Background: Many new targeted cancer drugs have received FDA approval based on durable responses in nonrandomized controlled trials (non-RCTs). The goal of this study was to evaluate whether the response rates (RRs) and durations of response (DoRs) of targeted cancer drugs observed in non-RCTs are consistent when these drugs are tested in RCTs. Methods: We used the FDA’s Table of Pharmacogenomic Biomarkers in Drug Labeling to identify cancer drugs that were approved based on changes in biomarker endpoints through December 2017. We then identified the non-RCTs and RCTs for these drugs for the given indications and extracted the RRs and DoRs. We compared the RRs and median DoR in non-RCTs versus RCTs using the ratio of RRs and the ratio of DoRs, defined as the RRs (or DoRs) in non-RCTs divided by the RRs (or DoRs) in RCTs. The ratio of RRs or DoRs was pooled across the trial pairs using random-effects meta-analysis. Results: Of the 21 drug–indication pairs selected, both non-RCTs and RCTs were available for 19. The RRs and DoRs in non-RCTs were greater than those in RCTs in 63% and 87% of cases, respectively. The pooled ratio of RRs was 1.06 (95% CI, 0.95–1.20), and the pooled ratio of DoRs was 1.17 (95% CI, 1.03–1.33). RRs and DoRs derived from non-RCTs were also poor surrogates for overall survival derived from RCTs. Conclusions: The RRs were not different between non-RCTs and RCTs of cancer drugs approved based on changes to a biomarker, but the DoRs in non-RCTs were significantly higher than in RCTs. Caution must be exercised when approving or prescribing targeted drugs based on data on durable responses derived from non-RCTs, because the responses could be overestimates and poor predictors of survival benefit.
Bishal Gyawali, Elvira D’Andrea, Jessica M. Franklin and Aaron S. Kesselheim
Daphna Y. Spiegel, Matthew J. Boyer, Julian C. Hong, Christina D. Williams, Michael J. Kelley, Joseph K. Salama and Manisha Palta
Background: Adjuvant chemotherapy (AC) after chemoradiation (CRT) and surgery for locoregionally advanced rectal cancer (LARC) is a standard of care in the United States. This study examined the role, optimal regimen, and duration of AC using data from the largest integrated health system in the United States. Patients and Methods: Using the Veterans Affairs Central Cancer Registry, patients with stage II–III rectal cancer diagnosed in 2001 through 2011 who received neoadjuvant CRT and surgery with or without AC were identified. Kaplan-Meier analysis, log-rank tests, and propensity score (PS) adjustment analysis were used to assess survival. Results: A total of 866 patients were identified; 417 received AC and 449 did not (observation [OBS] group). Median follow-up was 109 months. Median disease-specific survival (DSS) was not reached. Six-year DSS was 73.7%; 79.5% for the AC group versus 68.0% for the OBS group. PS-matched analysis for DSS favored AC (P=.0002). Median overall survival (OS) was 90.8 months. Six-year OS was 56.7%; 64.3% for AC versus 49.6% for OBS. In PS-matched analysis, median OS was 117.4 months for AC and 74.3 months for OBS (P<.0001). A DSS advantage was seen when comparing ≥4 months with <4 months of AC (P=.023). No difference in DSS or OS was seen with single-agent versus multiagent AC. Conclusions: In this population of patients with LARC treated with neoadjuvant CRT and surgery, OS and DSS were improved among those treated with AC versus OBS. DSS benefits were seen with ≥4 months of AC. No additional benefit was observed with multiagent therapy. In the absence of phase III data, these findings support the use of AC for LARC.
Christa Meyer, Lih-Wen Mau, Elizabeth A. Murphy, Ellen M. Denzen, Ellyce Hayes, Darlene Haven, Heather Moore, Jackie Foster, Jaime M. Preussler and Linda J. Burns
Background: Outcomes after hematopoietic cell transplantation (HCT) for acute myeloid leukemia (AML) are better when HCT is performed during first complete remission (CR1). This study aimed to identify and address knowledge gaps that affect the timely referral of patients for HCT consultation. Methods: A mixed-methods educational needs assessment included a national survey and focus groups consisting of hematologists/oncologists. An educational intervention of 3 webinars addressed identified knowledge gaps. Results: A total of 150 hematologists/oncologists were recruited for the survey, of whom 20 participated in focus groups. Physicians in practice 0 to 10 years were 4.2 times more likely to refer for HCT consultation in CR1 than those with >10 years in practice (P=.0027). Physicians seeing ≤10 patients with AML in the past year were 3.7 times more likely to refer for HCT consultation in CR1 than those seeing >10 patients (P=.0028). Knowledge gaps included (1) improper classification of molecular/cytogenetic results for risk stratification, (2) lack of understanding that disease stage impacts outcomes, and (3) use of chronologic age alone for referral decision-making. Combined attendance for the webinars was 1,098 clinicians; >74% of participants indicated that they would apply the knowledge they gained in clinical practice. Trends were observed toward improvement in identifying favorable-risk AML, from 48% to 60% (n=85; P=.12); improvement in identifying 2 poor-risk cytogenetic/molecular abnormalities, with the percentage of respondents indicating chromosome 7 deletion increasing from 51% to 70% (n=53; P=.05) and that of respondents indicating TP53 mutation increasing from 42% to 62% (n=62; P=.03); and improvement in identifying which patients with AML aged >60 years were most likely to benefit from HCT based on cytogenetic/molecular features, with the percentage of correct responses increasing from 66% to 81% (n=62; P=.07). Conclusions: The webinars met the educational needs of learners and improved knowledge gaps. This study provided novel insights into the learning needs of clinicians who care for patients with AML and a roadmap for future educational interventions.
Sierra Cheng, Matthew C. Cheung, Di Maria Jiang, Erica McDonald, Vanessa S. Arciero, Doreen Anuli Ezeife, Amanda Rahmadian, Alexandra Chambers, Kelley-Anne Sabarre, Ambika Parmar and Kelvin K.W. Chan
Background: Clinical benefit scores (CBS) are key elements of the ASCO Value Framework (ASCO-VF) and are weighted based on a hierarchy of efficacy endpoints: hazard ratio for death (HR OS), median overall survival (mOS), HR for disease progression (HR PFS), median progression-free survival (mPFS), and response rate (RR). When HR OS is unavailable, the other endpoints serve as “surrogates” to calculate CBS. CBS are computed from PFS or RR in 39.6% of randomized controlled trials. This study examined whether surrogate-derived CBS offer unbiased scoring compared with HR OS–derived CBS. Methods: Using the ASCO-VF, CBS for advanced disease settings were computed for randomized controlled trials of oncology drug approvals by the FDA, European Medicines Agency, and Health Canada in January 2006 through December 2017. Mean differences of surrogate-derived CBS minus HR OS–derived CBS assessed the tendency of surrogate-derived CBS to overestimate or underestimate clinical benefit. Spearman’s correlation evaluated the association between surrogate- and HR OS–derived CBS. Mean absolute error assessed the average difference between surrogate-derived CBS relative to HR OS–derived CBS. Results: CBS derived from mOS, HR PFS, mPFS, and RR overestimated HR OS–derived CBS in 58%, 68%, 77%, and 55% of pairs and overall by an average of 5.62 (n=90), 6.86 (n=110), 29.81 (n=101), and 3.58 (n=108), respectively. Correlation coefficients were 0.80 (95% CI, 0.70–0.86), 0.38 (0.20–0.53), 0.20 (0.00–0.38), and 0.01 (–0.18 to 0.19) for mOS-, HR PFS–, mPFS-, and RR-derived CBS, respectively, and mean absolute errors were 11.32, 12.34, 40.40, and 18.63, respectively. Conclusions: Based on the ASCO-VF algorithm, HR PFS–, mPFS-, and RR-derived CBS are suboptimal surrogates, because they were shown to be biased and poorly correlated to HR OS–derived CBS. Despite lower weighting than OS in the ASCO-VF algorithm, PFS still overestimated CBS. Simple rescaling of surrogate endpoints may not improve their validity within the ASCO-VF given their poor correlations with HR OS–derived CBS.
Joyce Valerie Veld, Femke Julie Amelung, Wernard Aat Antoine Borstlap, Emo Eise van Halsema, Esther Catharina Josephina Consten, Peter Derk Siersema, Frank ter Borg, Edwin Silvester van der Zaag, Paul Fockens, Willem Adrianus Bemelman, Jeanin Elise van Hooft, Pieter Job Tanis and for the Dutch Snapshot Research Group
Background: Previous analysis of Dutch practice in treatment of left-sided obstructive colon cancer (LSOCC) until 2012 showed that emergency resection (ER) was preferred, with high mortality in patients aged ≥70 years. Consequently, Dutch and European guidelines in 2014 recommended a bridge to surgery (BTS) with either self-expandable metal stent (SEMS) or decompressing stoma (DS) in high-risk patients. The implementation and effects of these guidelines have not yet been evaluated. Therefore, our aim was to perform an in-depth update of national practice concerning curative treatment of LSOCC, including an evaluation of guideline implementation. Patients and Methods: This multicenter cohort study was conducted in 75 of 77 hospitals in the Netherlands. We included data on patients who underwent curative resection of LSOCC in 2009 through 2016 obtained from the Dutch ColoRectal Audit. Additional data were retrospectively collected. Results: A total of 2,587 patients were included (2,013 ER, 345 DS, and 229 SEMS). A trend was observed in reversal of ER (decrease from 86.2% to 69.6%) and SEMS (increase from 1.3% to 7.8%) after 2014, with an ongoing increase in DS (from 5.2% in 2009 to 22.7% in 2016). DS after 2014 was associated with more laparoscopic resections (66.0% vs 35.5%; P<.001) and more 2-stage procedures (41.5% vs 28.6%; P=.01) with fewer permanent stomas (14.7% vs 29.5%; P=.005). Overall, more laparoscopic resections (25.4% vs 13.2%; P<.001) and shorter total hospital stays (14 vs 15 days; P<.001) were observed after 2014. However, similar rates of primary anastomosis (48.7% vs 48.6%; P=.961), 90-day complications (40.4% vs 37.9%; P=.254), and 90-day mortality (6.5% vs 7.0%; P=.635) were observed. Conclusions: Guideline revision resulted in a notable change from ER to BTS for LSOCC. This was accompanied by an increased rate of laparoscopic resections, more 2-stage procedures with a decreased permanent stoma rate in patients receiving DS as BTS, and a shorter total hospital stay. However, overall 90-day complication and mortality rates remained relatively high.
Ali Raza Khaki, V.K. Gadi and Vinay Prasad
Lucas K. Vitzthum, Chris Straka, Reith R. Sarkar, Rana McKay, J. Michael Randall, Ajay Sandhu, James D. Murphy and Brent S. Rose
Background: The addition of androgen deprivation therapy to radiation therapy (RT) improves survival in patients with intermediate- and high-risk prostate cancer (PCa), but it is not known whether combined androgen blockade (CAB) with a gonadotropin-releasing hormone agonist (GnRH-A) and a nonsteroidal antiandrogen improves survival over GnRH-A monotherapy. Methods: This study evaluated patients with intermediate- and high-risk PCa diagnosed in 2001 through 2015 who underwent RT with either GnRH-A alone or CAB using the Veterans Affairs Informatics and Computing Infrastructure. Associations between CAB and prostate cancer–specific mortality (PCSM) and overall survival (OS) were determined using multivariable regression with Fine-Gray and multivariable Cox proportional hazards models, respectively. For a positive control, the effect of long-term versus short-term GnRH-A therapy was tested. Results: The cohort included 8,423 men (GnRH-A, 4,529; CAB, 3,894) with a median follow-up of 5.9 years. There were 1,861 deaths, including 349 resulting from PCa. The unadjusted cumulative incidences of PCSM at 10 years were 5.9% and 6.9% for those receiving GnRH-A and CAB, respectively (P=.16). Compared with GnRH-A alone, CAB was not associated with a significant difference in covariate-adjusted PCSM (subdistribution hazard ratio [SHR], 1.05; 95% CI, 0.85–1.30) or OS (hazard ratio, 1.02; 95% CI, 0.93–1.12). For high-risk patients, long-term versus short-term GnRH-A therapy was associated with improved PCSM (SHR, 0.74; 95% CI, 0.57–0.95) and OS (SHR, 0.82; 95% CI, 0.73–0.93). Conclusions: In men receiving definitive RT for intermediate- or high-risk PCa, CAB was not associated with improved PCSM or OS compared with GnRH alone.