Al‐Mashhadi, Ahmed Ludvigsen

Marketing authorizations for oncology drugs are often based on single‐arm trials (SATs), and real‐world data‐based external comparator cohorts (ECCs) are increasingly explored to contextualize results. In retrospective studies, comparators may be identified by time of diagnosis but included based on time of relapse; such sampling strategies can introduce bias, potentially leading to erroneous efficacy conclusions. Simulated diffuse large B‐cell lymphoma (DLBCL) cohorts were generated using published time‐to‐relapse and post‐relapse survival distributions. Three ECC sampling strategies were evaluated: naïve (screening and inclusion periods coincide), delayed (inclusion period extends beyond screening), and displacement (screening and inclusion periods shifted relative to each other). Different sampling strategies caused significant changes in the time‐to‐relapse distribution in the ECC and, by proxy, the estimated 2‐year post‐relapse overall survival (22.5–52.2%). Naïve sampling consistently resulted in oversampling of early relapses, though bias was reduced with extended inclusion periods; in hypothetical trials, it produced inflated Type I errors (10.5–84.9%) despite α = 0.025. Delayed sampling reduced bias when the inclusion period was sufficiently extended to capture late relapses, yielding unbiased estimates under long delays (Type I error of 2.5% at a 6‐year delay). Displacement sampling depended strongly on the degree of shift: moderate shifts minimized bias, whereas long displacements introduced substantial distortion (Type I error of 2.7% and 0.0% at displacements of 2 and 5, respectively). Real‐world data‐based ECCs in relapsed/refractory oncology are susceptible to selection bias from sampling strategies, particularly through distortions in time‐to‐relapse, leading to erroneous efficacy conclusions; similar bias may occur in non‐oncology settings where time‐to‐treatment initiation is prognostic.

Background: Splenic marginal zone lymphoma (SMZL) is a rare indolent disease with a median overall survival (OS) of more than 10 years, although a proportion of patients may develop aggressive histology transformation. In a previous report from this large, international dataset, the 10-year cumulative incidence of transformation was 17% (95% 13-21) and in another study of 186 patients, the 10-year cumulative incidence was 14%Click or tap here to enter text.. In this report, we focus on risk factors for transformation as well as clinical characteristics and outcomes of transformed SMZL (tSMZL). Patients and methods: Adults diagnosed with SMZL in 2000-2018 were identified through regional or nationwide population-based registries or from hospital registries. Only patients likely to have SMZL as defined by Matutes et al. were included. Those with discordant lymphoma and/or transformation at diagnosis were excluded. Medical records were reviewed by local clinicians with experience in hematology/oncology, and detailed information on clinical characteristics, treatment lines, and outcomes was collected. Only histologically confirmed high-grade transformations (HT) were included. OS was defined as the time from transformation to death or censoring at last follow-up. Additional analyses stratified by treatment exposure prior to HT and treatment of HT were conducted. Multivariable Cox analyses were performed to determine clinicopathological features associated with transformation and OS. Results: Out of 940 patients with SMZL, 111 developed HT during a median follow-up of 9.1 years. The median time from diagnosis to HT was 3.4 years with an interquartile range of 1.6-7.4 years. Median age at HT was 71 years. Patients with HT shared similar baseline characteristics to those without in terms of age at diagnosis (66.4 vs 67.6), f:m ratio (1.5 vs 1.1) and ECOG ³2 (7.2% vs 7.4%). The 5-yr OS from the time of HT was 42% (CI 95%, 32-54). Of the 111 patients with tSMZL, a complete treatment history from SMZL diagnosis until HT was available for 88 included in the following analyses. By the time of HT, 46 had not received any prior systemic therapy (37 only splenectomy, 9 no therapy), 6 patients had received rituximab alone or combined with splenectomy, and 36 patients had received chemotherapy alone or as part of combined modality treatment. In a uni- and multivariable models for HT, we assessed age, treatment at diagnosis, sex, extra-hilar lymphadenopathy, and extranodal involvement. In both the uni- and multivariable model, age >70 (HR 1.9, 95% CI: 1.1-3.4), immediate treatment including splenectomy (HR 2.0, 95% CI: 1.05-3.6), and extra-hilar lymphadenopathy (HR 1.9, 95% CI: 1.1-3.3) were associated with higher HT hazard, while extranodal involvement (HR 0.23, 95% CI: 0.06-0.84) was associated with a lower HT hazard. At the time of first-line treatment, multivariable analysis revealed similar results and with no association between risk of transformation and treatment strategy (i.e splenectomy alone, rituximab monotherapy or chemotherapy with /without rituximab or splenectomy, and other). At the time of HT, patients who had been previously treated with chemotherapy had an inferior 5-year OS of 24% (95%CI: 13-44%) versus 54% (95%CI: 41-71%) for those who had not received chemotherapy prior to HT. In contrast, there was no difference in the survival of patients that transformed less than or more than 24 months from diagnosis with 5-year OS after HT of 35% (95%CI 20-60%) and 45% (95%CI, 33-61%) respectively. In a multivariable Cox regression analyses of age at time of HT, sex, time since last treatment <24 months, chemo-exposure in previous treatment lines and anthracycline-containing therapy (+/-R) at the time of HT, only prior chemo-exposure was borderline associated with poorer OS (HR 1.8, 95%CI: 0.9-3.5). Conclusion: Patients with SMZL face a notable risk of developing tSMZL over time. Patients in need of immediate treatment at first SMZL diagnosis, age >70 and extrahilar lymphadenopathy had a higher risk of tSMZL and outcomes at the time of HT were poor if patients had been exposed to prior chemotherapy after adjustment for age, sex, and time since last treatment.

Introduction: Splenic marginal zone lymphoma (SMZL) is a rare, indolent disease. There is no universally accepted standard therapy and long-term outcome data are limited. Rituximab monotherapy is increasingly used over splenectomy in the first-line setting despite a paucity of comparative studies. In the absence of randomized trials, large-scale international real-world data studies are critical to evaluate outcomes of different treatment interventions and to understand the natural history of SMZL in the rituximab-era. Methods: Adult patients with SMZL diagnosed between Jan 1 st 2000 and Dec 31 st 2018 were identified using regional/nationwide population-based registries or hospital registries in Europe, the UK, North America, and Australia. Medical records and pathology reports from eligible patients were reviewed locally by clinicians with specialty experience in hemato-oncology. SMZL cases were required to meet the diagnostic criteria by Matutes et al. Detailed data on clinico-pathological features, comorbidities, treatments (including treatment intention), treatment responses and survival outcomes were entered in a central study database. Overall survival (OS) was defined as time from diagnosis until death from any cause or censoring at last follow-up unless stated otherwise. Event-free survival (EFS) was defined as the time from diagnosis until histological transformation, initiation of new chemotherapy or death from any cause. Survival probabilities were estimated using the Kaplan-Meier estimator. Cumulative risk of transformation was estimated with death as a competing risk. Primary endpoints were 10-year OS and 5-year EFS respectivly. Results: A total of 934 patients from 25 sites were included. Median age at diagnosis was 68 years (IQR 60-76) and 54% were female. Bone marrow involvement was present in 96% (564/590) of those assessed, anemia (Hb <12g/dL for women or <13g/dL for men) in 58%, LDH >UNL in 46%, lymphocytosis (>5 x10 9/L) in 34%, and B-symptoms in 34%. Treatment data were available for 97% of patients. Median follow-up was 9.1 years (range 0-23). Watch and wait was the initial strategy in 28% and 88% of patients received at least one line of treatment during follow-up with the most common being splenectomy (45%), immuno-chemotherapy (19%) or rituximab monotherapy (8%). Fifteen percent received “other” treatments (i.e., combinations of listed therapies and/or radiation). The overall response rate to first-line treatment was 88% (95%CI: 85-90%) with 61% (95%CI: 57-64%) achieving CR. Second line (2L) therapy was needed in 34% during follow-up, 3L in 20% and 4L+ in 9%. The 5-year EFS and OS for all patients were 61% (95%CI: 57-65%) and 77% (95%CI: 74-80%) respectively. The 10-year OS and lymphoma-specific mortality (with non-SMZL deaths as competing risk) estimates were 60% (95%CI: 57-64%) and 11% (95%CI: 9-14%) respectively. The 5-year OS after 2L and 3L were 61% (95%CI: 55-68%) and 51% (95%CI: 42-61%) respectively (figure 1). The 10-year cumulative risk of histological transformation was 17% (95%CI: 13-21%), with 5-year post-transformation OS of 42% (32-54%). At the time of transformation, 60% were chemo-naive and 52% had never been treated for SMZL. The 5-year OS for chemo-naive patients with transformation was 54% (95%CI: 41-71%) versus 24% (95% CI: 13-44%) for transformations after (immuno)chemotherapy (p = 0.01). When comparing patients intended for treatment in first line with splenectomy (n=312) versus rituximab (n=70), patients treated with splenectomy more frequently presented with extra-hilar lymphadenopathy (35% vs 18%), splenomegaly (92% vs 87%) and anemia (64% vs 48%). OS was similar for the two groups (Figure 2, p = 0.53). The 5-year EFS were 63% (95%CI: 57-68%) and 64% (95%CI: 54-77%), respectively (p = 0.31). Conclusions: To date, this is the largest real-world study of SMZL with detailed treatment and outcome data. The study shows that histological transformation was not uncommon with 10-year risk of 17%. However, outcomes for the entire cohort were excellent irrespective of initial treatment and both OS and EFS were similar after first line rituximab versus splenectomy. Long-term survival remained relatively high even following multiple lines of therapy.

Background: Event-free survival at 24 months (EFS24) after frontline immunochemotherapy (IC) is an important endpoint in diffuse large B-cell lymphoma and follicular lymphoma, and patients who achieve EFS24 have similar survival compared to age- and sex-matched general population. The role of EFS24 in predicting subsequent survival has not been established in mantle cell lymphoma (MCL), possibly due to perceived poor survival historically. In the last decade, the outcomes of MCL are improving in the evolving treatment landscape. In this international multicenter study, we investigated conditional survival and cause of death in patients with MCL who achieved EFS24 after frontline IC in the older and more recent eras. Methods: Outcomes after frontline IC were evaluated in 5 independent cohorts that included over 3000 patients in total: Mayo/Iowa MER prospective cohort, BC Cancer retrospective population-based cohort, US 12-center retrospective cohort, Swedish Lymphoma Registry, and Danish National Lymphoma Registry. For each cohort, 2 treatment eras were defined based on cohort-specific shifts in treatment patterns (Table 1). Overall survival (OS) after diagnosis and after achieving EFS24 were compared to the background age- and sex-matched general population using a standardized mortality ratio (SMR). Cumulative incidences of cause-specific deaths were analyzed using a competing risk model. Results: In the MER cohort, patients treated in Era M1 (2002-2009; n=147) and Era M2 (2010-2015; n=153) both had inferior OS compared to the general US population. A lower SMR in Era M2 vs M1 (2.25 vs 3.46) suggests a narrower gap in OS compared to the general US population. Lymphoma was the leading cause of death in both eras. In Era M1, patients who achieved EFS24 still had inferior OS compared to the general US population (SMR=2.40, 95% CI 1.76-3.19), and lymphoma remained the leading cause of death. For patients in Era M2 who achieved EFS24, the difference in OS compared to the general US population was not statistically significant with current follow-up (SMR=1.43, 95% CI 0.93-2.09), and lymphoma was no longer the leading cause of death (Table 2). In the BC cohort, patients treated in Era B2 (6/2013-2019; n=188) vs Era B1 (2003-5/2013; n=250) had a narrower gap in OS compared to the general British Columbia population (SMR 4.53 vs 6.69). Lymphoma was the leading cause of death in both eras. For patients achieving EFS24, the gap in OS was narrower in Era B2 vs B1 (SMR 3.56 vs 4.99). After achieving EFS24, lymphoma was the single leading cause of death for patients in Era B1 but not in Era B2 (Table 2). In the US 12-center cohort, patients treated in Era U1 (2002-2011; n=312) and Era U2 (2012-2016; n=417) both had inferior OS compared to the general US population (SMR 2.68 and 2.92, respectively). In patients who achieved EFS24, with current follow up, the difference in OS compared to the general US population was statistically significant in Era U1 (SMR=2.01, 95% CI 1.50-2.64) but not in Era U2 (SMR=1.44, 95% CI 0.82-2.34). Lymphoma was not the leading cause of death after achieving EFS24 (Table 2). In the Swedish cohort, the gap in OS compared to the general Swedish population was narrower in Era S2 (2013-2018; n=439) vs S1 (2006-2012; n=442), both after frontline IC (SMR 4.8 vs 5.4) and after achieving EFS24 (SMR 2.6 vs 3.4). After achieving EFS24, lymphoma was the leading cause of death for patients in Era S1 but not in Era S2 (Table 2). In the Danish cohort, patients treated in Era D2 (2014-2020; n=370) vs Era D1 (2004-2013; n=461) had a slightly narrower gap in OS compared to the general Danish population (SMR 1.90 vs 2.10). For patients who achieved EFS24, those in Era D1 still had inferior OS compared to the general Danish population (SMR=1.44, 95% CI 1.22-1.68), but the OS difference compared to the general Danish population in Era D2 was not statistically significant (SMR=1.27, 95% CI 0.92-1.72) with current follow-up (Table 2). Cause of death data were not available in this cohort. Conclusion: Survival in patients with MCL who achieved EFS24 after frontline IC improved in the more recent treatment era and moved closer to the background expected survival. After achieving EFS24, lymphoma-related mortality was no longer the leading cause of death in the more recent era. EFS24 following frontline treatment may become a critical endpoint for predicting subsequent outcomes in patients with MCL in the modern era.