxic activity when combined with lenalidomide against H929, MM1.R and MM1.S cells as assessed by MTT assay and Annexin-V/PI staining. Using the Chou-Talalay method, the combination indices (CI) were < 1 for all three cell lines across a range of concentrations of ENMD-2076 free base (0.25–1.0 μM) plus lenalidomide (2.5–10 μM) indicating synergistic activity (CI=0.362 H929; CI=0.315 MM1.R; CI=0.415 MM1.S). Our results provide rationale for the investigation of ENMD-2076 alone and in combination with lenalidomide in patients with multiple myeloma. Figure Figure

PTH- PTHR1 Axis Control on Anti-Myeloma Effect of Proteasome Inhibitors

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 5017-5017
Author(s):  
Maurizio Zangari ◽  
Fang Xiao ◽  
Ye Yang ◽  
Hongwei Xu ◽  
Guido J. Tricot ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Conflicts Of Interest ◽  
Single Agent ◽  
Proteasome Inhibitors ◽  
In Vitro Study ◽  
Inhibitory Effect ◽  
Tumor Burden ◽  
Control Group

Abstract Abstract 5017 Multiple myeloma (MM) is a plasma cell malignancy with high osteolytic capacity and impaired bone formation. Our recent studies have demonstrated that PTH serum increases are associated with Bortezomib responses in multiple myeloma patients, indicating a possible role of PTH in anti myeloma effect of Bortezomib. We first tested the 5TGM1 cell line for sensitivity to bortezomib, PTH, and [TYR34]bPTH-(7-34) bovine (a specific PTHR1 inhibitor) in various combinations. In an in vitro study, 5TGM1 cells were sensitive to cytotoxicity of bortezomib and PTH in a dose dependent fashion. TYR compound was found to have no effect as single agent on 5TGM1 cell survival, but was able to partially block the inhibitory effect of bortezomib on cell growth (Figure 1). In an in vivo study using the 5TGM1 C 57BL/KaLwRijmice, we tested PTH-PTHR1 axis on bortezomib anti-myeloma activity. As shown in Figure 1, mice survival was positively affected by bortezomib administration (P = 0.04), and the combination of PTH + bortezomib showed a trend to further improve survival (P = 0.09). Interestingly, the concomitant use of [TYR] compound with bortezomib completely abrogated the efficacy of the proteasome inhibitor on survival. Tumor burden assessed by M-protein levels decreased consistently in mice treated with bortezomib alone, PTH alone, or a combination of PTH + bortezomib compared with the control group treated with PBS (P = 0.003, P = 0.05, P = 0.01 respectively). Importantly the tumor burden in the mice treated with bortezomib was significantly lower than in mice treated with bortezomib plus the PTH inhibitor (TYR), again indicating that the PTHR inhibitor abrogates the effect of Bortezomib on tumor growth. Similar results were obtained using the same systems for other commercially available proteasome inhibitors. Thus, we conclude that the PTH- PTHR1 pathway appears essential for proteasome inhibition activity in myeloma. Our observations may lead to novel treatment approaches in myeloma. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Pharmacodynamic, pharmacokinetic, and phase 1a study of bisthianostat, a novel histone deacetylase inhibitor, for the treatment of relapsed or refractory multiple myeloma

2021 ◽  
Author(s):  
Yu-bo Zhou ◽  
Yang-ming Zhang ◽  
Hong-hui Huang ◽  
Li-jing Shen ◽  
Xiao-feng Han ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Drug Targets ◽  
Single Agent ◽  
Hdac Inhibitors ◽  
Preclinical Study ◽  
Parp Cleavage ◽  
Rpmi 8226 ◽  
Ongoing Phase

AbstractHDAC inhibitors (HDACis) have been intensively studied for their roles and potential as drug targets in T-cell lymphomas and other hematologic malignancies. Bisthianostat is a novel bisthiazole-based pan-HDACi evolved from natural HDACi largazole. Here, we report the preclinical study of bisthianostat alone and in combination with bortezomib in the treatment of multiple myeloma (MM), as well as preliminary first-in-human findings from an ongoing phase 1a study. Bisthianostat dose dependently induced acetylation of tubulin and H3 and increased PARP cleavage and apoptosis in RPMI-8226 cells. In RPMI-8226 and MM.1S cell xenograft mouse models, oral administration of bisthianostat (50, 75, 100 mg·kg-1·d-1, bid) for 18 days dose dependently inhibited tumor growth. Furthermore, bisthianostat in combination with bortezomib displayed synergistic antitumor effect against RPMI-8226 and MM.1S cell in vitro and in vivo. Preclinical pharmacokinetic study showed bisthianostat was quickly absorbed with moderate oral bioavailability (F% = 16.9%–35.5%). Bisthianostat tended to distribute in blood with Vss value of 0.31 L/kg. This distribution parameter might be beneficial to treat hematologic neoplasms such as MM with few side effects. In an ongoing phase 1a study, bisthianostat treatment was well tolerated and no grade 3/4 nonhematological adverse events (AEs) had occurred together with good pharmacokinetics profiles in eight patients with relapsed or refractory MM (R/R MM). The overall single-agent efficacy was modest, stable disease (SD) was identified in four (50%) patients at the end of first dosing cycle (day 28). These preliminary in-patient results suggest that bisthianostat is a promising HDACi drug with a comparable safety window in R/R MM, supporting for its further phase 1b clinical trial in combination with traditional MM therapies.

scholarly journals Shortened platelet half-life in multiple myeloma

Blood ◽  
1986 ◽  
Vol 68 (2) ◽  
pp. 514-520
Author(s):  
E Fritz ◽  
H Ludwig ◽  
W Scheithauer ◽  
H Sinzinger
Keyword(s):  
Multiple Myeloma ◽  
Half Life ◽  
Serum Levels ◽  
Statistical Correlation ◽  
Control Group ◽  
Healthy Controls ◽  
Platelet Factor ◽  
Healthy Control

Various defects in platelet function have been reported as being associated with multiple myeloma. In 30 myeloma patients and 15 healthy controls, we investigated platelet survival using in vitro labeling of autologous platelets with 111indium-oxine and measuring the in vivo kinetics of the radioisotope. Significantly shortened platelet half- life in patients averaged 73 hours, while platelet half-life in the healthy controls averaged 107 hours. In myeloma patients, serum levels of thromboxane B2, beta-thromboglobulin, and platelet factor 4 were significantly elevated; aggregation indices were within the pathological range; platelet counts and spleen-liver indices, however, were comparable to those of the healthy control group. No statistical correlation was found between platelet half-life and paraprotein concentrations. Our findings suggest an initial--so far unexplained-- intravascular process of platelet activation and consumption that finally manifests in shortened platelet half-life. It seems that overt thrombocytopenia develops only when the compensatory capacity of the bone marrow finally becomes exhausted. Further studies should be able to elucidate the pathophysiologic processes involved.

Combined Fludarabine, Cyclophosphamide, and Alemtuzumab (FCC), an Active Regimen for Treated Patients with Chronic Lymphocytic Leukemia (CLL).

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3133-3133 ◽  
Author(s):  
Marco Montillo ◽  
Sara Miqueleiz ◽  
Alessandra Tedeschi ◽  
Francesca Ricci ◽  
Eleonora Vismara ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Residual Disease ◽  
Single Agent ◽  
Lymphocytic Leukemia ◽  
Combination Regimen ◽  
Synergistic Activity ◽  
Color Flow ◽  
Grade Iii

Abstract Fludarabine (F) in combination with cyclophosphamide (C) showed a relevant advantage over single-agent F in pts with relapsed CLL. Although minimal residual disease (MRD) remains detectable in many pts achieving CR, the combination of F and C seems to reduce MRD more efficiently. Still, pts in CR eventually relapse and require treatment, demonstrating the need for improved treatments able to further reduce or eliminate MRD and induce “better quality” and thus more durable responses. Alemtuzumab (CAM), anti-CD52 monoclonal antibody, acts synergistically with F in vitro and appears to have synergistic activity in vivo. Additionally, CAM is highly effective at clearing disease from bone marrow, the usual site of residual disease following purine analogue-based treatment. Therefore, we designed a phase II study to determine feasibility and efficacy, overall response rate (ORR)-duration of response-ability at clearing MRD, of a 4-weekly combination regimen consisting of F, C, and CAM (FCC). The study population is represented by pts with B-CLL with relapsed or refractory disease after at least one line of treatment. Subcutaneous route of administration of CAM has been adopted in this trial. MRD was measured by 4-color flow cytometry in the bone marrow. The FCC regimen consisted of F 40 mg/m2/d os (d 1–3), C 250 mg/m2/d os (d 1–3) and CAM 10 mg sc (d 1–3). This combination was repeated on d 29 for up to 6 cycles. The dose of CAM was increased after the first cohort of 10 treated pts from 10 mg to 20 mg sc. Currently, 25 pts have been enrolled in this trial. Median age was 57 years (range 42–79), 15/25 (60%) were male, 23/25 (92%) were in Binet stage B or C, median number of prior treatment regimens was 2 (range 1–4). In six (24%) pts 17p deletion was detected. IgVH unmutated was observed in 17 (68%) pts. At the moment of writing 19 pts are eligible for evaluation of toxicity and response. The ORR was 79%, with 7 (37%) pts achieving CR, 7 (37%) pts a PR, 1 (5%) pt a PRn. Three pts had SD, while 1 showed progression of the disease. MRD negativity was achieved in the bone marrow of 4/15 (27%) pts. Grade III-IV neutropenia episodes were observed in 43% of the administered courses while grade III-IV thrombocytopenia episodes were detected only in 8% of cycles. Four major infections were recorded: two sustained by Mycobacterium tuberculosis (1 cutis, 1 lung), one by Nocardia (lung) and one by E. coli (sepsis). The patient with pneumonia due to M. tuberculosis died because of respiratory failure. CMV reactivation occurred in 6 pts: no CMV disease was recorded. After a median follow up of 10 m (range 1–22) 73% of responding pts did not progressed. In conclusion, results from the interim analysis of this new, 4-weekly dosing FCC regimen suggest that combination therapy with F, C and CAM is feasible, safe, and effective in treating pts with relapsed and refractory CLL, even in those patients with inherent poor prognostic factors and who had received.

ANKHD1 Silencing Reduces In Vitro Clonogenicity and In Vivo Tumorogenicity Of Multiple Myeloma Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3168-3168
Author(s):  
Anamika Dhyani ◽  
João Agostinho Machado-Neto ◽  
Patricia Favaro ◽  
Sara Teresinha Olalla Saad
Keyword(s):  
Cell Cycle ◽  
Gene Therapy ◽  
Multiple Myeloma ◽  
Cell Lines ◽  
Tumor Size ◽  
Control Group ◽  
Mice Model ◽  
And Migration

Abstract Introduction ANKHD1 is a multiple ankyrin repeats containing protein, highly expressed in cancers, such as acute leukemia. Earlier studies showed that ANKHD1 is highly expressed and plays important role in proliferation and cell cycle progression of multiple myeloma (MM) cells. It was also observed that ANKHD1 downregulation modulates cell cycle gene expression and upregulates p21 irresepective of TP53 mutational status of MM cell lines. Objective The present study aimed to study the effect ofANKHD1 silencing on MM growth both in vitro (clonogenicity, migration) and in vivo (xenograft tumor mice model). The purpose was to investigate the feasibility of ANKHD1 gene therapy for MM. Methods In the present study, ANKHD1 expression was silenced using short hairpin RNA (shRNA)-lentiviral delivery vector in MM cell lines (U266 and MM1S). For control MM cells were tranduced by lentiviral shRNA against LacZ. Downregulation of ANKHD1 expression was confirmed by qPCR and Western blot. Colony formation capacity and migration of control and ANKHD1 silenced MM cells was determined by methylcellulose and transwell migration assays, respectively. For in vivo MM growth, NOD-SCID mice were divided in two groups injected with control and ANKHD1 silenced cells, separately. Mice were observed daily for tumor growth. Once the tumor size reached 1 mm3, mice in both groups were sacrificed and tumor was excised to measure tumor volume and weight. Results Corroborating the results obtained in our earlier studies, in the present study also inhibition of ANKHD1 expression suppressed growth of MM cells in vitro. MM cell lines tranduced with ANKHD1 shRNA showed significantly low number of colonies ten days after plating in methylcellulose medium as compared to control (p<0.05). Similarly, in transwell migration assay, cell lines transduced with ANKHD1 showed significantly less migration as in response to 10% FBS at lower chamber as compared to control group (p<0.05) in both the cell lines analyzed. Further in xenograft MM mice model, the growth of tumor was visibly suppressed in mice injected with ANKHD1 silenced cells compared to control group. There was significant difference in tumor size (volume) between these 2 groups (P< 0.006). The tumor weight of the inhibition group was 0.71 ±0.2 g, significantly lighter than those of the control group (1.211 ± 0.5 g, P =0.02) Conclusion Our data indicates ANKHD1 downregulation significantly inhibits colony-forming ability and migration of both glucocorticoid resistant (U266) and sensitive (MM1S) MM cells. Further, gene silencing of ANKHD1 also resulted in reduced in vivo tumor growth in NOD/SCID mice. Collectively, the result obtained indicates that ANKHD1 may be a target for gene therapy in MM. Disclosures: No relevant conflicts of interest to declare.

A Multicenter Phase II Study of Perifosine (KRX-0401) Alone and in Combination with Dexamethasone (Dex) for Patients with Relapsed or Relapsed/Refractory Multiple Myeloma (MM).

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3582-3582 ◽  
Author(s):  
Paul Richardson ◽  
S. Lonial ◽  
A. Jakubowiak ◽  
J. Wolf ◽  
A. Krishnan ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Adverse Events ◽  
Single Agent ◽  
Gene Array ◽  
In Vivo Studies ◽  
Cell Transplant ◽  
Prior Therapy ◽  
Grade 3

Abstract Perifosine is an oral, novel synthetic alkylphospholipid, with multiple effects on signal transduction pathways, including inhibition of Akt and activation of JNK. Preclinical in vitro studies showed that perifosine induces significant cytotoxicity in both multiple myeloma(MM) cell lines and patient MM cells resistant to conventional therapies, and augments dexamethasone(dex), doxorubicin, melphalan and bortezomib-induced MM cell cytotoxicity. In vivo studies showed significant antitumor activity in a human plasmacytoma mouse model. PhaseI studies in solid tumors have shown that perifosine is well tolerated at a dose of up to150mg daily, with responses also seen. We report preliminary results of a PhaseII trial of perifosine, alone and in combination with dex, in patients(pts) with relapsed or relapsed/refractory MM. Pts received 150mg of perifosine daily for a 21-day(d) cycle, and were assessed by serum and/or urine electrophoresis. Eligible pts had relapsed or relapsed/refractory MM with measurable disease. Pts were permitted bisphosphonate treatment. Concomitant steroids(prednisone>10 mg/d), serum creatinine of >3.0 mg/dL, and hemoglobin<8.0g/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 perifosine. Toxicities were assessed by NCI-CTCAE, v3.0. 40 pts (22 men and 18 women, median age 61 y, range 38–78) have been treated to date. All had relapsed/refractory MM, with a median of 4 lines of prior treatment (range 1–9). Prior therapy included dex(100%), thalidomide(100%), bortezomib(73%), lenalidomide(28%) and stem cell transplant(73%). Among 25 pts currently evaluable for response, best response(EBMT criteria) to single agent perifosine after≥2 cycles was stable disease(<25% reduction in M-protein) in 6 pts(24%). Dex was added in 15 of 25 pts with PD, with 9 pts evaluable for response on the combination: 3 pts(33%) achieved MR and 2(22%) pts achieved SD. The most common adverse events included nausea (45%, 3% grade 3); vomiting (40%); diarrhea(40%); fatigue(24%, 3% grade 3), and increased creatinine(55%, 11% grade 3/4 in the context of PD and light chain nephropathy). 2 pts had G3 neutropenia which resolved. Dose reduction(150 to 100 mgs/d) was required in 11 pts and 4 pts discontinued treatment due to adverse events. Attributable toxicities otherwise proved manageable with appropriate supportive care and perifosine was generally well tolerated, with no peripheral neuropathy or DVT seen. Perifosine as monotherapy and in combination with dex has activity in pts with advanced, relapsed/refractory MM, achieving MR and/or stabilization of disease in 55% 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. Future studies evaluate perifosine at other dosing schedules and in combination with other agents including bortezomib.

Efficacy of Panobinostat (LBH589) in Multiple Myeloma Cell Lines and In Vivo Mouse Model: Tumor-Specific Cytotoxicity and Protection of Bone Integrity in Multiple Myeloma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1510-1510 ◽  
Author(s):  
Joseph D. Growney ◽  
Peter Atadja ◽  
Wenlin Shao ◽  
Youzhen Wang ◽  
Minying Pu ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Bone Density ◽  
Mouse Model ◽  
Cortical Bone ◽  
Cell Lines ◽  
Single Agent ◽  
Synergistic Cytotoxicity

Abstract Panobinostat (LBH589) is a highly potent oral pan-deacetylase (DAC) inhibitor currently undergoing clinical development in hematologic and solid malignancies. Here we report the effects of panobinostat on multiple myeloma (MM) cells in vitro and in a murine xenograft model in vivo. Panobinostat exhibited potent cytotoxic activity (IC50 &lt;10 nM) against 8 MM cell lines (KMS-12PE, KMS-18, LP-1, NCI H929, KMS-11, RPMI8226, OPM-2, and U266). Panobinostat has been shown to affect signals involved in MM cell-cycle arrest and cell death, and to induce apoptosis via mitochondrial perturbation. In addition, panobinostat has been shown to selectively induce cell death of plasma cells isolated from MM patients without toxicity to normal lymphocytes or granulocytes. To investigate the effect of panobinostat in vivo, a disseminated luciferized MM.1S xenograft mouse model was treated with vehicle or panobinostat 15 mg/kg by intraperitoneal (i.p.) administration qd×5 for 3 weeks. Panobinostat treatment reduced the burden of MM.1S tumor cells to 22% treated over control (T/C) relative to vehicle-treated animals. In addition, MM.1S tumor-bearing mice treated with panobinostat displayed reduced trabecular and cortical bone damage relative to vehicle-treated animals. The mean ± SEM trabecular bone density and cortical bone density (% Bone Volume/Total Volume) of panobinostat-treated animals was 14.5% ± 2.0 and 98.1% ± 0.4, respectively, compared with 2.2% ± 0.3 and 89.1% ± 1.5 in vehicle-treated animals. In combination with the proteosome inhibitor bortezomib (BZ), panobinostat displayed significant synergistic cytotoxicity without additional toxicity to normal bone marrow stromal cells in vitro. In the MM.1S-luciferase tumor mouse model, combined treatment with panobinostat at 10 mg/kg i.p. qd×5 for 4 weeks and BZ at 0.2 mg/kg intravenously 1qw for 4 weeks reduced tumor burden to 7% T/C relative to vehicle, panobinostat alone (31% T/C), or BZ alone (44% T/C). Disease progression, measured as median time to endpoint (TTE) was improved from 37 to 54 days (P&lt;0.05) by panobinostat and to 46 days by BZ (P&lt;0.05). The combination treatment further improved clinical outcome relative to both single-agent treatment groups (P&lt;0.05), extending the TTE to 73 days. In contrast to BZ, the immunomodulatory drug thalidomide (TH) had no significant single-agent activity at 150 mg/kg p.o. qd for 4 weeks. However, combination activity (18% T/C) was observed when TH was combined with a sub-efficacious dose of panobinostat (5 mg/kg, 64% T/C). Combination of panobinostat and TH increased the TTE to 50 days, compared with 37.5, 43, and 39.5 days (P&lt;0.05), respectively, for the vehicle, panobinostat, or TH as single agents. These data demonstrate that panobinostat exhibits significant anti-proliferative and anti-tumor activities on MM cells both in vitro and in vivo. Panobinostat, as a single agent or in combination with BZ or TH, is a promising therapy for MM, and these studies may provide the rationale for clinical evaluation of panobinostat and BZ combination in the treatment of MM.

Combination of the mTOR inhibitor rapamycin and CC-5013 has synergistic activity in multiple myeloma

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4188-4193 ◽  
Author(s):  
Noopur Raje ◽  
Shaji Kumar ◽  
Teru Hideshima ◽  
Kenji Ishitsuka ◽  
Dharminder Chauhan ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Mtor Inhibitor ◽  
Mtor Inhibitors ◽  
Mitogen Activated Protein Kinase ◽  
Synergistic Activity ◽  
Growth And Survival ◽  
Mitogen Activated Protein ◽  
Induced Apoptosis

Abstract Previous studies have demonstrated the in vitro and in vivo activity of CC-5013 (Revlimid), an immunomodulatory analog (IMiD) of thalidomide, in multiple myeloma (MM). In the present study, we have examined the anti-MM activity of rapamycin (Rapamune), a specific mTOR inhibitor, combined with CC-5013. Based on the Chou-Talalay method, combination indices of less than 1 were obtained for all dose ranges of CC-5013 when combined with rapamycin, suggesting strong synergism. Importantly, this combination was able to overcome drug resistance when tested against MM cell lines resistant to conventional chemotherapy. Moreover, the combination, but not rapamycin alone, was able to overcome the growth advantage conferred on MM cells by interleukin-6 (IL-6), insulin-like growth factor-1 (IGF-1), or adherence to bone marrow stromal cells (BMSCs). Combining rapamycin and CC-5013 induced apoptosis of MM cells. Differential signaling cascades, including the mitogen-activated protein kinase (MAPK) and the phosphatidylinositol 3′-kinase/Akt kinase (PI3K/Akt) pathways, were targeted by these drugs individually and in combination, suggesting the molecular mechanism by which they interfere with MM growth and survival. These studies, therefore, provide the framework for clinical evaluation of mTOR inhibitors combined with IMiDs to improve patient outcome in MM.

scholarly journals DIPG-71. SELECTIVE HDAC INHIBITOR RG2833 INDUCES DIPG CELL DEATH VIA DOWNREGULATION OF THE NFĸB PATHWAY

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii300-iii301
Author(s):  
Katherine Barnett ◽  
Orlandi Novak ◽  
Charles Eberhart ◽  
Eric Raabe
Keyword(s):  
Cell Proliferation ◽  
Western Blot ◽  
Hdac Inhibitor ◽  
Single Agent ◽  
Diffuse Intrinsic Pontine Glioma ◽  
T Test ◽  
Growth And Survival ◽  
Histone 3

Abstract Histone deacetylase (HDAC) inhibitor panobinostat demonstrated activity against diffuse intrinsic pontine glioma (DIPG) in vitro, but its efficacy in vivo was limited by toxicity and poor blood brain barrier penetration. RG2833 (RGFP109) is a selective HDAC1/3 inhibitor that has established brain penetration. In clinical trials, the Cmax (plasma) of RG2833 was 32uM. RG2833 demonstrated cytotoxicity against temozolomide-resistant glioblastoma and downregulated the NFĸB pathway. Because this pathway is overexpressed in DIPG and may play a role in DIPG cell growth and survival, we hypothesized that RG2833 would kill DIPG cells. Treatment of DIPG cell lines with RG2833 as a single agent suppresses cell proliferation in the 5–10μM range (MTS assay for HSJD007 p=0.0004 10μM vs DMSO, JHH-DIPG1 p=0.001 10μM vs DMSO, SF-7761 p=0.04 10μM vs DMSO, SU-DIPG13 p=0.01 10μM vs DMSO by t-test). RG2833 induces apoptosis by 48 hours as measured by Western blot for cPARP and cleaved caspase 3 immunofluorescence (HSJD007 p&lt;0.003 8μM vs DMSO, JHH-DIPG1 p=0.0026 10μM vs DMSO by t-test). RG2833 also slows cell proliferation as measured by Western blot for pRb and immunofluorescence for BrdU (HSJD007 p=0.008 8μM vs DMSO, JHH-DIPG1 p=0.0002 10μM vs DMSO by t-test). Western blot confirmed a dose-dependent increase in histone 3 acetylation with RG2833 treatment at 5 hours. We detected increased acetylated p65 and decreased expression of the NFĸB regulated pro-survival genes BCL2, BCL-xL, and XIAP with RG2833 treatment. Together, this data shows that HDAC inhibitor RG2833 may be a promising therapeutic candidate for DIPG via downregulation of the NFĸB pathway.

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