A pooled analysis of outcomes according to cytogenetic abnormalities in patients receiving ixazomib- vs placebo-based therapy for multiple myeloma.

Some cytogenetic abnormalities (CAs) are associated with poorer prognosis in multiple myeloma (MM); proteasome inhibitors appear to benefit patients with high-risk CAs. We evaluated 2247 MM patients from the TOURMALINE-MM1/-MM2/-MM3/-MM4 trials to assess the PFS benefit of ixazomib plus lenalidomide-dexamethasone (Rd) vs placebo-Rd (TOURMALINE-MM1/-MM2) or ixazomib vs placebo (TOURMALINE-MM3/-MM4) in specific high-risk CAs. After a pooled median follow-up of 25.6 months, the hazard ratio (HR) for PFS with ixazomib- vs placebo-based therapy for high-risk patients was 0.74 (95% confidence interval [CI]: 0.59-0.93; median PFS [mPFS] 17.8 vs 13.2 months), and 0.70 (95% CI: 0.62-0.80; mPFS 26.3 vs 17.6 months) for complementary standard-risk patients. The HR for expanded high-risk patients was 0.75 (95% CI: 0.64-0.87; mPFS 18.1 vs 14.1 months), and 0.71 (95% CI: 0.59-0.85; mPFS 36.1 vs 21.4 months) for complementary standard-risk patients. The HR for PFS with ixazomib- vs placebo-based therapy was 0.68 in patients with t(4;14) (95% CI: 0.48-0.96; mPFS 22.4 vs 13.2 months), and 0.77 for patients with amp1q21 (95% CI: 0.63-0.93; mPFS 18.8 vs 14.5 months). A PFS benefit was demonstrated with ixazomib- vs placebo-based therapy regardless of cytogenetic status, with greatest benefit observed in patients with t(4;14) and amp1q21.

Periplocin and cardiac glycosides suppress the unfolded protein response.

The unfolded protein response (UPR) controls protein homeostasis through transcriptional and translational regulation. However, dysregulated UPR signaling has been associated with the pathogenesis of many human diseases. Therefore, the compounds modulating UPR may provide molecular insights for these pathologies in the context of UPR. Here, we screened small-molecule compounds that suppress UPR, using a library of Myanmar wild plant extracts. The screening system to track X-box binding protein 1 (XBP1) splicing activity revealed that the ethanol extract of the Periploca calophylla stem inhibited the inositol-requiring enzyme 1 (IRE1)-XBP1 pathway. We isolated and identified periplocin as a potent inhibitor of the IRE1-XBP1 axis. Periplocin also suppressed other UPR axes, protein kinase R-like endoplasmic reticulum kinase (PERK), and activating transcription factor 6 (ATF6). Examining the structure-activity relationship of periplocin revealed that cardiac glycosides also inhibited UPR. Moreover, periplocin suppressed the constitutive activation of XBP1 and exerted cytotoxic effects in the human multiple myeloma cell lines, AMO1 and RPMI8226. These results reveal a novel suppressive effect of periplocin or the other cardiac glycosides on UPR regulation, suggesting that these compounds will contribute to our understanding of the pathological or physiological importance of UPR.

Oral ixazomib maintenance following autologous stem cell transplantation (TOURMALINE-MM3): a double-blind, randomised, placebo-controlled phase 3 trial.

BACKGROUND: Maintenance therapy following autologous stem cell transplantation (ASCT) can delay disease progression and prolong survival in patients with multiple myeloma. Ixazomib is ideally suited for maintenance therapy given its convenient once-weekly oral dosing and low toxicity profile. In this study, we aimed to determine the safety and efficacy of ixazomib as maintenance therapy following ASCT. METHODS: The phase 3, double-blind, placebo-controlled TOURMALINE-MM3 study took place in 167 clinical or hospital sites in 30 countries in Europe, the Middle East, Africa, Asia, and North and South America. Eligible participants were adults with a confirmed diagnosis of symptomatic multiple myeloma according to International Myeloma Working Group criteria who had achieved at least a partial response after undergoing standard-of-care induction therapy followed by high-dose melphalan (200 mg/m2) conditioning and single ASCT within 12 months of diagnosis. Patients were randomly assigned in a 3:2 ratio to oral ixazomib or matching placebo on days 1, 8, and 15 in 28-day cycles for 2 years following induction, high-dose therapy, and transplantation. The initial 3 mg dose was increased to 4 mg from cycle 5 if tolerated during cycles 1-4. Randomisation was stratified by induction regimen, pre-induction disease stage, and response post-transplantation. The primary endpoint was progression-free survival (PFS) by intention-to-treat analysis. Safety was assessed in all patients who received at least one dose of ixazomib or placebo, according to treatment actually received. This trial is registered with ClinicalTrials.gov, number NCT02181413, and follow-up is ongoing. FINDINGS: Between July 31, 2014, and March 14, 2016, 656 patients were enrolled and randomly assigned to receive ixazomib maintenance therapy (n=395) or placebo (n=261). With a median follow-up of 31 months (IQR 27·3-35·7), we observed a 28% reduction in the risk of progression or death with ixazomib versus placebo (median PFS 26·5 months [95% CI 23·7-33·8] vs 21·3 months [18·0-24·7]; hazard ratio 0·72, 95% CI 0·58-0·89; p=0·0023). No increase in second malignancies was noted with ixazomib therapy (12 [3%] patients) compared with placebo (eight [3%] patients) at the time of this analysis. 108 (27%) of 394 patients in the ixazomib group and 51 (20%) of 259 patients in the placebo group experienced serious adverse events. During the treatment period, one patient died in the ixazomib group and none died in the placebo group. INTERPRETATION: Ixazomib maintenance prolongs PFS and represents an additional option for post-transplant maintenance therapy in patients with newly diagnosed multiple myeloma. FUNDING: Millennium Pharmaceuticals, a wholly owned subsidiary of Takeda Pharmaceutical Company.

Induction of class II major histocompatibility complex expression in human multiple myeloma cells by retinoid.

Class II major histocompatibility complex (MHC II) is normally silenced in plasma/multiple myeloma (MM) cells at the transcriptional level through downregulation of class II transactivator (CIITA), allowing MM cells to escape from immunological responses. Here we demonstrate that a retinoic acid receptor-alpha/beta-selective retinoid Am80 (tamibarotene) could induce the expression of functional MHC II molecules in human MM cell lines. Am80 upregulated expression of the interferon regulatory factor-1 gene, followed by enhancement of CIITA expression. This is the first report demonstrating that retinoid can induce the expression of MHC II in terminally-differentiated plasma/MM cells.