When planning an oncology clinical trial, the usual approach is to assume proportional hazards and even an exponential distribution for time-to-event endpoints. Often, besides the gold-standard endpoint overall survival (OS), progression-free survival (PFS) is considered as a second confirmatory endpoint. We use a survival multistate model to jointly model these two endpoints and find that neither exponential distribution nor proportional hazards will typically hold for both endpoints simultaneously.
View Article and Find Full Text PDFLandmarking is an alternative to complex multistate models when the aim is to calculate dynamic predictions. We develop the concept of landmarking for the case of left truncation and competing risks from the application background of drug safety assessment in pregnancy. The method is illustrated with a cohort study of the German Embryotox Pharmacovigilance Institute in Berlin to assess if the risk or the cumulative incidence of adverse pregnancy outcomes, like spontaneous abortions (SABs), is increased in fluoroquinolone-exposed women.
View Article and Find Full Text PDFAllogeneic hematopoietic stem cell transplantation (allo-HSCT) is the best curative treatment modality for many malignant hematologic disorders. In the absence of a matched related donor, matched unrelated donors (MUDs) and haploidentical donors are the most important stem cell sources. In this registry-based retrospective study, we compared the outcomes of allo-HSCTs from 10/10 MUDs with antithymocyte globulin (ATG)-based regimens (n = 7050) vs haploidentical transplants (Haplo-Tx) using posttransplant cyclophosphamide (PT-CY Haplo; n = 487) in adult patients with hematologic malignancies between 2010 and 2020.
View Article and Find Full Text PDFImproved long-term survival rates after allogeneic hematopoietic cell transplantation (alloHCT) make family planning for young adult cancer survivors an important topic. However, treatment-related infertility risk poses challenges. To assess pregnancy and birth rates in a contemporary cohort, we conducted a national multicenter study using data from the German Transplant Registry, focusing on adult women aged 18 to 40 years who underwent alloHCT between 2003 and 2018.
View Article and Find Full Text PDFBackground: The SAVVY project aims to improve the analyses of adverse events (AEs) in clinical trials through the use of survival techniques appropriately dealing with varying follow-up times and competing events (CEs). This paper summarizes key features and conclusions from the various SAVVY papers.
Methods: Summarizing several papers reporting theoretical investigations using simulations and an empirical study including randomized clinical trials from several sponsor organizations, biases from ignoring varying follow-up times or CEs are investigated.