A Phase I Study of an MPS1 Inhibitor (BAY 1217389) in Combination with Paclitaxel Using a Novel Randomized Continual Reassessment Method for Dose Escalation.

PURPOSE: Monopolar spindle 1 (MPS1) kinase inhibitor, BAY 1217389 (BAY) synergizes with paclitaxel. This phase I study assessed the combination of BAY with paclitaxel using a novel randomized continuous reassessment method (rCRM) to improve dose determination. PATIENTS AND METHODS: Patients with solid tumors were randomized to receive oral BAY (twice daily 2-days-on/5-days-off) with weekly paclitaxel (90 mg/m2) or paclitaxel monotherapy in cycle 1. Dose escalation was guided by CRM modeling. Primary objectives were to assess safety, establish the MTD of BAY, and to evaluate the pharmacokinetic profiles for both compounds. Simulations were performed to determine the contribution of the rCRM for dose determination. RESULTS: In total, 75 patients were enrolled. The main dose-limiting toxicities were hematologic toxicities (55.6%). The MTD of BAY was established at 64 mg twice daily with paclitaxel. Inclusion of a control arm enabled the definitive attribution of grade ≥3 neutropenia to higher BAY exposure [AUC0-12 (P< 0.001)]. After determining the MTD, we included 19 patients with breast cancer at this dose for dose expansion. Other common toxicities were nausea (45.3%), fatigue (41.3%), and diarrhea (40.0%). Overall confirmed responses were seen in 31.6% of evaluable patients. Simulations showed that rCRM outperforms traditional designs in determining the true MTD. CONCLUSIONS: The combination of BAY with paclitaxel was associated with considerable toxicity without a therapeutic window. However, the use of the rCRM design enabled us to determine the exposure-toxicity relation for BAY. Therefore, we propose that the rCRM could improve dose determination in phase I trials that combine agents with overlapping toxicities.

Unequal Access to Newly Registered Cancer Drugs Leads to Potential Loss of Life-Years in Europe.

BACKGROUND: Many new cancer medicines have been developed that can improve patients' outcomes. However, access to these agents comes later in Europe than in the United States (US). The aim of this study is to assess the access in Europe to newly registered cancer drugs and to get more insight in the implications of these variations for patients. METHODS: A retrospective database study was conducted. Analyses involved 12 cancer drugs and 28 European countries in the period 2011-2018. Time to patient access, speed of drug uptake, and the potential loss of life years due to a delay in access have been studied. RESULTS: Marketing approval for the cancer drugs came on average 242 days later in Europe than in the US, and actual patient access varied extensively across Europe. The average time to market in Europe was 403 days (range 17-1187 days). The delay in patient access of ipilimumab and abiraterone may have led to a potential loss of more than 30,000 life years. CONCLUSION: It takes a long time for patients to get access to newly registered cancer drugs and there is great variation in access. The health outcomes can be substantially improved by faster processes.

Iniparib administered weekly or twice-weekly in combination with gemcitabine/carboplatin in patients with metastatic triple-negative breast cancer: a phase II randomized open-label study with pharmacokinetics.

PURPOSE: Metastatic triple-negative breast cancer (TNBC) is a phenotypic breast cancer subgroup with a very poor prognosis, despite standard treatments. Combined twice-weekly iniparib and gemcitabine/carboplatin (GC+tw-iniparib) showed benefit over gemcitabine/carboplatin in a randomized phase II trial, and a phase III was initiated comparing these regimens. The present phase II study was initiated to compare GC+tw-iniparib with a more practical once-weekly schedule (GC+w-iniparib) in TNBC. METHODS: Metastatic TNBC patients were randomized to receive iniparib weekly (11.2 mg/kg on days 1 and 8) or twice-weekly (5.6 mg/kg on days 1, 4, 8, and 11) with gemcitabine (1000 mg/m2) and carboplatin (area under the curve 2 on days 1 and 8), every 3 weeks. The primary endpoint was the overall response rate (ORR). Pharmacokinetics of iniparib and its two metabolites were analyzed. RESULTS: A total of 163 patients were randomized, 82 GC+w-iniparib and 81 GC+tw-iniparib. Demographic and baseline characteristics were well balanced. ORR was 34.1% (95% CI 23.9-44.4%) vs. 29.6% (95% CI 19.7-39.6%) and median progression-free survival was 5.5 months (95% CI 4.2-5.7) vs. 4.3 months (95% CI 3.0-5.8) for GC+w-iniparib and GC+tw-iniparib, respectively. Safety was similar across treatment arms in terms of event severity and type. Iniparib plasma concentrations and exposure were two-fold higher with w-iniparib compared to tw-iniparib. Iniparib and its metabolites were cleared rapidly with a terminal half-life of < 1 h, without accumulation. CONCLUSIONS: Despite a doubled maximum concentration with weekly iniparib, no detectable differences in safety or efficacy were observed between the weekly and twice-weekly administration schedules in this population. TRIAL REGISTRATION: ClinicalTrial.gov Identifier NCT01045304.

Surrogate endpoints in advanced sarcoma trials: a meta-analysis.

BACKGROUND: Alternative endpoints to overall survival (OS) are frequently used to assess treatment efficacy in randomized controlled trials (RCT). Their properties in terms of surrogate outcomes for OS need to be assessed. We evaluated the surrogate properties of progression-free survival (PFS), time-to-progression (TTP) and time-to-treatment failure (TTF) in advanced soft tissue sarcomas (STS). RESULTS: A total of 21 trials originally met the selection criteria and 14 RCTs (N = 2846) were included in the analysis. Individual-level associations were moderate (highest for 12-month PFS: Spearman's rho = 0.66; 95% CI [0.63; 0.68]). Trial-level associations were ranked as low for the three endpoints as per the IQWiG criterion. MATERIALS AND METHODS: We performed a meta-analysis using individual-patient data (IPD). Phase II/III RCTs evaluating therapies for adults with advanced STS were eligible. We estimated the individual- and the trial-level associations between then candidate surrogates and OS. Statistical methods included weighted linear regression and the two-stage model introduced by Buyse and Burzykowski. The strength of the trial-level association was ranked according to the German Institute for Quality and Efficiency in Health Care (IQWiG) guidelines. CONCLUSIONS: Our results do not support strong surrogate properties of PFS, TTP and TTF for OS in advanced STS.

Effect of Neoadjuvant Chemotherapy Plus Regional Hyperthermia on Long-term Outcomes Among Patients With Localized High-Risk Soft Tissue Sarcoma: The EORTC 62961-ESHO 95 Randomized Clinical Trial.

IMPORTANCE: Patients with soft tissue sarcoma are at risk for local recurrence and distant metastases despite optimal local treatment. Preoperative anthracycline plus ifosfamide chemotherapy improves outcome in common histological subtypes. OBJECTIVE: To analyze whether the previously reported improvement in local progression-free survival by adding regional hyperthermia to neoadjuvant chemotherapy translates into improved survival. DESIGN, SETTING, AND PARTICIPANTS: Open-label, phase 3 randomized clinical trial to evaluate the efficacy and toxic effects of neoadjuvant chemotherapy plus regional hyperthermia. Adult patients (age ≥18 years) with localized soft tissue sarcoma (tumor ≥5 cm, French Federation Nationale des Centers de Lutte Contre le Cancer [FNCLCC] grade 2 or 3, deep) were accrued across 9 centers (6, Germany; 1, Norway; 1, Austria; 1, United States) from July 1997 to November 2006. Follow-up ended December 2014. INTERVENTIONS: After stratification for tumor presentation and site, patients were randomly assigned to either neoadjuvant chemotherapy consisting of doxorubicin, ifosfamide, and etoposide alone, or combined with regional hyperthermia. MAIN OUTCOMES AND MEASURES: The primary end point was local progression-free survival. Secondary end points included treatment safety and survival, with survival defined from date of randomization to death due to disease or treatment. Patients lost to follow-up were censored at the date of their last follow-up. RESULTS: A total of 341 patients were randomized, and 329 (median [range] age, 51 [18-70] years; 147 women, 182 men) were eligible for the intention-to-treat analysis. By December 2014, 220 patients (67%; 95% CI, 62%-72%) had experienced disease relapse, and 188 (57%; 95% CI, 52%-62%) had died. Median follow-up was 11.3 years. Compared with neoadjuvant chemotherapy alone, adding regional hyperthermia improved local progression-free survival (hazard ratio [HR], 0.65; 95% CI, 0.49-0.86; P = .002). Patients randomized to chemotherapy plus hyperthermia had prolonged survival rates compared with those randomized to neoadjuvant chemotherapy alone (HR, 0.73; 95% CI, 0.54-0.98; P = .04) with 5-year survival of 62.7% (95% CI, 55.2%-70.1%) vs 51.3% (95% CI, 43.7%-59.0%), respectively, and 10-year survival of 52.6% (95% CI, 44.7%-60.6%) vs 42.7% (95% CI, 35.0%-50.4%). CONCLUSIONS AND RELEVANCE: Among patients with localized high-risk soft tissue sarcoma the addition of regional hyperthermia to neoadjuvant chemotherapy resulted in increased survival, as well as local progression-free survival. For patients who are candidates for neoadjuvant treatment, adding regional hyperthermia may be warranted. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00003052.

Ten-Year Progression-Free and Overall Survival in Patients With Unresectable or Metastatic GI Stromal Tumors: Long-Term Analysis of the European Organisation for Research and Treatment of Cancer, Italian Sarcoma Group, and Australasian Gastrointestinal Trials Group Intergroup Phase III Randomized Trial on Imatinib at Two Dose Levels.

Purpose To report on the long-term results of a randomized trial comparing a standard dose (400 mg/d) versus a higher dose (800 mg/d) of imatinib in patients with metastatic or locally advanced GI stromal tumors (GISTs). Patients and Methods Eligible patients with advanced CD117-positive GIST from 56 institutions in 13 countries were randomly assigned to receive either imatinib 400 mg or 800 mg daily. Patients on the 400-mg arm were allowed to cross over to 800 mg upon progression. Results Between February 2001 and February 2002, 946 patients were accrued. Median age was 60 years (range, 18 to 91 years). Median follow-up time was 10.9 years. Median progression-free survival times were 1.7 and 2.0 years in the 400- and 800-mg arms, respectively (hazard ratio, 0.91; P = .18), and median overall survival time was 3.9 years in both treatment arms. The estimated 10-year progression-free survival rates were 9.5% and 9.2% for the 400- and 800-mg arms, respectively, and the estimated 10-year overall survival rates were 19.4% and 21.5%, respectively. At multivariable analysis, age (< 60 years), performance status (0 v ≥ 1), size of the largest lesion (smaller), and KIT mutation (exon 11) were significant prognostic factors for the probability of surviving beyond 10 years. Conclusion This trial was carried out on a worldwide intergroup basis, at the beginning of the learning curve of the use of imatinib, in a large population of patients with advanced GIST. With a long follow-up, 6% of patients are long-term progression free and 13% are survivors. Among clinical prognostic factors, only performance status, KIT mutation, and size of largest lesion predicted long-term outcome, likely pointing to a lower burden of disease. Genomic and/or immune profiling could help understand long-term survivorship. Addressing secondary resistance remains a therapeutic challenge.

miR-634 restores drug sensitivity in resistant ovarian cancer cells by targeting the Ras-MAPK pathway.

BACKGROUND: Drug resistance hampers the efficient treatment of malignancies, including advanced stage ovarian cancer, which has a 5-year survival rate of only 30 %. The molecular processes underlying resistance have been extensively studied, however, not much is known about the involvement of microRNAs. METHODS: Differentially expressed microRNAs between cisplatin sensitive and resistant cancer cell line pairs were determined using microarrays. Mimics were used to study the role of microRNAs in drug sensitivity of ovarian cancer cell lines and patient derived tumor cells. Luciferase reporter constructs were used to establish regulation of target genes by microRNAs. RESULTS: MiR-634 downregulation was associated with cisplatin resistance. Overexpression of miR-634 affected cell cycle progression and enhanced apoptosis in ovarian cancer cells. miR-634 resensitized resistant ovarian cancer cell lines and patient derived drug resistant tumor cells to cisplatin. Similarly, miR-634 enhanced the response to carboplatin and doxorubicin, but not to paclitaxel. The cell cycle regulator CCND1, and Ras-MAPK pathway components GRB2, ERK2 and RSK2 were directly repressed by miR-634 overexpression. Repression of the Ras-MAPK pathway using a MEK inhibitor phenocopied the miR-634 effects on viability and chemosensitivity. CONCLUSION: miR-634 levels determine chemosensitivity in ovarian cancer cells. We identify miR-634 as a therapeutic candidate to resensitize chemotherapy resistant ovarian tumors.

4ß-hydroxycholesterol as an endogenous CYP3A marker in cancer patients treated with taxanes.

AIM: Taxanes are anti-cancer agents used to treat several types of solid tumours. They are metabolized by cytochrome P450 (CYP) 3A, displaying a large pharmacokinetic (PK) variability. In this study, we evaluated the endogenous CYP3A4 marker 4ß-hydroxycholesterol (4ß-OHC) as a potential individual taxane PK predictor. METHODS: Serum 4ß-OHC and cholesterol concentrations were determined in 291 paclitaxel and 151 docetaxel-treated patients, and were subsequently correlated with taxane clearance. RESULTS: In the patients treated with paclitaxel, no clinically relevant correlations between the 4ß-OHC or 4ß-OHC : cholesterol ratio and paclitaxel clearance were found. In the patients treated with docetaxel, 4ß-OHC concentration was weakly correlated with docetaxel clearance in males (r = 0.35 P = 0.01, 95% CI 0.08, 0.58). Of the 10% patients with taxane outlier clearance values, 4ß-OHC did correlate with docetaxel clearance in males (r = 0.76, P = 0.03, 95% CI 0.12, 0.95). CONCLUSION: There was no clinical correlation between paclitaxel clearance and the CYP3A4 activity markers 4ß-OHC or the 4ß-OHC : cholesterol ratio. A weak correlation was observed between 4ß-OHC and docetaxel clearance, but only in males. This endogenous CYP3A4 marker has limited predictive value for taxane clearance in patients.

Development and validation of prognostic nomograms for metastatic gastrointestinal stromal tumour treated with imatinib.

PURPOSE: Metastatic gastrointestinal stromal tumour (GIST) is generally an incurable disease with variable response to imatinib. We aimed to develop prognostic nomograms to predict overall survival (OS) and progression-free survival (PFS) for patients treated with imatinib. METHODS: Nomograms were developed in a training cohort (n=330) of patients treated in a randomised trial (EORTC-ISG-AGITG 62005 phase III study) using Cox regression models, and validated in patients (n=236) treated in routine clinical care from six referral centres. Nomogram performance was assessed by calculating the c statistic. A classification based on the nomograms' scores was generated to group patients according to risk. RESULTS: Nomogram risk factors for OS and PFS were size of the largest metastasis, tumour genotype, primary tumour mitotic count, haemoglobin and blood neutrophil count at commencement of imatinib. The nomograms predicted survival with a c statistic of 0.75 (training) and 0.62 (validation) for OS, and 0.69 (training) and 0.62 (validation) for PFS. When tested in the validation cohort, the nomograms discriminated well the high and intermediate risk from low risk patients (hazard ratio [HR] for OS 3.83, 95% confidence interval [CI] 1.71-8.56; and 2.48, 95% CI 1.12-5.50; for PFS 2.84, 95% CI 1.66-4.87; and 1.45, 95% CI 0.87-2.41, respectively). CONCLUSION: The nomograms predicted the risk of GIST progression and death with good discrimination of risk groups, and may be of value for patient counselling and risk stratification.

Recurrence of melanoma following T cell treatment: continued antigen expression in a tumor that evades T cell recruitment.

Clinical therapy with T cells shows promise for cancer patients, but is currently challenged by incomplete responses and tumor relapse. The exact mechanisms that contribute to tumor relapse remain largely unclear. Here, we treated mouse melanomas with T cell receptor-engineered T cells directed against a human peptide-major histocompatibility complex antigen in immune-competent mice. T cells resulted in significant tumor regression, which was followed by relapse in about 80-90% of mice. Molecular analysis revealed that relapsed tumors harbored nonmutated antigen genes, not silenced by promoter methylation, and functionally expressed surface antigen at levels equal to nontreated tumors. Relapsed tumors resisted a second in vivo T cell treatment, but regained sensitivity to T cell treatment upon retransplantation in mice. Notably, relapsed tumors demonstrated decreased levels of CD8 T cells and monocytes, which were substantiated by downregulated expression of chemoattractants and adhesion molecules. These observations were confirmed when using T cells specific for a less immunogenic, endogenous mouse melanoma antigen. We conclude that tumors, when exposed to T cell treatment, can relapse without loss of antigen and develop a milieu that evades recruitment of effector CD8 T cells. Our findings support the concept to target the tumor milieu to aid T cell therapy in limiting tumor relapse.

Dose-response relationship in phase i clinical trials: a European Drug Development Network (EDDN) Collaboration Study.

INTRODUCTION: Because a dose-response relationship is characteristic of conventional chemotherapy, this concept is widely used for the development of novel cytotoxic (CTX) drugs. However, the need to reach the MTD to obtain optimal benefit with molecularly targeted agents (MTA) is controversial. In this study, we evaluated the relationship between dose and efficacy in a large cohort of phase I patients with solid tumors. EXPERIMENTAL DESIGN: We collected data on 1,182 consecutive patients treated in phase I trials in 14 European institutions in 2005-2007. Inclusion criteria were: (i) patients treated within completed single-agent studies in which a maximum-administered dose was defined and (ii) RECIST/survival data available. RESULTS: Seventy-two percent of patients were included in trials with MTA (N = 854) and 28% in trials with CTX (N = 328). The objective response (OR) rate was 3% and disease control at 6 months was 11%. OR for CTX was associated with higher doses (median 92% of MTD); this was not the case for MTA, where patients achieving OR received a median of 50% of MTD. For trials with MTA, patients treated at intermediate doses (40%-80%) had better survival compared with those receiving low or high doses (P = 0.038). On the contrary, there was a direct association between higher dose and better OS for CTX agents (P = 0.003). CONCLUSION: Although these results support the development of novel CTX based on MTD, we found no direct relationship between higher doses and response with MTA in unselected patients. However, the longest OS was seen in patients treated with MTA at intermediate doses (40%-80% of MTD).

Towards new methods for the determination of dose limiting toxicities and the assessment of the recommended dose for further studies of molecularly targeted agents--dose-Limiting Toxicity and Toxicity Assessment Recommendation Group for Early Trials of Targeted therapies, an European Organisation for Research and Treatment of Cancer-led study.

INTRODUCTION: Traditional dose-limiting toxicity (DLT) definition, which uses grade (G) 3-4 toxicity data from cycle 1 (C1) only, may not be appropriate for molecularly targeted agents (MTAs) of prolonged administration, for which late or lower grade toxicities also deserve attention. PATIENTS AND METHODS: In collaboration with pharmaceutical companies and academia, an European Organisation for Research and Treatment of Cancer (EORTC)-led initiative, Dose-Limiting Toxicity and Toxicity Assessment Recommendation Group for Early Trials of Targeted therapies (DLT-TARGETT), collected data from completed phase 1 trials evaluating MTAs as monotherapy. All toxicities at least possibly related to the study drugs that occurred during C1-6, their type, grade (CTCAEv3.0), and duration as well as patients' relative dose-intensity (RDI), were recorded. RESULTS: The 54 eligible trials enrolled 2084 evaluable adult patients with solid tumours between 1999 and 2013, and evaluated small molecules (40), antibodies (seven), recombinant peptides (five) and antisense oligodeoxynucleotides (two). A maximum tolerated dose was set in 43 trials. Fifteen percent of the patients received <75% of the intended RDI in C1, but only 9.1% of them presented protocol-defined DLTs. After C1, 16-19% of patients received <75% of the intended RDI. A similar proportion of G ⩾ 3 toxicities was recorded in C1 and after C1 (936 and 1087 toxicities, respectively), with the first G⩾3 toxicity occurring after C1 in 18.6% of patients. CONCLUSION: Although protocol-defined DLT period is traditionally limited to C1, almost 20% of patients present significant reductions in RDI at any time in phase 1 trials of MTAs. Recommended phase 2 dose assessment should incorporate all available information from any cycle (notably lower grade toxicities leading to such RDI decrease), and be based on achieving >75% RDI.

MicroRNA response to hypoxic stress in soft tissue sarcoma cells: microRNA mediated regulation of HIF3α.

BACKGROUND: Hypoxia is often encountered in solid tumors and known to contribute to aggressive tumor behavior, radiation- and chemotherapy resistance resulting in a poor prognosis for the cancer patient. MicroRNAs (miRNAs) play a role in the regulation of the tumor cell response to hypoxia, however, not much is known about the involvement of miRNAs in hypoxic signalling pathways in soft tissue sarcomas (STS). METHOD: A panel of twelve STS cell lines was exposed to atmospheric oxygen concentrations (normoxia) or 1% oxygen (hypoxia) for up to 48 h. Hypoxic conditions were verified and miRNA expression profiles were assessed by LNA™ oligonucleotide microarrays and RT-PCR after 24 h. The expression of target genes regulated by hypoxia responsive miRNAs is examined by end-point PCR and validated by luciferase reporter constructs. RESULTS: Exposure of STS cell lines to hypoxic conditions gave rise to upregulation of Hypoxia Inducible Factor (HIF) 1α protein levels and increased mRNA expression of HIF1 target genes CA9 and VEGFA. Deregulation of miRNA expression after 24 h of hypoxia was observed. The most differentially expressed miRNAs (p<0.001) in response to hypoxia were miR-185-3p, miR-485-5p, miR-216a-5p (upregulated) and miR-625-5p (downregulated). The well-known hypoxia responsive miR-210-3p could not be reliably detected by the microarray platform most likely for technical reasons, however, its upregulation upon hypoxic stress was apparent by qPCR. Target prediction algorithms identified 11 potential binding sites for miR-485-5p and a single putative miR-210-3p binding site in the 3'UTR of HIF3α, the least studied member of the HIF family. We showed that HIF3α transcripts, expressing a 3'UTR containing the miR-485-5p and miR-210-3p target sites, are expressed in all sarcoma cell lines and upregulated upon hypoxia. Additionally, luciferase reporter constructs containing the 3'UTR of HIF3α were used to demonstrate regulation of HIF3α by miR-210-3p and miR-485-5p. CONCLUSION: Here we provide evidence for the miRNA mediated regulation of HIF3α by hypoxia responsive miRNAs in STS, which may help to tightly regulate and fine-tune the hypoxic response. This provides a better insight into the mechanisms underlying the hypoxic response in STS and may ultimately yield information on novel prognostic and predictive markers or targets for treatment.

Defining dose-limiting toxicity for phase 1 trials of molecularly targeted agents: results of a DLT-TARGETT international survey.

INTRODUCTION: It is increasingly clear that definitions of dose-limiting toxicity (DLT) established for phase 1 trials of cytotoxic agents are not suitable for molecularly targeted agents because of specific toxicity profiles. An international survey collected expertise on the definition of DLT, as part of an initiative aimed at presenting new guidelines for phase 1 trials of targeted agents. METHODS: A 15-question survey was sent to corresponding authors of phase 1 reports. Questions involved: duration of the DLT assessment period, incorporation of specific grade 1 (G1) or G2 toxicity and their minimum duration to qualify as DLT, exclusion of specific G3 and inclusion of dose modification/delay. RESULTS: Among the 400 investigators contacted, 93 replied of whom 65 completed the questionnaires. A total of 87% opted for an extended DLT assessment period beyond cycle 1, with the proviso not to delay patient accrual. Reanalysis at the end of the study of all safety data was proposed in order to recommend the phase 2 dose. Most respondents (92%) suggested including dose modification in the definition of DLT when dose intensity was decreased to 70%. Whilst moderate toxicity was deemed relevant by 70%, the G1/2 toxicities selected to define DLT however varied. CONCLUSION: The majority of experts favoured a longer DLT assessment period as well as incorporation of specific G2 toxicities into the DLT definition. However, no clear consensus existed on a re-definition of DLT. Therefore analyses of a large international data warehouse were also used to develop guidelines presented in a companion paper.

A randomized phase I Bayesian dose escalation design for the combination of anti-cancer drugs.

Nowadays, treatment regimens for cancer often involve a combination of drugs. The determination of the doses of each of the combined drugs in phase I dose escalation studies poses methodological challenges. The most common phase I design, the classic '3+3' design, has been criticized for poorly estimating the maximum tolerated dose (MTD) and for treating too many subjects at doses below the MTD. In addition, the classic '3+3' is not able to address the challenges posed by combinations of drugs. Here, we assume that a control drug (commonly used and well-studied) is administered at a fixed dose in combination with a new agent (the experimental drug) of which the appropriate dose has to be determined. We propose a randomized design in which subjects are assigned to the control or to the combination of the control and experimental. The MTD is determined using a model-based Bayesian technique based on the difference of probability of dose limiting toxicities (DLT) between the control and the combination arm. We show, through a simulation study, that this approach provides better and more accurate estimates of the MTD. We argue that this approach may differentiate between an extreme high probability of DLT observed from the control and a high probability of DLT of the combination. We also report on a fictive (simulation) analysis based on published data of a phase I trial of ifosfamide combined with sunitinib.

Doxorubicin alone versus intensified doxorubicin plus ifosfamide for first-line treatment of advanced or metastatic soft-tissue sarcoma: a randomised controlled phase 3 trial.

BACKGROUND: Effective targeted treatment is unavailable for most sarcomas and doxorubicin and ifosfamide-which have been used to treat soft-tissue sarcoma for more than 30 years-still have an important role. Whether doxorubicin alone or the combination of doxorubicin and ifosfamide should be used routinely is still controversial. We assessed whether dose intensification of doxorubicin with ifosfamide improves survival of patients with advanced soft-tissue sarcoma compared with doxorubicin alone. METHODS: We did this phase 3 randomised controlled trial (EORTC 62012) at 38 hospitals in ten countries. We included patients with locally advanced, unresectable, or metastatic high-grade soft-tissue sarcoma, age 18-60 years with a WHO performance status of 0 or 1. They were randomly assigned (1:1) by the minimisation method to either doxorubicin (75 mg/m(2) by intravenous bolus on day 1 or 72 h continuous intravenous infusion) or intensified doxorubicin (75 mg/m(2); 25 mg/m(2) per day, days 1-3) plus ifosfamide (10 g/m(2) over 4 days with mesna and pegfilgrastim) as first-line treatment. Randomisation was stratified by centre, performance status (0 vs 1), age (<50 vs ≥50 years), presence of liver metastases, and histopathological grade (2 vs 3). Patients were treated every 3 weeks till progression or unacceptable toxic effects for up to six cycles. The primary endpoint was overall survival in the intention-to-treat population. The trial is registered with ClinicalTrials.gov, number NCT00061984. FINDINGS: Between April 30, 2003, and May 25, 2010, 228 patients were randomly assigned to receive doxorubicin and 227 to receive doxorubicin and ifosfamide. Median follow-up was 56 months (IQR 31-77) in the doxorubicin only group and 59 months (36-72) in the combination group. There was no significant difference in overall survival between groups (median overall survival 12·8 months [95·5% CI 10·5-14·3] in the doxorubicin group vs 14·3 months [12·5-16·5] in the doxorubicin and ifosfamide group; hazard ratio [HR] 0·83 [95·5% CI 0·67-1·03]; stratified log-rank test p=0·076). Median progression-free survival was significantly higher for the doxorubicin and ifosfamide group (7·4 months [95% CI 6·6-8·3]) than for the doxorubicin group (4·6 months [2·9-5·6]; HR 0·74 [95% CI 0·60-0·90], stratified log-rank test p=0·003). More patients in the doxorubicin and ifosfamide group than in the doxorubicin group had an overall response (60 [26%] of 227 patients vs 31 [14%] of 228; p<0·0006). The most common grade 3 and 4 toxic effects-which were all more common with doxorubicin and ifosfamide than with doxorubicin alone-were leucopenia (97 [43%] of 224 patients vs 40 [18%] of 223 patients), neutropenia (93 [42%] vs 83 [37%]), febrile neutropenia (103 (46%) vs 30 [13%]), anaemia (78 [35%] vs 10 [5%]), and thrombocytopenia (75 [33%]) vs one [<1%]). INTERPRETATION: Our results do not support the use of intensified doxorubicin and ifosfamide for palliation of advanced soft-tissue sarcoma unless the specific goal is tumour shrinkage. These findings should help individualise the care of patients with this disease. FUNDING: Cancer Research UK, EORTC Charitable Trust, UK NHS, Canadian Cancer Society Research Institute, Amgen.

Determining the optimal dose in the development of anticancer agents.

Identification of the optimal dose remains a key challenge in drug development. For cytotoxic drugs, the standard approach is based on identifying the maximum tolerated dose (MTD) in phase I trials and incorporating this to subsequent trials. However, this strategy does not take into account important aspects of clinical pharmacology. For targeted agents, the dose-effect relationships from preclinical studies are less obvious, and it is important to change the way these agents are developed to avoid recommending drug doses for different populations without evidence of differential antitumour effects in different diseases. The use of expanded cohorts in phase I trials to better define MTD and refine dose optimization should be further explored together with a focus on efficacy rather than toxicity-based predictions. Another key consideration in dose optimization is related to interindividual pharmacokinetic variability. High variability in intra-individual pharmacokinetics has been observed for many orally-administered drugs, especially those with low bioavailability, which might complicate identification of dose-effect relationships. End-organ dysfunction, interactions with other prescription drugs, herbal supplements, adherence, and food intake can influence pharmacokinetics. It is important these variables are identified during early clinical trials and considered in the development of further phase II and subsequent large-scale phase III studies.