TTK/MPS1 inhibitor OSU-13 targets the mitotic checkpoint and is a potential therapeutic strategy for myeloma.

Despite substantial recent advances in treatment, multiple myeloma (MM) remains an incurable disease, with a shortage of treatment options for patients with high-risk disease, warranting the need for novel therapeutic targets and treatment approaches. Threonine and tyrosine kinase (TTK), also known as monopolar spindle 1 (MPS1), is a kinase essential for the mitotic spindle checkpoint whose expression correlates to unfavorable prognosis in several cancers. Here, we report the importance of TTK in MM, and the effects of the TTK inhibitor OSU-13. Elevated TTK expression correlated with amplification/ gain of 1q21 and decreased overall and event-free survival in MM. Treatment with OSU-13 inhibited TTK activity efficiently and selectively at a similar concentration range to other TTK inhibitor clinical candidates. OSU-13 reduced proliferation and viability of primary human MM cells and cell lines, especially those with high 1q21 copy numbers, and triggered apoptosis through caspase 3 and 7 activation. In addition, OSU-13 induced DNA damage and severe defects in chromosome alignment and segregation, generating aneuploidy. In vivo, OSU-13 decreased tumor growth in mice with NCI-H929 xenografts. Collectively, our findings reveal that inhibiting TTK with OSU-13 is a potential therapeutic strategy for MM, particularly for a subset of high-risk patients with poor outcome.

Characterization of monoclonal gammopathy of undetermined significance progression to multiple myeloma through meta-analysis of GEO data.

The etiology of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) is still obscure as are the processes that enable the progression of MGUS to MM. Understanding the unique vs. shared transcriptomes can potentially elucidate why individuals develop one or the other. Furthermore, highlighting key pathways and genes involved in the pathogenesis of MM or the development of MGUS to MM may allow the discovery of novel drug targets and therapies. We employed STARGEO platform to perform three separate meta-analysis to compare MGUS and MM transcriptomes. For these analyses we tagged (1) 101 MGUS patient plasma cells from bone marrow samples and 64 plasma cells from healthy controls (2) 383 MM patient CD138+ cells from bone marrow and the 101 MGUS samples in the first analysis as controls (3) 517 MM patient peripheral blood samples and 97 peripheral blood samples from healthy controls. We then utilized Ingenuity Pathway Analysis (IPA) to analyze the unique genomic signatures within and across these samples. Our study identified genes that may have unique roles in MGUS (GADD45RA and COMMD3), but also newly identified signaling pathways (EIF2, JAK/STAT, and MYC) and gene activity (NRG3, RBFOX2, and PARP15) in MGUS that have previously been shown to be involved in MM suggesting a spectrum of molecular overlap. On the other hand, genes such as DUSP4, RN14, LAMP5, differentially upregulated in MM, may be seen as tipping the scales from benignity to malignancy and could serve as drug targets or novel biomarkers for risk of progression. Furthermore, our analysis of MM identified newly associated gene/pathway activity such as inhibition of Wnt-signaling and defective B cell development. Finally, IPA analysis, suggests the multifactorial, oncogenic qualities of IFNγ signaling in MM may be a unifying pathway for these diverse mechanisms and prompts the need for further studies.

Impact of interval progression before autologous stem cell transplant in patients with multiple myeloma.

In transplant-eligible patients who undergo upfront autologous stem cell transplant (ASCT) for multiple myeloma (MM), standard practice is to treat with six to eight cycles of induction therapy followed by high-dose chemotherapy with ASCT. A gap between the end of induction and the day of ASCT exists to allow stem cell mobilization and collection. Despite attempts to limit the length of this interval, we noticed that some patients experience interval progression (IP) of disease between the end of induction therapy and the day of ASCT. We analyzed 408 MM patients who underwent ASCT between 2011 and 2016. The median length of the interval between end of induction and ASCT was 38 days. We observed that 26% of patients in the entire cohort and 23.6% of patients who received induction with bortezomib-lenalidomide-dexamethasone (VRD) experienced IP. These patients deepened their responses with ASCT, independently of induction regimen. In the entire cohort, IP was significantly associated with shorter PFS in the univariable analysis (Hazard Ratio, HR = 1.37, P = 0.022) but not in the multivariable analysis (HR = 1.14, P = 0.44). However, analyzing only patients who received VRD as induction, progression-free survival (PFS) remained inferior in both the univariable (HR = 2.02; P = 0.002) and the multivariable analyses (HR = 1.96; P = 0.01). T cells and natural killer (NK) cells are increasingly studied targets of immunomodulatory therapy, as immune dysfunction is known to occur in patients with MM. Peripheral blood from 35 MM patients were analyzed. At time of ASCT, patients with IP had significantly increased percentages of CD3+CD8+CD57+ CD28- (P = 0.05) and CD3+CD4+LAG3+ (P = 0.0022) T-cells, as well as less CD56bright and CD56dim NK cells bearing activated markers such as CD69, NKG2D, and CD226. These data suggest that IP can impact the length of response to ASCT; therefore, further studies on the management of these patients are needed.

Survival outcomes following autologous stem cell transplant with melphalan 140mg/m2 versus 200mg/m2 preparative regimens in patients with multiple myeloma.

The standard preparative regimen for autologous stem cell transplant (ASCT) in multiple myeloma (MM) is 200 mg/m2 of intravenous melphalan; however, a dose of 140 mg/m2 is often used when concerns exist related to patient age, performance status, organ function, and other factors. It is unclear whether a lower dose of melphalan impacts post-transplant survival outcomes. We performed a retrospective review of 930 patients with MM who underwent ASCT with 200 mg/m2 versus 140 mg/m2 melphalan. On univariable analysis, no difference in progression-free survival (PFS) was observed, however, an overall survival (OS) benefit was observed in patients receiving 200 mg/m2 melphalan (p = 0.04). Multivariable analyses showed patients receiving 140 mg/m2 faired no worse than those receiving 200 mg/m2. While a subset of younger patients with normal renal function may achieve superior OS with a standard dose of 200 mg/m2 melphalan, these findings suggest an opportunity to individualize the ASCT preparative regimen to optimize outcomes.

Outcomes After Salvage Autologous Hematopoietic Cell Transplant for Patients With Relapsed/Refractory Multiple Myeloma: A Single-Institution Experience.

BACKGROUND: The role of salvage autologous hematopoietic cell transplantation (sAHCT2) for patients with relapsed/refractory multiple myeloma (RRMM) in the era of modern therapeutics is unclear. As prospective data is limited, we conducted a retrospective analysis to determine the outcomes of sAHCT2. PATIENTS AND METHODS: We conducted a single-institution, retrospective analysis of patients who received sAHCT2 at The Ohio State University from 2000 to 2018. Patients who received a second transplant as part of a planned tandem or autologous-allogeneic transplant were excluded. RESULTS: Fifty-seven patients were treated with sAHCT2. Patients had a median of 2 lines of therapy after AHCT1 prior to their sAHCT2; 70% had prior immunomodulatory imide drugs, 82% had prior proteasome inhibitor, and 20% had prior anti-CD38 monoclonal antibodies as part of re-induction therapy. Forty-two percent of patients attained ≥VGPR prior to sAHCT2. Seventy-four were treated with melphalan 200 mg/m2 as conditioning regimen before infusion of a median of 3.8 × 106 CD34+ cells/kg. Fifty-eight percent patients had maintenance therapy and 81% patients attained CR/VGPR as the best response after sAHCT2. The median PFS and OS after sAHCT2 were 1.6 and 3.6 years, respectively. On multivariable analysis, high-risk cytogenetics, not having attained CR/VGPR, and having more than 2 lines of therapy post-AHCT1 were associated with inferior PFS. Melphalan 140 mg/m2 compared to melphalan 200 mg/m2 and no maintenance therapy compared to maintenance therapy were not associated with inferior PFS. There was no transplant-related mortality in this patient cohort. CONCLUSIONS: For MM patients deriving durable remission after their AHCT1, sAHCT2 was safe and resulted in deep and durable remissions.

Comparison of Patient Outcomes With Two Different Formulations of Melphalan as Conditioning Chemotherapy for Autologous Hematopoietic Cell Transplantation in Multiple Myeloma.

BACKGROUND: High-dose melphalan (HDM) with autologous hematopoietic cell transplantation (AHCT) after induction chemotherapy is considered standard of care in transplant-eligible patients with newly-diagnosed multiple myeloma (MM). Alkeran melphalan has propylene glycol as a solvent (PG-mel) while Evomela utilizes a propylene glyclol-free formulation (PGF-mel). We evaluated the differences in efficacy and safety of the 2 formulations as there are no prospective head-to-head trials. METHODS: We retrospectively reviewed the medical records of all 259 consecutive MM patients who received PGF-mel as part of HDM-AHCT at The Ohio State University (OSU). The comparator group was the preceding 255 patients who received PG-mel. RESULTS: Baseline patient characteristics were similar between the 2 groups. Post-AHCT rates of relapse were comparable in the PG-mel and PGF-mel groups. Some adverse events were observed at a higher frequency in the PG-mel group compared to the PGF-mel group (grade ≥ 2 mucositis, febrile neutropenia, other infectious complications, and acute renal insufficiency). Time to neutrophil engraftment was slightly longer in the PG-mel group while time to platelet engraftment was longer in PGF-mel group. Red cell transfusion requirement was higher with the use of PG-mel but not platelet transfusion. Duration of hospitalization was slightly shorter with PGF-mel but readmission rates within 30 days of discharge were higher. CONCLUSION: Considering possible confounding factors could possibly account for observed differences in some adverse events, the comparable treatment responses, and difference in cost of the 2 formulation, The OSU reverted to PG-mel as the preferred formulation for HDM-AHCT in MM.

Longitudinal Survival Outcomes in Allogeneic Stem Cell Transplantation: An Institutional Experience.

Allogeneic hematopoietic stem cell transplantation (allo-SCT) is a potentially curative treatment for many hematological disorders, but is often complicated by relapse of the underlying disease, graft-versus-host disease (GVHD), and infectious complications. We conducted a retrospective analysis on patients undergoing allo-SCT from 1984 to 2018 to better understand how survival has changed longitudinally with therapeutic advancements made to mitigate these complications. Method: We analyzed data from 1943 consecutive patients who received allo-SCT. Patients were divided into groups (gps) based on the year (yr) of transplant. Primary endpoints were overall survival (OS), progression free survival (PFS), and GVHD-free relapse-free survival (GRFS). Secondary endpoints were the cumulative incidences of grade II−IV and grade III−IV acute GVHD (aGVHD), chronic GVHD (cGVHD), and non-relapse mortality (NRM). Results: Our study found statistically significant improvements in OS, PFS, and GRFS. Five-year PFS among the groups increased from 24% to 48% over the years. Five-year OS increased from 25% to 53%. Five-year GRFS significantly increased from 6% to 14%, but remained relatively unchanged from 2004 to 2018. Cumulative incidences of grade II−IV aGVHD increased since 2009 (p < 0.001). However, cumulative incidence of NRM decreased since 2004 (p < 0.001). Conclusions: Our data show improved OS, PFS, and GRFS post allo-SCT over decades. This may be attributed to advances in supportive care and treatments focused on mitigation of GVHD and relapse.

Early versus Late Discontinuation of Maintenance Therapy in Multiple Myeloma.

Maintenance therapy after autologous stem cell transplant (ASCT) in multiple myeloma (MM) is the standard treatment and recommended to be continued until disease progression. However, in the real world, patients discontinue treatment due to various reasons. We sought to determine the effect of early versus late discontinuation on survival outcomes in MM patients who underwent ASCT at The Ohio State University. We retrospectively reviewed 340 patients who underwent ASCT from 2005 to 2016 and received maintenance therapy for at least six months without progression. We compared the outcomes of patients who received maintenance for three years or less (early group) to the patients who continued maintenance beyond three years (late group). Lenalidomide (89%) and bortezomib (10%) were the most common agents used for maintenance chemotherapy. In Kaplan−Meier analysis, patients in the late group had prolonged progression-free (PFS) (p < 0.001) and overall survival (OS) (p < 0.001). The 5-year estimated OS in late group was 96% vs. 79% in the early group and 5-year PFS was 80% in late group vs. 50% in the early group. The most common reasons for discontinuation of maintenance in early group were adverse events (55.9%) and patient preference (22.5%). For the late group, it was disease progression (23.9%) and adverse events (14.3%). Fifty-five percent of patients in the late group were still on maintenance treatment at the last follow-up. Continuation of maintenance therapy was thus associated with improved outcomes, while adverse events prevented most patients from continuing treatment.

Improvement in Post-Autologous Stem Cell Transplant Survival of Multiple Myeloma Patients: A Long-Term Institutional Experience.

Multiple myeloma (MM) represents 1.8% of all new cancer cases in the U.S. While not curable, advances in treatment, including autologous stem cell transplant (ASCT) and maintenance therapy, have dramatically improved progression-free survival (PFS) and overall survival (OS). We performed a retrospective survival analysis on newly diagnosed MM (NDMM) patients receiving ASCT from 1992−2016 at the Ohio State University. A total of 1001 consecutive NDMM patients were eligible. Patients were split into five groups based on historic changes in novel agents for the treatment of MM. Across the years (1992−2016), there was a statistically significant improvement in both PFS (p < 0.01) and OS (p < 0.01). Significant improvements in both PFS and OS were seen in patients ≤65 years (p < 0.001 and p = 0.002) and >65 years old (p < 0.001 and p = 0.001), respectively. Improved PFS and OS were seen in both standard-risk (p < 0.001 and p < 0.001) and high-risk patients (p < 0.001 and p = 0.019). The post-transplant response showed statistically significant improvement across the years (p < 0.01). Survival rates for NDMM patients have significantly improved primarily due to the inclusion of novel therapies and post-ASCT maintenance.

Incidence, Treatment, and Survival of Patients With T-Cell Lymphoma, T-Cell Large Granular Leukemia, and Concomitant Plasma Cell Dyscrasias.

T-Cell malignancies are a group of heterogeneous disorders composed of primary cutaneous T-cell lymphomas (CTCLs), peripheral T-cell lymphomas (PTCLs), and T-cell leukemias, including T-cell large granular lymphocytic leukemia (T-LGLL). Cases of patients with combined T-cell malignancies and plasma cell dyscrasias (PCD) are reported in the literature, but these are mostly limited to case reports or small case series with <10 patients. Here, we described the clinical course of 26 patients and report baseline characteristics and clinical outcomes including overall survival (OS), progression-free survival (PFS), and objective response rates (ORRs) in this unique population. There was no survival difference in patients with CTCL or T-LGLL and concomitant PCD when treated with standard therapy directed at the T-cell malignancy when compared to historical controls. However, patients with PTCL and concomitant PCD had significantly inferior outcomes with rapid progression and worse OS and PFS at 1.7 years (p=0.006) and 4.8 months (p=0.08), respectively, when compared to historical controls for patients with PTCL, although the limited number of patients included in this analysis precludes drawing definitive conclusions. Treatment directed at the T-cell malignancy resulted in the eradication of the PCD clone in multiple patients (15.4%) including one with multiple myeloma (MM) who experienced a complete response after starting therapy directed at the T-cell malignancy. For patients with T-cell malignancies and concomitant PCD, treatment with standard T-cell-directed therapies is recommended based on this analysis with continued follow-up and monitoring of the concomitant PCD. Further studies are needed to definitively elucidate the increased risk of relapse in patients with PTCL and concomitant PCD, and larger, multi-center cohorts are needed to validate these findings across T-cell malignancies and PCDs.

Redefining CD56 as a Biomarker and Therapeutic Target in Multiple Myeloma.

Multiple myeloma cells aberrantly express surface antigens compared with normal plasma cells. Among others, CD56 is present at variable levels in approximately 70% of patients with multiple myeloma; however, very little is known about CD56 role in multiple myeloma. We demonstrated that patients with multiple myeloma with more than 10% of CD56-expressing clonal multiple myeloma cells have inferior clinical outcomes. By gain-of and loss-of function models, we revealed that CD56 promotes multiple myeloma cell growth, survival, and adhesion to stromal cells. These protumoral effects are induced by the activation of the RSK2/CREB1 signaling pathway, with increased mRNA and protein levels of the anti-apoptotic genes BCL2 and MCL1. Consequently, the genomic and pharmacological inhibition of RSK2 or CREB1 specifically induced multiple myeloma cell death in CD56-expressing multiple myeloma cells. Finally, we observed that CD56 signaling decreases CRBN expression, reducing responses to lenalidomide. RSK2 or CREB1 inhibition increased CRBN levels and were synergic with lenalidomide in inducing cell death, especially in CD56-expressing multiple myeloma cells. In conclusion, our findings demonstrate that CD56 promotes multiple myeloma cell growth, and pave the way to novel therapies based on targeting CD56, along with the use of CD56 as a predictive biomarker for multiple myeloma therapies. IMPLICATIONS: Multiple myeloma is an incurable, genetically heterogeneous disease, without available tailored therapeutic approaches. CD56 signaling promotes multiple myeloma growth and adhesion, by activating CREB1 target genes, MCL1 and BCL2. Inhibition of CREB1 alone or in combination with lenalidomide is an unexplored synthetic lethal approach in CD56-expressing patients with multiple myeloma.

Impact of Race and Geographic Area of Residence on Outcomes After Allogeneic Stem Cell Transplant.

Background: Allogeneic hematopoietic stem cell transplant (allo-HCT) is a potential curative therapy for a variety of hematologic disorders. However, it requires highly specialized care that is only available at select centers across the country. Thus, minority populations are at risk for healthcare disparities in access to and outcomes of allo-HCT. Our study aimed to assess the impact of race and location of residence on outcomes of allo-HCT. Methods: We performed a retrospective analysis of all patients who underwent allo-HCT at the Ohio State University from 1984 to 2018. Patients were divided by race (Caucasian, African American, and other) and grouped by zip code into rural, suburban, and urban groups. Primary endpoints included progression-free survival (PFS) and overall survival (OS). Results: Of the 1,943 patients included in the study, 94.3% self-identified as Caucasian, 4.6% African American, and 1.1% other. In total, 63.4% lived in rural areas, 22.9% suburban, and 13.8% urban. There was no significant difference in OS or PFS by race (p = 0.15, 0.21) or place of residence (p = 0.39, 0.17). In addition, no difference in nonrelapse mortality, acute and chronic graft-versus-host disease (GVHD), and GVHD-free relapse-free survival (GRFS) was seen among the race or place of residence. Conclusion: Our study suggests that when appropriate access to HCT is given, there is no difference in outcomes based on race, ethnicity or place of primary residence. Further research is needed to further evaluate barriers for these patients to undergo transplant and help mitigate these barriers.