Atezolizumab for Advanced Alveolar Soft Part Sarcoma.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare soft-tissue sarcoma with a poor prognosis and no established therapy. Recently, encouraging responses to immune checkpoint inhibitors have been reported. METHODS: We conducted an investigator-initiated, multicenter, single-group, phase 2 study of the anti-programmed death ligand 1 (PD-L1) agent atezolizumab in adult and pediatric patients with advanced ASPS. Atezolizumab was administered intravenously at a dose of 1200 mg (in patients ≥18 years of age) or 15 mg per kilogram of body weight with a 1200-mg cap (in patients <18 years of age) once every 21 days. Study end points included objective response, duration of response, and progression-free survival according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, as well as pharmacodynamic biomarkers of multistep drug action. RESULTS: A total of 52 patients were evaluated. An objective response was observed in 19 of 52 patients (37%), with 1 complete response and 18 partial responses. The median time to response was 3.6 months (range, 2.1 to 19.1), the median duration of response was 24.7 months (range, 4.1 to 55.8), and the median progression-free survival was 20.8 months. Seven patients took a treatment break after 2 years of treatment, and their responses were maintained through the data-cutoff date. No treatment-related grade 4 or 5 adverse events were recorded. Responses were noted despite variable baseline expression of programmed death 1 and PD-L1. CONCLUSIONS: Atezolizumab was effective at inducing sustained responses in approximately one third of patients with advanced ASPS. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT03141684.).

Comparative "nocebo effects" in older patients enrolled in cancer therapeutic trials: Observations from a 446-patient cohort.

BACKGROUND: A nocebo is an inert substance associated with adverse events. Although previous studies have examined the positive (placebo) effects of such inert substances, few have examined negative (nocebo) adverse event profiles, particularly in older patients who have higher morbidity and can experience frequent and severe adverse events from cancer therapy. METHODS: This study focused on placebo/nocebo-exposed patients who participated in 2 double-blind, placebo-controlled, cancer therapeutic studies, namely, North Central Cancer Therapy Group trial NCCTG 97-24-51 and American College of Surgeons Oncology Group trial Z9001, with the goal of reporting the comparative, age-based adverse event rates, as reported during the conduct of these trials. RESULTS: Among the 446 patients who received only placebo/nocebo and who were the focus of the current report, 161 were aged ≥65 years at the time of respective trial entry, and 5234 adverse events occurred. Unadjusted adverse event rates did not differ significantly between patients aged ≥65 years and younger patients (rate ratio, 1.01; 99% confidence interval, 0.47-2.02), and the findings were similar findings for grade 2 or worse adverse events and for all symptom-driven adverse events (for example, pain, loss of appetite, anxiety). Adjustment for sex, ethnicity, baseline performance score, and individual trial resulted in no significant age-based differences in adverse event rates. Similar findings were observed with an age threshold of 70 years. CONCLUSIONS: Adverse events are equally common in older and younger cancer patients who are exposed to nocebo and thus require the same degree of clinical consideration regardless of age. Cancer 2017;123:4193-4198. © 2017 American Cancer Society.

Effect of Longer-Interval vs Standard Dosing of Zoledronic Acid on Skeletal Events in Patients With Bone Metastases: A Randomized Clinical Trial.

Importance: Zoledronic acid, a third-generation aminobisphosphonate, reduces the incidence of skeletal-related events and pain in patients with bone metastases. The optimal dosing interval for zoledronic acid is uncertain. Objective: To determine whether zoledronic acid administered every 12 weeks is noninferior to zoledronic acid administered every 4 weeks. Design, Setting, Participants: Randomized, open-label clinical trial conducted at 269 academic and community sites in the United States. Patients (n = 1822) with metastatic breast cancer, metastatic prostate cancer, or multiple myeloma who had at least 1 site of bone involvement were enrolled between May 2009 and April 2012; follow-up concluded in April 2014. Interventions: Patients were randomized to receive zoledronic acid administered intravenously every 4 weeks (n = 911) vs every 12 weeks (n = 911) for 2 years. Main Outcomes and Measures: The primary end point was the proportion of patients having at least 1 skeletal-related event (defined as clinical fracture, spinal cord compression, radiation to bone, or surgery involving bone) within 2 years after randomization and a between-group absolute difference of 7% as the noninferiority margin. Secondary end points included the proportion of patients with at least 1 skeletal-related event by disease type, pain as assessed by the Brief Pain Inventory (range, 0-10; higher scores indicate worse pain), Eastern Cooperative Oncology Group performance status (range, 0-4; higher scores indicate worse disability), incidence of osteonecrosis of the jaw, kidney dysfunction, skeletal morbidity rate (mean number of skeletal-related events per year), and, in a subset of 553 patients, suppression of bone turnover (assessed by C-terminal telopeptide levels). Results: Among 1822 patients who were randomized (median age, 65 years; 980 [53.8%] women; 855 with breast cancer, 689 with prostate cancer, and 278 with multiple myeloma), 795 completed the study at 2 years. A total of 260 patients (29.5%) in the zoledronic acid every 4-week dosing group and 253 patients (28.6%) in the every 12-week dosing group experienced at least 1 skeletal-related event within 2 years of randomization (risk difference of -0.3% [1-sided 95% CI, -4% to ∞]; P < .001 for noninferiority). The proportions of skeletal-related events did not differ significantly between the every 4-week dosing group vs the every 12-week dosing group for patients with breast cancer, prostate cancer, or multiple myeloma. Pain scores, performance status scores, incidence of jaw osteonecrosis, and kidney dysfunction did not differ significantly between the treatment groups. Skeletal morbidity rates were numerically identical in both groups, but bone turnover was greater (C-terminal telopeptide levels were higher) among patients who received zoledronic acid every 12 weeks. Conclusions and Relevance: Among patients with bone metastases due to breast cancer, prostate cancer, or multiple myeloma, the use of zoledronic acid every 12 weeks compared with the standard dosing interval of every 4 weeks did not result in an increased risk of skeletal events over 2 years. This longer interval may be an acceptable treatment option. Trial Registration: clinicaltrials.gov Identifier: NCT00869206.

Simple subgroup approximations to optimal treatment regimes from randomized clinical trial data.

We consider the use of randomized clinical trial (RCT) data to identify simple treatment regimes based on some subset of the covariate space, A. The optimal subset, A, is selected by maximizing the expected outcome under a treat-if-in-A regime, and is restricted to be a simple, as it is desirable that treatment decisions be made with only a limited amount of patient information required. We consider a two-stage procedure. In stage 1, non-parametric regression is used to estimate treatment effects for each subject, and in stage 2 these treatment effect estimates are used to systematically evaluate many subgroups of a simple, prespecified form to identify A. The proposed methods were found to perform favorably compared with two existing methods in simulations, and were applied to prehypertension data from an RCT.

Reader reaction to "a robust method for estimating optimal treatment regimes" by Zhang et al. (2012).

A recent article (Zhang et al., 2012, Biometrics 168, 1010-1018) compares regression based and inverse probability based methods of estimating an optimal treatment regime and shows for a small number of covariates that inverse probability weighted methods are more robust to model misspecification than regression methods. We demonstrate that using models that fit the data better reduces the concern about non-robustness for the regression methods. We extend the simulation study of Zhang et al. (2012, Biometrics 168, 1010-1018), also considering the situation of a larger number of covariates, and show that incorporating random forests into both regression and inverse probability weighted based methods improves their properties.

Variable selection in monotone single-index models via the adaptive LASSO.

We consider the problem of variable selection for monotone single-index models. A single-index model assumes that the expectation of the outcome is an unknown function of a linear combination of covariates. Assuming monotonicity of the unknown function is often reasonable and allows for more straightforward inference. We present an adaptive LASSO penalized least squares approach to estimating the index parameter and the unknown function in these models for continuous outcome. Monotone function estimates are achieved using the pooled adjacent violators algorithm, followed by kernel regression. In the iterative estimation process, a linear approximation to the unknown function is used, therefore reducing the situation to that of linear regression and allowing for the use of standard LASSO algorithms, such as coordinate descent. Results of a simulation study indicate that the proposed methods perform well under a variety of circumstances and that an assumption of monotonicity, when appropriate, noticeably improves performance. The proposed methods are applied to data from a randomized clinical trial for the treatment of a critical illness in the intensive care unit.

Design of phase II oncology trials evaluating combinations of experimental agents.

We consider the design of phase II trials evaluating combinations of experimental therapies. In the modern era, many immunotherapy and targeted therapy regimens are being developed as combination regimens, including combinations consisting only of experimental agents. In some clinical or drug development scenarios, it may be difficult to isolate the effect of the individual agents composing a combination of this type, which makes the evaluation of the combination challenging. One such scenario arises when none of the agents making up the experimental combination have demonstrated single-agent activity in the clinical setting of interest. One solution to this problem is to use a randomized comparative trial in which the combination of interest is compared with 1 or both of its component agents, but some modifications to more traditional randomized comparative phase II trials must be made because all arms in such a trial would be experimental. In this manuscript, we present sensible modifications to randomized phase II trial designs that can be used in 2 common drug development scenarios of this type and provide a detailed discussion of the practical aspects of designing these trials. We also include 2 worked examples to further illustrate how to design such a trial.

Standardized Definitions for Efficacy End Points in Neoadjuvant Breast Cancer Clinical Trials: NeoSTEEP.

PURPOSE: The Standardized Definitions for Efficacy End Points (STEEP) criteria, established in 2007 and updated in 2021 (STEEP 2.0), provide standardized definitions of adjuvant breast cancer (BC) end points. STEEP 2.0 identified a need to separately address end points for neoadjuvant clinical trials. The multidisciplinary NeoSTEEP working group of experts was convened to critically evaluate and align neoadjuvant BC trial end points. METHODS: The NeoSTEEP working group concentrated on neoadjuvant systemic therapy end points in clinical trials with efficacy outcomes-both pathologic and time-to-event survival end points-particularly for registrational intent. Special considerations for subtypes and therapeutic approaches, imaging, nodal staging at surgery, bilateral and multifocal diseases, correlative tissue collection, and US Food and Drug Administration regulatory considerations were contemplated. RESULTS: The working group recommends a preferred definition of pathologic complete response (pCR) as the absence of residual invasive cancer in the complete resected breast specimen and all sampled regional lymph nodes (ypT0/Tis ypN0 per AJCC staging). Residual cancer burden should be a secondary end point to facilitate future assessment of its utility. Alternative end points are needed for hormone receptor-positive disease. Time-to-event survival end point definitions should pay particular attention to the measurement starting point. Trials should include end points originating at random assignment (event-free survival and overall survival) to capture presurgery progression and deaths as events. Secondary end points adapted from STEEP 2.0, which are defined from starting at curative-intent surgery, may also be appropriate. Specification and standardization of biopsy protocols, imaging, and pathologic nodal evaluation are also crucial. CONCLUSION: End points in addition to pCR should be selected on the basis of clinical and biologic aspects of the tumor and the therapeutic agent investigated. Consistent prespecified definitions and interventions are paramount for clinically meaningful trial results and cross-trial comparison.

Clinical Activity of Single-Agent Cabozantinib (XL184), a Multi-receptor Tyrosine Kinase Inhibitor, in Patients with Refractory Soft-Tissue Sarcomas.

PURPOSE: Soft-tissue sarcomas (STS) are a rare, heterogeneous group of mesenchymal tumors. For decades the mainstay of treatment for advanced, unresectable STS has been palliative chemotherapy. High levels of activated MET receptor have been reported in various sarcoma cell lines, together with elevated vascular endothelial growth factor (VEGF) levels in patients with STS, suggesting that dual targeting of the VEGF and MET pathways with the multi-receptor tyrosine kinase inhibitor cabozantinib would result in clinical benefit in this population. PATIENTS AND METHODS: We performed an open-label, multi-institution, single-arm phase II trial of single-agent cabozantinib in adult patients with advanced STS and progressive disease after at least 1 standard line of systemic therapy. Patients received 60 mg oral cabozantinib once daily in 28-day cycles, and dual primary endpoints of overall response rate and 6-month progression-free survival (PFS) were assessed. Changes in several circulating biomarkers were assessed as secondary endpoints. RESULTS: Six (11.1%; 95% CI, 4.2%-22.6%) of the 54 evaluable patients enrolled experienced objective responses (all partial responses). Six-month PFS was 49.3% (95% CI, 36.2%-67.3%), with a median time on study of 4 cycles (range, 1-99). The most common grade 3/4 adverse events were hypertension (7.4%) and neutropenia (16.7%). Patients' levels of circulating hepatocyte growth factor (HGF), soluble MET, and VEGF-A generally increased after a cycle of therapy, while soluble VEGFR2 levels decreased, regardless of clinical outcome. CONCLUSIONS: Cabozantinib single-agent antitumor activity was observed in patients with selected STS histologic subtypes (alveolar soft-part sarcoma, undifferentiated pleomorphic sarcoma, extraskeletal myxoid chondrosarcoma, and leiomyosarcoma) highlighting the biomolecular diversity of STS.

Subgroup identification from randomized clinical trial data.

We consider the problem of identifying a subgroup of patients who may have an enhanced treatment effect in a randomized clinical trial, and it is desirable that the subgroup be defined by a limited number of covariates. For this problem, the development of a standard, pre-determined strategy may help to avoid the well-known dangers of subgroup analysis. We present a method developed to find subgroups of enhanced treatment effect. This method, referred to as 'Virtual Twins', involves predicting response probabilities for treatment and control 'twins' for each subject. The difference in these probabilities is then used as the outcome in a classification or regression tree, which can potentially include any set of the covariates. We define a measure Q(Â) to be the difference between the treatment effect in estimated subgroup  and the marginal treatment effect. We present several methods developed to obtain an estimate of Q(Â), including estimation of Q(Â) using estimated probabilities in the original data, using estimated probabilities in newly simulated data, two cross-validation-based approaches, and a bootstrap-based bias-corrected approach. Results of a simulation study indicate that the Virtual Twins method noticeably outperforms logistic regression with forward selection when a true subgroup of enhanced treatment effect exists. Generally, large sample sizes or strong enhanced treatment effects are needed for subgroup estimation. As an illustration, we apply the proposed methods to data from a randomized clinical trial.

Updated Standardized Definitions for Efficacy End Points (STEEP) in Adjuvant Breast Cancer Clinical Trials: STEEP Version 2.0.

PURPOSE: The Standardized Definitions for Efficacy End Points (STEEP) criteria, established in 2007, provide standardized definitions of adjuvant breast cancer clinical trial end points. Given the evolution of breast cancer clinical trials and improvements in outcomes, a panel of experts reviewed the STEEP criteria to determine whether modifications are needed. METHODS: We conducted systematic searches of ClinicalTrials.gov for adjuvant systemic and local-regional therapy trials for breast cancer to investigate if the primary end points reported met STEEP criteria. On the basis of common STEEP deviations, we performed a series of simulations to evaluate the effect of excluding non-breast cancer deaths and new nonbreast primary cancers from the invasive disease-free survival end point. RESULTS: Among 11 phase III breast cancer trials with primary efficacy end points, three had primary end points that followed STEEP criteria, four used STEEP definitions but not the corresponding end point names, and four used end points that were not included in the original STEEP manuscript. Simulation modeling demonstrated that inclusion of second nonbreast primary cancer can increase the probability of incorrect inferences, can decrease power to detect clinically relevant efficacy effects, and may mask differences in recurrence rates, especially when recurrence rates are low. CONCLUSION: We recommend an additional end point, invasive breast cancer-free survival, which includes all invasive disease-free survival events except second nonbreast primary cancers. This end point should be considered for trials in which the toxicities of agents are well-known and where the risk of second primary cancer is small. Additionally, we provide end point recommendations for local therapy trials, low-risk populations, noninferiority trials, and trials incorporating patient-reported outcomes.

Molecular Profiling-Based Assignment of Cancer Therapy (NCI-MPACT): A Randomized Multicenter Phase II Trial.

This trial assessed the utility of applying tumor DNA sequencing to treatment selection for patients with advanced, refractory cancer and somatic mutations in one of four signaling pathways by comparing the efficacy of four study regimens that were either matched to the patient's aberrant pathway (experimental arm) or not matched to that pathway (control arm). MATERIALS AND METHODS: Adult patients with an actionable mutation of interest were randomly assigned 2:1 to receive either (1) a study regimen identified to target the aberrant pathway found in their tumor (veliparib with temozolomide or adavosertib with carboplatin [DNA repair pathway], everolimus [PI3K pathway], or trametinib [RAS/RAF/MEK pathway]), or (2) one of the same four regimens, but chosen from among those not targeting that pathway. RESULTS: Among 49 patients treated in the experimental arm, the objective response rate was 2% (95% CI, 0% to 10.9%). One of 20 patients (5%) in the experimental trametinib cohort had a partial response. There were no responses in the other cohorts. Although patients and physicians were blinded to the sequencing and random assignment results, a higher pretreatment dropout rate was observed in the control arm (22%) compared with the experimental arm (6%; P = .038), suggesting that some patients may have had prior tumor mutation profiling performed that led to a lack of participation in the control arm. CONCLUSION: Further investigation, better annotation of predictive biomarkers, and the development of more effective agents are necessary to inform treatment decisions in an era of precision cancer medicine. Increasing prevalence of tumor mutation profiling and preference for targeted therapy make it difficult to use a randomized phase II design to evaluate targeted therapy efficacy in an advanced disease setting.

Single-Arm Phase II Trials of Combination Therapies: A Review of the CTEP Experience 2008-2017.

Designing and interpreting single-arm phase II trials of combinations of agents is challenging because it can be difficult, based on historical data, to identify levels of activity for which the combination would be worth pursuing. We identified Cancer Therapy Evaluation Program single-arm combination trials that were activated in 2008-2017 and tabulated their design characteristics and results. Positive trials were evaluated as to whether they provided credible evidence that the combination was better than its constituents. A total of 125 trials were identified, and 120 trials had results available. Twelve had designs where eligible patients were required to be resistant or refractory to all but one element of the combination. Only 17.8% of the 45 positive trials were deemed to provide credible evidence that the combination was better than its constituents. Of the 10 positive trials with observed rates 10 percentage points higher than their upper (alternative hypothesis) targets, only five were deemed to provide such credible evidence. Many trials were definitively negative, with observed clinical activity at or below their lower (null hypothesis) targets. Ideally, use of single-arm combination trials should be restricted to settings where each agent is known to have minimal monotherapy activity (and a randomized trial is infeasible). In these settings, an observed signal is attributable to synergy and thus could be used to decide whether the combination is worth pursuing. In other settings, credible evidence can still be obtained if the observed activity is much higher than expected, but experience suggests that this is a rare occurrence.

Assessment of Cancer Therapy Evaluation Program Advocacy and Inclusion Rates of People Living With HIV in Anti-PD1/PDL1 Clinical Trials.

Importance: Anti-programmed death 1 and anti-programmed death ligand 1 (anti-PD1/PDL1) immune checkpoint blockade (ICB) constitutes the therapeutic backbone for multiple malignant neoplasms. People living with HIV (PLWH) have routinely been excluded from ICB clinical trials, thus inhibiting broad implementation of ICB to PLWH with cancer. Objective: To evaluate trends in the inclusion of PLWH in ICB cancer clinical trials that have occurred in association with ongoing efforts by the Cancer Therapy Evaluation Program (CTEP), National Cancer Institute, to promote inclusion of PLWH. Design, Setting, and Participants: This quality improvement study of ICB letters of intent (LOIs) included anti-PD1/PDL1 agents (nivolumab, pembrolizumab, atezolizumab, and durvalumab) submitted to CTEP that proceeded to approved protocols between January 2014 to May 2019. The setting was ICB clinical trial development and inclusion of underrepresented populations, specifically PLWH. All 97 submitted cancer clinical trial LOIs that included the aforementioned ICB agents were eligible for inclusion. Ten proposals were excluded, of which 3 were designed specifically for PLWH and 7 were LOIs that did not advance to approved protocols within the study period. Statistical analysis was performed from April to September 2020. Exposures: CTEP advocacy included the requirement for justification of exclusion of PLWH and formal discussion of inclusion criteria during conference calls between CTEP and trial investigators. Main Outcomes and Measures: The frequency of inclusion of PLWH in initially submitted LOIs was compared with final approved protocols using descriptive statistics. The probability of inclusion of PLWH in submitted LOIs and approved protocols over time was assessed using logistic regression. Results: Eighty-seven studies were included, of which 68 (78%) were pilot, phase 1, phase 1/2, or phase 2 studies and 19 (22%) were phase 2/3 or phase 3 studies. Thirty-nine studies (45%) included nivolumab, 23 (26%) included pembrolizumab, 19 (22%) included atezolizumab, and 6 (7%) included durvalumab. At initial LOI stage, 14 of 87 (16%) included PLWH. Following CTEP advocacy efforts, 61 of 87 protocols (70%) included PLWH. Of 36 LOIs to initially exclude PLWH, 24 (67%) included PLWH in final protocols. Among the 25 protocols to exclude PLWH, 21 (84%) were earlier phase studies (pilot to phase 2) and 4 (16%) were later phase studies (phase 2/3 to phase 3). Only 13 of 25 protocols (52%) provided justification for exclusion of PLWH, with safety being the most frequently cited concern (9 of 13 studies). The inclusion of PLWH on submitted LOIs increased over time (odds ratio, 3.38; 95% CI, 1.14-3.91), whereas inclusion on final protocols did not increase over time (odds ratio, 1.80; 95% CI, 0.81-1.59). Conclusions and Relevance: This study identified encouraging trends in the inclusion of PLWH in anti-PD1/PDL1 cancer trials that occurred in the period following the initiation of CTEP advocacy. Work is needed to examine what impact this will have on enrollment of PLWH in such trials. Similar advocacy may help to promote inclusion of other underrepresented populations in cancer clinical trials, including those with organ dysfunction and chronic infections.

Frequency and impact of grade three or four toxicities of novel agents on outcomes of older patients with chronic lymphocytic leukemia and non-Hodgkin lymphoma (alliance A151611).

OBJECTIVE: Older patients with cancer suffer from chemotherapy-related toxicities more frequently than younger patients. As novel agents are being used more commonly in chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL), toxicities of these agents in older patients have not been well studied. Further, impact of these toxicities on outcomes in the elderly is unknown. This study aimed to answer both questions. PATIENTS AND METHODS: We reviewed 14 Alliance for Clinical Trials in Oncology trials that enrolled CLL and/or NHL patients between 2004-2014. Toxicity was assessed per the NCI-CTCAE (version 3-5). Probabilities of experiencing grade three or four hematologic and non-hematologic toxicities were modeled as a function of clinical and disease-related factors using logistic regression. RESULTS: 1199 patients (409 age ≥ 65; 790 age < 65) were analyzed; 438 received only biologic therapy (145 age ≥ 65; 293 age < 65), and 761 received biologic + chemotherapy (264 age ≥ 65; 497 age < 65). The odds of grade three or four hematologic [odds ratio (OR) 1.70; p = 0.009: 95% CI (1.57-1.84)] and non-hematologic toxicities [OR 1.47; p = 0.022; 95% CI (1.39-1.55)] were increased in older patients with CLL, as well as odds of grade three or four non-hematologic toxicities [OR 1.89; p = 0.017; 95% CI (1.64-2.17)] in older patients with NHL. Grade three or four hematologic toxicities were associated with inferior OS and PFS in older patients with NHL [HR 3.14; p = 0.006; 95% CI (2.25-4.39) for OS and 3.06; p = 0.011; 95% CI (2.10-4.45) for PFS], though not in CLL. A prognostic model predicting grade three or four toxicities was also developed. CONCLUSIONS: CLL and NHL patients ≥ 65 year encounter more toxicities than younger patients even when treated with novel biologic agents. Development of grade three or four hematologic toxicities lead to inferior PFS and OS in NHL but not in CLL.

Identifying subgroups of enhanced predictive accuracy from longitudinal biomarker data using tree-based approaches: applications to fetal growth.

Longitudinal monitoring of biomarkers is often helpful for predicting disease or a poor clinical outcome. In this paper, We consider the prediction of both large and small-for-gestational-age births using longitudinal ultrasound measurements, and attempt to identify subgroups of women for whom prediction is more (or less) accurate, should they exist. We propose a tree-based approach to identifying such subgroups, and a pruning algorithm which explicitly incorporates a desired type-I error rate, allowing us to control the risk of false discovery of subgroups. The proposed methods are applied to data from the Scandinavian Fetal Growth Study, and are evaluated via simulations.

Cost-Effectiveness Analysis of Monthly Zoledronic Acid, Zoledronic Acid Every 3 Months, and Monthly Denosumab in Women With Breast Cancer and Skeletal Metastases: CALGB 70604 (Alliance).

Purpose Skeletal-related events (SREs) such as pathologic fracture, spinal cord compression, or the necessity for radiation or surgery to bone metastasis cause considerable morbidity, decrements in quality of life, and costs to the health care system. The results of a recent large randomized trial (Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology [CALGB/Alliance 70604]) showed that zoledronic acid (ZA) every 3 months was noninferior to monthly ZA in reducing the risks of SREs. We sought to determine the cost-effectiveness (CE) of monthly ZA, ZA every 3 months, and monthly denosumab in women with breast cancer and skeletal metastases. Methods Using a Markov model, costs per SRE avoided were calculated for the three treatments. Sensitivity analyses were performed where denosumab SRE probabilities were assumed to be 50%, 75%, and 90% lower than the ZA SRE probabilities. Quality-adjusted life-years were also calculated. The analysis was from the US payer perspective. Results The mean costs of the denosumab treatment strategy are nine-fold higher than generic ZA every 3 months. Quality-adjusted life-years were virtually identical in all the three treatment arms; hence, the optimal treatment would be ZA every 3 months because it was the least costly treatment. The sensitivity analyses showed that relative to ZA every 3 months, the incremental costs per mean SRE avoided for denosumab ranged from $162,918 to $347,655. Conclusion ZA every 3 months was more CE in reducing the risks of SRE than monthly denosumab. This analysis was one of the first to incorporate the costs of generic ZA and one of the first independent CE analyses not sponsored by either Novartis or Amgen, the makers of ZA and denosumab, respectively. ZA every 3 months is the more CE option and more reasonable alternative to monthly denosumab.

Accrual of Older Patients With Breast Cancer to Alliance Systemic Therapy Trials Over Time: Protocol A151527.

Purpose Despite increasing awareness of accrual challenges, it is unknown if accrual of older patients to breast cancer treatment trials is improving. Methods We examined accrual of older patients to Alliance for Clinical Trials in Oncology systemic therapy breast cancer trials during 1985-2012 and compared disease characteristics and reasons for therapy cessation for older (age ≥ 65 years and ≥ 70 years) versus younger (age < 65 years and < 70 years) participants. To examine accrual trends, we modeled age as a function of time, using logistic regression. Results Overall, 17% of study participants were ≥ 65 years of age. Approximately 15%, 24%, and 24% of participants in adjuvant, neoadjuvant, and metastatic trials were age ≥ 65 years, and 7%, 15%, and 13% were age ≥ 70 years, respectively. The odds of a patient age ≥ 65 years enrolling significantly increased over time for adjuvant trials (odds ratio [OR] per year, 1.04; 95% CI, 1.04 to 1.05) but decreased significantly for neoadjuvant and metastatic trials (OR, 0.62; 95% CI, 0.58 to 0.67 and OR, 0.98, 95% CI, 0.97 to 1.00). Similar trends were seen for those age ≥ 70 years but these were statistically significant for adjuvant and neoadjuvant trials only (OR, 1.05, 95% CI, 1.04 to 1.07; and OR, 0.57, 95% CI, 0.52 to 0.62). In general, those age ≥ 65 years ( v those < 65 years) in adjuvant studies had a higher mean number of lymph nodes involved and more hormone receptor-negative tumors, although tumor sizes were similar. Early protocol treatment cessation was also more frequent in those age ≥ 65 years (50%) versus < 65 years (35.9%) across trials. Conclusion Older patients with breast cancer remain largely underrepresented in cooperative group therapeutic trials. We observed some improvement in accrual to adjuvant trials but worsening of accrual for neoadjuvant/metastatic trials. Novel strategies to increase accrual of older patients are critical to meaningfully change the evidence base for this growing patient population.

Permutation Testing for Treatment-Covariate Interactions and Subgroup Identification.

We consider the problem of using permutation-based methods to test for treatment-covariate interactions from randomized clinical trial data. Testing for interactions is common in the field of personalized medicine, as subgroups with enhanced treatment effects arise when treatment-by-covariate interactions exist. Asymptotic tests can often be performed for simple models, but in many cases, more complex methods are used to identify subgroups, and non-standard test statistics proposed, and asymptotic results may be difficult to obtain. In such cases, it is natural to consider permutation-based tests, which shuffle selected parts of the data in order to remove one or more associations of interest; however, in the case of interactions, it is generally not possible to remove only the associations of interest by simple permutations of the data. We propose a number of alternative permutation-based methods, designed to remove only the associations of interest, but preserving other associations. These methods estimate the interaction term in a model, then create data that "looks like" the original data except that the interaction term has been permuted. The proposed methods are shown to outperform traditional permutation methods in a simulation study. In addition, the proposed methods are illustrated using data from a randomized clinical trial of patients with hypertension.