The SMN complex drives structural changes in human snRNAs to enable snRNP assembly.

Spliceosomal snRNPs are multicomponent particles that undergo a complex maturation pathway. Human Sm-class snRNAs are generated as 3'-end extended precursors, which are exported to the cytoplasm and assembled together with Sm proteins into core RNPs by the SMN complex. Here, we provide evidence that these pre-snRNA substrates contain compact, evolutionarily conserved secondary structures that overlap with the Sm binding site. These structural motifs in pre-snRNAs are predicted to interfere with Sm core assembly. We model structural rearrangements that lead to an open pre-snRNA conformation compatible with Sm protein interaction. The predicted rearrangement pathway is conserved in Metazoa and requires an external factor that initiates snRNA remodeling. We show that the essential helicase Gemin3, which is a component of the SMN complex, is crucial for snRNA structural rearrangements during snRNP maturation. The SMN complex thus facilitates ATP-driven structural changes in snRNAs that expose the Sm site and enable Sm protein binding.

Clinical characteristics and outcomes in risk-stratified patients with smoldering multiple myeloma: data from the Czech Republic Registry of Monoclonal Gammopathies.

Smoldering multiple myeloma (SMM) is an asymptomatic precursor to active multiple myeloma (MM). The aim of this study was to report clinical characteristics and outcomes of patients with SMM stratified based on their risk of progression to MM using the Mayo 20/2/20 criteria. Data were leveraged from the Czech Myeloma Group Registry of Monoclonal Gammopathies (RMG). Key outcomes included progression-free survival from SMM diagnosis to active MM diagnosis or death (PFS), progression-free survival from SMM diagnosis to progression on first line (1 L) MM treatment or death (PFS2), and overall survival (OS). Of 498 patients, 174 (34.9%) were classified as high risk and 324 (65.1%) as non-high risk. Median follow-up was approximately 65 months. During follow-up, more patients in the high-risk vs non-high-risk group received 1 L MM treatment (76.4% vs 46.6%, p < 0.001). PFS, PFS2, and OS were significantly shorter in high-risk vs non-high-risk patients (13.2 vs 56.6 months, p < 0.001; 49.9 vs 84.9 months, p < 0.001; 93.2 vs 131.1 months, p = 0.012, respectively). The results of this study add to the growing body of evidence that patients with high-risk vs non-high-risk SMM have significantly worse outcomes, including OS.

Bortezomib-based therapy for newly diagnosed multiple myeloma patients ineligible for autologous stem cell transplantation: Czech Registry Data.

OBJECTIVES: This study compared the use of bortezomib in different combination regimens in newly diagnosed multiple myeloma (NDMM) patients who were transplant ineligible. PATIENTS AND METHODS: We analyzed data from the Registry of Monoclonal Gammopathies (RMG) of the Czech Myeloma Group (CMG) to provide real-world evidence of outcome for 794 newly diagnosed MM transplant ineligible patients. The most frequently used regimen was VCd (bortezomib-cyclophosphamide-dexamethasone) (47.5%) over VMP (bortezomib-melphalan-prednisone) (21.7%), BDd (bortezomib-doxorubicin-dexamethasone) (9.8%), and VTd (bortezomib-thalidomide-dexamethasone) (2.9%). RESULTS: The overall response rate (ORR) was 69.2% (478/691), including 12.6% (≥ CR); 34.7% very good partial responses (VGPR); and 21.9% partial responses (PR). Among triplet regimens, VMP was the most effective regimen compared to VCd, BDd, and VTd. Median PFS was 22.3 vs. 18.5 vs. 13.7 vs. 13.8 mo, (P = .275), respectively, and median OS was 49 vs. 41.7 vs. 37.9 vs. 32.2 mo (P = .004), respectively. The most common grade 3-4 toxicities were anemia in 17.4% and infections in 18% of patients. CONCLUSION: Our study confirmed that bortezomib-based treatment is effective and safe in NDMM transplant ineligible patients, especially VMP, which was identified as superior between bortezomib-based induction regimens not only in clinical trials, but also in real clinical practice.

Survival benefit of ixazomib, lenalidomide and dexamethasone (IRD) over lenalidomide and dexamethasone (Rd) in relapsed and refractory multiple myeloma patients in routine clinical practice.

BACKGROUND: We have performed a head to head comparison of all-oral triplet combination of ixazomib, lenalidomide and dexamethasone (IRD) versus lenalidomide and dexamethasone (RD) in patients with relapsed and refractory multiple myeloma (RRMM) in the routine clinical practice. METHODS: A total of 344 patients treated with IRD (N = 127) or RD (N = 217) were selected for analysis from the Czech Registry of Monoclonal Gammopathies (RMG). Descriptive statistics were used to assess patient's characteristics associated with the respective therapy. The primary endpoint was progression free survival (PFS), secondary end points included response rates and overall survival (OS). Survival endpoints were plotted using Kaplan-Meier methodology at 95% Greenwood confidence interval. Univariable and multivariable Cox proportional hazards models were used to evaluate the effect of treatment regimens and the significance of uneven variables. Statistical tests were performed at significance level 0.05. RESULTS: In the whole cohort, median PFS for IRD was 17.5 and for RD was 11.5 months favoring the all-oral triplet, p = 0.005; in patients within relapse 1-3, the median PFS was 23.1 vs 11.6 months, p = 0.001. The hazard ratio for PFS was 0.67 (95% confidence interval [CI] 0.51-0.89, p = 0.006). The PFS advantage translated into improved OS for patients treated with IRD, median 36.6 months vs 26.0 months (p = 0.008). The overall response rate (ORR) was 73.0% in the IRD group vs 66.2% in the RD group with a complete response rate (CR) of 11.1% vs 8.8%, and very good partial response (VGPR) 22.2% vs 13.9%, IRD vs RD respectively. The IRD regimen was most beneficial in patients ≤75 years with ISS I, II, and in the first and second relapse. Patients with the presence of extramedullary disease did not benefit from IRD treatment (median PFS 6.5 months). Both regimens were well tolerated, and the incidence of total as well as grade 3/4 toxicities was comparable. CONCLUSIONS: Our analysis confirms the results of the TOURMALINE-MM1 study and shows benefit of all-oral triplet IRD treatment versus RD doublet. It demonstrates that the addition of ixazomib to RD improves key survival endpoints in patients with RRMM in a routine clinical setting.

Validation of multiple myeloma risk stratification indices in routine clinical practice: Analysis of data from the Czech Myeloma Group Registry of Monoclonal Gammopathies.

This study used data from the Czech Myeloma Group Registry of Monoclonal Gammopathies to validate the International Myeloma Working Group (IMWG) and revised International Staging System (R-ISS) indices for risk stratification in patients with multiple myeloma (MM) in clinical practice. Patients were included if they had symptomatic MM, complete data allowing R-ISS and IMWG staging (including cytogenetic information regarding t(4;14), t(14;16), and del(17p)), and key parameters for treatment evaluation. Median overall survival (OS) in included patients (n = 550) was 47.7 (95% CI: 39.5-55.9) and 46.2 (95% CI: 38.9-53.5) months from diagnosis and initiation of first-line therapy, respectively. Patients categorized as higher vs lower risk had reduced survival; median OS from diagnosis was 35.4 (95% CI: 30.5-40.3) vs 58.3 (95% CI: 53.8-62.9) months in high-risk vs other patients (IMWG; P = .001) and 34.1 (95% CI: 30.2-38.0) vs 47.2 (95% CI: 43.4-51.0) months in Stage III vs Stage II patients (R-ISS; P < .001). In conclusion, IMWG and R-ISS risk stratification indices are applicable to patients with MM in a real-world setting.

Real-world Outcomes of Multiple Myeloma: Retrospective Analysis of the Czech Registry of Monoclonal Gammopathies.

INTRODUCTION: Real-world data on patient outcomes and treatment patterns in multiple myeloma (MM) are limited. MATERIALS AND METHODS: The present noninterventional, observational, retrospective analysis of prospectively collected Czech patient medical record data from the Registry of Monoclonal Gammopathies estimated real-world outcomes in adults with a diagnosis of symptomatic MM made between May 2007 and June 2014. RESULTS: In total, 2446 patients had initiated first-line treatment. The median overall survival since the diagnosis (primary endpoint) was 50.3 months (95% confidence interval, 46.1-54.5 months) and decreased with each successive treatment line. A similar trend was observed for progression-free survival and the depth of response. In line with European guidelines and clinical practice, bortezomib-, thalidomide-, and lenalidomide-based regimens were most commonly used across all treatment lines (42.3%, 28.9%, and 18.4%, respectively). In the first line, bortezomib and thalidomide were used most often, with lenalidomide the most commonly used agent in the relapse setting (second to fourth lines). Exploratory analyses revealed that younger age (≤ 65 years), lower international staging system stage, and previous stem cell transplantation were associated with significant improvements in overall and progression-free survival, especially in the early treatment lines. CONCLUSION: The present study is the first analysis of Czech data from the Registry of Monoclonal Gammopathies, and it provides important insights into the real-world management of MM for physicians and healthcare providers.

Adjusted comparison of daratumumab monotherapy versus real-world historical control data from the Czech Republic in heavily pretreated and highly refractory multiple myeloma patients.

OBJECTIVES: We conducted an adjusted comparison of progression-free survival (PFS) and overall survival (OS) for daratumumab monotherapy versus standard of care, as observed in a real-world historical cohort of heavily pretreated multiple myeloma patients from Czech Republic. METHODS: Using longitudinal chart data from the Registry of Monoclonal Gammopathies (RMG) of the Czech Myeloma Group, patient-level data from the RMG was pooled with pivotal daratumumab monotherapy studies (GEN501 and SIRIUS; 16 mg/kg). RESULTS: From the RMG database, we identified 972 treatment lines in 463 patients previously treated with both a proteasome inhibitor and an immunomodulatory drug. Treatment initiation dates for RMG patients were between March 2006 and March 2015. The most frequently used treatment regimens were lenalidomide-based regimens (33.4%), chemotherapy (18.1%), bortezomib-based regimens (13.6%), thalidomide-based regimens (8.0%), and bortezomib plus thalidomide (5.3%). Few patients were treated with carfilzomib-based regimens (2.5%) and pomalidomide-based regimens (2.4%). Median observed PFS for daratumumab and the RMG cohort was 4.0 and 5.8 months (unadjusted hazard ratio [HR], 1.14; 95% confidence interval [CI], 0.94-1.39), respectively, and unadjusted median OS was 20.1 and 11.9 months (unadjusted HR, 0.61; 95% CI, 0.48-0.78), respectively. Statistical adjustments for differences in baseline characteristics were made using patient-level data. The adjusted HRs (95% CI) for PFS and OS for daratumumab versus the RMG cohort were 0.79 (0.56-1.12; p = .192) and 0.33 (0.21-0.52; p < .001), respectively. CONCLUSIONS: Adjusted comparisons between trial data and historical cohorts can provide useful insights to clinicians and reimbursement decision makers on relative treatment efficacies in the absence of head-to-head comparison studies for daratumumab monotherapy.

Subcutaneous bortezomib in multiple myeloma patients induces similar therapeutic response rates as intravenous application but it does not reduce the incidence of peripheral neuropathy.

OBJECTIVE: Subcutaneous (SC) application of bortezomib has been recently introduced as a new application route in multiple myeloma (MM) patients. We performed an analysis to compare the outcomes of bortezomib-based therapy in multiple myeloma (MM) patients treated using either intravenous (IV) or subcutaneous (SC) route of administration. PATIENTS AND METHODS: During January 2012 through December 2013, we performed a retrospective analysis of 446 patients with MM treated with bortezomib-based regimens (either once weekly - 63% or twice weekly - 27%) in both, the first line setting, and in relapse, with separate analysis of patients undergoing autologous stem cell transplantation. We assessed the response rates and toxicity profiles in both, IV and SC route of bortezomib administration. RESULTS: The response rates in both IV and SC arm were similar with overall response rate 71.7% vs 70.7%, complete remissions in 13.9% vs 8.6%, very good partial remissions in 30.8% vs 34.5% and partial remissions in 27% vs 27.6%. The most frequent grade ≥ 3 toxicities were anemia, thrombocytopenia and neutropenia, with no significant differences between IV and SC group. There were no significant differences in the rate of peripheral neuropathy (PN). PN of any grade was present in 48% in the IV arm and in 41% in the SC arm. PN grade ≥ 2 was present in 20% vs 18% and PN grade ≥ 3 was present in 6% vs 4%. CONCLUSIONS: We conclude that subcutaneous application of bortezomib has similar therapeutic outcomes and toxicity profile as intravenous route of application. In our cohort there was no difference in the incidence of PN, suggesting that PN is dose dependent and might be reduced by lower intensity schemes rather than by the route of administration.