Dynamic Risk Prediction of Treatment Discontinuation Using Patient-Reported Outcomes Data in the Phase III NSABP B-35 Trial.

Predicting an individual's risk of treatment discontinuation is critical for the implementation of precision chemoprevention. We developed partly conditional survival models to predict discontinuation of tamoxifen or anastrozole using patient-reported outcome (PRO) data from postmenopausal women with ductal carcinoma in situ enrolled in the NSABP B-35 clinical trial. In a secondary analysis of the NSABP B-35 clinical trial PRO data, we proposed two models for treatment discontinuation within each treatment arm (anastrozole or tamoxifen treated patients) using partly conditional Cox-type models with time-dependent covariates. A 70/30 split of the sample was used for the training and validation datasets. The predictive performance of the models was evaluated using calibration and discrimination measures based on the Brier score and AUC from time-dependent ROC curves. The predictive models stratified high-risk versus low-risk early discontinuation at a 6-month horizon. For anastrozole-treated patients, predictive factors included baseline body mass index (BMI) and longitudinal patient-reported symptoms such as insomnia, joint pain, hot flashes, headaches, gynecologic symptoms, and vaginal discharge, all collected up to 12 months [Brier score, 0.039; AUC, 0.76; 95% confidence interval (CI), 0.57-0.95]. As for tamoxifen-treated patients, predictive factors included baseline BMI, and time-dependent covariates: cognitive problems, feelings of happiness, calmness, weight problems, and pain (Brier score, 0.032; AUC, 0.78; 95% CI, 0.65-0.91). A real-time calculator based on these models was developed in Shiny to create a web-based application with a future goal to aid healthcare professionals in decision-making. PREVENTION RELEVANCE: The dynamic prediction provided by partly conditional models offers valuable insights into the treatment discontinuation risks using PRO data collected over time from clinical trial participants. This tool may benefit healthcare professionals in identifying patients at high risk of premature treatment discontinuation and support interventions to prevent potential discontinuation.

A multi-laboratory preclinical trial in rodents to assess treatment candidates for acute ischemic stroke.

Human diseases may be modeled in animals to allow preclinical assessment of putative new clinical interventions. Recent, highly publicized failures of large clinical trials called into question the rigor, design, and value of preclinical assessment. We established the Stroke Preclinical Assessment Network (SPAN) to design and implement a randomized, controlled, blinded, multi-laboratory trial for the rigorous assessment of candidate stroke treatments combined with intravascular thrombectomy. Efficacy and futility boundaries in a multi-arm multi-stage statistical design aimed to exclude from further study highly effective or futile interventions after each of four sequential stages. Six independent research laboratories performed a standard focal cerebral ischemic insult in five animal models that included equal numbers of males and females: young mice, young rats, aging mice, mice with diet-induced obesity, and spontaneously hypertensive rats. The laboratories adhered to a common protocol and efficiently enrolled 2615 animals with full data completion and comprehensive animal tracking. SPAN successfully implemented treatment masking, randomization, prerandomization inclusion and exclusion criteria, and blinded assessment of outcomes. The SPAN design and infrastructure provide an effective approach that could be used in similar preclinical, multi-laboratory studies in other disease areas and should help improve reproducibility in translational science.

Simulation study comparing analytical methods for single-item longitudinal patient-reported outcomes data.

PURPOSE: Efficient analytical methods are necessary to make reproducible inferences on single-item longitudinal ordinal patient-reported outcome (PRO) data. A thorough simulation study was performed to compare the performance of the semiparametric probabilistic index models (PIM) with a longitudinal analysis using parametric cumulative logit mixed models (CLMM). METHODS: In the setting of a control and intervention arm, we compared the power of the PIM and CLMM to detect differences in PRO adverse event (AE) between these groups using several existing and novel summary scores of PROs. For each scenario, PRO data were simulated using copula multinomial models. Comparisons were also exemplified using clinical trial data. RESULTS: On average, CLMM provided substantially greater power than the PIM to detect differences in PRO-AEs between the groups when the baseline-adjusted method was used, and a small advantage in power when using the baseline symptom as a covariate. CONCLUSION: Although the CLMM showed the best performance among analytical methods, it relies on assumptions difficult to verify and that might not be fulfilled in the real world, therefore our recommendation is the use of PIM models with baseline symptom as a covariate.

Toxicity Index, patient-reported outcomes, and persistence of breast cancer chemotherapy-associated side effects in NRG Oncology/NSABP B-30.

Adjuvant chemotherapy improves breast cancer survival but is associated with bothersome short- and long-term toxicity. Factors associated with toxicity, especially subacute toxicity up to 2 years following chemotherapy, have not been fully elucidated. The NRG Oncology/NSABP B-30 clinical trial compared 3 different doxorubicin-, cyclophosphamide-, and docetaxel-based chemotherapy regimens given over 3-6 months. Patients with hormone receptor-positive breast cancer received subsequent adjuvant endocrine therapy. From baseline through 24 months, 2156 patients completed questionnaires serially. We used multivariable probabilistic index models to identify factors associated with acute (>0-12 months) and subacute (>12-24 months) difficulties with pain, cognition, vasomotor symptoms, and vaginal symptoms. For all symptom domains, presence of symptoms prior to chemotherapy initiation were associated with symptoms in the subacute period (all p < 0.001). In addition, different combinations of patient factors and breast cancer treatments were associated with increased likelihood of pain, vasomotor, and vaginal symptoms in the subacute period. Consideration of pre-treatment symptoms and patient factors, as well as treatments for breast cancer, can facilitate identification of groups of patients that may experience symptoms following completion of chemotherapy. This information may be important for treatment-decision-making when alternative regimens are equivalent in benefit.

Health-related quality of life outcomes after neoadjuvant chemoradiotherapy for rectal cancer in NRG Oncology/NSABP R-04.

BACKGROUND: There has been limited evaluation of health-related quality of life (HRQOL) in rectal cancer patients receiving neoadjuvant chemoradiotherapy. HRQOL outcomes in the National Surgical Adjuvant Breast and Bowel Project R-04 trial are examined in this article. METHODS: Between 2004 and 2010, R-04 patients were invited to enroll in the HRQOL substudy, with questionnaires administered before randomization, after completion of chemoradiotherapy, and 1-year after surgery. HRQOL measures included: Functional Assessment of Cancer Therapy for colorectal cancer (FACT-C); Short Form-36v.2 Vitality scale; a treatment-specific symptom scale; and the FACT neurotoxicity scale. A 5-year postsurgery assessment was added to the protocol in 2012. Mixed-effects models examined neoadjuvant therapy treatment effects in the 1-year sample and models that explored associations of host factors and treatment impact on 5-year HRQOL. RESULTS: A total of 1373 patients completed baseline HRQOL and at least one additional assessment. The average age was 58 years (range, 23-85 years), male (68%), and 59% Stage II. There were no statistically significant differences in HRQOL outcomes by treatment arm, but HRQOL worsened from baseline to postneoadjuvant chemoradiotherapy, with statistically significant effect sizes changes ranging from 0.6 (Vitality) to 0.9 (FACT-C Trial Outcome Index). Neurotoxicity was greater in the oxaliplatin-treated groups. Obese/overweight patients had statistically significantly worse FACT-C Trial Outcome Index scores than did underweight/normal weight groups. At 5 years, younger patients and those with normal baseline weight had statistically significantly better physical function scores and older patients had better mental health outcomes. CONCLUSIONS: HRQOL did not differ across the four R-04 treatment arms; however, host factors explained significant variation in posttreatment HRQOL. CLINICALTRIALS: gov: NCT00058474 (https://ClinicalTrials.gov/ct2/show/NCT00058474). LAY SUMMARY: This article reports on the health-related quality of life (HRQOL) outcomes of patients treated with four different chemotherapy regimens combined with radiation in rectal cancer patients before definitive surgical treatment. There were no significant differences in HRQOL by treatment regimen, but all patients experienced decreased vitality (energy) and physical functioning. By 1 year after treatment, most patients had returned to pretreatment vitality and physical functioning, with the exception of increased neurotoxicity. In a subsample of patients assessed at 5 years after surgery, physical function was better in those who at pretreatment were younger, normal weight, and had better performance status. Mental function was better in those who at pretreatment were older and had better performance status.

The Stroke Preclinical Assessment Network: Rationale, Design, Feasibility, and Stage 1 Results.

Cerebral ischemia and reperfusion initiate cellular events in brain that lead to neurological disability. Investigating these cellular events provides ample targets for developing new treatments. Despite considerable work, no such therapy has translated into successful stroke treatment. Among other issues-such as incomplete mechanistic knowledge and faulty clinical trial design-a key contributor to prior translational failures may be insufficient scientific rigor during preclinical assessment: nonblinded outcome assessment; missing randomization; inappropriate sample sizes; and preclinical assessments in young male animals that ignore relevant biological variables, such as age, sex, and relevant comorbid diseases. Promising results are rarely replicated in multiple laboratories. We sought to address some of these issues with rigorous assessment of candidate treatments across 6 independent research laboratories. The Stroke Preclinical Assessment Network (SPAN) implements state-of-the-art experimental design to test the hypothesis that rigorous preclinical assessment can successfully reduce or eliminate common sources of bias in choosing treatments for evaluation in clinical studies. SPAN is a randomized, placebo-controlled, blinded, multilaboratory trial using a multi-arm multi-stage protocol to select one or more putative stroke treatments with an implied high likelihood of success in human clinical stroke trials. The first stage of SPAN implemented procedural standardization and experimental rigor. All participating research laboratories performed middle cerebral artery occlusion surgery adhering to a common protocol and rapidly enrolled 913 mice in the first of 4 planned stages with excellent protocol adherence, remarkable data completion and low rates of subject loss. SPAN stage 1 successfully implemented treatment masking, randomization, prerandomization inclusion/exclusion criteria, and blinded assessment to exclude bias. Our data suggest that a large, multilaboratory, preclinical assessment effort to reduce known sources of bias is feasible and practical. Subsequent SPAN stages will evaluate candidate treatments for potential success in future stroke clinical trials using aged animals and animals with comorbid conditions.

HSP90-Specific nIR Probe Identifies Aggressive Prostate Cancers: Translation from Preclinical Models to a Human Phase I Study.

A noninvasive test to discriminate indolent prostate cancers from lethal ones would focus treatment where necessary while reducing overtreatment. We exploited the known activity of heat shock protein 90 (Hsp90) as a chaperone critical for the function of numerous oncogenic drivers, including the androgen receptor and its variants, to detect aggressive prostate cancer. We linked a near-infrared fluorescing molecule to an HSP90 binding drug and demonstrated that this probe (designated HS196) was highly sensitive and specific for detecting implanted prostate cancer cell lines with greater uptake by more aggressive subtypes. In a phase I human study, systemically administered HS196 could be detected in malignant nodules within prostatectomy specimens. Single-cell RNA sequencing identified uptake of HS196 by malignant prostate epithelium from the peripheral zone (AMACR+ERG+EPCAM+ cells), including SYP+ neuroendocrine cells that are associated with therapeutic resistance and metastatic progression. A theranostic version of this molecule is under clinical testing.

Modeling synergism in early phase cancer trials with drug combination with continuous dose levels: is there an added value?

In parametric Bayesian designs of early phase cancer clinical trials with drug combinations exploring a discrete set of partially ordered doses, several authors claimed that there is no added value in including an interaction term to model synergism between the two drugs. In this paper, we investigate these claims in the setting of continuous dose levels of the two agents. Parametric models will be used to describe the relationship between the doses of the two agents and the probability of dose limiting toxicity and efficacy. Trial design proceeds by treating cohorts of two patients simultaneously receiving different dose combinations and response adaptive randomization. We compare trial safety and efficiency of the estimated maximum tolerated dose (MTD) curve between models that include an interaction term with models without the synergism parameter with extensive simulations. Under a selected class of dose-toxicity models and dose escalation algorithm, we found that not including an interaction term in the model can compromise the safety of the trial and reduce the pointwise reliability of the estimated MTD curve.

Visualizing adverse events in clinical trials using correspondence analysis with R-package visae.

BACKGROUND: Graphical displays and data visualization are essential components of statistical analysis that can lead to improved understanding of clinical trial adverse event (AE) data. Correspondence analysis (CA) has been introduced decades ago as a multivariate technique that can communicate AE contingency tables using two-dimensional plots, while quantifying the loss of information as other dimension reduction techniques such as principal components and factor analysis. METHODS: We propose the application of stacked CA using contribution biplots as a tool to explore differences in AE data among treatments in clinical trials. We defined five levels of refinement for the analysis based on data derived from the Common Terminology Criteria for Adverse Events (CTCAE) grades, domains, terms and their combinations. In addition, we developed a Shiny app built in an R-package, visae, publicly available on Comprehensive R Archive Network (CRAN), to interactively investigate CA configurations based on the contribution to the explained variance and relative frequency of AEs. Data from two randomized controlled trials (RCT) were used to illustrate the proposed methods: NSABP R-04, a neoadjuvant rectal 2 × 2 factorial trial comparing radiation therapy with either capecitabine (Cape) or 5-fluorouracil (5-FU) alone with or without oxaliplatin (Oxa), and NSABP B-35, a double-blind RCT comparing tamoxifen to anastrozole in postmenopausal women with hormone-positive ductal carcinoma in situ. RESULTS: In the R04 trial (n = 1308), CA biplots displayed the discrepancies between single agent treatments and their combinations with Oxa at all levels of AE classes, such that these discrepancies were responsible for the largest portion of the explained variability among treatments. In addition, an interaction effect when adding Oxa to Cape/5-FU was identified when the distance between Cape+Oxa and 5-FU + Oxa was observed to be larger than the distance between 5-FU and Cape, with Cape+Oxa and 5-FU + Oxa in different quadrants of the CA biplots. In the B35 trial (n = 3009), CA biplots showed different patterns for non-adherent Anastrozole and Tamoxifen compared with their adherent counterparts. CONCLUSION: CA with contribution biplot is an effective tool that can be used to summarize AE data in a two-dimensional display while minimizing the loss of information and interpretation.

Toxicity Index, Patient-Reported Outcomes, and Early Discontinuation of Endocrine Therapy for Breast Cancer Risk Reduction in NRG Oncology/NSABP B-35.

PURPOSE: The US National Cancer Institute Moonshot initiative calls for improving analysis and reporting of toxicity to inform treatment tolerability. We used existing clinician-reported adverse event (AE) and patient-reported outcome (PRO) questionnaire data from the randomized, double-blind NSABP B-35 clinical trial to explore reasons for anastrozole and tamoxifen discontinuation. METHODS: Postmenopausal women with ductal carcinoma in situ treated with breast-conserving therapy were randomly assigned to anastrozole or tamoxifen for 5 years. The primary outcome for this analysis was time to treatment discontinuation. AEs were collected every 6 months post-random assignment from all 3,104 participants and summarized using the Toxicity Index (TI). PRO data were collected at baseline and every 6 months from 1,194 participants. Univariate and multivariable analyses of time to treatment discontinuation were performed using Cox regression models with TIs and PROs as time-dependent covariates. RESULTS: Of 3,046 analyzed participants, 869 (28.5%) discontinued treatment prematurely. In multivariable analysis, when both baseline PROs and on-treatment AEs were considered, thrombosis and arthralgia AEs were associated with discontinuation of both tamoxifen and anastrozole; additional AEs associated with discontinuation varied by drug. In addition, baseline pain interference, hot flashes, and unhappiness were associated with tamoxifen discontinuation (n = 589; overall Harrell's C-statistic 0.686 [95% CI, 0.640 to 0.732]); no baseline PROs were associated with anastrozole discontinuation (n = 589; overall Harrell's C-statistic 0.656 [95% CI, 0.630 to 0.681]). When only baseline PROs were examined, pain interference, hot flashes, and unhappiness were associated with shorter time to discontinuation of tamoxifen; only hot flashes were associated with discontinuation of anastrozole. CONCLUSION: Analysis of AEs using the TI yielded important insights into reasons for discontinuation of endocrine therapy that was enhanced by the addition of PRO baseline and treatment-emergent symptoms.

Applying the Toxicity Index to Patient-Reported Symptom Data: An Example Using the European Organization for Research and Treatment of Cancer Colorectal Cancer-Specific Quality of Life Questionnaire.

PURPOSE: The toxicity index (TI) is a summary index that accounts for toxicity grades associated with cancer symptoms that is more sensitive than other toxicity systems to treatment differences. The TI can be used with patient-reported symptoms but requires that scores for different items represent equivalent severity. The purpose of this article is to provide an example of scoring patient-reported symptoms that satisfies the requirement of equivalent symptom severity. METHODS: A sample of 1232 adults with rectal cancer from a Phase III clinical trial self-reported 18 symptoms on the European Organization for Research and Treatment of Cancer colorectal cancer measure using a 4-category response scale (not at all, a little bit, quite a bit, or very much). The participants were 22 to 85 years of age (mean age, 57 years), 30% were female, 85% were non-Hispanic white, 59% had stage II cancer, and 41% had stage III cancer. A recoded TI was created using item response theory category thresholds. FINDINGS: The recoded TI had larger rank-order correlations than the original TI with Karnofsky performance status index, hemoglobin level, symptom bother, and other aspects of health-related quality of life. IMPLICATIONS: Recoding items based on category thresholds yielded a more valid TI score that can be used to summarize adverse events.

Phase II trial of cisplatin, gemcitabine and pembrolizumab for platinum-resistant ovarian cancer.

OBJECTIVE: To evaluate the combination of pembrolizumab, cisplatin and gemcitabine in recurrent platinum-resistant ovarian cancer. METHODS: Patients received six cycles of chemotherapy with gemcitabine and cisplatin on day 1 and day 8 of a 21-day treatment cycle. Pembrolizumab was administered on day 1 of cycles 3-6 and as maintenance monotherapy in cycles 7-34. Palliative radiation to a non-target symptomatic lesion was allowed. The primary objective was overall response rate by RECIST 1.1 criteria. Secondary objectives included safety, progression-free survival, time to progression, duration of response and overall survival. RESULTS: An interim analysis for futility was performed at 18 evaluable patients. Overall response rate was 60%, duration of response was 4.9 months and time to progression was 5.2 months. Progression-free survival at 6 and 12 months was 43% and 5%. Median progression-free survival was 6.2 months and median overall survival was 11.3 months. In all patients, CA125 levels reflected response and progression. There were no pseudoprogression events. After receiving palliative radiation during pembrolizumab maintenance, a patient with recurrent ovarian clear cell carcinoma had an exceptional and durable response that is ongoing for greater than 2 years. After consultation with the sponsor, based on the modest duration of response observed at the interim analysis for futility, the decision was made to close the trial to further accrual. CONCLUSIONS: The addition of pembrolizumab to cisplatin and gemcitabine did not appear to provide benefit beyond chemotherapy alone in patients with recurrent platinum-resistant ovarian cancer.

Rationale and design of the Women's Ischemia Trial to Reduce Events in Nonobstructive CAD (WARRIOR) trial.

BACKGROUND: Approximately half of all women with anginal symptoms and/or signs of ischemia and no obstructive coronary artery disease (INOCA) referred for coronary angiography have elevated risk for major adverse cardiac events (MACE), poor quality of life and resource consumption. Yet, guidelines focus on symptom management while clinical practice typically advocates only reassurance. Pilot studies of INOCA subjects suggest benefit with intensive medical therapy (IMT) that includes high-intensity statins and angiotensin converting enzyme inhibitors (ACE-I) or receptor blockers (ARB) to provide the rationale for a randomized pragmatic trial to limit MACE. METHODS: The Women's IschemiA TRial to Reduce Events In Non-ObstRuctive CAD is a multicenter, prospective, randomized, blinded outcome evaluation (PROBE design) of a pragmatic strategy of IMT vs usual care (UC) in 4,422 symptomatic women with INOCA (NCT03417388) in approximately 70 United States sites. The hypothesis is that IMT will reduce the primary outcome of first occurrence of MACE by 20% vs. UC at ∼2.5 year followup. Secondary outcomes include quality of life, time to return to "duty"/work, healthcare utilization, angina, cardiovascular death and individual primary outcome components over 3 years follow-up. The study utilizes web-based data capture, e-consents, single IRB and centralized pharmacy distribution of strategy medications directly to patients' homes to reduce site and patient burden. A biorepository will collect blood samples to assess potential mechanisms. CONCLUSIONS: The results of this trial will provide important data necessary to inform guidelines regarding how best to manage this growing and challenging population of women with INOCA.

Phase II Trial of Costimulation Blockade With Abatacept for Prevention of Acute GVHD.

PURPOSE: Severe (grade 3-4) acute graft-versus-host disease (AGVHD) is a major cause of death after unrelated-donor (URD) hematopoietic cell transplant (HCT), resulting in particularly high mortality after HLA-mismatched transplantation. There are no approved agents for AGVHD prevention, underscoring the critical unmet need for novel therapeutics. ABA2 was a phase II trial to rigorously assess safety, efficacy, and immunologic effects of adding T-cell costimulation blockade with abatacept to calcineurin inhibitor (CNI)/methotrexate (MTX)-based GVHD prophylaxis, to test whether abatacept could decrease AGVHD. METHODS: ABA2 enrolled adults and children with hematologic malignancies under two strata: a randomized, double-blind, placebo-controlled stratum (8/8-HLA-matched URD), comparing CNI/MTX plus abatacept with CNI/MTX plus placebo, and a single-arm stratum (7/8-HLA-mismatched URD) comparing CNI/MTX plus abatacept versus CNI/MTX CIBMTR controls. The primary end point was day +100 grade 3-4 AGVHD, with day +180 severe-AGVHD-free-survival (SGFS) a key secondary end point. Sample sizes were calculated using a higher type-1 error (0.2) as recommended for phase II trials, and were based on predicting that abatacept would reduce grade 3-4 AGVHD from 20% to 10% (8/8s) and 30% to 10% (7/8s). ABA2 enrolled 142 recipients (8/8s, median follow-up = 716 days) and 43 recipients (7/8s, median follow-up = 708 days). RESULTS: In 8/8s, grade 3-4 AGVHD was 6.8% (abatacept) versus 14.8% (placebo) (P = .13, hazard ratio = 0.45). SGFS was 93.2% (CNI/MTX plus abatacept) versus 82% (CNI/MTX plus placebo, P = .05). In the smaller 7/8 cohort, grade 3-4 AGVHD was 2.3% (CNI/MTX plus abatacept, intention-to-treat population), which compared favorably with a nonrandomized matched cohort of CNI/MTX (30.2%, P < .001), and the SGFS was better (97.7% v 58.7%, P < .001). Immunologic analysis revealed control of T-cell activation in abatacept-treated patients. CONCLUSION: Adding abatacept to URD HCT was safe, reduced AGVHD, and improved SGFS. These results suggest that abatacept may substantially improve AGVHD-related transplant outcomes, with a particularly beneficial impact on HLA-mismatched HCT.

On the properties of the toxicity index and its statistical efficiency.

Cancer clinical trials typically generate detailed patient toxicity data. The most common measure used to summarize patient toxicity is the maximum grade among all toxicities and it does not fully represent the toxicity burden experienced by patients. In this article, we study the mathematical and statistical properties of the toxicity index (TI), in an effort to address this deficiency. We introduce a total ordering, (T-rank), that allows us to fully rank the patients according to how frequently they exhibit toxicities, and show that TI is the only measure that preserves the T-rank among its competitors. Moreover, we propose a Poisson-Limit model for sparse toxicity data. Under this model, we develop a general two-sample test, which can be applied to any summary measure for detecting differences among two population of toxicity data. We derive the asymptotic power function of this class as well as the asymptotic relative efficiency (ARE) of the members of the class. We evaluate the ARE formula empirically and show that if the data are drawn from a random Poisson-Limit model, the TI is more efficient, with high probability, than the maximum and the average summary measures. Finally, we evaluate our method on clinical trial toxicity data and show that TI has a higher power in detecting the differences in toxicity profile among treatments. The results of this article can be applied beyond toxicity modeling, to any problem where one observes a sparse array of scores on subjects and a ranking based on extreme scores is desirable.

Evaluating Treatment Tolerability in Cancer Clinical Trials Using the Toxicity Index.

BACKGROUND: The National Cancer Institute Moonshot research initiative calls for improvements in the analysis and reporting of treatment toxicity to advise key stakeholders on treatment tolerability and inform regulatory and clinical decision making. This study illustrates alternative approaches to toxicity evaluation using the National Surgical Adjuvant Breast and Bowel Project R-04 clinical trial as an example. METHODS: National Surgical Adjuvant Breast and Bowel Project R-04 was a neoadjuvant chemoradiation trial in stage II-III rectal cancer patients. A 2 x 2 factorial design was used to evaluate whether the addition of oxaliplatin (Oxa) to 5-fluorouracil (5FU) or capecitabine (Cape) with radiation therapy improved local-regional tumor control. The toxicity index (TI), which accounts for the frequency and severity of toxicities, was compared across treatments using multivariable probabilistic index models, where Pr A < B indicates the probability that higher values of TI were observed for A when compared with B. Baseline age, sex, performance status, body mass index, surgery type, and stage were evaluated as independent risk factors. RESULTS: A total of 4560 toxicities from 1558 patients were analyzed. Results from adjusted probabilistic index models indicate that oxaliplatin-containing regimens had statistically significant (P < .001) probability (Pr) for higher TI compared with regimens without oxaliplatin (Pr 5FU < 5FU + Oxa = 0.619, 95% confidence interval [CI] = 0.560 to 0.674; Pr 5FU < Cape + Oxa = 0.627, 95% CI = 0.568 to 0.682; Pr Cape < 5FU + Oxa = 0.587, 95% 0.527 to 0.644; and Pr Cape < Cape + Oxa = 0.596, 95% 0.536 to 0.653). When compared with other existing toxicity analysis methods, TI provided greater power to detect differences between treatments. CONCLUSIONS: This article uses standard data collected in a cancer clinical trial to introduce descriptive and analytic methods that account for the additional burden of multiple toxicities. These methods may provide a more accurate description of a patient's treatment experience that could lead to individualized dosing for better toxicity control. Future research will evaluate the generalizability of these findings in trials with similar drugs.

Vaccine-Induced Memory CD8+ T Cells Provide Clinical Benefit in HER2 Expressing Breast Cancer: A Mouse to Human Translational Study.

PURPOSE: Immune-based therapy for metastatic breast cancer has had limited success, particularly in molecular subtypes with low somatic mutations rates. Strategies to augment T-cell infiltration of tumors include vaccines targeting established oncogenic drivers such as the genomic amplification of HER2. We constructed a vaccine based on a novel alphaviral vector encoding a portion of HER2 (VRP-HER2). PATIENTS AND METHODS: In preclinical studies, mice were immunized with VRP-HER2 before or after implantation of hHER2+ tumor cells and HER2-specific immune responses and antitumor function were evaluated. We tested VRP-HER2 in a phase I clinical trial where subjects with advanced HER2-overexpressing malignancies in cohort 1 received VRP-HER2 every 2 weeks for a total of 3 doses. In cohort 2, subjects received the same schedule concurrently with a HER2-targeted therapy. RESULTS: Vaccination in preclinical models with VRP-HER2 induced HER2-specific T cells and antibodies while inhibiting tumor growth. VRP-HER2 was well tolerated in patients and vaccination induced HER2-specific T cells and antibodies. Although a phase I study, there was 1 partial response and 2 patients with continued stable disease. Median OS was 50.2 months in cohort 1 (n = 4) and 32.7 months in cohort 2 (n = 18). Perforin expression by memory CD8 T cells post-vaccination significantly correlated with improved PFS. CONCLUSIONS: VRP-HER2 increased HER2-specific memory CD8 T cells and had antitumor effects in preclinical and clinical studies. The expansion of HER2-specific memory CD8 T cells in vaccinated patients was significantly correlated with increased PFS. Subsequent studies will seek to enhance T-cell activity by combining with anti-PD-1.

Comparison between continuous and discrete doses for model based designs in cancer dose finding.

Despite of an extensive statistical literature showing that discretizing continuous variables results in substantial loss of information, categorization of continuous variables has been a common practice in clinical research and in cancer dose finding (phase I) clinical trials. The objective of this study is to quantify the loss of information incurred by using a discrete set of doses to estimate the maximum tolerated dose (MTD) in phase I trials, instead of a continuous dose support. Escalation With Overdose Control and Continuous Reassessment Method were used because they are model-based designs where dose can be specified either as continuous or as a set of discrete levels. Five equally spaced sets of doses with different interval lengths and three sample sizes with sixteen scenarios were evaluated to compare the operating characteristics between continuous and discrete dose designs by Monte Carlo simulation. Loss of information was quantified by safety and efficiency measures. We conclude that if there is insufficient knowledge about the true MTD value, as commonly happens in phase I clinical trials, a continuous dose scheme minimizes information loss. If one is required to implement a design using discrete doses, then a scheme with 9 to 11 doses may yield similar results to the continuous dose scheme.

Adenosine vs Regadenoson Pharmacologic Stress Differs in Women with Suspected Coronary Microvascular Dysfunction: A Report from the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) Study.

Background: Stress cardiac magnetic resonance (CMR) imaging with myocardial perfusion reserve index (MPRI) measurement has emerged as a noninvasive method for assessing coronary microvascular dysfunction (CMD) in the absence of obstructive coronary artery disease (CAD). Pharmacologic stress with adenosine or regadenoson is typically used with comparable coronary vasodilation, but higher unadjusted MPRI has been reported with regadenoson in healthy men. This difference has not been assessed in symptomatic or healthy women. Methods: In a prospective cohort study, 139 symptomatic women with suspected CMD and no obstructive CAD underwent stress CMR and invasive coronary flow reserve (CFR) testing. Adenosine was the default vasodilator (n=99), while regadenoson was used if history of asthma or prior adenosine intolerance (n=40). Stress CMR was also performed in 40 age-matched healthy controls using adenosine (n=20) and regadenoson (n=20). Unpaired t-tests and analysis of covariance were performed to compare MPRI with adenosine and regadenoson in the symptomatic women and healthy controls. Results: Compared to regadenoson cases, adenosine cases had lower invasive CFR (2.64±0.62 vs 2.94±0.68, p=0.01) and pharmacologic heart rate change (28±16 vs 38±15 bpm, p=0.0008). Unadjusted MPRI was lower in the adenosine compared to regadenoson cases (1.73±0.38 vs 2.27±0.59, p<0.0001). When adjusted for heart rate, rate-pressure-product, and invasive CFR, MPRI remained lower in the adenosine cases (p<0.0001). Invasive CFR to adenosine correlated with adenosine MPRI (r 0.17, p=0.02) but not regadenoson MPRI (r -0.14, p=0.19). There was no significant difference in MPRI in the controls who received adenosine vs regadenoson (2.27±0.33 vs 2.38±0.44, p=0.36). Conclusion: In women undergoing stress CMR for suspected CMD, those who received adenosine had lower MPRI than those who received regadenoson. However, there were no differences in MPRI in the healthy controls. These findings suggest there may be physiologic differences in adenosine and regadenoson response in the coronary microcirculation of symptomatic women.