Duo Shared Genomic Segment analysis identifies a genome-wide significant risk locus at 18q21.33 in myeloma pedigrees

Aim: High-risk pedigrees (HRPs) are a powerful design to map highly penetrant risk genes. We previously described Shared Genomic Segment (SGS) analysis, a mapping method for single large extended pedigrees that also addresses genetic heterogeneity inherent in complex diseases. SGS identifies shared segregating chromosomal regions that may inherit in only a subset of cases. However, single large pedigrees that are individually powerful (at least 15 meioses between studied cases) are scarce. Here, we expand the SGS strategy to incorporate evidence from two extended HRPs by identifying the same segregating risk locus in both pedigrees and allowing for some relaxation in the size of each HRP.Methods: Duo-SGS is a procedure to combine single-pedigree SGS evidence. It implements statistically rigorous duo-pedigree thresholding to determine genome-wide significance levels that account for optimization across pedigree pairs. Single-pedigree SGS identifies optimal segments shared by case subsets at each locus across the genome, with nominal significance assessed empirically. Duo-SGS combines the statistical evidence for SGS segments at the same genomic location in two pedigrees using Fisher’s method. One pedigree is paired with all others and the best duo-SGS evidence at each locus across the genome is established. Genome-wide significance thresholds are determined through distribution-fitting and the Theory of Large Deviations. We applied the duo-SGS strategy to eleven extended, myeloma HRPs.Results: We identified one genome-wide significant region at 18q21.33 (0.85 Mb, P = 7.3 × 10-9) which contains one gene, CDH20. Thirteen regions were genome-wide suggestive: 1q42.2, 2p16.1, 3p25.2, 5q21.3, 5q31.1, 6q16.1, 6q26, 7q11.23, 12q24.31, 13q13.3, 18p11.22, 18q22.3 and 19p13.12.Conclusion: Our results provide novel risk loci with segregating evidence from multiple HRPs and offer compelling targets and specific segment carriers to focus a future search for functional variants involved in inherited risk formyeloma

Allogeneic stem cell transplant for multiple myeloma & myelofibrosis with split-dose busulfan, fludarabine & cyclophosphamide

Allogeneic stem cell transplant can have high morbidity and mortality in patients with myelofibrosis (MF) and multiple myeloma (MM). This phase 2 study used a novel myeloablative regimen of split-dose busulfan, fludarabine, and then post-transplant cyclophosphamide. Four patients with MF and 2 with MM were enrolled. At 1 year, non-relapse mortality was 33.3%, and overall survival was 50%. Incidence of acute and chronic GVHD was 33.3% and 16.7%, respectively. Those surviving beyond 1 year (MF = 1, MM = 2) had durable remissions with a median follow-up of 42 months. This small study demonstrates relative safety & favorable key outcomes using this novel approach

Characteristics of clinical trials for haematological malignancies from 2015 to 2020: A systematic review.

BackgroundAs the landscape of haematological malignancies dramatically changes due to diagnostic and therapeutic advances, it is important to evaluate trends in clinical trial designs. The objective of our study was to describe the design of clinical trials for five common haematological malignancies with respect to randomisation and end-points. We also aimed to assess trends over time and examine the relationships of funding source and country of origin to proportions of randomisation and utilisation of clinical end-points.MethodsThis systematic review identified haematological malignancy clinical trials starting in 2015-2020 registered at ClinicalTrials.gov as of 20th February 2021. Trial-related variables including randomisation status, type of primary end-point, and both projected and actual enrolment numbers were captured. Clinical end-points were defined as overall survival and quality of life, while surrogate end-points included all other end-points.ResultsOf 2609 relevant trials included in this analysis, only one-fifth were randomised (538, 21%), with a significant decrease in the proportion of randomised clinical trials from 26% of trials in 2015 to 19% in 2020 (p < 0.00001). Between the years 2015 and 2020, the proportion of randomised trials for all haematological malignancies using primary surrogate end-points remained relatively consistent, ranging from 84% in 2015 to 78% in 2020 (p = 0.352). Overall, only 15% of trials utilised primary end-points of overall survival or quality of life in a randomised design.ConclusionsThis systematic review of haematological malignancy trials found that the majority of trials are non-randomised and that there has been an increase in the ratio of non-randomised to randomised studies over time. The vast majority of randomised haematological malignancy trials use surrogate primary end-points

Global Myeloma Trial Participation and Drug Access in the Era of Novel Therapies

The globalization of clinical trials has accelerated recent advances in multiple myeloma (MM). However, it is unclear whether trial enrollment locations are reflective of the global burden of MM and whether access to novel therapies is timely and equitable for countries that participate in those trials. MM trials are generally conducted in countries that are high-income and located in Europe or Central Asia

Time-to-event surrogate end-points in multiple myeloma randomised trials from 2005 to 2019: A surrogacy analysis

Use of surrogate end-points such as progression-free survival (PFS) and other time-to-event (TTE) end-points is common in multiple myeloma (MM) clinical trials. This systematic review characterises all published randomised controlled trials (RCTs) in MM using PFS or other TTE end-points between 2005 and 2019 and assesses strength of surrogacy of PFS for overall survival (OS). The association between OS hazard ratios (HRs) and PFS HRs was evaluated with linear regression, and the coefficient of determination with Pearson's correlation. We identified 88 RCTs of which 67 (76%) used PFS as the primary/co-primary end-point. One trial indicated whether progression was biochemical or clinical. Of the variance in OS, 39% was due to variance in PFS. Correlation between PFS and OS was weak (0.62, 95% confidence interval [CI] 0.38–0.78). In newly diagnosed MM, 43% of the variance in OS was due to changes in PFS. The correlation between PFS and OS was weak (0.65, 95% CI 0.30–0.84). In relapsed/refractory MM, 58% of the variance in OS was due to changes in PFS. Correlation between PFS and OS was medium (0.76, 95% CI 0.42–0.91). We demonstrate that PFS and progression characteristics are characterised poorly in MM trials and that PFS is a poor surrogate for OS in MM