Adding Cyclophosphamide to Bortezomib and Dexamethasone was not Associated With Improved Outcomes of Patients With Newly Diagnosed Light Chain Amyloidosis: A Retrospective Study.

INTRODUCTION: Before 2021, the combination of bortezomib, cyclophosphamide, and dexamethasone (VCd) was one of the most used upfront therapy for systemic immunoglobulin light chain (AL) amyloidosis. Recently, daratumumab in combination with VCd resulted in improved outcomes compared to VCd. However, it's still unclear the role of cyclophosphamide in this combination. MATERIALS AND METHODS: We conducted this retrospective single-institutional study to compare the outcomes of upfront bortezomib and dexamethasone with or without cyclophosphamide (VD vs. VCd). RESULTS: Of 136 total patients, 62 received VD and 74 received VCd. The median age was 64 and the median number of organs involved was 2. Hematologic response was achieved among 73.4% patients in the VD arm and 85.9% in the VCd arm at 3 months (P = .15). Best organ response was not different between 2 arms (34.1% vs. 52.9% for VD and VCd arms, respectively; P = .28). After a median follow-up of 24.4 months, 2-year OS for VD and VCd arm was 70.6% and 84.6% respectively. The median overall survival was 70 months for VD arm and not reached for VCd arm (P = .30). There was no statistically significant difference in median time to next therapy (9.3 vs. 13.5 months for VD and VCd arms, respectively. P = .99). CONCLUSION: the addition of cyclophosphamide to VD was not associated with improved outcomes of patients with AL amyloidosis in this retrospective study.

Therapeutic Targeting of Protein Disulfide Isomerase PDIA1 in Multiple Myeloma.

Multiple myeloma is a genetically complex hematologic neoplasia in which malignant plasma cells constantly operate at the maximum limit of their unfolded protein response (UPR) due to a high secretory burden of immunoglobulins and cytokines. The endoplasmic reticulum (ER) resident protein disulfide isomerase, PDIA1 is indispensable for maintaining structural integrity of cysteine-rich antibodies and cytokines that require accurate intramolecular disulfide bond arrangement. PDIA1 expression analysis from RNA-seq of multiple myeloma patients demonstrated an inverse relationship with survival in relapsed or refractory disease, supporting its critical role in myeloma persistence. Using a structure-guided medicinal chemistry approach, we developed a potent, orally bioavailable small molecule PDIA1 inhibitor CCF642-34. The inhibition of PDIA1 overwhelms the UPR in myeloma cells, resulting in their apoptotic cell death at doses that do not affect the normal CD34+ hematopoietic stem and progenitor cells. Bortezomib resistance leads to increased PDIA1 expression and thus CCF642-34 sensitivity, suggesting that proteasome inhibitor resistance leads to PDIA1 dependence for proteostasis and survival. CCF642-34 induces acute unresolvable UPR in myeloma cells, and oral treatment increased survival of mice in the syngeneic 5TGM1 model of myeloma. Results support development of CCF642-34 to selectively target the plasma cell program and overcome the treatment-refractory state in myeloma.

DNA methylation inhibition in myeloma: Experience from a phase 1b study of low-dose continuous azacitidine in combination with lenalidomide and low-dose dexamethasone in relapsed or refractory multiple myeloma.

The DNA methyltransferase inhibitor azacytidine (aza) may reactivate pathways associated with plasma cell differentiation, cell cycle control, apoptosis, and immune recognition and thereby restore sensitivity to lenalidomide (len) and dexamethasone (dex) in relapsed and/or refractory multiple myeloma (RRMM). We aimed to develop an aza regimen that reaches epigenetically active levels 8 times in 28 days with less bone marrow toxicity than the myeloid malignancy standard of 7 consecutive doses to enable safe combination with len. Aza was escalated from 30 mg/m2 once a week up to a predefined maximum of 50 mg/m2 twice a week in combination with GFR-adjusted len (≥ 60 mL/min: 25 mg, 3059 mL/min: 10 mg) day 1 to 21 every 28 days and dex 40 mg once a week followed by a limited expansion study to a total N of 23 at the highest tolerated dose. Fifty-one patients (pts) with RRMM were screened, 42 were treated and 41 were evaluable for response based on at least 1 response assessment or progression after treatment start. The median number of prior lines of therapy was 5 (1-11) and 81% (34) were refractory to len and/or pomalidomide (pom). Two DLTs occurred in different cohorts, 1 neutropenic fever in 1/6 pts on the aza 40 mg/m2 twice a week GFR ≥ 60 mL/min cohort and 1 GGT elevation in 1/6 pts on the aza 50 mg/m2 GFR 30-59 mL/min cohort. An MTD was not reached and aza 50 mg/m2 SC twice a week was chosen for the expansion study. At least possibly related Grade 3/4 AEs occurred in 28 pts (67%) with the following in > 1 pt: neutropenia (N = 16, 38%), anemia (N = 6, 14%), lymphopenia (N = 5, 12%), thrombocytopenia (N = 4, 10%), leukopenia (N = 4, 10%), febrile neutropenia (N = 4, 10%), fatigue (N = 3, 7%), fever (N = 2, 5%), and infection (N = 2, 5%). At a median follow up time for alive pts of 60.2 months (range: 36.1-82.5 months), the overall response rate (≥ partial response) and clinical benefit response rate (≥ minor response) was 22 and 32%, respectively, with 4 very good partial responses (10%), 5 partial responses (12%), and 4 minor responses (10%). The median PFS was 3.1 months (95% confidence interval [CI]: 2.1-5.1 months), median TTP 2.7 months (95% CI: 2.1-7.5 months), and median OS 18.6 months (95% CI: 12.9-33.0 months). Achieving at least minor response and reaching TTP > 6 months was associated with approximately 35% lower median plasma levels of the enzyme that inactivates aza, plasma cytidine deaminase (CDA, P< .0001). Two of the len refractory pts achieved longer disease control than with any prior regimen and 1 responded immediately after progression on len, bortezomib, and prednisone. Analyses of the methylation state of over 480,000 CpG sites in purified myeloma cells at screening were possible in 11 pts and on day 28 in 8 of them. As in other studies, the majority of differentially methylated CpGs compared to normal plasma cells were hypomethylated in myeloma. Treatment decreased the number of CpGs that were differentially methylated in normal plasma cells by > 0.5% in 6 and by > 5% in 3 of the 8 pts, most pronounced in 2 pts with clinically convincing aza contribution who achieved a reduction in overall differentially methylated CpGs by 23 and 68%, respectively, associated with increased expression of immunoglobulin genes. The study demonstrated tolerability of twice a week SC aza at 50 mg/m2 with len and dex in RRMM and suggested aza may help overcome the len/pom refractory state, possibly by activating differentiation pathways. Relatively low response rates and association of clinical benefit with low plasma levels of the aza inactivating enzyme CDA suggest the aza regimen will need to be optimized further and pt selection may be required to maximize benefit.

Longer term follow-up of the randomized phase III trial SWOG S0777: bortezomib, lenalidomide and dexamethasone vs. lenalidomide and dexamethasone in patients (Pts) with previously untreated multiple myeloma without an intent for immediate autologous stem cell transplant (ASCT).

SWOG S0777, a randomized phase III trial, compared bortezomib, lenalidomide and dexamethasone (VRd) with lenalidomide and dexamethasone (Rd). This updated analysis includes 460 patients evaluable for survival endpoints: 225 eligible and analyzable patients were randomized to Rd and 235 to VRd. The 6-month induction was six 28-day cycles of Rd and eight 21-day cycles of VRd followed by Rd maintenance for all patients. Median follow up is 84 months. Median PFS is 41 months for VRd and 29 months for Rd: stratified hazard ratio (96% Wald Confidence Interval) was 0.742 (0.594, 0.928) and one-sided stratified log-rank P-value 0.003. Median OS for VRd is still not reached with median OS for Rd being 69 months: stratified hazard ratio (96% Wald Confidence Interval) was 0.709 (0.543, 0.926) and stratified two-sided P-value was 0.0114. Both PFS and OS were improved with VRd versus Rd adjusting for age (P-values: 0.013 [PFS]; 0.033 [OS])). Median duration of Rd maintenance was 17.1 months. The addition of bortezomib to lenalidomide dexamethasone for induction therapy results in a statistically significant and clinically meaningful improvement in PFS as well as better OS. VRd continues to represent an appropriate standard of care irrespective of age.

Targeting the MALAT1/PARP1/LIG3 complex induces DNA damage and apoptosis in multiple myeloma.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a highly conserved long non-coding RNA (lncRNA). Overexpression of MALAT1 has been demonstrated to related to poor prognosis of multiple myeloma (MM) patients. Here, we demonstrated that MALAT1 plays important roles in MM DNA repair and cell death. We found bone marrow plasma cells from patients with monoclonal gammopathy of undetermined significance (MGUS) and MM express elevated MALAT1 and involve in alternative non-homozygous end joining (A-NHEJ) pathway by binding to PARP1 and LIG3, two key components of the A-NHEJ protein complex. Degradation of the MALAT1 RNA by RNase H using antisense gapmer DNA oligos in MM cells stimulated poly-ADP-ribosylation of nuclear proteins, defected the DNA repair pathway, and further provoked apoptotic pathways. Anti-MALAT1 therapy combined with PARP1 inhibitor or proteasome inhibitor in MM cells showed a synergistic effect in vitro. Furthermore, using novel single-wall carbon nanotube (SWCNT) conjugated with anti-MALAT1 oligos, we successfully knocked-down MALAT1 RNA in cultured MM cell lines and xenograft murine models. Most importantly, anti-MALAT1 therapy induced DNA damage and cell apoptosis in vivo, indicating that MALAT1 could serve as a potential novel therapeutic target for MM treatment.

Neuropathy and efficacy of once weekly subcutaneous bortezomib in multiple myeloma and light chain (AL) amyloidosis.

INTRODUCTION: Randomized studies have shown that bortezomib (BTZ) can be given weekly via intravenous (IV) route or twice weekly via subcutaneous (SC) route with lower neuropathy risk and no loss of anti-myeloma efficacy compared to original standard IV twice weekly schedule. Weekly SC should therefore yield the best therapeutic index and is widely used but has not been compared to established administration schedules in the context of a clinical trial. METHODS: Comprehensive electronic medical record review was done for disease control and neuropathy symptoms of 344 consecutive patients who received their first BTZ-containing regimen for myeloma or AL amyloidosis before or after we changed to SC weekly in December 2010. Univariate and multivariable analyses were carried out that adjusted for age, underlying disease, concurrently used anticancer agents, underlying conditions predisposing to neuropathy, and number of prior regimens compared SC weekly to other schedules. RESULTS: Fifty-three patients received BTZ SC weekly, 17 SC twice weekly, 127 IV weekly and 147 IV twice weekly. Risk for neuropathy of any grade was higher with other schedules compared to SC weekly (44.3% vs. 26.9%, p = 0.001) while response rate was similar (72.1% vs. 76.6%, respectively, p = 0.15). Multivariable analyses upheld higher neuropathy risk (Odds ratio 2.45, 95% CI 1.26-4.76, p = 0.008) while the likelihood of not achieving a response (= partial response or better) was comparable (Odds ratio 1.25, 95% CI 0.58-2.71, p = 0.56) for other schedules compared to SC weekly, respectively. Lower neuropathy risk translated into longer treatment duration when BTZ was started SC weekly (p = 0.001). CONCLUSIONS: Weekly SC BTZ has activity comparable to other schedules and causes low rates of neuropathy.

Multiple Myeloma, Version 3.2017, NCCN Clinical Practice Guidelines in Oncology.

Multiple myeloma (MM) is caused by the neoplastic proliferation of plasma cells. These neoplastic plasma cells proliferate and produce monoclonal immunoglobulin in the bone marrow causing skeletal damage, a hallmark of multiple myeloma. Other MM-related complications include hypercalcemia, renal insufficiency, anemia, and infections. The NCCN Multiple Myeloma Panel members have developed guidelines for the management of patients with various plasma cell dyscrasias, including solitary plasmacytoma, smoldering myeloma, multiple myeloma, systemic light chain amyloidosis, and Waldenström's macroglobulinemia. The recommendations specific to the diagnosis and treatment of patients with newly diagnosed MM are discussed in this article.

Bortezomib with lenalidomide and dexamethasone versus lenalidomide and dexamethasone alone in patients with newly diagnosed myeloma without intent for immediate autologous stem-cell transplant (SWOG S0777): a randomised, open-label, phase 3 trial.

BACKGROUND: Lenalidomide plus dexamethasone is a reference treatment for patients with newly diagnosed myeloma. The combination of the proteasome inhibitor bortezomib with lenalidomide and dexamethasone has shown significant efficacy in the setting of newly diagnosed myeloma. We aimed to study whether the addition of bortezomib to lenalidomide and dexamethasone would improve progression-free survival and provide better response rates in patients with previously untreated multiple myeloma who were not planned for immediate autologous stem-cell transplant. METHODS: In this randomised, open-label, phase 3 trial, we recruited patients with newly diagnosed multiple myeloma aged 18 years and older from participating Southwest Oncology Group (SWOG) and National Clinical Trial Network (NCTN) institutions (both inpatient and outpatient settings). Key inclusion criteria were presence of CRAB (C=calcium elevation; R=renal impairment; A=anaemia; B=bone involvement) criteria with measurable disease (measured by assessment of free light chains), Eastern Cooperative Oncology Group (ECOG) performance status of 0-3, haemoglobin concentration 9 g/dL or higher, absolute neutrophil count 1 × 103 cells per mm3 or higher, and a platelet count of 80 000/mm3 or higher. We randomly assigned (1:1) patients to receive either an initial treatment of bortezomib with lenalidomide and dexamethasone (VRd group) or lenalidomide and dexamethasone alone (Rd group). Randomisation was stratified based on International Staging System stage (I, II, or III) and intent to transplant (yes vs no). The VRd regimen was given as eight 21-day cycles. Bortezomib was given at 1·3 mg/m2 intravenously on days 1, 4, 8, and 11, combined with oral lenalidomide 25 mg daily on days 1-14 plus oral dexamethasone 20 mg daily on days 1, 2, 4, 5, 8, 9, 11, and 12. The Rd regimen was given as six 28-day cycles. The standard Rd regimen consisted of 25 mg oral lenalidomide once a day for days 1-21 plus 40 mg oral dexamethasone once a day on days 1, 8, 15, and 22. The primary endpoint was progression-free survival using a prespecified one-sided stratified log rank test at a significance level of 0·02. Analyses were intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00644228. FINDINGS: Between April, 2008, and February, 2012, we randomly assigned 525 patients at 139 participating institutions (264 to VRd and 261 to Rd). In the randomly assigned patients, 21 patients in the VRd group and 31 in the Rd group were deemed ineligible based mainly on missing, insufficient, or early or late baseline laboratory data. Median progression-free survival was significantly improved in the VRd group (43 months vs 30 months in the Rd group; stratified hazard ratio [HR] 0·712, 96% CI 0·56-0·906; one-sided p value 0·0018). The median overall survival was also significantly improved in the VRd group (75 months vs 64 months in the Rd group, HR 0·709, 95% CI 0·524-0·959; two-sided p value 0·025). The rates of overall response (partial response or better) were 82% (176/216) in the VRd group and 72% (153/214) in the Rd group, and 16% (34/216) and 8% (18/214) of patients who were assessable for response in these respective groups had a complete response or better. Adverse events of grade 3 or higher were reported in 198 (82%) of 241 patients in the VRd group and 169 (75%) of 226 patients in the Rd group; 55 (23%) and 22 (10%) patients discontinued induction treatment because of adverse events, respectively. There were no treatment-related deaths in the Rd group, and two in the VRd group. INTERPRETATION: In patients with newly diagnosed myeloma, the addition of bortezomib to lenalidomide and dexamethasone resulted in significantly improved progression-free and overall survival and had an acceptable risk-benefit profile. FUNDING: NIH, NCI, NCTN, Millennium Pharmaceuticals, Takeda Oncology Company, and Celgene Corporation.

Microarray-based analysis and clinical validation identify ubiquitin-conjugating enzyme E2E1 (UBE2E1) as a prognostic factor in acute myeloid leukemia.

BACKGROUND: Previous research suggested that single gene expression might be correlated with acute myeloid leukemia (AML) survival. Therefore, we conducted a systematical analysis for AML prognostic gene expressions. METHODS: We performed a microarray-based analysis for correlations between gene expression and adult AML overall survival (OS) using datasets GSE12417 and GSE8970. Positive findings were validated in an independent cohort of 50 newly diagnosed, non-acute promyelocytic leukemia (APL) AML patients by quantitative RT-PCR and survival analysis. RESULTS: Microarray-based analysis suggested that expression of eight genes was each associated with 1-year and 3-year AML OS in both GSE12417 and GSE8970 datasets (p < 0.05). Next, we validated our findings in an independent cohort of AML samples collected in our hospital. We found that ubiquitin-conjugating enzyme E2E1 (UBE2E1) expression was adversely correlated with AML survival (p = 0.04). Multivariable analysis showed that UBE2E1 high patients had a significant shorter OS and shorter progression-free survival after adjusting other known prognostic factors (p = 0.03). At last, we found that UBE2E1 expression was negatively correlated with patients' response to induction chemotherapy (p < 0.05). CONCLUSIONS: In summary, we demonstrated that UBE2E1 expression was a novel prognostic factor in adult, non-APL AML patients.

Role of Myeloma-Derived MIF in Myeloma Cell Adhesion to Bone Marrow and Chemotherapy Response.

BACKGROUND: Multiple myeloma (MM) remains an incurable cancer characterized by accumulation of malignant plasma cells in the bone marrow (BM). The mechanism underlying MM homing to BM is poorly elucidated. METHODS: The clinical significance of migration inhibitory factor (MIF) expression was examined by analyzing six independent gene expression profile databases of primary MM cells using the Student's t test and Kaplan-Meier test. Enzyme-linked immunosorbent assay was used to examine MIF expression. In vivo bioluminescent imaging was used to determine MM cell localization and treatment efficacy in human MM xenograft mouse models, with three to four mice per group. MM cell attachment to BM stromal cells (BMSCs) was monitored by cell adhesion assay. MIF regulation of the expression of adhesion molecules was determined by chromatin immunoprecipitation (ChIP) assay. Statistical tests were two-sided. RESULTS: High levels of MIF were detected in MM BM (MIF level in BM plasma: healthy = 10.72 ± 5.788 ng/mL, n = 5; MM = 1811 ± 248.7 ng/mL, n = 10; P < .001) and associated with poor survival of patients (Kaplan-Meier test for MM OS: 87 MIF(high) patients, 86 MIF(low) patients, P = .02). Knocking down MIF impaired MM cell adhesion to BMSCs in vitro and led to formation of extramedullary tumors in SCID mice. MIF acted through surface receptor CXCR4 and adaptor COPS5 to regulate the expression of adhesion molecules ALCAM, ITGAV, and ITGB5 on MM cells. More importantly, MIF-deficient MM cells were sensitive to chemotherapy in vitro when cocultured with BMSCs and in vivo. MIF inhibitor 4-IPP sensitized MM cells to chemotherapy. CONCLUSIONS: MIF is an important player and a novel therapeutic target in MM. Inhibiting MIF activity will sensitize MM cells to chemotherapy.

Novel Protein Disulfide Isomerase Inhibitor with Anticancer Activity in Multiple Myeloma.

Multiple myeloma cells secrete more disulfide bond-rich proteins than any other mammalian cell. Thus, inhibition of protein disulfide isomerases (PDI) required for protein folding in the endoplasmic reticulum (ER) should increase ER stress beyond repair in this incurable cancer. Here, we report the mechanistically unbiased discovery of a novel PDI-inhibiting compound with antimyeloma activity. We screened a 30,355 small-molecule library using a multilayered multiple myeloma cell-based cytotoxicity assay that modeled disease niche, normal liver, kidney, and bone marrow. CCF642, a bone marrow-sparing compound, exhibited a submicromolar IC50 in 10 of 10 multiple myeloma cell lines. An active biotinylated analog of CCF642 defined binding to the PDI isoenzymes A1, A3, and A4 in MM cells. In vitro, CCF642 inhibited PDI reductase activity about 100-fold more potently than the structurally distinct established inhibitors PACMA 31 and LOC14. Computational modeling suggested a novel covalent binding mode in active-site CGHCK motifs. Remarkably, without any further chemistry optimization, CCF642 displayed potent efficacy in an aggressive syngeneic mouse model of multiple myeloma and prolonged the lifespan of C57BL/KaLwRij mice engrafted with 5TGM1-luc myeloma, an effect comparable to the first-line multiple myeloma therapeutic bortezomib. Consistent with PDI inhibition, CCF642 caused acute ER stress in multiple myeloma cells accompanied by apoptosis-inducing calcium release. Overall, our results provide an illustration of the utility of simple in vivo simulations as part of a drug discovery effort, along with a sound preclinical rationale to develop a new small-molecule therapeutic to treat multiple myeloma. Cancer Res; 76(11); 3340-50. ©2016 AACR.

NCCN Guidelines Insights: Multiple Myeloma, Version 3.2016.

These NCCN Guidelines Insights highlight the important updates/changes specific to the 2016 version of the NCCN Clinical Practice Guidelines in Oncology for Multiple Myeloma. These changes include updated recommendations to the overall management of multiple myeloma from diagnosis and staging to new treatment options.

Structural optimization of non-nucleoside DNA methyltransferase inhibitor as anti-cancer agent.

Inhibition of DNA methyltransferase 1 (DNMT1) can reverse the malignant behavior of cancer cells by restoring expression of aberrantly silenced genes that are required for differentiation, senescence, and apoptosis. Clinically used DNMT1 inhibitors decitabine and azacitidine inhibit their target by covalent trapping after incorporation into DNA as azacytidine analogs. These nucleoside compounds are prone to rapid enzymatic inactivation in blood, posing challenges to the development of purely epigenetic dosing schedules. Non-nucleoside compounds that suppress expression or function of DNMT1 may overcome this problem. Using a high-throughput PCR-based site specific chromatin condensation assay, we identified a compound that reactivated Cyclin-Dependent Kinase Inhibitor 2A (CDKN2A) in myeloma cells and suppressed expression of DNMT1 from a library of 5120 chemically diverse small molecules. Lead optimization was performed to generate 26 new analogs with lung cancer proliferation and DNMT1 expression as activity readout. Two of the new derivatives showed 2 fold improvement of growth inhibiting potency and also decreased DNMT1 protein levels in lung cancer cells.

Phase I Study of Anti-GM2 Ganglioside Monoclonal Antibody BIW-8962 as Monotherapy in Patients with Previously Treated Multiple Myeloma.

INTRODUCTION: BIW-8962 is a monoclonal antibody to GM2 ganglioside that shows preclinical activity towards multiple myeloma (MM) cell lines and in animal models bearing MM xenografts. The objective of this study was to determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, potential immunogenicity, and preliminary clinical efficacy of BIW-8962 in patients with heavily pretreated MM. METHODS: Patients (n = 23) received escalating doses of BIW-8962 (0.03-3 mg/kg) intravenously every 2 weeks in phase Ia. The highest anticipated dose (10 mg/kg) was not tested and the study was discontinued without proceeding to phases Ib and II. RESULTS: The MTD of BIW-8962 was not established and BIW-8962 was relatively well tolerated. No pattern of consistent toxicity could be inferred from treatment-related AEs grade ≥3 and only two dose-limiting toxicities were recorded (atrial thrombosis + cardiomyopathy and chest pain, respectively). In the efficacy evaluable population (n = 22), no patient had a response (complete or partial) and 16 (72.7%) had a best response of stable disease, which was generally not durable. CONCLUSION: BIW-8962 did not show evidence of clinical activity. The study was therefore stopped and further development of BIW-8962 in MM was halted. FUNDING: This work was funded by Kyowa Kirin Pharmaceutical Development, Inc. TRIAL REGISTERED: ClinicalTrials.gov identifier, NCT00775502.

A synthetic peptide targeting the BH4 domain of Bcl-2 induces apoptosis in multiple myeloma and follicular lymphoma cells alone or in combination with agents targeting the BH3-binding pocket of Bcl-2.

Bcl-2 inhibits apoptosis by two distinct mechanisms but only one is targeted to treat Bcl-2-positive malignancies. In this mechanism, the BH1-3 domains of Bcl-2 form a hydrophobic pocket, binding and inhibiting pro-apoptotic proteins, including Bim. In the other mechanism, the BH4 domain mediates interaction of Bcl-2 with inositol 1,4, 5-trisphosphate receptors (IP3Rs), inhibiting pro-apoptotic Ca2+ signals. The current anti-Bcl-2 agents, ABT-263 (Navitoclax) and ABT-199 (Venetoclax), induce apoptosis by displacing pro-apoptotic proteins from the hydrophobic pocket, but do not inhibit Bcl-2-IP3R interaction. Therefore, to target this interaction we developed BIRD-2 (Bcl-2 IP3 Receptor Disruptor-2), a decoy peptide that binds to the BH4 domain, blocking Bcl-2-IP3R interaction and thus inducing Ca2+-mediated apoptosis in chronic lymphocytic leukemia, multiple myeloma, and follicular lymphoma cells, including cells resistant to ABT-263, ABT-199, or the Bruton's tyrosine kinase inhibitor Ibrutinib. Moreover, combining BIRD-2 with ABT-263 or ABT-199 enhances apoptosis induction compared to single agent treatment. Overall, these findings provide strong rationale for developing novel therapeutic agents that mimic the action of BIRD-2 in targeting the BH4 domain of Bcl-2 and disrupting Bcl-2-IP3R interaction.

Chemokines CCL2, 3, 14 stimulate macrophage bone marrow homing, proliferation, and polarization in multiple myeloma.

We previously showed that macrophages (MΦs) infiltrate the bone marrow (BM) of patients with myeloma and may play a role in drug resistance. This study analyzed chemokines expressed by myeloma BM that are responsible for recruiting monocytes to the tumor bed. We found that chemokines CCL3, CCL14, and CCL2 were highly expressed by myeloma and BM cells, and the levels of CCL14 and CCL3 in myeloma BM positively correlated with the percentage of BM-infiltrating MΦs. In vitro, these chemokines were responsible for chemoattracting human monocytes to tumor sites and in vivo for MΦ infiltration into myeloma-bearing BM in the 5TGM1 mouse model. Surprisingly, we also found that these chemokines stimulated MΦ in vitro proliferation induced by myeloma cells and in vivo in a human myeloma xenograft SCID mouse model. The chemokines also activated normal MΦ polarization and differentiation into myeloma-associated MΦs. Western blot analysis revealed that these chemokines promoted growth and survival signaling in MΦs via activating the PI3K/Akt and ERK MAPK pathways and c-myc expression. Thus, this study provides novel insight into the mechanism of MΦ infiltration of BM and also potential targets for improving the efficacy of chemotherapy in myeloma.

Evaluation of noncytotoxic DNMT1-depleting therapy in patients with myelodysplastic syndromes.

BACKGROUND: Mutational inactivation in cancer of key apoptotic pathway components, such as TP53/p53, undermines cytotoxic therapies that aim to increase apoptosis. Accordingly, TP53 mutations are reproducibly associated with poor treatment outcomes. Moreover, cytotoxic treatments destroy normal stem cells with intact p53 systems, a problem especially for myeloid neoplasms, as these cells reverse the low blood counts that cause morbidity and death. Preclinical studies suggest that noncytotoxic concentrations of the DNA methyltransferase 1 (DNMT1) inhibitor decitabine produce p53-independent cell-cycle exits by reversing aberrant epigenetic repression of proliferation-terminating (MYC-antagonizing) differentiation genes in cancer cells. METHODS: In this clinical trial, patients with myelodysplastic syndrome (n=25) received reduced decitabine dosages (0.1-0.2 mg/kg/day compared with the FDA-approved 20-45 mg/m2/day dosage, a 75%-90% reduction) to avoid cytotoxicity. These well-tolerated doses were frequently administered 1-3 days per week, instead of pulse cycled for 3 to 5 days over a 4- to 6-week period, to increase the probability that cancer S-phase entries would coincide with drug exposure, which is required for S-phase-dependent DNMT1 depletion. RESULTS: The median subject age was 73 years (range, 46-85 years), 9 subjects had relapsed disease or were refractory to 5-azacytidine and/or lenalidomide, and 3 had received intensive chemoradiation to treat other cancers. Adverse events were related to neutropenia present at baseline: neutropenic fever (13 of 25 subjects) and septic death (1 of 25 subjects). Blood count improvements meeting the International Working Group criteria for response occurred in 11 of 25 (44%) subjects and were highly durable. Treatment-induced freedom from transfusion lasted a median of 1,025 days (range, 186-1,152 days; 3 ongoing), and 20% of subjects were treated for more than 3 years. Mutations and/or deletions of key apoptosis genes were frequent (present in 55% of responders and in 36% of nonresponders). Noncytotoxic DNMT1 depletion was confirmed by serial BM γ-H2AX (DNA repair/damage marker) and DNMT1 analyses. MYC master oncoprotein levels were markedly decreased. CONCLUSION: Decitabine regimens can be redesigned to minimize cytotoxicity and increase exposure time for DNMT1 depletion, to safely and effectively circumvent mutational apoptotic defects. TRIAL REGISTRATION: Clinicaltrials.gov NCT01165996. FUNDING: NIH (R01CA138858, CA043703); Department of Defense (PR081404); Clinical and Translational Science Award (CTSA) (UL1RR024989); and the Leukemia and Lymphoma Society (Translational Research Program).

Mature results of MM-011: a phase I/II trial of liposomal doxorubicin, vincristine, dexamethasone, and lenalidomide combination therapy followed by lenalidomide maintenance for relapsed/refractory multiple myeloma.

A previous interim report of MM-011, the first study that combined lenalidomide with anthracycline-based chemotherapy followed by lenalidomide maintenance for relapsed and/or refractory multiple myeloma (RRMM), showed promising safety and activity. We report the long-term outcomes of all 76 treated patients with follow-up ≥ 5 years. This single-center phase I/II study administered lenalidomide (10 mg on days 1-21 of every 28-day cycle), intravenous liposomal doxorubicin (40 mg/m(2) on day 1), dexamethasone (40 mg on days 1-4), and intravenous vincristine (2 mg on day 1). After 4-6 planned induction cycles, lenalidomide maintenance therapy was given at the last tolerated dose until progression, with or without 50 mg prednisone every other day. The median number of previous therapies was 3 (range, 1-7); 49 (64.5%) patients had refractory disease. Forty-three (56.6%) patients received maintenance therapy. Grade 3/4 adverse events occurred during induction and maintenance therapy in 48.7% and 25.6% of patients, respectively. Four (5.3%) treatment-related deaths occurred during induction. Responses were seen in 53.0% (at least partial response) and 71.2% (at least minor response) of patients. Overall, median progression-free survival and overall survival were 10.5 and 19.0 months, respectively; in patients with refractory disease these values were 7.5 and 11.3 months, respectively. Lenalidomide with anthracycline-based chemotherapy followed by maintenance lenalidomide provided durable control in patients with RRMM (ClinicalTrials.gov number, NCT00091624).