Homoharringtonine inhibits the NOTCH/MYC pathway and exhibits antitumor effects in T-cell acute lymphoblastic leukemia.

ABSTRACT: We report on the antileukemic activity of homoharringtonine (HHT) in T-cell acute lymphoblastic leukemia (T-ALL). We showed that HHT inhibited the NOTCH/MYC pathway and induced significantly longer survival in mouse and patient-derived T-ALL xenograft models, supporting HHT as a promising agent for T-ALL.

Hainanolide inhibits the progression of colon cancer via inducing the cell cycle arrest, cell apoptosis and activation of the MAPK signaling pathway.

Hainanolide (HN) is a norditerpenoid metabolite extract from Cephalotaxus fortunei Hook. f. C. fortunei Hook. f. is renowned for the active alkaloids, such as harringtonine (HT) and homoharringtonin (HTT), which have been clinically used to treat chronic myeloid leukemia. Nowadays, diterpenoids, another important metabolite, attracted the attention of chemists. Among them, Hainanolide (HN), a cephalotane-type diterpenoid, has been proven to possess potent antitumor activities. However, the underlying therapeutic mechanisms of HN in anti-tumor have not been investigated yet. Our present study demonstrated that HN inhibited HCT-116 and HCT-15 cell proliferation in a dose- and time-dependent manner. Further studies demonstrated that HN can induce G2/M phase arrest and alter the Cdc25C/Cdc2/CyclinB1 proteins. Western blot indicated that HN promoted apoptosis by up-regulating Bax and down-regulated Bcl-2. And the caspase-3 and caspase-9 activities of HCT-116 and HCT-15 cells were increased. Transcriptome analysis is used to reveal the possible mechanism. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggested the genes were mainly enriched in the MAPK signaling pathway. Certainly, HN activates MAPK signaling pathway. In vivo, HN prevented the AOM/DSS-induced tumorigenesis of colon cancer in C57BL/6 mice. Our study indicated that HN inhibits the progression of colon cancer cells by blocking the cell cycle, inducing apoptosis, and activating the MAPK pathway. This study provides a theoretical and experimental scientific basis for future investigations of the antitumor effects of HN against colon cancer.

Final analysis of the efficacy and safety of omacetaxine mepesuccinate in patients with chronic- or accelerated-phase chronic myeloid leukemia: Results with 24 months of follow-up.

BACKGROUND: Omacetaxine, a protein synthesis inhibitor, is indicated in the United States for the treatment of patients with chronic-phase (CP) or accelerated-phase (AP) chronic myeloid leukemia (CML) with resistance and/or intolerance to 2 or more tyrosine kinase inhibitors. METHODS: The final analysis, with 24 months of follow-up, included additional efficacy and safety analyses to assess the benefit of long-term omacetaxine administration (1.25 mg/m(2) twice daily for 14 days every 28 days followed by 7 days every 28 days) in CP-CML and AP-CML patients receiving >3 cycles. RESULTS: Eighteen percent of CP-CML patients achieved a major cytogenetic response (MCyR) with a median duration of 12.5 months (95% confidence interval [CI], 3.5 months to not reached [NR]); responses were maintained for ≥12 months in 3 of 14 responders, and the median overall survival (OS) was 40.3 months (95% CI, 23.8 months to NR). Among patients with AP-CML, 14% achieved or maintained a major hematologic response for a median of 4.7 months (95% CI, 3.6 months to NR); MCyR was not achieved, and the median OS was 14.3 months (95% CI, 6.7-18.7 months). In patients with CP-CML and patients with AP-CML who received >3 cycles of treatment (n = 50 and n = 14, respectively), the median OS was 49.3 months (95% CI, 23.8 months to NR) and 24.6 months (95% CI, 12-37.2 months), respectively. Grade 3 or higher hematologic toxicities were the major side effects (79% and 73% for CP-CML and AP-CML, respectively), with discontinuation due to toxicity in 10% of CP patients and in 5% of AP patients. CONCLUSIONS: These results suggest that the long-term administration of omacetaxine is feasible with dose adjustments to manage toxicities and that omacetaxine provides a durable benefit for some patients.

Effects of changes in serum endostatin and fibroblast growth factor 19 on the chemotherapeutic sensitivity in acute myeloid leukemia patients.

The present study aimed to explore the changes in serum endostatin and fibroblast growth factor 19 (FGF-19) in acute myeloid leukemia patients, and to determine their effects on chemotherapeutic sensitivity. Sixty acute myeloid leukemia patients and 30 healthy controls were included in the study. Patient serum endostatin and FGF-19 levels were measured on admission, and then, standard chemotherapy was administered. The patients were divided into 2 groups according to chemotherapeutic effects: 21 patients in the chemotherapeutic sensitivity group (complete remission + partial remission) and 39 in the chemotherapeutic resistance group (no remission + degradation). A receiver operating characteristic (ROC) curve was used to analyze the relationship of serum endostatin and FGF-19 levels with chemotherapeutic sensitivity in acute myeloid leukemia patients. The levels of serum endostatin and FGF-19 in acute myeloid leukemia patients before chemotherapy were significantly higher than those in the control group. Moreover, these levels significantly decreased after chemotherapy (P < 0.01). The levels of serum endostatin and FGF-19 in the chemotherapeutic sensitivity group were lower than those in the chemotherapeutic resistance group, both before and after chemotherapy (P < 0.05 and P < 0.01, respectively). ROC curve analysis showed that the predictive values of endostatin and FGF-19 were good, and there was no significant difference between these results. In conclusion, serum endostatin and FGF-19 can be used as predictors of chemotherapeutic sensitivity for acute myeloid leukemia patients, and may be important for determining prognosis.

U.S. Food and Drug Administration approval summary: omacetaxine mepesuccinate as treatment for chronic myeloid leukemia.

On October 26, 2012, the U.S. Food and Drug Administration (FDA) granted accelerated approval to omacetaxine mepesuccinate (Synribo; Teva Pharmaceuticals USA, Inc., North Wales, PA, http://www.tevausa.com) for the treatment of adult patients with chronic phase (CP) or accelerated phase (AP) chronic myeloid leukemia (CML) with resistance and/or intolerance to two or more tyrosine kinase inhibitors (TKIs). The approval was based on the FDA review of data from 111 patients with CML in CP or in AP who had received two or more prior TKIs, including imatinib. Major cytogenetic response was achieved in 18% of patients with CP, with a median response duration of 12.5 months. Major hematologic response was achieved in 14% of patients with AP, with a median response duration of 4.7 months. The FDA safety evaluation was based on submitted data from 163 patients with CP or AP CML who had received at least one dose of omacetaxine mepesuccinate. The safety evaluation was limited by the single-arm design of the clinical trials as conducted in a small number of previously treated patients. The most common (≥20%) adverse reactions of any grade in enrolled patients included thrombocytopenia, anemia, neutropenia, diarrhea, nausea, fatigue, asthenia, injection site reaction, pyrexia, and infection. The FDA concluded that omacetaxine mepesuccinate has shown activity and a favorable benefit-to-risk profile for the studied population of adult patients with CML (CP or AP) with resistance and/or intolerance to two or more TKIs. Further evidence of response durability to verify clinical benefit is pending.

Homoharringtonine-based induction regimens for patients with de-novo acute myeloid leukaemia: a multicentre, open-label, randomised, controlled phase 3 trial.

BACKGROUND: Homoharringtonine-based induction regimens have been widely used in China for patients with acute myeloid leukaemia. However, their efficacy has not been tested in a multicentre randomised controlled trial in a large population. We assessed the efficacy and safety of homoharringtonine-based induction treatment for management of newly diagnosed acute myeloid leukaemia. METHODS: This open-label, randomised, controlled, phase 3 study was done in 17 institutions in China between September, 2007, and July, 2011. Untreated patients aged 14-59 years with acute myeloid leukaemia were randomly assigned (by a computer-generated allocation schedule without stratification) to receive one of three induction regimens in a 1:1:1 ratio: homoharringtonine 2 mg/m(2) per day on days 1-7, cytarabine 100 mg/m(2) per day on days 1-7, and aclarubicin 20 mg/day on days 1-7 (HAA); homoharringtonine 2 mg/m(2) per day on days 1-7, cytarabine 100 mg/m(2) per day on days 1-7, and daunorubicin 40 mg/m(2) per day on days 1-3 (HAD); or daunorubicin 40-45 mg/m(2) per day on days 1-3 and cytarabine 100 mg/m(2) per day on days 1-7 (DA). Patients in complete remission were offered two cycles of intermediate-dose cytarabine (2 g/m(2) every 12 h on days 1-3). The primary endpoints were the proportion of patients who achieved complete remission after two cycles of induction treatment and event-free survival in the intention-to-treat population. The trial is registered in the Chinese Clinical Trial Register, number ChiCTR-TRC-06000054. FINDINGS: We enrolled 620 patients, of whom 609 were included in the intention-to-treat analysis. 150 of 206 patients (73%) in the HAA group achieved complete remission versus 125 of 205 (61%) in the DA group (p=0.0108); 3-year event-free survival was 35.4% (95% CI 28.6-42.2) versus 23.1% (95% CI 17.4-29.3; p=0.0023). 133 of 198 patients (67%) in the HAD group had complete remission (vs DA, p=0·20) and 3-year event-free survival was 32.7% (95% CI 26.1-39.5; vs DA, p=0.08). Adverse events were much the same in all groups, except that more patients in the HAA (12 of 206 [5.8%]) and HAD (13 of 198 [6.6%]) groups died within 30 days than in the DA group (two of 205 [1%]; p=0.0067 vs HAA; p=0.0030 vs HAD). INTERPRETATION: A regimen of homoharringtonine, cytarabine, and aclarubicin is a treatment option for young, newly diagnosed patients with acute myeloid leukaemia. FUNDING: Chinese National High Tech Programme, Key Special Research Foundation of the Ministry of Science and Technology of China, National Nature Science Foundation of China, National Clinical Key Specialty Construction Project.

Phase 2 study of subcutaneous omacetaxine mepesuccinate for chronic-phase chronic myeloid leukemia patients resistant to or intolerant of tyrosine kinase inhibitors.

Omacetaxine mepesuccinate (omacetaxine) is a first-in-class cephalotaxine with a unique mode of action, independent of BCR-ABL, that has shown promising activity in patients with chronic myeloid leukemia (CML). This multicenter, noncomparative, open-label phase 2 study evaluated the efficacy and safety of subcutaneous omacetaxine in CML patients with resistance or intolerance to two or more tyrosine kinase inhibitors (TKIs); results in patients in chronic phase are reported here. Patients received subcutaneous omacetaxine 1.25 mg/m² twice daily days 1-14 every 28 days until hematologic response (up to a maximum of six cycles), then days 1-7 every 28 days as maintenance. Primary endpoints were rates of hematologic response lasting >8 weeks and major cytogenetic response (MCyR). Forty-six patients were enrolled: all had received imatinib, 83% had received dasatinib, and 57% nilotinib. A median 4.5 cycles of omacetaxine were administered (range, 1-36). Hematologic response was achieved or maintained in 31 patients (67%); median response duration was 7.0 months. Ten patients (22%) achieved MCyR, including 2 (4%) complete cytogenetic responses. Median progression-free survival was 7.0 months [95% confidence interval (CI), 5.9-8.9 months], and overall survival was 30.1 months (95% CI, 20.3 months-not reached). Grade 3/4 hematologic toxicity included thrombocytopenia (54%), neutropenia (48%), and anemia (33%). Nonhematologic adverse events were predominantly grade 1/2 and included diarrhea (44%), nausea (30%), fatigue (24%), pyrexia (20%), headache (20%), and asthenia (20%). Subcutaneous omacetaxine may offer clinical benefit to patients with chronic-phase CML with resistance or intolerance to multiple TKI therapies.

Over-expression of RPL23 in myelodysplastic syndromes is associated with apoptosis resistance of CD34+ cells and predicts poor prognosis and distinct response to CHG chemotherapy or decitabine.

Ribosomal protein (RP) L23 has been suggested to be a negative regulator of cell apoptosis. In the present study, we analyzed RPL23 expression in 169 patients with myelodysplastic syndrome (MDS) by using real-time PCR. The apoptosis of CD34(+) marrow cells was examined by flow cytometry, and the correlation between RPL23 expression levels and apoptosis in CD34(+) cells was assessed. We then analyzed the clinical significance of RPL23 expression for predicting disease progression and patient survival as well as therapeutic response in patients administered with a cytarabine, homoharringtonine, and G-CSF (CHG) regimen or decitabine therapy. Increased RPL23 expression was found in patients with higher-risk MDS than in patients with lower-risk disease (p = 0.004). RPL23 expression levels were found being inversely correlated with decreased apoptotic ratio of CD34(+) cells in higher-risk patients (r = -0.672, p < 0.001). Compared to patients with normal RPL23 expression levels, those with increased RPL23 expression presented higher rates of transformation to acute myeloid leukemia (p = 0.005) and reduced 2-year survival rates (p = 0.012). Multivariate regression analysis showed that RPL23 expression level was an independent predictor of prognosis, regardless of patient age, IPSS score, or hemoglobin level. Moreover, patients with RPL23 over-expression appeared to have lower response rates to CHG chemotherapy (p = 0.027) but similar response rates to decitabine treatment. In conclusion, the over-expression of RPL23 might confer apoptosis resistance in CD34(+) cells, which may lead to disease progression and adverse prognosis in MDS. Increased RPL23 expression was an inverse indicator for CHG regimen, but not for decitabine treatment.

Standard-dose imatinib plus low-dose homoharringtonine and granulocyte colony-stimulating factor is an effective induction therapy for patients with chronic myeloid leukemia in myeloid blast crisis who have failed prior single-agent therapy with imatinib.

We investigated the efficacy of the induction therapy involving granulocyte colony-stimulating factor (G-CSF) and low-dose homoharringtonine as well as standard-dose imatinib, which we called the G-CSF + homoharringtonine + imatinib (GHI) regimen, in patients with chronic myelogenous leukemia (CML) in blast crisis who have failed prior single-agent therapy with imatinib. Twelve patients were enrolled. The GHI regimen consisted in a unique induction course where imatinib was administered at 400 mg day(-1) until remission, together with homoharringtonine (1 mg/m(2) s.c. twice daily for 14 days every 28 days), and G-CSF, which was administered 1 day before chemotherapy (5 µg/kg s.c. daily). Patients who failed to obtain at least a partial hematologic response (PHR) after three courses were taken off study. Patients who responded to induction treatment and who had a matched donor received allogeneic hematopoietic stem cell transplantation (allo-HSCT). The results demonstrates that the GHI regimen re-induce hematologic responses or improve the cytogenetic responses in all evaluable patients. Furthermore, eligible patients have benefited from allo-HSCT after response to this induction treatment. We conclude that the GHI regimen may overcome disease-poor response to conventional doses of imatinib and this approach deserves further evaluation as frontline therapy for newly diagnosed CML.

Retrospective robustness of the continual reassessment method.

We study model sensitivity of the continual reassessment method (CRM). The context is that of dose-finding designs where certain design parameters are fixed by the investigator. Although our focus is on the CRM (O'Quigley et al., 1990), the essential ideas can be applied to any sequential dose-finding method. It is expected that different choices of a model family and particular parameterizations will have an impact on performance. Assuming that the constraints outlined in Shen and O'Quigley (1996) are respected, large sample performance is unaffected. However small sample performance will be affected by these choices, which are to some degree arbitrary. This work focuses on the retrospective robustness of the CRM in practice. The question is not of a general theoretical nature where, in the background, we would want to consider large numbers of true potential situations. Instead, the question is raised in the specific context of any actual completed study and is the following: Would we have come to the same conclusion concerning the MTD had we worked with a design specified differently? The sequential nature of the CRM means that this question cannot be answered in any definitive way. We can, though, by appealing to the retrospective CRM (O'Quigley, 2005), provide consistent estimates of the relationships between the MTD and the chosen model. If these estimates suggest that changes in different family model parameters will be accompanied by changes in final recommendation, then we would not be confident in the reliability of the estimated MTD and more work would be needed. Also, of course, at the planning stage, prospective robustness could be studied by simulating trials using particular models and parameterizations.

Intensive induction chemotherapy with regimen containing intermediate dose cytarabine in the treatment of de novo acute myeloid leukemia.

To improve long-term outcome of de novo acute myeloid leukemia (AML) patients by intermediate dose of cytarabine integrated in induction therapy and to explore the impact of cytogenetic abnormalities on the prognosis. Eighty-seven AML patients were treated with HAD regimen containing intermediate dose cytarabine (IDAra-C) as induction therapy, 83 from which with karyotype results were divided into three cytogenetic groups according to SWOG criteria. Complete remission (CR) rate, disease-free survival (DFS), and overall survival (OS) among different groups were evaluated. The CR rate of the 87 cases was 80/87 (92%). Median DFS and OS have not reached (NR). DFS rates at 1 and 3 years were 76.3% and 63.4%, respectively. OS rates at 1 and 3 years were 86.0% and 58.7%, respectively. According to SWOG criteria, CR rate, median DFS, and OS were 100%, NR and NR for the favorable group; 88.9%, NR, and 16 months for the intermediate group; 83.3%, 4.5 months, and 7.5 months for the adverse group. The differences among the three groups were statistically significant excepting for CR rate between adverse and intermediate groups. HAD regimen containing IDAra-C as induction chemotherapy regimen is effective in de novo AML of adult patients and can achieve higher CR rate and longer survival than standard dose of cytarabine (SDAra-C) regimen. Most of the patients were able to endure the therapy. Cytogenetics is still an important prognostic factor despite of the incorporation of IDAra-C in induction chemotherapy. The differences among the three groups were statistically significant. Am. J. Hematol., 2009. (c) 2009 Wiley-Liss, Inc.

Homoharringtonine affects the JAK2-STAT5 signal pathway through alteration of protein tyrosine kinase phosphorylation in acute myeloid leukemia cells.

OBJECTIVES: Homoharringtonine (HHT) was efficient in therapying patients with acute myeloid leukemia (AML) in China, but little is known about the mechanism of its action. As the abnormal activation of JAK2 associated pathway is important to AML, we try to explore the effect of HHT on JAK2-STAT pathway in AML cells, thus supplying theoretical basis for wider use of HHT. METHODS: The cell viability was tested by MTT. Apoptosis was tested by flow cytometry. RT-PCR was used to measure the expression of JAK2, STAT5 and the effect gene Bcl-xL. The signal proteins such as p-JAK2, p-STAT5, p-AKT, p-ERK activated by abnormal activated JAK2 were tested by Western blotting. RESULTS: HHT obviously inhibited the viability of primary AML cells and AML cell lines HEL, K562 and HL-60 cells, AnnexinV-PI double staining confirmed early apoptosis in a dose-dependent manner. In immunoblotting analysis, when AML cells were affected by HHT for 6 h (much ahead of the time when apoptosis could be induced). The expressions of p-JAK2, p-STAT5, and p-AKT were down-regulated, while the total JAK2, STAT5 and AKT protein levels were stable. There were no changes in p-ERK and BcL-xL proteins. When it prolonged to 24 h, Bcl-xL decreased obviously. Similar results were obtained by using JAK2 specific inhibitor AG490. CONCLUSIONS: HHT possibly acts as a broad-spectrum PTK inhibitor and inhibits the phosphorylation of the signal proteins caused by oncogenic proteins such as JAK2V617F, BCR/ABL, thus blocking the survival and proliferative signal pathway of malignant cells.

Omacetaxine mepesuccinate--a semisynthetic formulation of the natural antitumoral alkaloid homoharringtonine, for chronic myelocytic leukemia and other myeloid malignancies.

Homoharringtonine (HHT), a natural alkaloid extracted from various Cephalotaxus species, exerts its antitumoral and anti-angiogenic activity through an inhibition of protein synthesis and the promotion of apoptosis. ChemGenex Pharmaceuticals Ltd, in collaboration with Stragen Group, is developing omacetaxine mepesuccinate, a semisynthetic formulation of HHT, as a potential treatment for chronic myelocytic leukemia (CML), myelodysplastic syndrome (MDS) and acute myelogenous leukemia (AML). In preclinical studies, omacetaxine mepesuccinate induced apoptosis in leukemia cell lines. Results from phase II clinical trials revealed omacetaxine mepesuccinate to be active in patients with CML that was resistant to tyrosine kinase inhibitor (TKI) therapy, including those patients who carry the BCR-ABL1T315I mutation, which is highly insensitive to the TKIs imatinib, nilotinib and dasatinib; the therapeutic was also generally well tolerated. Phase II and III clinical trials are underway to assess the activity of omacetaxine mepesuccinate, either alone or in combination with TKIs or other cytotoxic drugs, in patients with CML that is resistant to TKI therapy. Phase I and II clinical trials for omacetaxine mepesuccinate in the treatment of AML and MDS are also ongoing; intravenous, subcutaneous and oral formulations of the drug are being developed. Omacetaxine mepesuccinate appears to hold potential for the treatment of CML and, in particular, imatinib-resistant CML; the development of alternative formulations of the therapeutic further expands the potential for success in drug development.

Efficacy of common salvage chemotherapy regimens in patients with refractory or relapsed acute myeloid leukemia: A retrospective cohort study.

To assess treatment response and overall survival (OS) in refractory or relapsed acute myeloid leukemia (R/R AML) patients treated by different common salvage chemotherapy regimens.Medical records data from 142 R/R AML patients were reviewed in this retrospective study. Patients were treated with regimens based on the following drugs: cytarabine, granulocyte colony-stimulating factor (G-CSF), and fludarabine (FLAG) (n = 46); cytarabine and G-CSF in addition to aclarubicin or daunorubicin (CAG/DAG) (n = 30); cytarabine, G-CSF, and cladribine (CLAG) (n = 27); cytarabine, etoposide, and mitoxantrone (MEA) (n = 17); cytarabine plus idarubicin, daunorubicin, or mitoxantrone (IA/DA/MA) (n = 12); and homoharringtonine, cytarabine, and aclarubicin or daunorubicin (HAA/HAD) (n = 10).A total of 43 (35.2%) patients achieved complete remission (CR), 60 (49.2%) patients achieved overall remission rate (ORR), and 18 (14.8%) patients received allogeneic hematopoietic stem cell transplantation (allo-HSCT) after CR. Median OS was 8.0 (95% CI 6.6-9.4) months with a 1-year OS rate of (29.9 ±â€Š3.9)% and 3-year OS rate of (11.1 ±â€Š3.6)%. No difference of CR (P = .621), ORR (P = .385), and allo-HSCT (P = .537) achievement was observed among different chemotherapy regimens. Interestingly, we observed that the CLAG-based regimen did not affect CR (P = .165), while it achieved a numerically higher ORR (P = .093) and was an independent factor for prolonged OS (P = .016). No other regimens were determined to be correlated with CR, ORR, or OS.FLAG-, CAG/DAG-, CLAG-, MEA-, IA/DA/MA- and HAA/HAD-based regimens were found to achieve similar CR rates, while the CLAG-based regimen achieved numerically higher ORR rates and significant favorable OS. Therefore, CLAG-based regimens should be a prioritized treatment option for R/R AML patients.

[Research Progress of Homoharringtonine Effect on IM-resistant Chronic Myelogenous Leukemia -Review].

Homoharringtonine(HHT) is an alkaloid with anti-tumor activity, having a good therapeutic effect on chronic myeloid leukemia(CML), and its toxicity is much lower than other anti-cancer drugs. However, the remarkable therapeutic efficacy of imatinib on CML treatment made HHT to be forgotten gradually. Today, the omacetaxine mepesuccinate, a semisynthetic form of HHT, display a good clinical response to TKI-resistant CML patients. Therefore, the HHT again attracts more attention from the medical field. Here, the clinical effects of HHT on IM-resistant CML patients and its mechanism are briefly reviewed.

Homoharringtonine enhances bortezomib antimyeloma activity in myeloma cells adhesion to bone marrow stromal cells and in SCID mouse xenografts.

Despite the great progress in the treatment, multiple myeloma (MM) still remains incurable. Bortezomib (BTZ), a reversible inhibitor of the 26S proteasome, is very effective against MM but unable to eradicate the MM cells in bone marrow niche eventually causing the disease relapse. Homoharringtonine (HHT) is a known anti-leukemia drug that inhibits MM both in vitro and in vivo. This study aimed to investigate whether HHT could potentiate the anti-tumor activity of BTZ in MM cells cocultured with bone marrow stromal cells and in vivo xenograft models. We found that coculture of myeloma cells with a human stroma cell line significantly decreased the sensitivity of myeloma cells to BTZ treatment. HHT inhibited the proliferation of MM cells and potentiated the anti-myeloma effects of BTZ by inhibition of both canonical and noncanonical NF-κB pathways. HHT also enhanced the anti-myeloma effect of BTZ in vivo xenograft models. Taken together, our data suggest that HHT can enhance the anti-myeloma activity of BTZ both in vitro and in vivo, which may represent a new clinical treatment in MM.