Phase 1/2 study of daratumumab, lenalidomide, and dexamethasone for relapsed multiple myeloma.

Daratumumab, a human CD38 immunoglobulin G1 kappa (IgG1κ) monoclonal antibody, has activity as monotherapy in multiple myeloma (MM). This phase 1/2 study investigated daratumumab plus lenalidomide/dexamethasone in refractory and relapsed/refractory MM. Part 1 (dose escalation) evaluated 4 daratumumab doses plus lenalidomide (25 mg/day orally on days 1-21 of each cycle) and dexamethasone (40 mg/week). Part 2 (dose expansion) evaluated daratumumab at the recommended phase 2 dose (RP2D) plus lenalidomide/dexamethasone. Safety, efficacy, pharmacokinetics, immunogenicity, and accelerated daratumumab infusions were studied. In part 1 (13 patients), no dose-limiting toxicities were observed, and 16 mg/kg was selected as the R2PD. In part 2 (32 patients), median time since diagnosis was 3.2 years, with a median of 2 prior therapies (range, 1-3 prior therapies), including proteasome inhibitors (91%), alkylating agents (91%), autologous stem cell transplantation (78%), thalidomide (44%), and lenalidomide (34%); 22% of patients were refractory to the last line of therapy. Grade 3 to 4 adverse events (≥5%) included neutropenia, thrombocytopenia, and anemia. In part 2, infusion-related reactions (IRRs) occurred in 18 patients (56%); most were grade ≤2 (grade 3, 6.3%). IRRs predominantly occurred during first infusions and were more common during accelerated infusions. In part 2 (median follow-up of 15.6 months), overall response rate was 81%, with 8 stringent complete responses (25%), 3 complete responses (9%), and 9 very good partial responses (28%). Eighteen-month progression-free and overall survival rates were 72% (95% confidence interval, 51.7-85.0) and 90% (95% confidence interval, 73.1-96.8), respectively. Daratumumab plus lenalidomide/dexamethasone resulted in rapid, deep, durable responses. The combination was well tolerated and consistent with the safety profiles observed with lenalidomide/dexamethasone or daratumumab monotherapy. This trial was registered at www.clinicaltrials.gov as #NCT01615029.

Abiraterone acetate and prednisolone for metastatic castration-resistant prostate cancer failing androgen deprivation and docetaxel-based chemotherapy: a phase II bridging study in Korean and Taiwanese patients.

OBJECTIVES: To evaluate the safety and efficacy of abiraterone acetate and prednisolone in Korean and Taiwanese patients with metastatic castration-resistant prostate cancer not responding to docetaxel-based chemotherapy. METHODS: In this single-arm study, 82 metastatic castration-resistant prostate cancer patients who failed docetaxel-based chemotherapy were treated with abiraterone (1000 mg, once daily) and prednisolone (5 mg, twice daily). Patients achieving a prostate-specific antigen decline ≥ 50% were considered as responding. RESULTS: A total of 35 patients (43%) achieved prostate-specific antigen response (95% confidence interval 32-54). The median time to prostate-specific antigen progression was 4.7 months (95% confidence interval 3.7-8.3); the median overall survival was 11.8 months. Two (4%) of 50 patients with measurable disease achieved partial response. The median testosterone concentration was in the castration range (1.21 nmol/L) throughout the treatment period. Median dehydroepiandrosterone sulfate decreased from 0.725 µmol/L (baseline) to 0.080 µmol/L (cycle 4). The most common adverse event was bone pain (20%); grade 3/4 adverse event of special interest were hypokalemia (7%), fluid retention and liver function abnormalities (5% each), hypertension (2%), and cardiac disorders (1%). CONCLUSIONS: A combination of abiraterone acetate and prednisolone appears to be a favorable second-line treatment in Taiwanese and Korean patients with advanced metastatic castration-resistant prostate cancer after failed docetaxel-based chemotherapy.

Delaying skeletal-related events in a randomized phase 3 study of denosumab versus zoledronic acid in patients with advanced cancer: an analysis of data from patients with solid tumors.

PURPOSE: Bone complications of metastatic disease, including skeletal-related events (SREs), impair patients' functioning and quality of life. In a randomized, phase 3 trial of 1,776 patients with metastases from solid tumors (except breast or prostate) or multiple myeloma, denosumab was non-inferior to zoledronic acid (ZA) in delaying or preventing SREs. This ad hoc analysis reports outcomes in the subgroup of 1,597 patients with solid tumors, excluding patients with multiple myeloma. METHODS: Patients received monthly subcutaneous denosumab 120 mg or intravenous ZA 4 mg, adjusted for creatinine clearance, with calcium and vitamin D supplementation recommended. Endpoints included times to first on-study SRE, first-and-subsequent SREs, and pain worsening. RESULTS: Denosumab significantly delayed time to first on-study SRE compared with ZA (HR, 0.81; 95 % CI, 0.68-0.96) and time to first-and-subsequent SREs (RR, 0.85; 95 % CI, 0.72-1.00). Denosumab also significantly delayed time to development of moderate or severe pain (HR, 0.81; 95 % CI, 0.66-1.00), pain worsening (HR, 0.83; 95 % CI, 0.71-0.97), and worsening pain interference in patients with no/mild baseline pain (HR, 0.77; 95 % CI, 0.61-0.96). Adverse event rates were 96 % in both groups. Grade 3 or 4 hypocalcemia, mostly without clinical sequelae, was more frequent in denosumab-treated patients (denosumab 4 %, ZA 2 %). Osteonecrosis of the jaw occurred infrequently (denosumab 0.8 %, ZA 1.1 %). CONCLUSIONS: Denosumab was more effective in delaying or preventing SREs in patients with bone metastases from solid tumors and also prevented pain progression compared to ZA in this ad hoc analysis.

NADPH inhibits [2Fe-2S] cluster protein transfer from diabetes drug target MitoNEET to an apo-acceptor protein.

MitoNEET (mNT) is the founding member of the recently discovered CDGSH family of [2Fe-2S] proteins capable of [2Fe-2S] cluster transfer to apo-acceptor proteins. It is a target of the thiazolidinedione (TZD) class of anti-diabetes drugs whose binding modulate both electron transfer and cluster transfer properties. The [2Fe-2S] cluster in mNT is destabilized upon binding of NADPH, which leads to loss of the [2Fe-2S] cluster to the solution environment. Because mNT is capable of transferring [2Fe-2S] clusters to apo-acceptor proteins, we sought to determine whether NADPH binding also affects cluster transfer. We show that NADPH inhibits transfer of the [2Fe-2S] cluster to an apo-acceptor protein with an inhibition constant (K(i)) of 200 µm, which reflects that of NADPH concentrations expected under physiological conditions. In addition, we determined that the strictly conserved cluster interacting residue Asp-84 in the CDGSH domain is necessary for the NADPH-dependent inhibition of [2Fe-2S] cluster transfer. The most critical cellular function of NADPH is in the maintenance of a pool of reducing equivalents, which is essential to counteract oxidative damage. Taken together, our findings suggest that NADPH can regulate both mNT [2Fe-2S] cluster levels in the cell as well as the ability of the protein to transfer [2Fe-2S] clusters to cytosolic or mitochondrial acceptors.

Randomized, double-blind study of denosumab versus zoledronic acid in the treatment of bone metastases in patients with advanced cancer (excluding breast and prostate cancer) or multiple myeloma.

PURPOSE: This study compared denosumab, a fully human monoclonal anti-receptor activator of nuclear factor kappa-B ligand antibody, with zoledronic acid (ZA) for delaying or preventing skeletal-related events (SRE) in patients with advanced cancer and bone metastases (excluding breast and prostate) or myeloma. PATIENTS AND METHODS: Eligible patients were randomly assigned in a double-blind, double-dummy design to receive monthly subcutaneous denosumab 120 mg (n = 886) or intravenous ZA 4 mg (dose adjusted for renal impairment; n = 890). Daily supplemental calcium and vitamin D were strongly recommended. The primary end point was time to first on-study SRE (pathologic fracture, radiation or surgery to bone, or spinal cord compression). RESULTS: Denosumab was noninferior to ZA in delaying time to first on-study SRE (hazard ratio, 0.84; 95% CI, 0.71 to 0.98; P = .0007). Although directionally favorable, denosumab was not statistically superior to ZA in delaying time to first on-study SRE (P = .03 unadjusted; P = .06 adjusted for multiplicity) or time to first-and-subsequent (multiple) SRE (rate ratio, 0.90; 95% CI, 0.77 to 1.04; P = .14). Overall survival and disease progression were similar between groups. Hypocalcemia occurred more frequently with denosumab. Osteonecrosis of the jaw occurred at similarly low rates in both groups. Acute-phase reactions after the first dose occurred more frequently with ZA, as did renal adverse events and elevations in serum creatinine based on National Cancer Institute Common Toxicity Criteria for Adverse Events grading. CONCLUSION: Denosumab was noninferior (trending to superiority) to ZA in preventing or delaying first on-study SRE in patients with advanced cancer metastatic to bone or myeloma. Denosumab represents a potential novel treatment option with the convenience of subcutaneous administration and no requirement for renal monitoring or dose adjustment.

Effects of denosumab in patients with bone metastases with and without previous bisphosphonate exposure.

Bone metastases place patients at increased risk of skeletal-related events (SREs), including pathologic fractures, spinal cord compression, severe pain requiring radiotherapy or surgery, and hypercalcemia, because of increased osteoclast-mediated bone resorption. Denosumab, a fully human monoclonal antibody, decreases bone resorption by inhibiting RANKL, which mediates osteoclast activity. We compared the effects of denosumab in two phase 2 studies in patients with bone metastases naive to intravenous bisphosphonate therapy (IV BP; n = 255) and those with elevated levels of the bone resorption marker urinary N-telopeptide (uNTX) despite ongoing IV BP treatment (n = 111). Patients were randomized to receive IV BP every 4 weeks or subcutaneous denosumab every 4 weeks (30/120/180 mg) or every 12 weeks (60/180 mg). Patients treated with denosumab experienced a rapid and sustained reduction in bone turnover regardless of prior IV BP exposure. After 25 weeks, the median uNTX reduction was 75% (IV BP-naive) and 80% (prior IV BP) after denosumab treatment and 71% (IV BP-naive) and 56% (prior IV BP) in the IV BP arms. Denosumab patients with prior IV BP exposure had marked suppression of the osteoclast marker TRAP-5b (median reduction: denosumab 73%, IV BP 11%). SRE incidence was low across both studies. In patients previously treated with BPs, the rate of first on-study SRE was lower in the denosumab groups (8%) than the IV BP group (17%). Denosumab appeared to be well tolerated in both studies. Denosumab suppresses bone resorption markers independently of prior BP treatment, even in patients who appear to respond poorly to BPs.

An open-label, phase 2 trial of denosumab in the treatment of relapsed or plateau-phase multiple myeloma.

RANKL is a key mediator of osteoclast differentiation, activation, and survival. Preclinical data suggest that aberrant production and activation of osteoclasts may influence proliferation of multiple myeloma (MM) cells in the bone marrow. Reports have also shown that inhibiting RANKL may have a direct effect on RANK-expressing myeloma cells and a therapeutic role in treating the disease. In mouse myeloma models, inhibition of RANKL led to reduced serum paraprotein levels and tumor burden. Based on this hypothesis, this proof-of-concept, single-arm study investigated whether RANKL inhibition with denosumab could reduce serum M-protein levels in relapsed or plateau-phase myeloma subjects. All subjects received denosumab monthly, with loading doses on days 8 and 15 of month one, until disease progression or subject discontinuation. Results of this ongoing study demonstrated that no subjects in either cohort met the protocol-defined objective response criteria of complete response (CR) or partial response (PR), but that denosumab effectively inhibited the RANKL pathway regardless of previous exposure to bisphosphonates, as evidenced by suppressed levels of the bone turnover marker, serum C-terminal telopeptide of type 1 collagen (sCTx). Eleven (21%) subjects who relapsed within 3 months before study entry maintained stable disease for up to 16.5 months. Nineteen (46%) subjects with plateau-phase myeloma maintained stable disease for up to 18.3 months. The adverse event (AE) profile for denosumab and its dosing schedule in these populations was consistent with that for advanced cancer patients receiving systemic therapy. Additional controlled clinical studies of denosumab in subjects with both relapsed and plateau-phase MM are warranted.

A phase I/II study of arsenic trioxide/bortezomib/ascorbic acid combination therapy for the treatment of relapsed or refractory multiple myeloma.

PURPOSE: This multicenter, open-label, phase I/II dose escalation study assessed the safety/tolerability and initial efficacy of arsenic trioxide/bortezomib/ascorbic acid (ABC) combination therapy in patients with relapsed/refractory multiple myeloma. EXPERIMENTAL DESIGN: Enrolled in six cohorts, patients were given arsenic trioxide (0.125 or 0.250 mg/kg), bortezomib (0.7, 1.0, or 1.3 mg/m(2)), and a fixed dose of ascorbic acid (1 g) i.v. on days 1, 4, 8, and 11 of a 21-day cycle for a maximum of eight cycles. The primary end point was safety/tolerability of the ABC regimen. RESULTS: Twenty-two patients (median age, 63 years) were enrolled, having failed a median of 4 (range, 3-9) prior therapies. One occurrence of grade 4 thrombocytopenia was observed. One patient had asymptomatic arrhythmia and withdrew from the study. Objective responses were observed in 6 (27%) patients, including two partial responses and four minor responses. Median progression-free survival was 5 months (95% confidence interval, 2-9 months), and median overall survival had not been reached. The 12-month progression-free survival and overall survival rates were 34% and 74%, respectively. One (minor response) of six patients receiving the lowest dose of bortezomib (0.7 mg/m(2)) and 5 (2 partial responses and 3 minor responses) of 16 patients receiving the higher doses (1.0 or 1.3 mg/m(2)) responded. CONCLUSIONS: The ABC regimen was well tolerated by most patients, and it produced preliminary signs of efficacy with an objective response rate of 27% in this heavily pretreated study population. These findings warrant further clinical evaluation of the ABC combination for treatment of relapsed/refractory multiple myeloma.

Treatment for myeloma bone disease.

Multiple myeloma (MM) is a B cell malignancy characterized by enhanced bone loss commonly associated with diffuse osteopenia, focal lytic lesions, pathologic fractures, hypercalcemia, and bony pain. Bone destruction in MM results from asynchronous bone turnover wherein increased osteoclastic bone resorption is not accompanied by a comparable increase in bone formation. Consequently, patients with MM frequently require radiation therapy, surgery, and analgesic medications. The recent development of minimally invasive surgical procedures such as kyphoplasty allows patients with myeloma with vertebral compression fractures to have immediate improvement in their quality of life with shorter hospital stays. Bisphosphonates are specific inhibitors of osteoclastic activity, and these agents have been evaluated in patients with MM with bone disease during the past 15 years. Monthly i.v. infusions of either pamidronate or zoledronic acid have reduced the skeletal complications among patients with MM and are now a mainstay of myeloma therapy. Orally administered bisphosphonates, in contrast, have shown little ability to slow the development of skeletal complications in these patients. Although preclinical studies suggest that nitrogen-containing bisphosphonates have potent antitumor effects, clinical trials will be necessary, probably at higher doses given more slowly, to establish their possible antitumor effects clinically. Moreover, recent advances in the use of bone-seeking radiopharmaceuticals make these attractive therapeutic candidates to combine with bisphosphonates or radiosensitizing drugs (e.g., bortezomib) to achieve a synergistic effect. As our understanding of the pathophysiology of myeloma bone disease continues to grow, new target therapies will continue to emerge, offering new and more advanced options for the management of myeloma bone disease.

Efficacy and safety of melphalan, arsenic trioxide and ascorbic acid combination therapy in patients with relapsed or refractory multiple myeloma: a prospective, multicentre, phase II, single-arm study.

We assessed the safety and efficacy of melphalan, arsenic trioxide (ATO) and ascorbic acid (AA) (MAC) combination therapy for patients with multiple myeloma (MM) who failed more than two different prior regimens. Patients received melphalan (0.1 mg/kg p.o.), ATO (0.25 mg/kg i.v.) and AA (1 g i.v) on days 1-4 of week 1, ATO and AA twice weekly during weeks 2-5 and no treatment during week 6 of cycle 1; during cycles 2-6, the schedule remained the same except ATO and AA were given twice weekly in week 1. Objective responses occurred in 31 of 65 (48%) patients, including two complete, 15 partial and 14 minor responses. Median progression-free survival and overall survival were 7 and 19 months respectively. Twenty-two patients had elevated serum creatinine levels (SCr) at baseline, and 18 of 22 (82%) showed decreased SCr levels during treatment. Specific grade 3/4 haematological (3%) or cardiac adverse events occurred infrequently. Frequent grade 3/4 non-haematological adverse events included fever/chills (15%), pain (8%) and fatigue (6%). This steroid-free regimen was effective and well tolerated in this heavily pretreated group. These results indicate that the MAC regimen is a new therapeutic option for patients with relapsed or refractory MM.

Myeloma bone disease and treatment options.

Multiple myeloma (MM) is a B-cell malignancy characterized by enhanced bone loss commonly associated with a diffuse osteopenia, focal lytic lesions, pathologic fractures, hypercalcemia, and bony pain. Bone destruction in MM results from asynchronous bone turnover wherein increased osteoclastic bone resorption is not accompanied by a comparable increase in bone formation. Recent characterization of osteoclast-activating factors (OAFs), receptor activator of nuclear factor-kappaB (RANK) ligand (RANKL)-osteoprotegerin-RANK system, and inhibitors of Wnt signaling have provided a better understanding of myeloma bone disease in molecular level. The development of minimally invasive surgical procedures such as kyphoplasty and vertebroplasty allows myeloma patients with vertebral compression fractures to have immediate improvement in quality of life and shorter hospital stays. Monthly intravenous infusion of either pamidronate or zoledronic acid have reduced the skeletal complications among MM patients and are now a mainstay of myeloma therapy. Orally administered bisphosphonates, in contrast, have shown little ability to slow the development of skeletal complications in these patients. Although pre-clinical studies suggest nitrogen-containing bisphosphonates have potent anti-tumor effects, clinical trials will be necessary, probably at higher doses given more slowly, to establish their possible anti-tumor effects clinically. As our understanding of the pathophysiology of myeloma bone disease continues to increase, new target therapies will continue to emerge offering new and more advanced options for the management of myeloma bone disease.

Serum pleiotrophin levels are elevated in multiple myeloma patients and correlate with disease status.

Pleiotrophin (PTN), a tightly regulated angiogenic and mitogenic heparin-binding protein, is markedly elevated in a variety of aggressive solid tumours. The role of PTN in haematological malignancies, however, has not been previously evaluated. This study demonstrated that PTN serum levels were elevated in multiple myeloma (MM) patients when compared with healthy subjects (P < 0.0001). Serum levels of this protein significantly increased during progression of disease, and decreased during response to anti-MM therapy (P < 0.001). These results suggest that serum PTN may be a new biomarker for monitoring the disease status and therapeutic response of MM patients.

Arsenic compounds in the treatment of multiple myeloma: a new role for a historical remedy.

Arsenic compounds have been used since ancient times to treat a wide variety of ailments. Although the use of arsenic to treat hematologic cancers has been documented since the 19th century, widespread use of arsenic compounds in patients with hematologic malignancies did not occur until the 1990s, when several groups in China reported impressive clinical response rates in patients with acute promyelocytic leukemia who had received arsenic trioxide. Subsequently, clinical studies conducted in the United States confirmed earlier reports, and arsenic trioxide was approved by the Food and Drug Administration for the treatment of relapsed/refractory acute promyelocytic leukemia. The use of arsenic compounds in the treatment of multiple myeloma (MM) is supported by the proposed mechanisms of action underlying the antitumor activity of arsenic and by preclinical studies showing antiproliferative and cytotoxic activities in cell culture and animal models. Moreover, clinical studies of arsenic compounds, particularly arsenic trioxide-based regimens, have shown that this drug is clinically active in patients with relapsed/refractory MM. Combination studies with other antimyeloma agents have shown evidence of synergy with arsenic trioxide. Furthermore, arsenic trioxide-based regimens in MM appear to be well tolerated, particularly with regard to cardiac toxicity. The activity and tolerability observed in clinical studies promise to make arsenic-based chemotherapy a viable treatment option for patients whose disease does not respond to or who cannot tolerate other chemotherapy regimens.

Purification and characterization of a cyclooxygenase-2 and angiogenesis suppressing factor produced by human fibroblasts.

Cyclooxygenase-2 (COX-2) is an inducible enzyme that plays an important role in several pathophysiological processes, including inflammation, angiogenesis, and tumorigenesis. We have recently observed that COX-2 induction is restrained in proliferating fibroblasts. The mechanism by which this occurs is unclear. Here, we report the detection and isolation from the conditioned medium of proliferating fibroblasts a factor that suppressed COX-2 expression. This factor, which was named cytoguardin, suppressed COX-2 protein levels induced by phorbol 12-myristate 13-acetate, interleukin-1beta, tumor necrosis factor alpha, and lipopolysaccharide (LPS) in fibroblasts and LPS-induced COX-2 protein levels and promoter activities in human endothelial cells and murine RAW 264.7 cells in a comparable concentration-dependent manner. It inhibited COX-2 expression induced by angiogenic factors and endothelial tube formation induced by angiogenic factors and colon cancer cell medium. These findings provide evidence for the control of COX-2 transcription by an endogenous cellular factor.

Dynamic regulation of cyclooxygenase-2 promoter activity by isoforms of CCAAT/enhancer-binding proteins.

To elucidate the mechanism by which isoforms of CCAAT/enhancer-binding proteins regulate cyclooxygenase-2 expression, we determined by a novel technique binding of six isoforms of this transactivator to two sequence-specific CCAAT/enhancer-binding protein (-132/-125) and cyclic AMP (-59/-53) regulatory elements in human foreskin fibroblasts treated with phorbol 12-myristate 13-acetate for 4 h. The delta isoform bound to these two elements at basal state, which was displaced by full-length as well as two truncated beta isoforms, a 41-kDa liver-enriched activating protein and a 16-kDa liver-enriched inhibitory protein, after phorbol ester stimulation. Kinetic analysis shows time-dependent changes in beta and delta binding that were concordant with time-dependent increase in cyclooxygenase-2 induction. Overexpression of the 16-kDa beta isoform blocked the promoter activity and protein level induced by phorbol ester. Paradoxically, it increased binding of beta isoforms to the sequence-specific promoter DNA but suppressed cyclooxygenase-2 promoter activation by p300 cotransfection. These findings provide new insight into the regulation of cyclooxygenase-2 promoter by an interplay between two opposite beta isoforms and p300 co-activator.