Design Issues of Randomized Phase II Trials and a Proposal for Phase II Screening Trials

Viraemia, immunogenicity, and survival outcomes of cytomegalovirus chimeric epitope vaccine supplemented with PF03512676 (CMVPepVax) in allogeneic haemopoietic stem-cell transplantation: randomised phase 1b trial

BACKGROUND

Patients seropositive for cytomegalovirus (CMV) and undergoing allogeneic haemopoietic stem-cell transplantation (HCT) are at risk for CMV reactivation. Stimulating viral immunity by vaccination might achieve CMV viraemia control without the need for antiviral agents. CMVPepVax is a chimeric peptide composed of a cytotoxic CD8 T-cell epitope from CMV pp65 and a tetanus T-helper epitope. It is formulated with the adjuvant PF03512676, a Toll-like receptor 9 agonist, which augments cellular immunity. We aimed to assess safety, immunogenicity, and possible clinical benefit of the CMVPepVax vaccine in patients undergoing HCT.

METHODS

We did a randomised, open-label, phase 1b trial at one transplant centre in the USA. Eligible patients were CMV-seropositive, positive for HLA-A*0201, aged 18-75 years, and undergoing HCT from a matched-related or matched-unrelated donor. Patients were reassessed for eligibility on day 28 after HCT. We randomly allocated patients to either the CMVPepVax vaccine or observation, in blocks stratified by CMV donor serostatus. CMVPepVax was administered subcutaneously on days 28 and 56. The primary outcome was safety, which consisted of secondary graft failure, grade III-IV acute GVHD, non-relapse mortality by day 100, serious adverse events related to the vaccine (judged by the data and safety monitoring committee [DSMC]) grade 3-4 adverse events related to the vaccine (judged by the DSMC) within 2 weeks of vaccination, and development of double-strand (ds) DNA autoantibodies. Statistical analyses included all randomised patients and were done per-protocol. This study is registered with ClinicalTrials.gov, number NCT01588015. This trial is closed to accrual and the final analysis is presented in this report.

FINDINGS

Between Oct 31, 2012, and Nov 5, 2014, 36 eligible patients were allocated to either CMVPepVax (n=18) or observation (n=18), with no adverse effect on HCT (no secondary graft failures in either group) or cases of acute GVHD (seven patients assigned vaccine and six under observation had acute GVHD of grade 2 or less), and no unexpected adverse events. Compared with observation, better relapse-free survival was recorded in patients allocated the vaccine (seven vs one; hazard ratio [HR] 0·12, 95% CI 0·01-0·94; p=0·015). No patients had non-relapse mortality by day 100. One serious adverse event (grade 1 fever) was attributed to CMVPepVax but resolved within 48 h. Four patients assigned the vaccine had a serious adverse event, which was unrelated to the vaccine (grade 3 thrombocytopenia, grade 3 device-related infection, grade 2 nausea, and grade 1 fever), compared with nine patients under observation (grade 4 maculopapular rash, grade 3 nausea, grade 3 infection, grade 3 thrombotic thrombocytopenic purpurea, grade 2 nausea, grade 2 generalised muscle weakness, grade 2 infection, grade 1 fever, and grade 1 fatigue; p=0·16). 54 grade 3-4 adverse events were reported in patients assigned the vaccine compared with 91 in patients who were under observation (p=0·2). No patients had grade III-IV acute GVHD or developed dsDNA autoantibodies.

INTERPRETATION

The results show safety and immunogenicity of the CMVPepVax vaccine. The prospect of substantial clinical benefits warrant testing in a phase 2 trial.

FUNDING

National Cancer Institute.

Comparison of single-arm vs. randomized phase II clinical trials: a Bayesian approach

Single-arm studies are typically used in phase II of clinical trials, whose main objective is to determine whether a new treatment warrants further testing in a randomized phase III trial. The introduction of randomization in phase II, to avoid the limits of studies based on historical controls, is a critical issue widely debated in the recent literature. We use a Bayesian approach to compare single-arm and randomized studies, based on a binary response variable, in terms of their abilities of reaching the correct decision about the new treatment, both when it performs better than the standard one and when it is less effective. We evaluate how the historical control rate, the total sample size, and the elicitation of the prior distributions affect the decision about which study performs better.

Estriol combined with glatiramer acetate for women with relapsing-remitting multiple sclerosis: a randomised, placebo-controlled, phase 2 trial

BACKGROUND

Relapses of multiple sclerosis decrease during pregnancy, when the hormone estriol is increased. Estriol treatment is anti-inflammatory and neuroprotective in preclinical studies. In a small single-arm study of people with multiple sclerosis estriol reduced gadolinium-enhancing lesions and was favourably immunomodulatory. We assessed whether estriol treatment reduces multiple sclerosis relapses in women.

METHODS

We did a randomised, double-blind, placebo-controlled phase 2 trial at 16 academic neurology centres in the USA, between June 28, 2007, and Jan 9, 2014. Women aged 18-50 years with relapsing-remitting multiple sclerosis were randomly assigned (1:1) with a random permuted block design to either daily oral estriol (8 mg) or placebo, each in combination with injectable glatiramer acetate 20 mg daily. Patients and all study personnel, except for pharmacists and statisticians, were masked to treatment assignment. The primary endpoint was annualised relapse rate after 24 months, with a significance level of p=0.10. Relapses were confirmed by an increase in Expanded Disability Status Scale score assessed by an independent physician. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00451204.

FINDINGS

We enrolled 164 patients: 83 were allocated to the estriol group and 81 were allocated to the placebo group. The annualised confirmed relapse rate was 0.25 relapses per year (95% CI 0.17-0.37) in the estriol group versus 0.37 relapses per year (0.25-0.53) in the placebo group (adjusted rate ratio 0.63, 95% CI 0.37-1.05; p=0.077). The proportion of patients with serious adverse events did not differ substantially between the estriol group and the placebo group (eight [10%] of 82 patients vs ten [13%] of 76 patients). Irregular menses were more common in the estriol group than in the placebo group (19 [23%] vs three [4%], p=0.0005), but vaginal infections were less common (one [1%] vs eight [11%], p=0.0117). There were no differences in breast fibrocystic disease, uterine fibroids, or endometrial lining thickness as assessed by clinical examination, mammogram, uterine ultrasound, or endometrial lining biopsy.

INTERPRETATION

Estriol plus glatiramer acetate met our criteria for reducing relapse rates, and treatment was well tolerated over 24 months. These results warrant further investigation in a phase 3 trial.

FUNDING

National Institutes of Health, National Multiple Sclerosis Society, Conrad N Hilton Foundation, Jack H Skirball Foundation, Sherak Family Foundation, and the California Community Foundation.

Cediranib combined with carboplatin and paclitaxel in patients with metastatic or recurrent cervical cancer (CIRCCa): a randomised, double-blind, placebo-controlled phase 2 trial

BACKGROUND

Patients treated with standard chemotherapy for metastatic or relapsed cervical cancer respond poorly to conventional chemotherapy (response achieved in 20-30% of patients) with an overall survival of less than 1 year. High tumour angiogenesis and high concentrations of intratumoural VEGF are adverse prognostic features. Cediranib is a potent tyrosine kinase inhibitor of VEGFR1, 2, and 3. In this trial, we aimed to assess the effect of the addition of cediranib to carboplatin and paclitaxel chemotherapy in patients with metastatic or recurrent cervical cancer.

METHODS

In this randomised, double-blind, placebo-controlled phase 2 trial, which was done in 17 UK cancer treatment centres, patients aged 18 years or older initially diagnosed with metastatic carcinoma or who subsequently developed metastatic disease or local pelvic recurrence after radical treatment that was not amenable to exenterative surgery were recruited. Eligible patients received carboplatin AUC of 5 plus paclitaxel 175 mg/m(2) by infusion every 3 weeks for a maximum of six cycles and were randomised centrally (1:1) through a minimisation approach to receive cediranib 20 mg or placebo orally once daily until disease progression. The stratification factors were disease site, disease-free survival after primary therapy or primary stage IVb disease, number of lines of previous treatment, Eastern Cooperative Oncology Group performance status, and investigational site. All patients, investigators, and trial personnel were masked to study drug allocation. The primary endpoint was progression-free survival. Efficacy analysis was by intention to treat, and the safety analysis included all patients who received at least one dose of study drug. This trial is registered with the ISCRTN registry, number ISRCTN23516549, and has been completed.

FINDINGS

Between Aug 19, 2010, and July 27, 2012, 69 patients were enrolled and randomly assigned to cediranib (n=34) or placebo (n=35). After a median follow-up of 24·2 months (IQR 21·9-29·5), progression-free survival was longer in the cediranib group (median 8·1 months [80% CI 7·4-8·8]) than in the placebo group (6·7 months [6·2-7·2]), with a hazard ratio (HR) of 0·58 (80% CI 0·40-0·85; one-sided p=0·032). Grade 3 or worse adverse events that occurred in the concurrent chemotherapy and trial drug period in more than 10% of patients were diarrhoea (five [16%] of 32 patients in the cediranib group vs one [3%] of 35 patients in the placebo group), fatigue (four [13%] vs two [6%]), leucopenia (five [16%] vs three [9%]), neutropenia (10 [31%] vs four [11%]), and febrile neutropenia (five [16%] vs none). The incidence of grade 2-3 hypertension was higher in the cediranib group than in the control group (11 [34%] vs four [11%]). Serious adverse events occurred in 18 patients in the placebo group and 19 patients in the cediranib group.

INTERPRETATION

Cediranib has significant efficacy when added to carboplatin and paclitaxel in the treatment of metastatic or recurrent cervical cancer. This finding was accompanied by an increase in toxic effects (mainly diarrhoea, hypertension, and febrile neutropenia).

FUNDING

Cancer Research UK and AstraZeneca.

Nanoparticle-siRNA: A potential cancer therapy?

PURPOSE

To explore current developments in short interfering RNA (siRNA) delivery systems in nanooncology, in particular nanoparticles that encapsulate siRNA for targeted treatment of cancer. siRNA has a high specificity towards the oncogenic mRNA in cancer cells, while application of nanoparticles can improve stable delivery and enhance efficacy.

METHODS

A literature search was performed using the terms "siRNA", "nanoparticles", "targeted delivery", and "cancer". These databases included Medline, Embase, Cochrane Review, Pubmed, and Scopus.

RESULTS

siRNA anti-cancer drugs utilize endogenous RNAi mechanisms to silence oncogene expression, which promotes cancer remission. However, current delivery methods have poor efficacy, requiring assistance by nanoparticles for successful delivery. Recently several preclinical studies have crossed into clinical trials utilizing siRNA nanoparticle therapeutics.

CONCLUSION

Great potential exists for nano-siRNA drugs in cancer treatment, but issues exist with nanoparticle toxicity and off target siRNA effects. Further research is needed in this rapidly developing and promising field of nano-siRNA drugs.

Statistical controversies in clinical research: assessing pathologic complete response as a trial-level surrogate end point for early-stage breast cancer

BACKGROUND

A trial-level surrogate end point for a randomized clinical trial may allow assessment of the relative benefits of the treatment to be performed at an earlier time point and potentially with a smaller sample size. However, determining whether an end point is a reliable trial-level surrogate based on results of previous trials is not straightforward. The question of trial-level surrogacy is easily confused with the question of individual-level surrogacy, and this confusion can lead to controversy. A recent example concerns the evaluation of pathologic complete response (pCR) as a surrogate for event-free survival (EFS) and overall survival (OS) in early-stage breast cancer.

MATERIALS AND METHODS

The differences between individual-level surrogacy (i.e. for patients receiving a specific treatment, the surrogate end point predicts the definitive end point) and trial-level surrogacy (the results of the trial for the surrogate end point predict the results of the trial for the definitive end point) are discussed. Trial-level data used in two previous meta-analyses evaluating pCR as a trial-level surrogate for EFS and OS were re-analyzed using methods that appropriately account for the variability in pCR rates as well as the variability in the hazard ratios for EFS and OS.

RESULTS

There is no evidence that pCR is a trial-level surrogate for EFS or OS, nor is there evidence that pCR could be used reliably to screen out nonpromising agents from further drug development.

CONCLUSIONS

At present, neoadjuvant RCTs should continue to follow patients to observe EFS and OS to assess clinical benefit, and they should be designed with sufficient sample size to reliably assess EFS. However, one cannot rule out the possibility that future meta-analyses involving more trials and in which the patient population or class of treatments is restricted could suggest the validity of pCR as a trial-level surrogate for EFS or OS in some focused settings.

A Pilot Study to Determine if Vitamin D Repletion Improves Endothelial Function in Lupus Patients

BACKGROUND

The endothelium is important not only in regulating vascular tone but also in modulating inflammation. Patients with systemic lupus erythematosus (SLE) have deficits in these endothelial functions. Vitamin D is a nuclear hormone that regulates vascular endothelial nitric oxide synthase activity and expression. Many SLE patients have insufficient levels of vitamin D. The effect of this hormone on vascular endothelial function in SLE patients is not known. This study was designed to determine the effect size of repleting vitamin D levels on endothelial function in patients with SLE and vitamin D deficiency.

METHODS

SLE patients with 25(OH) vitamin D (25(OH)D) levels <20 ng/mL were randomized to oral vitamin D3 (D3) doses that did or did not raise 25(OH)D levels to ≥32 ng/mL. Endothelial function was measured with flow-mediated dilation (FMD) before and after 16 weeks of vitamin D3 supplementation.

RESULTS

Half of those who achieved 25(OH)D levels of ≥32 ng/mL experienced increases in FMD, whereas none of those with continued low 25(OH)D levels did. Those with increases in FMD had significantly higher final 25(OH)D levels. Using the effect size from this study, future studies designed to test the effect of repleting 25(OH)D on FMD in vitamin D-deficient SLE patients will require 35 patients in each group.

CONCLUSIONS

These results suggest a potential role for vitamin D in SLE-related endothelial dysfunction and that an adaptive, multi-arm, treat-to-target, serum-level trial design may increase the efficiency and likelihood of success of such a study.

Correlation of single arm versus randomised phase 2 oncology trial characteristics with phase 3 outcome

BACKGROUND AND AIM

The primary aim of this study was to determine whether randomised phase 2 (RP2) trials predict phase 3 trial outcome better than single arm phase 2 (SAP2) studies. Although theoretical superiority of RP2 trials has been postulated, no empiric studies have been conducted.

METHODS

Published phase 3 trials testing systemic cancer therapy were identified through a Medline search. Those of superiority design, which cited phase 2 trials supporting the experimental arm, were included. Trial design and outcome details were extracted. Statistical analysis was performed using the Generalized Estimating Equation method correlating phase 2 features with phase 3 outcome, accounting for any phase 3 duplication.

RESULTS

Of 189 eligible phase 3 trials, 18.5% were in haematological malignancies and 81.5% in solid tumors. The primary outcome was positive in 79 (41.8%). These were supported by 336 phase 2 trials (range 1-9 per phase 3 trial) including 66 RP2 trials. Positive phase 2 outcome, randomised or not, correlated with positive phase 3 outcome (p=0.03). RP2 studies were not superior to SAP2 studies at predicting phase 3 study success. Phase 2 trial features not predictive of phase 3 outcome included primary endpoint, sponsorship, sample size, similarity in patient population and therapy.

CONCLUSIONS

RP2 studies were not superior to SAP2 trials at predicting phase 3 study success. Further research into phase 2 trial design is required given the added resources required to conduct RP2 studies and the lack of empiric evidence supporting superiority over single arm studies.

Intermittent high dose proton pump inhibitor enhances the antitumor effects of chemotherapy in metastatic breast cancer

BACKGROUND

Acidity is a hallmark of malignant tumor, representing a very efficient mechanism of chemoresistance. Proton pump inhibitors (PPI) at high dosage have been shown to sensitize chemoresistant human tumor cells and tumors to cytotoxic molecules. The aim of this pilot study was to investigate the efficacy of PPI in improving the clinical outcome of docetaxel + cisplatin regimen in patients with metastatic breast cancer (MBC).

METHODS

Patients enrolled were randomly assigned to three arms: Arm A, docetaxel 75 mg/m(2) followed by cisplatin 75 mg/m(2) on d4, repeated every 21 days with a maximum of 6 cycles; Arm B, the same chemotherapy preceded by three days esomeprazole (ESOM) 80 mg p.o. bid, beginning on d1 repeated weekly. Weekly intermittent administration of ESOM (3 days on 4 days off) was maintained up to maximum 66 weeks; Arm C, the same as Arm B with the only difference being dose of ESOM at 100 mg p.o. bid. The primary endpoint was response rate.

RESULTS

Ninety-four patients were randomly assigned and underwent at least one injection of chemotherapy. Response rates for arm A, B and C were 46.9, 71.0, and 64.5 %, respectively. Median TTP for arm A (n = 32), B (n = 31), C (n = 31) were 8.7, 9.4, and 9.7 months, respectively. A significant difference was observed between patients who had taken PPI and who not with ORR (67.7 % vs. 46.9 %, p = 0.049) and median TTP (9.7 months vs. 8.7 months, p = 0.045) [corrected]. Exploratory analysis showed that among 15 patients with triple negative breast cancer (TNBC), this difference was bigger with median TTP of 10.7 and 5.8 months, respectively (p = 0.011). PPI combination showed a marked effect on OS as well, while with a borderline significance (29.9 vs. 19.2 months, p = 0.090). No additional toxicity was observed with PPI.

CONCLUSIONS

The results of this pilot clinical trial showed that intermittent high dose PPI enhance the antitumor effects of chemotherapy in MBC patients without evidence of additional toxicity, which requires urgent validation in a multicenter, randomized, phase III trial.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT01069081 .

The use of Bayesian hierarchical models for adaptive randomization in biomarker-driven phase II studies

The role of biomarkers has increased in cancer clinical trials such that novel designs are needed to efficiently answer questions of both drug effects and biomarker performance. We advocate Bayesian hierarchical models for response-adaptive randomized phase II studies integrating single or multiple biomarkers. Prior selection allows one to control a gradual and seamless transition from randomized-blocks to marker-enrichment during the trial. Adaptive randomization is an efficient design for evaluating treatment efficacy within biomarker subgroups, with less variable final sample sizes when compared to nested staged designs. Inference based on the Bayesian hierarchical model also has improved performance in identifying the sub-population where therapeutics are effective over independent analyses done within each biomarker subgroup.

Randomized Phase II Trial of Gemcitabine Plus TH-302 Versus Gemcitabine in Patients With Advanced Pancreatic Cancer

PURPOSE

TH-302 is an investigational hypoxia-activated prodrug that releases the DNA alkylator bromo-isophosphoramide mustard in hypoxic settings. This phase II study (NCT01144455) evaluated gemcitabine plus TH-302 in patients with previously untreated, locally advanced or metastatic pancreatic cancer.

PATIENTS AND METHODS

Patients were randomly assigned 1:1:1 to gemcitabine (1,000 mg/m(2)), gemcitabine plus TH-302 240 mg/m(2) (G+T240), or gemcitabine plus TH-302 340 mg/m(2) (G+T340). Randomized crossover after progression on gemcitabine was allowed. The primary end point was progression-free survival (PFS). Secondary end points included overall survival (OS), tumor response, CA 19-9 response, and safety.

RESULTS

Two hundred fourteen patients (77% with metastatic disease) were enrolled between June 2010 and July 2011. PFS was significantly longer with gemcitabine plus TH-302 (pooled combination arms) compared with gemcitabine alone (median PFS, 5.6 v 3.6 months, respectively; hazard ratio, 0.61; 95% CI, 0.43 to 0.87; P = .005; median PFS for metastatic disease, 5.1 v 3.4 months, respectively). Median PFS times for G+T240 and G+T340 were 5.6 and 6.0 months, respectively. Tumor response was 12%, 17%, and 26% in the gemcitabine, G+T240, and G+T340 arms, respectively (G+T340 v gemcitabine, P = .04). CA 19-9 decrease was greater with G+T340 versus gemcitabine (-5,398 v -549 U/mL, respectively; P = .008). Median OS times for gemcitabine, G+T240, and G+T340 were 6.9, 8.7, and 9.2 months, respectively (P = not significant). The most common adverse events (AEs) were fatigue, nausea, and peripheral edema (frequencies similar across arms). Skin and mucosal toxicities (2% grade 3) and myelosuppression (55% grade 3 or 4) were the most common TH-302-related AEs but were not associated with treatment discontinuation.

CONCLUSION

PFS, tumor response, and CA 19-9 response were significantly improved with G+TH-302. G+T340 is being investigated further in the phase III MAESTRO study (NCT01746979).

Study protocol of REGOSARC trial: activity and safety of regorafenib in advanced soft tissue sarcoma: a multinational, randomized, placebo-controlled, phase II trial

Background

Angiogenesis, among other signaling pathways, plays a key-role in sarcoma biology. Regorafenib (RE) has recently been shown to be effective in imatinib and sunitinib-refractory GIST in a phase III trial.

Methods/design

We are conducting an international trial (France, Austria and Germany) consisting in 4 parallel double-blind placebo-controlled randomized (1/1) phase II trials to assess the activity and safety of RE in doxorubicin-refractory STS (ClinicalTrials.gov: NCT01900743). Each phase II trial is dedicated to one of the 4 following histological subgroups: liposarcoma, leiomyosarcoma, synovial sarcoma and other sarcoma. Within each randomized trial the following stratification factors will be applied: countries and prior exposure to pazopanib. Key-eligibility criteria are: measurable disease, age ≥18, not > 3 previous systemic treatment lines for metastatic disease, metastatic disease not amenable to surgical resection. The primary endpoint is progression-free survival (PFS) according to central radiological review. Secondary endpoints are: Toxicity (NCI-CTC AE V4.0); time to progression; Growth modulation index in pts receiving RE after randomization; 3 and 6 months PFS-Rates, best response rate and overall survival. Each phase II trial will be separately analyzed. In 3 trials, statistical assumptions are: PFS0 = 1.6 & PFS1 = 4.6 months; 1-sided α = 0.1; β = 0.05 with a total sample size of 192 pts. To take into account the rarity of synovial sarcoma, the statistical assumptions are: PFS0 = 1.6 & PFS1 = 4.6 months; 1-sided α = 0.1; β = 0.2 Tumor assessment is done monthly during the 4 first months, and every 3 months thereafter. After central radiological confirmation of tumor progression, an optional open-label option is offered to eligible patients.

Discussion

The design of this trial allows an assessment of regorafenib activity over placebo in four sarcoma strata and might provide evidence for launching a phase III trial. This study includes both integrative and exploratory translational research program. The study is enrolling since June 2013 (Trial Registration Number: EudraCT N°: 2012-005743-24, on the 15^th February 2012).

Chemotherapy With or Without Maintenance Sunitinib for Untreated Extensive-Stage Small-Cell Lung Cancer: A Randomized, Double-Blind, Placebo-Controlled Phase II Study-CALGB 30504 (Alliance)

PURPOSE

To evaluate the efficacy of maintenance sunitinib after chemotherapy for small-cell lung cancer (SCLC).

PATIENTS AND METHODS

The Cancer and Leukemia Group B 30504 trial was a randomized, placebo-controlled, phase II study that enrolled patients before chemotherapy (cisplatin 80 mg/m(2) or carboplatin area under the curve of 5 on day 1 plus etoposide 100 mg/m(2) per day on days 1 to 3 every 21 days for four to six cycles). Patients without progression were randomly assigned 1:1 to placebo or sunitinib 37.5 mg per day until progression. Cross-over after progression was allowed. The primary end point was progression-free survival (PFS) from random assignment for maintenance placebo versus sunitinib using a one-sided log-rank test with α = .15; 80 randomly assigned patients provided 89% power to detect a hazard ratio (HR) of 1.67.

RESULTS

One hundred forty-four patients were enrolled; 138 patients received chemotherapy. Ninety-five patients were randomly assigned; 10 patients did not receive maintenance therapy (five on each arm). Eighty-five patients received maintenance therapy (placebo, n = 41; sunitinib, n = 44). Grade 3 adverse events with more than 5% incidence were fatigue (19%), decreased neutrophils (14%), decreased leukocytes (7%), and decreased platelets (7%) for sunitinib and fatigue (10%) for placebo; grade 4 adverse events were GI hemorrhage (n = 1) and pancreatitis, hypocalcemia, and elevated lipase (n = 1; all in same patient) for sunitinib and thrombocytopenia (n = 1) and hypernatremia (n = 1) for placebo. Median PFS on maintenance was 2.1 months for placebo and 3.7 months for sunitinib (HR, 1.62; 70% CI, 1.27 to 2.08; 95% CI, 1.02 to 2.60; one-sided P = .02). Median overall survival from random assignment was 6.9 months for placebo and 9.0 months for sunitinib (HR, 1.28; 95% CI, 0.79 to 2.10; one-sided P = .16). Three sunitinib and no placebo patients achieved complete response during maintenance. Ten (77%) of 13 patients evaluable after cross-over had stable disease on sunitinib (6 to 27 weeks).

CONCLUSION

Maintenance sunitinib was safe and improved PFS in extensive-stage SCLC.

Remaining challenges in childhood cancer and newer targeted therapeutics

Despite the enormously important and gratifying advances in cancer treatment outcomes for children with cancer, cancer remains the biggest cause of death from disease in children. Because the etiology and biology of cancers that occur in children differ dramatically from those that occur in adults, the immediate extrapolation of efficacy and safety of new cancer drugs to childhood cancer indications is not possible. We discuss factors that will play key roles in guiding pediatric oncologists as they select lines of research to pursue in their quest for more effective treatments for children with cancer.

Randomized phase II clinical trials

Traditionally, Phase II trials have been conducted as single-arm trials to compare the response probabilities between an experimental therapy and a historical control. Historical control data, however, often have a small sample size, are collected from a different patient population, or use a different response assessment method, so that a direct comparison between a historical control and an experimental therapy may be severely biased. Randomized Phase II trials entering patients prospectively to both experimental and control arms have been proposed to avoid any bias in such cases. The small sample sizes for typical Phase II clinical trials imply that the use of exact statistical methods for their design and analysis is appropriate. In this article, we propose two-stage randomized Phase II trials based on Fisher's exact test, which does not require specification of the response probability of the control arm for testing. Through numerical studies, we observe that the proposed method controls the type I error accurately and maintains a high power. If we specify the response probabilities of the two arms under the alternative hypothesis, we can identify good randomized Phase II trial designs by adopting the Simon's minimax and optimal design concepts that were developed for single-arm Phase II trials.

The direct assignment option as a modular design component: an example for the setting of two predefined subgroups

Background. A phase II design with an option for direct assignment (stop randomization and assign all patients to experimental treatment based on interim analysis, IA) for a predefined subgroup was previously proposed. Here, we illustrate the modularity of the direct assignment option by applying it to the setting of two predefined subgroups and testing for separate subgroup main effects. Methods. We power the 2-subgroup direct assignment option design with 1 IA (DAD-1) to test for separate subgroup main effects, with assessment of power to detect an interaction in a post-hoc test. Simulations assessed the statistical properties of this design compared to the 2-subgroup balanced randomized design with 1 IA, BRD-1. Different response rates for treatment/control in subgroup 1 (0.4/0.2) and in subgroup 2 (0.1/0.2, 0.4/0.2) were considered. Results. The 2-subgroup DAD-1 preserves power and type I error rate compared to the 2-subgroup BRD-1, while exhibiting reasonable power in a post-hoc test for interaction. Conclusion. The direct assignment option is a flexible design component that can be incorporated into broader design frameworks, while maintaining desirable statistical properties, clinical appeal, and logistical simplicity.

Surveillance or metastasis-directed Therapy for OligoMetastatic Prostate cancer recurrence (STOMP): study protocol for a randomized phase II trial

Background

Metastases-directed therapy (MDT) with surgery or stereotactic body radiotherapy (SBRT) is emerging as a new treatment option for prostate cancer (PCa) patients with a limited number of metastases (≤3) at recurrence – so called “oligometastases”. One of the goals of this approach is to delay the start of palliative androgen deprivation therapy (ADT), with its negative impact on quality of life. However, the lack of a control group, selection bias and the use of adjuvant androgen deprivation therapy prevent strong conclusions from published studies.

The aim of this multicenter randomized phase II trial is to assess the impact of MTD on the start of palliative ADT compared to patients undergoing active surveillance.

Methods/Design

Patients with an oligometastatic recurrence, diagnosed on choline PET/CT after local treatment with curative intent, will be randomised in a 1:1 ratio between arm A: active surveillance only and arm B: MTD followed by active surveillance. Patients will be stratified according to the location of metastasis (node vs. bone metastases) and PSA doubling time (≤3 vs. > 3 months). Both surgery and SBRT are allowed as MDT. Active surveillance means 3-monthly PSA testing and re-imaging at PSA progression. The primary endpoint is ADT-free survival. ADT will be started in both arms at time of polymetastatic disease (>3 metastatic lesions), local progression or symptoms. The secondary endpoints include progression-free survival, quality of life, toxicity and prostate-cancer specific survival.

Discussion

This is the first randomized phase 2 trial assessing the possibility of deferring palliative ADT with MDT in oligometastatic PCa recurrence.

Trial registration

Clinicaltrials.gov identifier: NCT01558427

What is an active regimen in carcinoma of unknown primary sites? Analysis of correlation between activity endpoints reported in phase II trials. Correlation of activity endpoints in phase II trials

BACKGROUND

The choice of the activity endpoint is crucial when designing phase II screening trials. This choice is usually guided by convention, but the level of evidence for picking-up one of them is limited.

METHODS

We have analysed the phase II trials in carcinoma of unknown primary patients (CUP; 48 strata). We calculated the Pearson correlation coefficient using weighted linear regression to measure the degree of association between the different available activity endpoints (Best objective response - BORR, best tumour control rate - BTCR, 3- and 6-month progression-free rates, 3- and 6-month PFR and median progression-free survival). We also explored the correlation between these endpoints and OS.

RESULTS

All activity endpoints were strongly correlated in CUP studies; all of these endpoints were strongly correlated with OS. The median BORR across the studies was 30%. Positive trials defined by BORR ≥ 30% were associated with statistically longer PFS (4.8 versus 3.7 months, P = 0.013) and OS (10.0 versus 8.0, P = 0.0007).

DISCUSSION

In phase II studies with CUP patients, BORR and the threshold of BORR > 30% for defining promising drug appears adequate.

Integrated smoking cessation and binge drinking intervention for young adults: a pilot efficacy trial

Alcohol consumption is strongly associated with cigarette smoking in young adults. The primary aim of this investigation was to complete a pilot evaluation of the efficacy of an integrated intervention that targets both cigarette smoking and binge drinking on the cigarette smoking and binge behavior of young adults at 6-month follow-up. Participants were 95 young adult (M=24.3; SD=3.5 years) smokers (≥1 cigarettes per day) who binge drink (≥1 time per month) and who were randomly assigned to standard treatment (n=47) involving six individual treatment visits plus eight weeks of nicotine patch therapy or the identical smoking cessation treatment integrated with a binge drinking intervention (integrated intervention; n=48). Using an intent-to-treat analysis for tobacco abstinence, at both 3 month end of treatment and 6 month follow-up, more participants who received integrated intervention were biochemically confirmed abstinent from tobacco than those who received standard treatment at 3 months (19% vs. 9%, p=0.06) and 6 months (21% vs. 9%, p=0.05). At 6 months, participants who completed the study and who received integrated intervention consumed fewer drinks per month (p<0.05) and number of binge drinking episodes per month (p<0.05) than those who received standard treatment. Preliminary data supports that integrated intervention enhances smoking cessation and reduces binge drinking compared to standard treatment.

Accelerating clinical development of HIV vaccine strategies: methodological challenges and considerations in constructing an optimised multi-arm phase I/II trial design

Background

Many candidate vaccine strategies against human immunodeficiency virus (HIV) infection are under study, but their clinical development is lengthy and iterative. To accelerate HIV vaccine development optimised trial designs are needed. We propose a randomised multi-arm phase I/II design for early stage development of several vaccine strategies, aiming at rapidly discarding those that are unsafe or non-immunogenic.

Methods

We explored early stage designs to evaluate both the safety and the immunogenicity of four heterologous prime-boost HIV vaccine strategies in parallel. One of the vaccines used as a prime and boost in the different strategies (vaccine 1) has yet to be tested in humans, thus requiring a phase I safety evaluation. However, its toxicity risk is considered minimal based on data from similar vaccines. We newly adapted a randomised phase II trial by integrating an early safety decision rule, emulating that of a phase I study. We evaluated the operating characteristics of the proposed design in simulation studies with either a fixed-sample frequentist or a continuous Bayesian safety decision rule and projected timelines for the trial.

Results

We propose a randomised four-arm phase I/II design with two independent binary endpoints for safety and immunogenicity. Immunogenicity evaluation at trial end is based on a single-stage Fleming design per arm, comparing the observed proportion of responders in an immunogenicity screening assay to an unacceptably low proportion, without direct comparisons between arms. Randomisation limits heterogeneity in volunteer characteristics between arms. To avoid exposure of additional participants to an unsafe vaccine during the vaccine boost phase, an early safety decision rule is imposed on the arm starting with vaccine 1 injections. In simulations of the design with either decision rule, the risks of erroneous conclusions were controlled <15%. Flexibility in trial conduct is greater with the continuous Bayesian rule. A 12-month gain in timelines is expected by this optimised design. Other existing designs such as bivariate or seamless phase I/II designs did not offer a clear-cut alternative.

Conclusions

By combining phase I and phase II evaluations in a multi-arm trial, the proposed optimised design allows for accelerating early stage clinical development of HIV vaccine strategies.

Ethics, error, and initial trials of efficacy

Clinical trial reforms aimed at boosting phase 2 positive predictivity may involve ethical and social trade-offs.

Biomarker enrichment strategies: matching trial design to biomarker credentials

The use of biomarkers to identify patients who can benefit from treatment with a specific anticancer agent has the potential to both improve patient care and accelerate drug development. The development of targeted agents and their accompanying biomarkers frequently occurs contemporaneously, and confidence in a putative biomarker's performance might, therefore, be insufficient to restrict the definitive testing of a new agent to the subgroup of biomarker-positive patients. This Review considers which clinical trial designs and analysis strategies are appropriate for use in phase III, biomarker-driven, randomized clinical trials, on the basis of pre-existing evidence that the biomarker can successfully identify patients who will respond to the treatment in question. The types of interim monitoring that are appropriate for these trials are also discussed. In addition, enrichment strategies based on the use of prognostic biomarkers to separate a population into subgroups with better and worse outcomes, regardless of treatment, are described. Finally, the possibility of formally using a biomarker during phase II drug development, to select what type of biomarker-driven strategy should be used in the phase III trial, is discussed.

New challenges for comparative effectiveness in oncology: choice of primary end points for randomized clinical trials

Recent advances have led to a steady improvement in cancer treatments. The increasing number of therapeutic options and the corresponding improvement in outcomes pose a number of challenges for comparative effectiveness research in oncology. This review is focused on the choice of primary end points and their interpretation in randomized clinical trials that are designed to inform patients and clinicians on the relative benefits of cancer therapies. We discuss end points that directly measure clinical benefit as well as end points that are thought to be surrogates for clinical benefit. Particular attention is given to the issues associated with the use of overall survival as the primary end point in randomized clinical trials.

Randomised phase II study of S-1/cisplatin plus TSU-68 vs S-1/cisplatin in patients with advanced gastric cancer

Background:

This study aimed to determine whether combination S-1 plus cisplatin (CDDP) therapy, the most widely used therapy for Japanese patients with advanced gastric cancer, and the novel oral antiangiogenic agent TSU-68 could contribute to gastric cancer treatment.

Methods:

Ninety-three patients with chemotherapy-naïve unresectable or recurrent advanced gastric cancers were randomised into two groups: TSU-68 plus S-1/CDDP (group A) and S-1/CDDP (group B) groups. Both patient groups received identical S-1 and CDDP dosages. TSU-68 was orally administered for 35 consecutive days. Group B patients received S-1 orally twice daily for three consecutive weeks, followed by intravenous CDDP on day 8. The primary endpoint was progression-free survival (PFS).

Results:

Median PFS periods were 208 and 213 days in groups A and B, respectively (P=0.427). Median survival periods for groups A and B were 497.0 and 463.5 days, respectively (P=0.219). No statistically significant differences were noted for PFS, survival or the adverse event (AE) incidence rate. All AEs were expected according to previous reports for TSU-68, TS-1, and CDDP.

Conclusion:

Combination therapy involving TSU-68, S-1, and CDDP was safe and well tolerated in patients with chemotherapy-naïve unresectable or recurrent advanced gastric cancers. However, factors related to therapeutic efficacy should be investigated further.

Considerations in the design of clinical trials for pediatric acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric malignancy. Although outcomes for children with ALL have improved dramatically over the last 50 years, ALL remains the leading cause of childhood cancer death. In addition, high-risk patient subsets can be identified with significantly inferior survival. In the current era of therapies directed at specific molecular targets, the use of conventional randomized Phase III trials to show benefit from a new treatment regimen may not be feasible when these biologically defined subsets are small. This review presents the traditional approaches to designing trials for children with ALL, as well as innovative approaches attempting to study the benefit of new treatments as reliably as possible for patient subsets with distinctive biological characteristics.

Statistical evaluation of the use of concurrent controls in treatment screening studies

A well-designed pilot study can advance science by providing essential preliminary data to support or motivate further research, refine study logistics, and demonstrate proof of concept. Often, the outcomes of such studies can be quantified by a success/failure dichotomy. For example, a novel compound may show activation of a neural pathway, or it may not. When an intervention's efficacy is quantified using a dichotomous outcome, probability mass functions can be enumerated to determine the probability that the observed result from a pilot study supports further evaluation of the intervention since there is only a finite, and often small, number of sample configurations possible. The purpose of this research was to determine the probability of an "efficacy signal" for pilot studies using one- and two-sample pilot study designs. Efficacy signal was defined as the probability of observing a more favorable response proportion relative to a historical control (one-sample setting) or to a concurrent control (two-sample setting). An enumeration study (exact simulation) was conducted to calculate the efficacy signal probability. One-sample study designs yielded higher probability of determining an efficacy signal than the two-sample setting; however, sampling variation must be accounted for. A 68% score confidence interval is recommended for this purpose.

Correlation between overall survival and growth modulation index in pre-treated sarcoma patients: a study from the French Sarcoma Group

BACKGROUND

Growth modulation index (GMI), the ratio of two times to progression measured in patients receiving two successive treatments (GMI = TTP2/TTP1), has been proposed as a criterion of phase II clinical trials. Nevertheless, its use has been limited until now.

PATIENTS AND METHODS

We carried out a retrospective multicentre study in soft tissue sarcoma patients receiving a second-line treatment after doxorubicin-based regimens to evaluate the link between overall survival and GMI. Second-line treatments were classified as 'active' according to the EORTC-STBSG criteria (3-month progression-free rate >40% or 6-month PFR >14%). Comparisons used chi-squared and log-rank tests.

RESULTS

The population consisted in 106 men and 121 women, 110 patients (48%) received 'active drugs'. Median OS from the second-line start was 317 days. Sixty-nine patients experienced GMI >1.33 (30.4%). Treatments with 'active drug' were not associated with OS improvement: 490 versus 407 days (P = 0.524). Median OS was highly correlated with GMI: 324, 302 and 710 days with GMI <1, GMI = [1.00-1.33], and GMI >1.33, respectively (P < 0.0001). In logistic regression analysis, the sole predictive factor was the number of doxorubicin-based chemotherapy cycles.

CONCLUSION

GMI seems to be an interesting end point that provides additional information compared with classical criteria. GMI >1.33 is associated with significant OS improvement.

Screened selection design for randomised phase II oncology trials: an example in chronic lymphocytic leukaemia

BACKGROUND

As there are limited patients for chronic lymphocytic leukaemia trials, it is important that statistical methodologies in Phase II efficiently select regimens for subsequent evaluation in larger-scale Phase III trials.

METHODS

We propose the screened selection design (SSD), which is a practical multi-stage, randomised Phase II design for two experimental arms. Activity is first evaluated by applying Simon's two-stage design (1989) on each arm. If both are active, the play-the-winner selection strategy proposed by Simon, Wittes and Ellenberg (SWE) (1985) is applied to select the superior arm. A variant of the design, Modified SSD, also allows the arm with the higher response rates to be recommended only if its activity rate is greater by a clinically-relevant value. The operating characteristics are explored via a simulation study and compared to a Bayesian Selection approach.

RESULTS

Simulations showed that with the proposed SSD, it is possible to retain the sample size as required in SWE and obtain similar probabilities of selecting the correct superior arm of at least 90%; with the additional attractive benefit of reducing the probability of selecting ineffective arms. This approach is comparable to a Bayesian Selection Strategy. The Modified SSD performs substantially better than the other designs in selecting neither arm if the underlying rates for both arms are desirable but equivalent, allowing for other factors to be considered in the decision making process. Though its probability of correctly selecting a superior arm might be reduced, it still performs reasonably well. It also reduces the probability of selecting an inferior arm.

CONCLUSIONS

SSD provides an easy to implement randomised Phase II design that selects the most promising treatment that has shown sufficient evidence of activity, with available R codes to evaluate its operating characteristics.

Performance of multinomial designs in comparison with response-based designs in non-randomized phase II trials of targeted cancer agents

BACKGROUND

In phase II trials of cytotoxic agents, a multinomial phase II design incorporating early progression and response end points was shown to perform more efficiently than designs based only on response. We undertook a study to evaluate the performance of these designs in trials of targeted agents using the actual phase II data.

PATIENTS AND METHODS

Using best response data from sequentially enrolled patients in 15 NCIC Clinical Trials Group and 7 European Organization for Research and Treatment of Cancer trials of targeted agents, we determined that trials would have been stopped at the end of stage I of accrual by applying rules generated by the multinomial and Fleming designs. Two variants of the multinomial design were studied: to stop accrual after stage I of enrolment, Variant A required either response or progression criteria to be met, whereas Variant B required that both response and progression criteria to be met.

RESULTS

Using early progression, null/alternate hypotheses of 60% and 40% (60/40), the multinomial A variant recommended early stopping more often than the Fleming design. In most of the cases, this recommendation was correct given the final trial outcome. In contrast, the multinomial B variant never led to recommendations for early stopping and changing progression hypotheses did not improve the performance of this design.

CONCLUSIONS

The multinomial A design using 60/40 hypotheses carried out better than the Fleming design in appropriately stopping trials of inactive targeted agents early. The multinomial B design was not useful for early stopping decisions. The multinomial A design may be favored over response-based designs in phase II trials of targeted agents.

Children's Oncology Group's 2013 blueprint for research: neuroblastoma

Estimated 5-year survival rates for patients with non-high-risk and high-risk neuroblastoma are 90% and 50%, respectively. Recent clinical trials have shown excellent outcomes with reduced therapy for non-high-risk disease. For patients with high-risk neuroblastoma treated with chemoradiotherapy, surgery, and stem cell transplantation, the addition of anti-disialoganglioside (GD2) immunotherapy plus cytokines improves survival. Upcoming trials will study the incorporation of targeted radionuclide therapy prior to myeloablative chemotherapy into high-risk treatment. Phase 2 trials will investigate druggable target(s) including mTOR inhibition and GD2-directed therapy in combination with chemotherapy for patients with recurrent neuroblastoma, and ALK inhibition for those with ALK-aberrant tumors.

A phase II flexible screening design allowing for interim analysis and comparison with historical control

Sargent and Goldberg [1] proposed a randomized phase II flexible screening design (SG design) which took multiple characteristics of candidate regimens into consideration in selecting a regimen for further phase III testing. In this paper, we extend the SG design by including provisions for an interim analysis and/or a comparison to a historical control. By including a comparison with a historical control, a modified SG design not only identifies a more promising treatment but also assures that the regimen has a clinically meaningful level of efficacy as compared to a historical control. By including an interim analysis, a modified SG design could reduce the number of patients exposed to inferior treatment regimens. When compared to the original SG design, the modified designs increase the sample size moderately, but expand the utility of the flexible screening design substantially.

Activity endpoints reported in soft tissue sarcoma phase II trials: quality of reported endpoints and correlation with overall survival

BACKGROUND

Despite extensive research over the past 3 decades, few investigational drugs are considered as promising and these drugs failed to improve overall survival. Therefore we performed a systematic review of the literature to improve our understanding of the reasons that explain these failures.

METHODS

We reviewed 53 phase II trial reports that investigated new treatments in patients with advanced soft tissue sarcoma from 1999 to 2011. We critically reviewed the selected primary endpoint used in these trials.

RESULTS

Forty percent of trials were not interpretable because of major inherent methodological flaws. Only 3 primary endpoints were correlated with median overall survival (mOS): 3- and 6-month progression free rates and median progression-free survival. Nevertheless, the mOS was not significantly higher in the cases of active drugs.

DISCUSSION

We need to improve the definition of primary active endpoints and develop better designs for future trials. The current definition of promising drugs must be refined.

Modeling the relationship between progression-free survival and overall survival: the phase II/III trial

The standard phase II trial design has changed dramatically over the past decade. Randomized phase II studies have essentially become the standard phase II design in oncology for a variety of reasons. The use of these designs is motivated by concerns about the use of historical data to determine if a new agent or regimen shows promise of activity. However, randomized phase II designs come with the cost of increased study duration and patient resources. Progression-free survival (PFS) is an important endpoint used in many phase II designs. In many clinical settings, changes in PFS with the introduction of a new treatment may represent true benefit in terms of the gold standard outcome, overall survival (OS). The phase II/III design has been proposed as an approach to shorten the time of discovery of an active regimen. In this article, design considerations for a phase II/III trial are discussed and presented in terms of a model defining the relationship between OS and PFS. The design is also evaluated using 15 phase III trials completed in the Southwest Oncology Group (SWOG) between 1990 and 2005. The model provides a framework to evaluate the validity and properties of using a phase II/III design. In the evaluation of SWOG trials, three of four positive studies would have also proceeded to the final analysis and 10 of 11 negative studies would have stopped at the phase II analysis if a phase II/III design had been used. Through careful consideration and thorough evaluation of design properties, substantial gains could occur using this approach.

Randomized phase II, double-blind, placebo-controlled study of exemestane with or without entinostat in postmenopausal women with locally recurrent or metastatic estrogen receptor-positive breast cancer progressing on treatment with a nonsteroidal aromatase inhibitor

PURPOSE

Entinostat is an oral isoform selective histone deacetylase inhibitor that targets resistance to hormonal therapies in estrogen receptor-positive (ER+) breast cancer. This randomized, placebo-controlled, phase II study evaluated entinostat combined with the aromatase inhibitor exemestane versus exemestane alone.

PATIENTS AND METHODS

Postmenopausal women with ER+ advanced breast cancer progressing on a nonsteroidal aromatase inhibitor were randomly assigned to exemestane 25 mg daily plus entinostat 5 mg once per week (EE) or exemestane plus placebo (EP). The primary end point was progression-free survival (PFS). Blood was collected in a subset of patients for evaluation of protein lysine acetylation as a biomarker of entinostat activity.

RESULTS

One hundred thirty patients were randomly assigned (EE group, n = 64; EP group, n = 66). Based on intent-to-treat analysis, treatment with EE improved median PFS to 4.3 months versus 2.3 months with EP (hazard ratio [HR], 0.73; 95% CI, 0.50 to 1.07; one-sided P = .055; two-sided P = .11 [predefined significance level of .10, one-sided]). Median overall survival was an exploratory end point and improved to 28.1 months with EE versus 19.8 months with EP (HR, 0.59; 95% CI, 0.36 to 0.97; P = .036). Fatigue and neutropenia were the most frequent grade 3/4 toxicities. Treatment discontinuation because of adverse events was higher in the EE group versus the EP group (11% v 2%). Protein lysine hyperacetylation in the EE biomarker subset was associated with prolonged PFS.

CONCLUSION

Entinostat added to exemestane is generally well tolerated and demonstrated activity in patients with ER+ advanced breast cancer in this signal-finding phase II study. Acetylation changes may provide an opportunity to maximize clinical benefit with entinostat. Plans for a confirmatory study are underway.

Comparative effectiveness of the nicotine lozenge and tobacco-free snuff for smokeless tobacco reduction

Long-term smokeless tobacco (ST) use is associated with cardiovascular disease and cancer, but not all ST users want to quit. Previous studies have evaluated the effectiveness of nicotine lozenges and tobacco-free snuff for reducing ST use among ST users not ready to quit, but no comparative effectiveness trials of these two products have been conducted. We conducted a multicenter, randomized clinical pilot study evaluating the comparative effectiveness of the 4-mg nicotine lozenge and tobacco-free snuff for reducing ST use and increasing tobacco abstinence among ST users with no intention of quitting in the next 30 days. Participants received 8 weeks of treatment and behavioral counseling on tobacco reduction strategies with follow-up to 26 weeks. We randomized 81 participants (40 nicotine lozenges, 41 tobacco-free snuff). No significant differences in reduction were observed between the two groups at weeks 8, 12, and 26. No significant differences were observed between groups in nicotine withdrawal or tobacco craving. However, both groups significantly reduced (p<.001) ST use in cans/week and dips/day from baseline which was sustained through the end-of-study. The observed biochemically-confirmed abstinence rates at week 26 were similar between groups (12% vs. 12%, one-tailed p=.615). The 4-mg nicotine lozenge and the tobacco-free snuff both appear to be effective and comparable for reducing ST use among ST users not ready to quit in the next 30 days.

Early-stage squamous cell carcinoma of the oropharynx: radiotherapy vs. trans-oral robotic surgery (ORATOR)--study protocol for a randomized phase II trial

Background

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) has markedly increased over the last three decades due to newly found associations with human papillomavirus (HPV) infection. Primary radiotherapy (RT) is the treatment of choice for OPSCC at most centers, and over the last decade, the addition of concurrent chemotherapy has led to a significant improvement in survival, but at the cost of increased acute and late toxicity. Transoral robotic surgery (TORS) has emerged as a promising alternative treatment, with preliminary case series demonstrating encouraging oncologic, functional, and quality of life (QOL) outcomes. However, comparisons of TORS and RT in a non-randomized fashion are susceptible to bias. The goal of this randomized phase II study is to compare QOL, functional outcomes, toxicity profiles, and survival following primary RT (± chemotherapy) vs. TORS (± adjuvant [chemo] RT) in patients with OPSCC.

Methods/Design

The target patient population comprises OPSCC patients who would be unlikely to require chemotherapy post-resection: Tumor stage T1-T2 with likely negative margins at surgery; Nodal stage N0-2, ≤3 cm in size, with no evidence of extranodal extension on imaging. Participants will be randomized in a 1:1 ratio between Arm 1 (RT ± chemotherapy) and Arm 2 (TORS ± adjuvant [chemo] RT). In Arm 1, patients with N0 disease will receive RT alone, whereas N1-2 patients will receive concurrent chemoradiation. In Arm 2, patients will undergo TORS along with selective neck dissections, which may be staged. Pathologic high-risk features will be used to determine the requirement for adjuvant radiotherapy +/- chemotherapy. The primary endpoint is QOL score using the M.D. Anderson Dysphagia Inventory (MDADI), with secondary endpoints including survival, toxicity, other QOL outcomes, and swallowing function. A sample of 68 patients is required.

Discussion

This study, if successful, will provide a much-needed randomized comparison of the conventional strategy of primary RT vs. the novel strategy of primary TORS. The trial is designed to provide a definitive QOL comparison between the two arms, and to inform the design of an eventual phase III trial for survival outcomes.

Trial registration

NCT01590355

Smaller sample sizes for phase II trials based on exact tests with actual error rates by trading-off their nominal levels of significance and power

Background:

Sample sizes for single-stage phase II clinical trials in the literature are often based on exact (binomial) tests with levels of significance (alpha (α) <5% and power >80%). This is because there is not always a sample size where α and power are exactly equal to 5% and 80%, respectively. Consequently, the opportunity to trade-off small amounts of α and power for savings in sample sizes may be lost.

Methods:

Sample-size tables are presented for single-stage phase II trials based on exact tests with actual levels of significance and power. Trade-off in small amounts of α and power allows the researcher to select from several possible designs with potentially smaller sample sizes compared with existing approaches. We provide SAS macro coding and an R function, which for a given treatment difference, allow researchers to examine all possible sample sizes for specified differences are provided.

Results:

In a single-arm study with P₀ (standard treatment)=10% and P₁ (new treatment)=20%, and specified α=5% and power=80%, the A’Hern approach yields n=78 (exact α=4.53%, power=80.81%). However, by relaxing α to 5.67% and power to 77.7%, a sample size of 65 can be used (a saving of 13 patients).

Interpretation:

The approach we describe is especially useful for trials in rare disorders, or for proof-of-concept studies, where it is important to minimise the trial duration and financial costs, particularly in single-arm cancer trials commonly associated with expensive treatment options.

A prospective multicenter phase II study evaluating multimodality treatment of patients with peritoneal carcinomatosis arising from appendiceal and colorectal cancer: the COMBATAC trial

Background

Peritoneal carcinomatosis is regarded as a common sign of advanced tumor stage, tumor progression or local recurrence of appendiceal and colorectal cancer and is generally associated with poor prognosis. Although survival of patients with advanced stage CRC has markedly improved over the last 20 years with systemic treatment, comprising combination chemotherapy +/− monoclonal antibodies, the oncological outcome—especially of the subgroup of patients with peritoneal metastases—is still unsatisfactory. In addition to systemic therapy, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) are specific treatment options for a selected group of these patients and may provide an additional therapeutic benefit in the framework of an interdisciplinary treatment concept.

Methods/design

The COMBATAC trial is a prospective, multicenter, open-label, single-arm, single-stage phase II trial investigating perioperative systemic polychemotherapy including cetuximab in combination with CRS and HIPEC patients with histologically proven wild-type KRAS colorectal or appendiceal adenocarcinoma and synchronous or metachronous peritoneal carcinomatosis. The planned total number of patients to be recruited is 60. The primary endpoint is progression-free survival (PFS). Secondary endpoints include overall survival (OS), perioperative morbidity and treatment-associated toxicity, feasibility of the combined treatment regimen, quality of life (QoL) and histopathological regression after preoperative chemotherapy.

Discussion

The COMBATAC trial is designed to evaluate the feasibility and efficacy of the combined multidisciplinary treatment regimen consisting of perioperative systemic combination chemotherapy plus cetuximab and CRS plus bidirectional HIPEC with intraperitoneal oxaliplatin.

Trial registration

ClinicalTrials.gov Identifier: NCT01540344, EudraCT number: 2009-014040-11

NCI-RTOG translational program strategic guidelines for the early-stage development of radiosensitizers

The addition of chemotherapeutic agents to ionizing radiation has improved survival in many malignancies. Cure rates may be further improved by adding novel targeted agents to current radiotherapy or radiochemotherapy regimens. Despite promising laboratory data, progress in the clinical development of new drugs with radiation has been limited. To define and address the problems involved, a collaborative effort between individuals within the translational research program of the Radiation Oncology Therapy Group and the National Cancer Institute was established. We discerned challenges to drug development with radiation including: 1) the limited relevance of preclinical work, 2) the pharmaceutical industry's diminished interest, and 3) the important individual skills and institutional commitments required to ensure a successful program. The differences between early-phase trial designs with and without radiation are noted as substantial. The traditional endpoints for early-phase clinical trials-acute toxicity and maximum-tolerated dose-are of limited value when combining targeted agents with radiation. Furthermore, response rate is not a useful surrogate marker of activity in radiation combination trials.Consequently, a risk-stratified model for drug-dose escalation with radiation is proposed, based upon the known and estimated adverse effects. The guidelines discuss new clinical trial designs, such as the time-to-event continual reassessment method design for phase I trials, randomized phase II "screening" trials, and the use of surrogate endpoints, such as pathological response. It is hoped that by providing a clear pathway, this article will accelerate the rate of drug development with radiation.

Integrated phase II/III clinical trials in oncology: a case study

BACKGROUND

Integrated phase II/III trial designs implement the phase II and phase III aspects of oncology studies into a single trial. Despite a body of literature discussing the merits of integrated phase II/III clinical trial designs within the past two decades, implementation of this design has been limited in oncology studies.

PURPOSE

We provide a brief discussion of the potential advantages and disadvantages of integrated phase II/III clinical trial designs in oncology and provide an example of the operating characteristics of a Radiation Therapy Oncology Group (RTOG) trial.

METHODS

We review the differences among proposed integrated phase II/III designs. Then, we illustrate the use of the design in a brain tumor trial to be conducted by the RTOG and examine the impact of association between endpoints on design performance in terms of type I error, power, study duration, and expected sample size.

RESULTS

Although integrated phase II/III designs should not be used in all situations, under appropriate conditions, significant gains can be achieved when using integrated phase II/III designs, including smaller sample size, time and resources savings, and shorter study duration.

LIMITATIONS

Data submission without delay and sufficient evaluation of intermediate endpoints are assumed.

CONCLUSIONS

Although there are potential benefits in using phase II/III designs, there also may be disadvantages. We recommend running design simulations incorporating theoretical and practical issues before implementing an integrated phase II/III design.

A Crossover Randomized Prospective Pilot Study Evaluating a Central Venous Catheter Team in Reducing Catheter-Related Bloodstream Infections in Pediatric Oncology Patients

Background: Treatment for most children with cancer includes the use of a central venous catheter (CVC). CVCs provide reliable venous access for delivery of chemotherapy and supportive care. This advantage is mitigated by an increased risk of bloodstream infections (BSIs). Despite the ubiquitous use of CVCs, few prospective studies have been conducted to address infection prevention strategies in pediatric oncology patients. Design: Prospective, crossover pilot study of a CVC team intervention versus standard care. Setting: Two inpatient oncology units in a metropolitan children’s hospital. Patients: A total of 41 patients/135 admissions for the experimental unit (EU) and 41/129 admissions for the control unit (CU). Methods: Patients received a CVC blood draw bundle procedure by a CVC registered nurse (RN) team member (experimental intervention: EU) for 6 months and by the assigned bedside RN (standard care: CU) for 6 months. Feasibility of implementing a CVC RN team; a significant difference in CVC-related BSIs between the team intervention versus standard care and risk factors associated in the development of CVC-related BSIs were determined. Results: There were 7 CVC-related BSIs/1238 catheter days in the EU group (5.7/1000 catheter days) versus 3 CVC-related BSIs/1419 catheter days in the CU group (2.1/1000 catheter days; P = .97). Selected risk factors were not significantly associated with the development of a CVC-related BSI. Conclusions: A CVC team in the care of pediatric oncology patients is feasible; however, a larger cohort will be required to adequately determine the effectiveness of the team reducing CVC-related BSIs.