Canadian cancer trials group LY.17: A randomized phase II study evaluating novel salvage therapy pre-autologous stem cell transplant in relapsed/refractory diffuse large B-cell lymphoma-outcome of rituximab-dose-intensive cyclophosphamide, etoposide, cisplatin (R-DICEP) versus R-GDP.

The Canadian Cancer Trials Group (CCTG) LY.17 is an ongoing multi-arm randomized phase II trial evaluating novel salvage therapies compared with R-GDP (rituximab, gemcitabine, dexamethasone and cisplatin) in autologous stem cell transplantation (ASCT)-eligible patients with relapsed/refractory diffuse large B-cell lymphoma (RR-DLBCL). This component of the LY.17 trial evaluated a dose-intensive chemotherapy approach using a single cycle of inpatient R-DICEP (rituximab, dose-intensive cyclophosphamide, etoposide and cisplatin) to achieve both lymphoma response and stem cell mobilization, shortening time to ASCT. This report is the result of the protocol-specified second interim analysis of the 67 patients who were randomized to either 1 cycle of R-DICEP or to 3 cycles of R-GDP. The overall response rate (ORR) was 65.6% for R-DICEP and 48.6% for R-GDP. The ASCT rate was 71.9% versus 54.3%, and 1-year progression-free survival rate was 42% versus 32%, respectively, for R-DICEP versus R-GDP. Although the improvement in ORR for R-DICEP versus R-GDP exceeded the pre-specified 10% threshold to proceed to full accrual of 64 patients/arm, higher rates of grade 3-5 toxicities, and the need for hospitalization led to the decision to stop this arm of the study. CCTG LY.17 will continue to evaluate different salvage regimens that incorporate novel agents.

Contact Days Associated With Cancer Treatments in the CCTG LY.12 Trial.

BACKGROUND: When cancer treatments have similar oncologic outcomes, the number of days with in-person healthcare contact (""contact days'') can help contextualize expected time use with each treatment. We assessed contact days in a completed randomized clinical trial. PATIENTS AND METHODS: We conducted a secondary analysis of the CCTG LY.12 RCT that evaluated 2-3 cycles of gemcitabine, dexamethasone, and cisplatin (GDP) vs. dexamethasone, cytarabine, and cisplatin (DHAP) in 619 patients with relapsed/refractory lymphoma prior to stem cell transplant. Primary analyses reported similar response rates and survival. We calculated patient-level "contact days" by analyzing trial forms. The study period was from assignment to progression or transplant. Days without healthcare contact were considered "home days''. We compared measures of contact days across arms. RESULTS: The study period was longer in the GDP arm (median 50, vs. 47 days, P = .007). Contact days were comparable in both arms (median 18 vs 19, P = 0.79), but home days were higher in the GDP arm (median 33 vs 28, P < .001). The proportion of contact days was lower in the GDP arm (34%, vs. 38%, P = .009). The GDP arm experienced more contact days related to planned outpatient chemotherapy (median, 10 vs. 8 days), but the DHAP arm experienced many more inpatient contact days (median, 11 vs. 0 days). CONCLUSIONS: Measures of time use, such as contact days, can be extracted from RCTs. In LY.12, despite comparable oncologic outcomes, GDP was associated with fewer contact days. Such information can guide decision-making for patients with hematological cancers, who already face significant healthcare contact.

Power and sample size calculation for incremental net benefit in cost effectiveness analyses with applications to trials conducted by the Canadian Cancer Trials Group.

BACKGROUND: Historically, a priori power and sample size calculations have not been routinely performed cost-effectiveness analyses (CEA), partly because the absence of published cost and effectiveness correlation and variance data, which are essential for power and sample size calculations. Importantly, the empirical correlation between cost and effectiveness has not been examined with respect to the estimation of value-for-money in clinical literature. Therefore, it is not well established if cost-effectiveness studies embedded within randomized-controlled-trials (RCTs) are under- or over-powered to detect changes in value-for-money. However, recently guidelines (such as those from ISPOR) and funding agencies have suggested sample size and power calculations should be considered in CEAs embedded in clinical trials. METHODS: We examined all RCTs conducted by the Canadian Cancer Trials Group with an embedded cost-effectiveness analysis. Variance and correlation of effectiveness and costs were derived from original-trial data. The incremental net benefit method was used to calculate the power of the cost-effectiveness analysis, with exploration of alternative correlation and willingness-to-pay values. RESULTS: We identified four trials for inclusion. We observed that a hypothetical scenario of correlation coefficient of zero between cost and effectiveness led to a conservative estimate of sample size. The cost-effectiveness analysis was under-powered to detect changes in value-for-money in two trials, at willingness-to-pay of $100,000. Based on our observations, we present six considerations for future economic evaluations, and an online program to help analysts include a priori sample size and power calculations in future clinical trials. CONCLUSION: The correlation between cost and effectiveness had a potentially meaningful impact on the power and variance of value-for-money estimates in the examined cost-effectiveness analyses. Therefore, the six considerations and online program, may facilitate a priori power calculations in embedded cost-effectiveness analyses in future clinical trials.

Health-related quality of life in early-stage Hodgkin lymphoma: a longitudinal analysis of the ABVD arm in the randomized controlled trial HD.6.

Early-stage Hodgkin lymphoma has become one of the most curable hematologic malignancies. Depending upon the disease location, possible toxicities, and patient preference, chemotherapy alone with ABVD remains an accepted treatment modality for this disease. There remains a paucity of data regarding the longitudinal trajectory of health-related quality of life (HRQoL) in patients treated for HL. The impact of disease and treatment on HRQoL is increasingly important to understand as the number of long-term survivors increases. We report the longitudinal HRQoL using data prospectively collected from diagnosis up to 10 years post-treatment in the ABVD arm of the HD.6 randomized controlled trial for early-stage HL patients (N=169). We analyzed HRQoL using the EORTC QLQ-C30 collected at baseline, 3 months, 6 months, and 12 months after completion of chemotherapy and yearly up to year 10. Clinically and statistically significant improvements were noted for specific domains including emotional (3 months post-treatment), social (12 months post-treatment) and financial functioning (2 years post-treatment), and the specific symptom of fatigue (6 months post-treatment) during the follow-up period. To our knowledge, this is the first prospective, longitudinal analysis of HRQoL specifically among patients with early-stage HL treated with ABVD therapy alone. Although improvements were noted, sustained clinically and statistically significant improvements were noted only in select symptoms emphasizing the need to better understand and optimize HRQoL among this patient group.

Validating Restricted Mean Survival Time Estimates From Reconstructed Kaplan-Meier Data Against Original Trial Individual Patient Data From Trials Conducted by the Canadian Cancer Trials Group.

OBJECTIVES: The development of novel cancer therapies, including immuno-oncology agents, has increased interest in reconstructed individual patient data (IPD) based restricted mean survival time (RMST) analyses. Additionally, reconstructed IPD-based RMST is recommended in cost-effectiveness analyses when original trial IPD are not available. Nevertheless, recently concerns regarding potential bias of reconstructed-IPD RMST have been presented, because reconstructed-IPD RMSTs have not been validated and previous validation endpoints may not capture the entire Kaplan-Meier (KM) curve, especially the "tail." Our study aims to validate the recommended method of IPD reconstruction by comparing reconstructed IPD- and original trial IPD-based RMST. METHODS: Canadian Cancer Trials Group trials from 1990 to 2017 were included. Overall survival and progression-free survival IPD were reconstructed based on published KM curves using the Guyot method. Analysts were blinded to original trial IPD. RMST was calculated at 1 year and over the entire KM curve. Reconstructed-IPD and original trial-IPD (gold-standard) RMSTs were compared for accuracy and predictive error via mean deviation, mean absolute error (MAE), mean percentage bias, and Bland-Altman plots and across KM curve quality (vector traced or bitmapped). RESULTS: We identified 39 trials. The mean deviation, MAE, and mean percentage bias of RMST between the reconstructed IPD and original trial IPD were small. In particular, the mean deviation was -0.01 months and -0.04 months, MAE was 0.19 months and 0.24 months, and mean percentage bias was 0.82% and 0.84% in overall survival KM curves in control and experimental arms, respectively. Accuracy was generally not associated with KM curve quality. CONCLUSIONS: RMST derived from reconstructed IPD displayed excellent accuracy and predictive error compared with the gold standard. Reconstructed IPD could be used to calculate RMST in lieu of original trial IPD, to facilitate decision making for clinicians, researchers, and policy makers.

A descriptive cost-analysis of MYX.1/MCRN003, a phase 2 clinical trial evaluating high-dose weekly carfilzomib, cyclophosphamide, and dexamethasone in relapsed and refractory multiple myeloma.

BACKGROUND: The prevalence of multiple myeloma is increasing and there is a need to evaluate escalating therapy costs (Canadian Cancer Statistics A, 2020). The MYX.1 phase II trial showed that high-dose weekly carfilzomib, cyclophosphamide, and dexamethasone (wKCD) is efficacious in relapsed and refractory disease. We conducted a descriptive cost analysis, from the perspective of the Canadian public healthcare system, using trial data. METHODS: The primary outcome was the mean total cost per patient. Resource utilization data were collected from all 75 trial patients over a trial time horizon. Costs are presented in Canadian dollars (2020). RESULTS: The cost of treatment was calculated from the time of patient (pt) enrollment until the second data lock. The mean total cost was $203 336.08/pt (range $17 891.27-$505 583.55) Canadian dollars (CAD, where 1 CAD = 0.67 Euro (EUR)) and $14 081.45/pt per cycle. The median number of cycles was 15. The predominant cost driver was the cost of chemotherapy accounting for an average of $179 332.78/pt or $12 419.17/pt per cycle. Carfilzomib acquisition accounted for the majority of chemotherapy costs - $162 471.65/pt or $11 251.50/pt per cycle. Fifty-six percent (56%) of patients had at least one hospitalization during the trial period with an average cost of $12 657.86 per hospitalization. Three patients developed thrombotic microangiopathy (TMA) with an average cost of $18 863.32/pt including the cost of hospitalizations and therapeutic plasma exchange. CONCLUSIONS: High-dose wKCD is an active triplet regimen for relapsed and refractory multiple myeloma (RRMM) associated with reduced total cost compared with twice-weekly carfilzomib-based regimens.

Weekly carfilzomib plus cyclophosphamide and dexamethasone in the treatment of relapsed/refractory multiple myeloma: Final results from the MCRN-003/MYX.1 single arm phase II trial.

The MCRN-003/CCTGMYX.1 is a single arm phase II trial of weekly carfilzomib, cyclophosphamide and dexamethasone (wKCd), exploring a convenient immunomodulator (IMiD)-free regimen in relapsed myeloma. Weekly carfilzomib (20/70 mg/m2 ), dexamethasone 40 mg and cyclophosphamide 300 mg/m2 was delivered over 28-day cycles. The primary endpoint was overall response after four cycles. Secondary endpoints included toxicity, response depth, PFS and OS. Exploratory endpoints included the impact of cytogenetics, prior therapy exposure and serum free light chain (sFLC) escape; 76 patients were accrued. The ORR was 85% (68% ≥very good partial response [VGPR] and 29% ≥complete response [CR]). The median OS and PFS were 27 and 17 months respectively. High-risk cytogenetics conferred a worse ORR (75% vs. 97%, p = .013) and median OS (18 months vs. NR, p = .002) with a trend toward a worse median PFS (14 vs. 22 months, p = .06). Prior proteasome inhibitor (PI) or lenalidomide did not influence OS or PFS. The sFLC was noted in 15% of patients with a median PFS of 17 months when included as a progression event. The most common ≥ grade 3 non-hematologic adverse events were infectious (40%), vascular (17%) and cardiac (15%). The wKCD is a safe and effective regimen in relapse, especially for patients ineligible for lenalidomide-based therapies.

Minimization of resource utilization data collected within cost-effectiveness analyses conducted alongside Canadian Cancer Trials Group phase III trials.

BACKGROUND: Cost-effectiveness analyses embedded within randomized trials allow for evaluation of value alongside conventional efficacy outcomes; however, collection of resource utilization data can require considerable trial resources. METHODS: We re-analyzed the results from four phase III Canadian Cancer Trials Group trials that embedded cost-effectiveness analyses to determine the impact of minimizing potential cost categories on the incremental cost-effectiveness ratios. For each trial, we disaggregated total costs into component incremental cost categories and recalculated incremental cost-effectiveness ratios using (1) only the top 3 cost categories, (2) the top 5 cost categories, and (3) all cost components. Using individual trial-level data, confidence intervals for each incremental cost-effectiveness ratio simulation were generated by bootstrapping and descriptively presented with the original confidence intervals (and incremental cost-effectiveness ratios) from the publications. RESULTS: Drug acquisition costs represented the highest incremental cost category in three trials, while hospitalization costs represented the other consistent cost driver and the top incremental cost category in the fourth trial. Recalculated incremental cost-effectiveness ratios based on fewer cost components (top 3 and top 5) did not differ meaningfully from the original published results. Based on conventional willingness-to-pay thresholds (US$50,000-US$100,000 per quality-adjusted life-year), none of the re-analyses would have changed the original perception of whether the experimental therapies were considered cost-effective. CONCLUSIONS: These results suggest that the collection of resource utilization data within cancer trials could be narrowed. Omission of certain cost categories that have minimal impact on incremental cost-effectiveness ratio, such as routine laboratory investigations, could reduce the costs and undue burden associated with the collection of data required for cancer trial cost-effectiveness analyses.

Outcomes in refractory diffuse large B-cell lymphoma: results from the international SCHOLAR-1 study.

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma. Although 5-year survival rates in the first-line setting range from 60% to 70%, up to 50% of patients become refractory to or relapse after treatment. Published analyses of large-scale outcome data from patients with refractory DLBCL are limited. SCHOLAR-1, an international, multicohort retrospective non-Hodgkin lymphoma research study, retrospectively evaluated outcomes in patients with refractory DLBCL which, for this study, was defined as progressive disease or stable disease as best response at any point during chemotherapy (>4 cycles of first-line or 2 cycles of later-line therapy) or relapsed at ≤12 months from autologous stem cell transplantation. SCHOLAR-1 pooled data from 2 phase 3 clinical trials (Lymphoma Academic Research Organization-CORAL and Canadian Cancer Trials Group LY.12) and 2 observational cohorts (MD Anderson Cancer Center and University of Iowa/Mayo Clinic Lymphoma Specialized Program of Research Excellence). Response rates and overall survival were estimated from the time of initiation of salvage therapy for refractory disease. Among 861 patients, 636 were included on the basis of refractory disease inclusion criteria. For patients with refractory DLBCL, the objective response rate was 26% (complete response rate, 7%) to the next line of therapy, and the median overall survival was 6.3 months. Twenty percent of patients were alive at 2 years. Outcomes were consistently poor across patient subgroups and study cohorts. SCHOLAR-1 is the largest patient-level pooled retrospective analysis to characterize response rates and survival for a population of patients with refractory DLBCL.

Advantages of the net benefit regression framework for trial-based economic evaluations of cancer treatments: an example from the Canadian Cancer Trials Group CO.17 trial.

BACKGROUND: Economic evaluations commonly accompany trials of new treatments or interventions; however, regression methods and their corresponding advantages for the analysis of cost-effectiveness data are not widely appreciated. METHODS: To illustrate regression-based economic evaluation, we review a cost-effectiveness analysis conducted by the Canadian Cancer Trials Group's Committee on Economic Analysis and implement net benefit regression. RESULTS: Net benefit regression offers a simple option for cost-effectiveness analyses of person-level data. By placing economic evaluation in a regression framework, regression-based techniques can facilitate the analysis and provide simple solutions to commonly encountered challenges (e.g., the need to adjust for potential confounders, identify key patient subgroups, and/or summarize "challenging" findings, like when a more effective regimen has the potential to be cost-saving). CONCLUSIONS: Economic evaluations of patient-level data (e.g., from a clinical trial) can use net benefit regression to facilitate analysis and enhance results.

Pilot study of the ability to probabilistically link clinical trial patients to administrative data and determine long-term outcomes.

BACKGROUND: Clinical trials are important but extremely costly. Utilization of routinely collected administrative data may simplify and enhance clinical trial data collection. PURPOSE: The aim of this study was to test the feasibility of use of administrative databases in Ontario, Canada, for long-term clinical trial follow-up, specifically (a) to determine whether limited patient identifiers held by the Canadian Cancer Trials Group can be used to probabilistically link with individuals in the Institute for Clinical Evaluative Sciences databases and if so, (b) the level of concordance between the two data sets. METHODS: This retrospective study was conducted through collaboration of established health service (Institute for Clinical Evaluative Sciences) and clinical trial (Canadian Cancer Trials Group) research groups in the province of Ontario, Canada, where healthcare is predominantly funded by the government. Adults with pre-treated metastatic colorectal cancer previously enrolled in the Canadian Cancer Trials Group CO.17 and CO.20 randomized phase III trials were included, limited to those in Ontario. The main outcomes were rate of successful probabilistic linkage and concordance of survival data, stated a priori. RESULTS: Probabilistic linkage was successful in 266/293 (90.8%) participants. In those patients for whom linkage was successful, the Canadian Cancer Trials Group (trial) and the Institute for Clinical Evaluative Sciences (administrative) data sets were concordant with regard to the occurrence of death during the period of clinical trial follow-up in 206/209 (98.6%). Death was recorded in the Institute for Clinical Evaluative Sciences, but not the Canadian Cancer Trials Group, for 57 cases, where the event occurred after the clinical trial cut-off dates. The recorded date of death matched closely between both databases. During the period of clinical trial conduct, administrative databases contained details of hospitalizations and emergency room visits not captured in the clinical trial electronic database. CONCLUSION: Prospective use of administrative data could enhance clinical trial data collection, both for long-term follow-up and resource utilization for economic analyses and do so less expensively than current primary data collection. Recording a unique identifier (e.g. health insurance number) in trial databases would allow deterministic linkage for all participants.

Salvage chemotherapy and autologous stem cell transplantation for transformed indolent lymphoma: a subset analysis of NCIC CTG LY12.

The treatment of transformed indolent lymphoma (TRIL) often includes salvage chemotherapy (SC) and autologous stem cell transplant (ASCT). NCIC CTG LY12 is a randomized phase 3 trial comparing gemcitabine, dexamethasone, and cisplatin (GDP) with dexamethasone, cytarabine, and cisplatin (DHAP) before ASCT. This analysis compares the results of SC and ASCT for TRIL with de novo diffuse large B-cell lymphoma (DLBCL). Six-hundred nineteen patients with relapsed/refractory aggressive non-Hodgkin lymphoma were randomized to GDP or DHAP; 87 patients (14%) had TRIL and 429 (69%) had DLBCL. The response rate to SC was 47% in TRIL and 45% in DL (P = .81). Transplantation rates were similar: TRIL 53% and DL 52% (P = 1.0). With a median follow-up of 53 months, 4 year overall survival was 39% for TRIL and 41% for DL (P = .78); 4 year event-free survival (EFS) was 27% for TRIL and 27% for DL (P = .83). Post-ASCT, 4-year EFS was 45% for TRIL and 46% for DL. Histology (TRIL or DL) was not a predictor of any outcome in multivariate models. Patients with relapsed or refractory TRIL and DLBCL have similar outcomes with SC and ASCT; this therapy should be considered the standard of care for patients with TRIL who have received prior systemic chemotherapy. NCIC CTG LY12 is registered at ClinicalTrials.gov as #NCT00078949.

Determining the Associations Between Glucocorticoid Use During Hematologic Chemotherapy Treatment and New-onset Diabetes and Hyperglycemia and Mortality: A Population-based Cohort Study.

OBJECTIVES: The aim of this study was to determine the associations between glucocorticoid administration during chemotherapy for hematologic malignancy and hyperglycemia, new-onset diabetes, and mortality in Ontario, Canada. Hospitalization and emergency room utilization during the chemotherapy treatment period were also described. METHODS: We conducted a retrospective cohort study using health administrative data from ICES, Ontario, to assess risk of new-onset diabetes, new-onset hyperglycemia, and hyperglycemia for individuals with leukemia, non-Hodgkin lymphoma (NHL), and Hodgkin lymphoma (HL) receiving glucocorticoids during chemotherapy between 2006 and 2016. Using multivariable regression models, we determined the associations between glucocorticoid exposure and our outcomes of interest, controlling for age, sex, marginalization, and comorbidities. RESULTS: Our cohort included 19,530 individuals; 71.1% (n=13,893) received a glucocorticoid. The highest proportion of hyperglycemia occurred with leukemia (25.4%, n=1,301). Of the 15,580 individuals with no history of diabetes, those with leukemia had the highest rate of new-onset diabetes (7.1%, n=279) and new-onset hyperglycemia (18.1%, n=641), and glucocorticoid exposure increased the risk of new-onset diabetes (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.01 to 1.64, p=0.04) and new-onset hyperglycemia (HR 1.28, 95% CI 1.09 to 1.5, p=0.003). Hyperglycemia during chemotherapy increased the risk of all-cause mortality for the combined (HR 1.18, 95% CI 1.09 to 1.27, p<0.0001) and NHL (HR 1.16, 95% CI 1.04 to 1.28, p=0.007) cohorts. CONCLUSIONS: Hyperglycemia is common during hematologic chemotherapy treatment and is associated with a modest increased risk of all-cause mortality. Routine screening, monitoring, and management of hyperglycemia should be an integral part of treatment plans for leukemia, NHL, or HL, with or without glucocorticoid administration.

Development and testing of a lymphoma clinical trial-specific frailty index: a secondary analysis of the NCIC-CTG LY.12 clinical trial.

The prevalence of frailty in clinical trials of lymphoma is unknown. We conducted a secondary analysis of the phase III LY.12 trial in which patients with relapsed aggressive non-Hodgkin lymphoma were randomized to different salvage regimens before autologous stem cell transplant. The primary objective was to construct a lymphoma clinical trials-specific frailty index (LyFI) using previously described methods. The secondary objective was to describe the association of frailty withover all and event-free survival (OS, EFS). The LyFI was constructed using 619 patients, and11% (N = 70) were classified as frail. Frailty was associated with EFS (HR 1.94, 95%CI 1.53-2.46) and OS (HR 2.01, 95%CI 1.57-2.58) in univariable analysis, but was only significant as a continuous (not binary) variable in multivariable analysis controlling for prognostic score, suggesting limitations of a FI in this trial population. Future work could validate the FI using clinical assessments and/or apply it to an older trial population.

Management and use of healthcare resources in patients with chronic lymphocytic leukemia initiating venetoclax in routine clinical practice.

Venetoclax is a first-in-class B-cell lymphoma-2 (BCL-2) inhibitor approved as continuous monotherapy and in combination with rituximab as fixed-treatment duration for relapsed and refractory chronic lymphocytic leukemia (R/R CLL). DEVOTE was a 24-week, multicenter observational study (NCT03310190) evaluating the safety, healthcare resource utilization (HCRU) and health-related quality of life (HRQoL) of patients initiating venetoclax for R/R CLL in Canada. Overall, 89 patients received 1 dose of venetoclax; 80% had prior exposure (42% resistant) to ibrutinib. Biochemical tumor lysis syndrome (TLS) occurred in five patients. We observed differences in hospitalization across Canadian provinces including in patients at low risk for TLS with no clear impact on TLS incidence. Additionally, a rapid and sustained improvement in several domains of HRQoL was observed during venetoclax initiation. Early adoption of venetoclax was mainly for R/R CLL patients with few treatment options; nonetheless, acceptable toxicity and a positive impact on HRQoL were observed.

COVID-19 vaccine immunogenicity and safety surrounding fourth and subsequent vaccine doses in patients with hematologic malignancies.

BACKGROUND: Immune response to COVID-19 vaccine is diminished in patients with hematologic malignancy. There is limited data regarding response to vaccine doses in these patients. PURPOSE: To quantify the humoral immune response engendered by 4th and subsequent doses of SARS-CoV-2 vaccination as measured by anti-Spike (anti-S) antibody levels, based on dried blood spot (DBS) testing, in patients with hematologic malignancies. Anti-S binds to the spike protein of the SARS-CoV-2 virus and is indicative of vaccine immunogenicity. METHODS: We conducted a prospective study of hematologic malignancies between August 2021 and January 2023 at 12 sites across Canada. Participants were followed longitudinally and submitted finger-prick DBS cards at set intervals associated with vaccination. Samples were processed via high throughput ELISA assay to detect serum antibodies against nucleocapsid (N) and spike (S) proteins. RESULTS: We obtained 3071 samples on 790 unique patients. Of these, 372 unique participants with 1840 samples had anti-S results available post-4th, 5th or 6th COVID-19 vaccine dose and were included for analysis. Three hundred thirty-three patients of the 372 participants submitted a DBS sample post 4th dose. Of these, 257 patients (77.2%) had a positive anti-S antibody. A total of 198 patients had paired samples pre- and post-dose 4, of which 59 (29.7%) had a negative anti-S antibody pre-dose 4. Of these, 20 (33.4%) developed positive anti-S antibody post-dose 4. One hundred forty-nine patients submitted a DBS sample post-dose 5. Of these, 135 patients (90.6%) had positive anti-S antibody. A total of 52 had paired samples pre- and post-dose 5. Six (8.7%) had a negative anti-S antibody pre-dose 5, of which two (33.3%) developed positive anti-S antibody post-dose 5. Of these 372 patients, 123 (34%) reported COVID-19 infection and 4 (1%) had a COVID-19 related hospitalization. There were no reported deaths from COVID-19. CONCLUSIONS: This prospective cohort study showed that humoral immune response improved with subsequent doses of COVID-19 vaccines.

A retrospective study of autologous stem cell mobilization to guide an immediate salvage protocol using plerixafor for patients who mobilize stem cells poorly.

The addition of plerixafor to G-CSF decreases the risk of failed stem cell collection, but at considerable extra cost. Using a logistic regression model based on 354 autologous mobilizations, we have identified a local minimum peripheral blood CD34 count at which the probability of a successful collection is 50%. This seems an appropriate CD34 count at which to add immediate salvage plerixafor.

Augmenting clinical trial economic analysis by linking cancer trial data to administrative data: current landscape and future opportunities.

BACKGROUND: Economic analyses based on clinical trial data are costly and time consuming, and alternative methods for performing economic analyses should be explored. OBJECTIVE AND METHODS: In this perspective, we examine the emerging role of administrative data for economic analyses in cancer. RESULTS: Compared with routinely collected clinical trial data, routinely collected administrative data have several strengths including high capture rates for healthcare encounters, less resource utilisation, low rates of misclassification, long follow-up periods and the opportunity to collect data points not traditionally captured in clinical trials. However, there are also limitations including the need for accurate data linkage across multiple databases and systems, the costs and time associated with data linkage, the potential time lag between trial data collection and the availability of administrative data, and limited data on quality of life, toxicity and indirect costs. In this perspective, we identify important barriers and potential solutions to performing economic analyses for oncology using administrative data, and outline strategies to increase research in this field. CONCLUSION: The use of routinely collected administrative data sets for economic analyses of clinical trials presents a unique opportunity that could complement and validate economic analyses based on trial-level data.