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 [AUC_0-12 (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.

Abstract ED01-01: Successes and failures of targeted drug development in adult and pediatric sarcomas

Development of molecularly targeted anticancer agents has seen major successes in the last 2 decades, also in Soft Tissue Sarcomas. But at the same time, many of those agents never made it beyond the stage of initial excitement. Moreover, the rare incidence of soft tissue sarcomas, and the even more rare incidence of its enormously high number of subtypes, frequently with subtype specific molecular aberrations in the malignancy, has led to different levels of evidence for success, if any. The development of Imatinib in c-KIT expressing GIST, does not only exemplify hallmarks of success, but also identifies some features of development failure. In Pediatric GIST for instance, Imatinib is basically ineffective. This was found to be due to the absence of KIT mutations in pediatric GIST, and the likely presence of different tumor growth drivers that are not sensitive to Imatinib. Taken together these features indicate that similar histologies do not necessarily express similar genetic changes in adult vs pediatric sarcomas, and indicate that it is essential to identify changes that represent true driving factors of tumor growth. And likely crucial to genetically analyse the tumor specimens of individual patients prior to treatment- and/or clinical trial selection. Apart from GIST, most of the other interesting suggestions of clinically successful specific targeting are yet based on fairly limited data. And thus, the level of evidence is much less than for Imatinib in adult GIST. These other subtypes and treatments include for instance Imatinib in PDGFR-beta mutant Dermatofibrosarcoma protruberans (DFSP), PLX3397 in colony-stimulating factor 1 (CSF1) expressing (1;2) translocated Tenosynovial Giant Cell Tumors (TGCT), Larotrectinib in TRK mutated Infantile Fibrosarcoma, Sirolimus in TSC1 or TSC2 mutated Perivascular Epitheloid Cell tumors (PEComa) and Crizotinb for ALK mutated Inflammatory Myofibroblastic Tumor (IMT). While the anti-VEGF monoclonal antibody Bevazicumab as a single agent hardly yielded effect in soft tissue sarcoma subsets such as angiosarcomas and hemangioendothelial sarcomas, the effect of multitargeted agents that a.o included VEGF as a target, has been proven effective in diseases such as non-subtype specific soft tissue Sarcomas (Pazopanib), GIST (Sunitinib, Regorafinib) Desmoid tumors (Sorafenib), and Alveolar Soft Part Sarcoma (Cediranib). Yet, given the inability to differentiate one target from the other, it is difficult to ascribe the successful trials to any of them. While for some drugs and targets (such as MDM2 and CDK4/6) the jury is still out, there is a large number of targets and targeted agents that failed the threshold. Among these are the mTOR inhibitors for other soft tissue sarcoma subtypes than PEComa, pPARgamma inhibitors for liposarcomas, EGFR inhibitors in synovial sarcomas, MET inhibitors in soft tissue sarcomas with specific amplifications and translocations, and again most recently the PDGFR-alpha monoclonal antibody Olaratumab. The failure to achieve clinical effect by inhibition of PDGFR will be discussed in somewhat more detail. In conclusion, to increase success rates and reduce failures, it seems important to closely analyze which preclinical biological factors can better predict clinical success and/or failure.

Citation Format: Jaap Verweij. Successes and failures of targeted drug development in adult and pediatric sarcomas [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr ED01-01. doi:10.1158/1535-7163.TARG-19-ED01-01

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.

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.

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.

Hypertension (HTN) as a potential biomarker of efficacy in pazopanib-treated patients with advanced non-adipocytic soft tissue sarcoma. A retrospective study based on European Organisation for Research and Treatment of Cancer (EORTC) 62043 and 62072 trials

BACKGROUND

Reliable biomarkers of pazopanib's efficacy in soft tissue sarcoma (STS) are lacking. Hypertension (HTN) is an on-target effect of vascular endothelial growth factor (VEGF)-receptor inhibitors such as pazopanib. We evaluated the association of pazopanib-induced HTN with antitumour efficacy in patients with metastatic non-adipocytic STS.

METHODS

Associations between pazopanib-induced-HTN and antitumour efficacy were retrospectively assessed across 2 prospective studies (European Organisation for Research and Treatment of Cancer (EORTC) study 62043 and 62072) in metastatic STS patients who received pazopanib 800 mg daily. Only patients with baseline blood pressure (BP)<150/90 mmHg, were included. BP was measured monthly. HTN was reported according to National Cancer Institute-Common Toxicity Criteria Adverse Events (NCI-CTC AE) grading (v3.0), and as absolute differences compared to baseline. The effect of HTN developing in patients without baseline anti-hypertensive medication was assessed on progression-free (PFS) and overall survival (OS) using a landmark analysis stratified by study; univariately using the Kaplan-Meier method and a log-rank test, and in a multivariate Cox regression model after adjustment for important prognostic factors.

RESULTS

Of the 337 patients eligible for this analysis, 21.7% received anti-hypertensive medication at baseline and had a similar PFS and OS compared to those who did not. In patients without baseline anti-hypertensive medication, 38.6% developed HTN. As the majority of patients developing HTN did so within 5 weeks after initiation of pazopanib (68.6%), this time point was used as landmark. Univariately, there was no effect on PFS or OS from occurrence of HTN within 5 weeks of treatment expressed either in NCI-CTC AE criteria or as maximal differences from baseline in systolic and diastolic BP. Also in multivariate analysis, after adjusting for important prognostic factors, the occurrence of HTN expressed in the different parameters was not associated with PFS and OS.

CONCLUSIONS

In this retrospective analysis, pazopanib-induced HTN did not correlate with outcome in pazopanib-treated STS patients. The occurrence of HTN cannot serve as biomarker in this setting.

4β-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 4β-hydroxycholesterol (4β-OHC) as a potential individual taxane PK predictor.

METHODS

Serum 4β-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 4β-OHC or 4β-OHC : cholesterol ratio and paclitaxel clearance were found. In the patients treated with docetaxel, 4β-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, 4β-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 4β-OHC or the 4β-OHC : cholesterol ratio. A weak correlation was observed between 4β-OHC and docetaxel clearance, but only in males. This endogenous CYP3A4 marker has limited predictive value for taxane clearance in patients.

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.

Irinotecan chemotherapy during valproic acid treatment: Pharmacokinetic interaction and hepatotoxicity

PURPOSE

Because of its supposed inhibiting capacities of uridine-diphosphate glucuronosyltransferase 1A (UGT1A)-mediated glucuronidation in rats, the antiepileptic drug valproic acid has been investigated as modulator of irinotecan-induced delayed-type diarrhea in rats. Here, we report on the pharmacokinetic and pharmacodynamic effects of this combination in a cancer patient.

EXPERIMENTAL DESIGN

A patient who used valproic acid was administered irinotecan (600 mg). To investigate dose-limiting hepatotoxicity encountered during the first course, which was clinically attributed to a supposed higher exposure to the active irinotecan metabolite SN-38, valproic acid was tapered off. Blood samples for pharmacokinetic purposes were drawn during a course with and a course without concomitant valproic acid. Plasma-levels of irinotecan, SN-38, and SN-38G were determined using HPLC-assays.

RESULTS

When irinotecan was combined with valproic acid, the exposure to SN-38 was 41% lower. Additionally, reversible elevations of the liver enzyme tests were noted. In particular, seven days after irinotecan administration gammaGT and transaminase levels raised up to 5.3-11.3 times the ULN (CTCAE grade 3).

CONCLUSIONS

Valproic acid-induced plasma protein binding displacement and/or metabolic modulation of enzymes and drug transporters involved in irinotecan disposition may explain the reduced exposure to SN-38 in the presence of valproic acid. Given the herewith-coupled potential undertreatment, patients should firstly switch to another antiepileptic drug not known to interfere with irinotecan treatment. Additionally, this particular combination should not be implemented in clinical studies without simultaneously adjusting the irinotecan dose, and the risk of (severe) hepatotoxicity should be considered when designing protocols studying valproic acid (as histone deacetylase-inhibitor) in combination with other (anticancer) drugs.

Hepatic transport, Metabolism and biliary excretion of irinotecan in a cancer patient with an external bile drain

BACKGROUND

Irinotecan is metabolized by various enzymes, including carboxylesterases, cytochrome P450 3A isozymes (CYP3A) and uridine-diphosphate glucuronosyltransferase 1A isoforms (UGT1A). Here we report on the disposition of irinotecan and its metabolites in plasma, urine, bile and feces of a single cancer patient with an external bile drain.

METHODOLOGY

Irinotecan (450 mg) was administered during a 90-minutes continuous infusion to a cancer patient with an external bile drain. Blood samples were collected up to 55 hours after infusion, while bile, feces and urine were collected during six consecutive days after administration. Samples were analyzed using high-performance liquid chromatography (HPLC)-assays with fluorescence detection.

RESULTS

Plasma pharmacokinetics were characterized by a relatively slow clearance of irinotecan and a relatively high exposure to 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino] carbonyloxycamptothecin (APC). Exposures to the other metabolites was within the normal range. Overall, 83.4% of the administered dose was recovered in the excreta, with the majority excreted during the first 24 hours.

CONCLUSIONS

Enterohepatic recirculation is of minor importance for the plasma disposition of irinotecan and its metabolites. The high percentage of the dose recovered in urine, the relatively slow clearance of irinotecan and the preferential urinary over biliary excretion of APC in this particular patient are likely related to reduced functioning of ABC-transporters. Circumstantial evidence was found that APC is subject to further intestinal biotransformation indicating a role in the etiology of irinotecan-induced diarrhea. Since intra-luminal exposure to SN-38 in patients with an external bile drain is limited, neutropenia will be the dose-limiting toxicity. Based on presented data, although collected from only one patient, irinotecan therapy in patients with an external bile drain is feasible. No a priori dose adjustments are recommended, although in the absence of severe side-effects in previous courses, a higher dose may be considered.

Abstract 1450: MicroRNAs in myxoid/round cell liposarcomas: FUS-CHOP regulated miR-497 and miR-30a target the insulin-like growth factor receptor pathway

Myxoid/round cell liposarcomas (MRCLS) are characterized by a t(12;16)(q13;p11) translocation in 90% of the cases, which gives rise to a FUS-CHOP (FUS-DDIT3) fusion gene. The resulting fusion oncoprotein acts as an abnormal transcription factor, inducing distinct transcriptional programs. However, not much is known about the deregulation of microRNA (miRNA) expression in MRCLS and about the role of FUS-CHOP herein. We examined miRNA expression in MRCLS (n=14) and normal fat (n=9) by LNA™ oligonucleotide microarrays. The 50 most differentially expressed miRNAs (p&lt;0.03) discriminate MRCLS and fat samples in a supervised hierarchical clustering. The miR-23a/27a/24-2 and miR-23b/27b/24-1 cluster members were all significantly downregulated in MRCLS, which was validated by RT-PCR in an extended sample set (MRCLS, n=33; normal fat, n=20). Functional analyses showed that overexpression of miR-24 induced doxorubicin resistance in two myxoid liposarcoma cell lines (MLS 402-91 and MLS 1765-92), while miR-24 inhibitors sensitized a liposarcoma (SW872) and a rhabdomyosarcoma (RH30) cell line to doxorubicin treatment. To identify miRNAs controlled by the fusion gene, FUS-CHOP levels were modulated by expression constructs or siRNA in four sarcoma cell lines. MiR-497, miR-30a and miR-34b expression was found to be inversely correlated with FUS-CHOP expression. Accordingly, their expression was significantly lower in MRCLS compared to normal fat, as determined by RT-PCR analysis. MiR-497 and miR-30a share many predicted target genes of the insulin(-like) growth factor (IGF) pathway. Overexpression of miR-497 and miR-30a considerably downregulated protein expression of IGF1 receptor (IGF1R) and its substrates IRS1 and IRS2. Luciferase reporter constructs containing wild-type and mutated 3′UTR fragments of these genes were used to demonstrate direct regulation of IRS1 by miR-497, IRS2 by miR-30a, and IGF1R by both miRNAs. Surprisingly miR-497 and miR-30a overexpression had little effect on cell proliferation, but significantly sensitized myxoid liposarcoma cell lines to doxorubicin treatment, which is possibly mediated via the IGF1R signaling pathway. In conclusion, the FUS-CHOP oncoprotein in MRCLS mediates differential expression of several miRNAs, which affect the IGF1R pathway and doxorubicin sensitivity. Based on these results, combination therapy of miR-497 / miR-30a overexpression and chemotherapeutic or targeted agents against MRCLS should be further explored.

Citation Format: Caroline MM Gits, Patricia F. van Kuijk, Wilfred F. van IJcken, Ron HJ Mathijssen, Michael A. den Bakker, Jaap Verweij, Stefan Sleijfer, Erik AC Wiemer. MicroRNAs in myxoid/round cell liposarcomas: FUS-CHOP regulated miR-497 and miR-30a target the insulin-like growth factor receptor pathway. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1450. doi:10.1158/1538-7445.AM2014-1450

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.

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.

Outcome of patients with sarcoma and other mesenchymal tumours participating in phase I trials: a subset analysis of a European Phase I database

BACKGROUND

Although sarcomas account for only 1% of all solid tumours, patients with sarcomas comprise a larger proportion of patients entering phase I trials, due to the limited number of registered or active drugs for these diseases. To help in patient selection, we evaluated the utility of the predictive Royal Marsden Score which had been derived in carcinoma patients. In addition, we analysed efficacy and toxicity regarding the sarcoma population enrolled in phase I trials.

PATIENTS AND METHODS

We used data from a European Database comprising 2182 patients treated in phase I trials in 14 European institutions between 2005 and 2007.

RESULTS

One hundred and seventy-eight patients diagnosed with advanced sarcoma or other mesenchymal tumours were identified and accounted for 217 phase I trial participations during the study period. Histological type, class of drug, number of metastatic sites, high serum lactate dehydrogenase activity (LDH), low albumin and high white blood cell count were independent prognostic factors. Poor performance status (PS), liver metastases and high leucocyte count were associated with increased risk of early death. The class of drug used was the strongest predictor of progression-free survival (PFS) duration, inhibitors of angiogenesis and histone deacetylase giving the best results. Poor PS, high serum LDH and low lymphocyte count correlated with shorter PFS. In this heterogeneous population, PFS with investigational agents appeared comparable with that previously published for patients receiving standard treatments beyond first line.

CONCLUSION

Prognostic factors in sarcoma patients do not differ from a broader phase I population. Efficacy measures suggest that some patients with sarcoma derive benefit from therapy in this setting which could therefore be considered for patients with no remaining standard therapeutic option.

Long-term responders and survivors on pazopanib for advanced soft tissue sarcomas: subanalysis of two European Organisation for Research and Treatment of Cancer (EORTC) clinical trials 62043 and 62072

BACKGROUND

Pazopanib recently received approval for the treatment of certain soft tissue sarcoma (STS) subtypes. We conducted a retrospective analysis on pooled data from two EORTC trials on pazopanib in STS in order to characterize long-term responders and survivors.

PATIENTS AND METHODS

Selected patients were treated with pazopanib in phase II (n = 118) and phase III study (PALETTE) (n = 226). Combined median progression-free survival (PFS) was 4.4 months; the median overall survival (OS) was 11.7 months. Thirty-six percent of patients had a PFS ≥ 6 months and were defined as long-term responders; 34% of patients survived ≥18 months, defined as long-term survivors. Patient characteristics were studied for their association with long-term outcomes.

RESULTS

The median follow-up was 2.3 years. Patient characteristics were compared among four subgroups based on short-/long-term PFS and OS, respectively. Seventy-six patients (22.1%) were both long-term responders and long-term survivors. The analysis confirmed the importance of known prognostic factors in metastatic STS patients treated with systemic treatment, such as performance status and tumor grading, and additionally hemoglobin at baseline as new prognostic factor. We identified 12 patients (3.5%) remaining on pazopanib for more than 2 years: nine aged younger than 50 years, nine females, four with smooth muscle tumors and nine with low or intermediate grade tumors at initial diagnosis. The median time on pazopanib in these patients was 2.4 years with the longest duration of 3.7 years.

CONCLUSIONS

Thirty-six percent and 34% of all STS patients who received pazopanib in these studies had a long PFS and/or OS, respectively. For more than 2 years, 3.5% of patients remained progression free under pazopanib. Good performance status, low/intermediate grade of the primary tumor and a normal hemoglobin level at baseline were advantageous for long-term outcome. NCT00297258 (phase II) and NCT00753688 (phase III, PALETTE).

MicroRNA expression profiles distinguish liposarcoma subtypes and implicate miR-145 and miR-451 as tumor suppressors

Liposarcomas are rare, heterogeneous and malignant tumors that can be divided into four histological subtypes with different characteristics and clinical behavior. Treatment consists of surgery in combination with systemic chemotherapy, but nevertheless mortality rates are high. More insight into the biology of liposarcoma tumorigenesis is needed to devise novel therapeutic approaches. MicroRNAs (miRNAs) have been associated with carcinogenesis in many tumors and may function as tumor suppressor or oncogene. In this study we examined miRNA expression in an initial series of 57 human liposarcomas (including all subtypes), lipomas and normal fat by miRNA microarrays. Supervised hierarchical clustering of the most differentially expressed miRNAs (p < 0.0002) distinguished most liposarcoma subtypes and control tissues. The distinction between well differentiated liposarcomas and benign lipomas was blurred, suggesting these tumor types may represent a biological continuum. MiRNA signatures of liposarcoma subtypes were established and validated in an independent series of 58 liposarcomas and control tissues. The expression of the miR-143/145 and miR-144/451 cluster members was clearly reduced in liposarcomas compared to normal fat. Overexpression of miR-145 and miR-451 in liposarcoma cell lines decreased cellular proliferation rate, impaired cell cycle progression and induced apoptosis. In conclusion, we show that miRNA expression profiling can be used to discriminate liposarcoma subtypes, which can possibly aid in objective diagnostic decision making. In addition, our data indicate that miR-145 and miR-451 act as tumor suppressors in adipose tissue and show that re-expression of these miRNAs could be a promising therapeutic strategy for liposarcomas.

A pharmacogenetic predictive model for paclitaxel clearance based on the DMET platform

PURPOSE

Paclitaxel is used in the treatment of solid tumors and displays high interindividual variation in exposure. Low paclitaxel clearance could lead to increased toxicity during treatment. We present a genetic prediction model identifying patients with low paclitaxel clearance, based on the drug-metabolizing enzyme and transporter (DMET)-platform, capable of detecting 1,936 genetic variants in 225 metabolizing enzyme and drug transporter genes.

EXPERIMENTAL DESIGN

In 270 paclitaxel-treated patients, unbound plasma concentrations were determined and pharmacokinetic parameters were estimated from a previously developed population pharmacokinetic model (NONMEM). Patients were divided into a training- and validation set. Genetic variants determined by the DMET platform were selected from the training set to be included in the prediction model when they were associated with low paclitaxel clearance (1 SD below mean clearance) and subsequently tested in the validation set.

RESULTS

A genetic prediction model including 14 single-nucleotide polymorphisms (SNP) was developed on the training set. In the validation set, this model yielded a sensitivity of 95%, identifying most patients with low paclitaxel clearance correctly. The positive predictive value of the model was only 22%. The model remained associated with low clearance after multivariate analysis, correcting for age, gender, and hemoglobin levels at baseline (P = 0.02).

CONCLUSIONS

In this first large-sized application of the DMET-platform for paclitaxel, we identified a 14 SNP model with high sensitivity to identify patients with low paclitaxel clearance. However, due to the low positive predictive value we conclude that genetic variability encoded in the DMET-chip alone does not sufficiently explain paclitaxel clearance.

A pharmacogenetic model predicting low paclitaxel clearance based on the DMET platform

2597

Background: Paclitaxel (PTX) is a commonly used cytotoxic agent. It is metabolized by P450 cytochrome iso-enzymes CYP3A4 and CYP2C8 and has high interindividual variability in pharmacokinetics (PK) and toxicity. Here, we present a genetic prediction model to identify patients with low PTX clearance (CL) using the new Drug-Metabolizing Enzyme and Transporter (DMET; Affymetrix) platform, capable of detecting 1,936 genetic variants (SNPs) in 225 genes. Methods: In a PK study, 270 Caucasian cancer patients were treated with PTX. PK parameters were determined using a limited sampling strategy. HPLC or LC-MS/MS were used to determine PTX plasma concentrations and non-linear mixed effects modelling (NONMEM) was used to estimate individual unbound CL from previously developed PK population models. Subsequently, the cohort of patients was randomly split into a training and validation set. In all patients, the presence of SNPs in metabolic enzymes and transporters was determined using the DMET platform. Selected SNPs were subsequently validated in the validation set. Results: Baseline characteristics were comparable in both sets. The mean CL of the total cohort was 488 ± 149 L/h and the threshold for low CL was set at 339 L/h (1 SD < total mean CL). 14 SNPs were selected to be included in the prediction model and validated in the validation set. For none of these 14 SNPs, evidence for a biological plausible link to taxane metabolism exists. The developed prediction model had a sensitivity of 95% to identify low PTX CL, a positive predictive value of 22% and remained significantly associated with low CL after multivariate analysis correcting for age, gender and Hb levels at start of therapy (P=0.024). Conclusions: This is the first considerably-sized application of the DMET platform to explain PK variability of a widely used anti-cancer drug. Although this validated prediction model for PTX CL had a high sensitivity, its positive predictive value is too low to be of direct clinical use. Likely, genetic variability in DMET genes alone does not sufficiently explain PTX CL, as for example environmental factors may also influence PTX metabolism.

Long-term responders and survivors on pazopanib for soft tissue sarcomas (STS): Subanalysis of two European Organisation for Research and Treatment of Cancer (EORTC) clinical trials 62043 and 62072

10553

Background: Pazopanib has recently received approval in US, EU & Japan for use in certain STS subtypes. We conducted a retrospective analysis on pooled data from two EORTC clinical trials on pazopanib in STS in order to characterize long term responders and survivors. Methods: Patients selected for analysis were treated with pazopanib in phase II study 62043 (n = 142) and phase III study 62072 (PALETTE) (n = 246). Combined median progression-free survival (PFS) was 4.0 months; median overall survival (OS) was 11.3 months. 34 % of patients had a PFS ≥ 6 months (n = 133) and were defined as long term responders; 33 % of patients survived ≥ 18 months (n = 128), defined as long term survivors. Following patient characteristics were studied: gender, age, performance status, tumor localization, histology, grading, treatment exposure and dose modifications, severity of adverse events and post protocol therapy. Results: Clinical cut-off dates for this analysis resulted in a pooled database with a median follow-up of 2.3 years. Patient characteristics were compared between four subgroups based on short / long term PFS and OS, respectively. 79 patients were both long term responders and long term survivors. The descriptive analysis confirmed the importance of known prognostic factors such as age, performance status and grading, but did not add additional characteristics translating into long term response or survival. We identified 12 patients remaining on pazopanib for more than two years: 9 aged younger than 55 years, 9 females, four with smooth muscle tumors and nine with low or intermediate grade tumors at initial diagnosis. Only two of those patients achieved a partial response; the remaining 10 experienced stable disease as best overall response. Median time on pazopanib in these patients was 2.4 years with the longest duration of 3.7 years. Four patients were still on pazopanib at the end of the studies with a median PFS of 2.3 years and a median OS of 2.8 years. Conclusions: 34 % and 33 % of STS patients given pazopanib in these studies have a long PFS and / or OS respectively. 3.1 % of patients demonstrate a clinical benefit even beyond 2 years.

CYP3A4*22 genotype and systemic exposure affect paclitaxel-induced neurotoxicity

PURPOSE

Paclitaxel is used for the treatment of several solid tumors and displays a high interindividual variation in exposure and toxicity. Neurotoxicity is one of the most prominent side effects of paclitaxel. This study explores potential predictive pharmacokinetic and pharmacogenetic determinants for the onset and severity of neurotoxicity.

EXPERIMENTAL DESIGN

In an exploratory cohort of patients (n = 261) treated with paclitaxel, neurotoxicity incidence, and severity, pharmacokinetic parameters and pharmacogenetic variants were determined. Paclitaxel plasma concentrations were measured by high-performance liquid chromatography or liquid chromatography/tandem mass spectrometry, and individual pharmacokinetic parameters were estimated from previously developed population pharmacokinetic models by nonlinear mixed effects modeling. Genetic variants of paclitaxel pharmacokinetics tested were CYP3A4*22, CYP2C8*3, CYP2C8*4, and ABCB1 3435 C>T. The association between CYP3A4*22 and neurotoxicity observed in the exploratory cohort was validated in an independent patient cohort (n = 239).

RESULTS

Exposure to paclitaxel (logAUC) was correlated with severity of neurotoxicity (P < 0.00001). Female CYP3A4*22 carriers were at increased risk of developing neurotoxicity (P = 0.043) in the exploratory cohort. CYP3A4*22 carrier status itself was not associated with pharmacokinetic parameters (CL, AUC, Cmax, or T>0.05) of paclitaxel in males or females. Other genetic variants displayed no association with neurotoxicity. In the subsequent independent validation cohort, CYP3A4*22 carriers were at risk of developing grade 3 neurotoxicity (OR = 19.1; P = 0.001).

CONCLUSIONS

Paclitaxel exposure showed a relationship with the severity of paclitaxel-induced neurotoxicity. In this study, female CYP3A4*22 carriers had increased risk of developing severe neurotoxicity during paclitaxel therapy. These observations may guide future individualization of paclitaxel treatment.

Abstract 949: miR-634 restores drug sensitivity in tumor cells derived from patients with terminal drug-resistant ovarian cancer

The development of drug resistance is still a major impediment for the successful treatment of cancer. This is particularly pressing in the case of advanced ovarian cancer, which has a 5-year survival rate of 30%. Ovarian cancer is treated with paclitaxel and platinum (e.g cisplatin or carboplatin) combination chemotherapy. Despite an initial high chemo-responsiveness, most ovarian cancer patients will relapse and ultimately die of drug-resistant disease. The molecular processes that contribute to resistance have been extensively studied, however, not much is known about the role of microRNAs (miRNAs), small non-coding RNAs that regulate gene expression.

We compared miRNA expression profiles of isogenic cisplatin sensitive and resistant cell line pairs. The only miRNA that was consistently downregulated in all three resistant cell lines was miR-634 (FDR&lt;1%). Overexpression of miR-634 in ovarian cancer cell lines gave rise to a minor, but reproducible, cell cycle block and reduced cellular viability by 20-50%. In addition, miR-634 transfection resensitized cisplatin-resistant ovarian cancer cell lines. We next investigated whether miR-634 overexpression could enhance therapy response in a more clinical setting. We isolated and cultured tumor cells from 7 patients that had become refractory to carboplatin-paclitaxel combination chemotherapy. We show that miR-634 overexpression causes a ∼two-fold decrease in IC50 for cisplatin and carboplatin treatment. In addition, a ∼1.3-fold decrease in doxorubicin sensitivity was observed upon miR-634 overexpression. Finally, overexpression of miR-634 resulted in downregulation of its predicted targets Cyclin D1 and GRB2, ERK2, RSK1 and RSK2, components of the Ras-MAPK pathway. The combined effect on these miR-634 targets may explain the effects on the cell cycle, cellular viability and response to chemotherapy.

Altogether, our findings suggest that miR-634 modulates important cancer relevant targets and that raising miR-634 levels can be a means to resensitize chemotherapy resistant ovarian tumors.

Citation Format: Marijn TM van Jaarsveld, Patricia F. van Kuijk, Antonius WM Boersma, Jozien Helleman, Wilfred F. van Ijcken, Ron HJ Mathijssen, Joris Pothof, Els MJJ Berns, Jaap Verweij, Erik AC Wiemer. miR-634 restores drug sensitivity in tumor cells derived from patients with terminal drug-resistant ovarian cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 949. doi:10.1158/1538-7445.AM2013-949

Pazopanib, a new therapy for metastatic soft tissue sarcoma

INTRODUCTION

Pazopanib (GW786034, Votrient®) is a vascular endothelial growth factor receptor-focused multi-tyrosine kinase inhibitor involved in inhibiting the angiogenesis pathway. The agent was recently registered for use in soft tissue sarcomas, a group of diseases with a major unmet medical need.

AREAS COVERED

The relevance of angiogenesis in soft tissue sarcomas is discussed. These data were the basis to decide on the development of pazopanib in these diseases. The clinical pharmacology of pazopanib, as far as practically relevant, is summarized. After the first observations of possible activity in soft tissue sarcomas in the Phase I study, a Phase II and subsequent randomized placebo-controlled Phase III study were performed and are being put into perspective in this review.

EXPERT OPINION

Pazopanib is an active drug for the treatment of chemotherapy-failing nonadipocytic soft tissue sarcomas. It almost triples progression-free survival significantly from 1.6 to 4.6 months in this heavily pretreated population. The safety profile is manageable, exemplified by the high dose intensity that can be achieved over time. Pazopanib can be considered as part of the standard of care for patients with soft tissue sarcomas.

SDHA mutations in adult and pediatric wild-type gastrointestinal stromal tumors

Most gastrointestinal stromal tumors (GISTs) harbor oncogenic mutations in KIT or platelet-derived growth factor receptor-α. However, a small subset of GISTs lacks such mutations and is termed 'wild-type GISTs'. Germline mutation in any of the subunits of succinate dehydrogenase (SDH) predisposes individuals to hereditary paragangliomas and pheochromocytomas. However, germline mutations of the genes encoding SDH subunits A, B, C or D (SDHA, SDHB, SDHC or SDHD; collectively SDHx) are also identified in GISTs. SDHA and SDHB immunohistochemistry are reliable techniques to identify pheochromocytomas and paragangliomas with mutations in SDHA, SDHB, SDHC and SDHD. In this study, we investigated if SDHA immunohistochemistry could also identify SDHA-mutated GISTs. Twenty-four adult wild-type GISTs and nine pediatric/adolescent wild-type GISTs were analyzed with SDHB, and where this was negative, then with SDHA immunohistochemistry. If SDHA immunohistochemistry was negative, sequencing analysis of the entire SDHA coding sequence was performed. All nine pediatric/adolescent GISTs and seven adult wild-type GISTs were negative for SDHB immunohistochemistry. One pediatric GIST and three SDHB-immunonegative adult wild-type GISTs were negative for SDHA immunohistochemistry. In all four SDHA-negative GISTs, a germline SDHA c.91C>T transition was found leading to a nonsense p.Arg31X mutation. Our results demonstrate that SDHA immunohistochemistry on GISTs can identify the presence of an SDHA germline mutation. Identifying GISTs with deficient SDH activity warrants additional genetic testing, evaluation and follow-up for inherited disorders and paragangliomas.

Evaluation of patient enrollment in oncology phase I clinical trials

INTRODUCTION

For anticancer drug development, it is crucial that patients participate in early-phase clinical trials. The main aim of this study was to gain insight into the motivations and other variables influencing patients in their decision to participate in phase I oncology trials.

MATERIALS AND METHODS

Over a period of 25 months, all patients who were informed about (specific) phase I trials in our cancer center were retrospectively included in this study. Data on providing informed consent and final phase I enrollment were collected.

RESULTS

In total, 365 patients, with a median age of 59 years and a median World Health Organization performance status score of 1, were evaluated. The majority of patients (71%) were pretreated with systemic therapy, with a median of two lines. After specific study information had been given, 145 patients (40%) declined informed consent, 54% of them mainly because of low expectations regarding treatment benefits and concerns about potential side effects. Patients who had received previous systemic therapy consented more frequently than others. After initial consent, 61 patients (17%) still did not receive study treatment, mostly because of secondary withdrawal of consent or rapid clinical deterioration prior to first dosing.

DISCUSSION

After specific referral to our hospital for participation in early clinical trials, only 44% of all patients who were informed about a specific phase I trial eventually participated. Reasons for both participation and nonparticipation were diverse. Patient participation rates could be improved by forming an experienced and dedicated study team.

Growth modulation index as metric of clinical benefit assessment among advanced soft tissue sarcoma patients receiving trabectedin as a salvage therapy

BACKGROUND

The growth modulation index (GMI) is the ratio of time to progression with the nth line (TTP(n)) of therapy to the TTP(n)(-1) with the n-1th line. GMI >1.33 is considered as a sign of activity in phase II trials.

PATIENTS AND METHODS

This retrospective analysis evaluated the concordance between the GMI and the efficacy outcomes in 279 patients with advanced soft tissue sarcoma (ASTS) treated with trabectedin 1.5 mg/m² (24-h infusion every 3 weeks) in four phase II trials.

RESULTS

One hundred and forty-two (51%) patients received one prior line and 137 ≥ 2 lines. The median TTP(n) was 2.8 months (range 0.2-26.8), whereas the median TTP(n)(-1) was 4.0 months (0.3-79.5). The median GMI was 0.6 (0.0-14.4). Overall, 177 patients (63%) had a GMI <1; 21 (8%) a GMI equal to 1-1.33 and 81 (29%) a GMI >1.33, which correlated with the median overall survival in those patients (9.1, 13.9 and 23.8 months, respectively, P = 0.0005). A high concordance rate between the GMI and response rate (P < 0.0001) and progression-free survival (PFS, P < 0.0001) was observed. Good performance status (PS) was the only factor associated with GMI >1.33 (PS = 0; P < 0.04).

CONCLUSIONS

A high GMI was associated with favorable efficacy outcomes in patients treated with trabectedin. Further research is needed to assess GMI as an indicator in this setting.

Tumor volume as an alternative response measurement for imatinib treated GIST patients

Background

Assessment of tumor size changes is crucial in clinical trials and patient care. We compared imatinib-induced volume changes of liver metastases (LM) from gastro-intestinal stromal tumors (GIST) to RECIST and Choi criteria and their association with overall survival (OS).

Methods

LM from 84 GIST patients (training and validation set) were evaluated using manual and semi-automated Computed Tomography measurements at baseline, after 3, 6 and 12 months of imatinib. The ability of uni-dimensional (1D) and three-dimensional (3D) measurements to detect size changes (increase/decrease) ≥20% was evaluated. Volumetric response cut-offs were derived from minimally relevant changes (+20/−30%) by RECIST, considering lesions as spherical or ellipsoidal.

Results

3D measurements detected size changes ≥20% more frequently than 1D at every time-point (P≤0.008). 3D and Choi criteria registered more responses than RECIST at 3 and 6 months for 3D-spheres (P≤0.03) and at all time-points for 3D-ellipsoids and Choi criteria (P<0.001). Progressive disease by 3D criteria seems to better correlate to OS at late time-points than other criteria.

Conclusion

Volume criteria (especially ellipsoids) classify a higher number of patients as imatinib-responders than RECIST. Volume discriminates size changes better than diameter in GIST and constitutes a feasible and robust method to evaluate response and predict patient benefit.

Adjuvant therapy in primary GIST: state-of-the-art

BACKGROUND

The management of primary gastrointestinal stromal tumours (GISTs) has evolved with the introduction of adjuvant therapy. Recently reported results of the SSG XVIII/AIO trial by the Scandinavian Sarcoma Group (SSG) and the German Working Group on Medical Oncology (AIO) represent a significant change in the evidence for adjuvant therapy duration. The objectives of this European Expert Panel meeting were to describe the optimal management and best practice for the systemic adjuvant treatment of patients with primary GISTs.

MATERIALS AND METHODS

A panel of medical oncology experts from European sarcoma research groups were invited to a 1-day workshop. Several questions and discussion points were selected by the organising committee prior to the conference. The experts reviewed the current literature of all clinical trials available on adjuvant therapy for primary GISTs, considered the quality evidence and formulated recommendations for each discussion point.

RESULTS

Clinical issues were identified and provisional clinical opinions were formulated for adjuvant treatment patient selection, imatinib dose, duration and patient recall, mutational analysis and follow-up of primary GIST patients. Adjuvant imatinib 400 mg/day for 3 years duration is a standard treatment in all patients with significant risk of recurrence following resection of primary GISTs. Patient selection for adjuvant therapy should be based on any of the three commonly used patient risk stratification schemes. R1 surgery (versus R0) alone is not an indication for adjuvant imatinib in low-risk GIST. Recall and imatinib restart could be proposed in patients who discontinued 1-year adjuvant imatinib within the previous 3 months and may be considered on a case-by-case basis in patients who discontinued within the previous year. Mutational analysis is recommended in all cases of GISTs using centralised laboratories with good quality control. Treatment is not recommended in an imatinib-insensitive D842V-mutated GIST. During adjuvant treatment, patients are recommended to be clinically assessed at 1- to 3-month intervals. Upon discontinuation, computed tomography scan (CT) scans are recommended every 3 to 4 months for 2 years when the risk of relapse is highest, followed by every 6 months until year 5 and annually until year 10 after treatment discontinuation.

CONCLUSIONS

Key points in systemic adjuvant treatment and clinical management of primary GISTs as well as open questions were identified during this European Expert Panel meeting on GIST management.

The kinase RSK2 modulates the sensitivity of ovarian cancer cells to cisplatin

Platinum-based chemotherapy (e.g. cisplatin, carboplatin) is standard of care for many types of cancer including ovarian cancer, however, the efficacy of treatment is hampered by the development of therapy resistance. The mechanisms behind platinum resistance are not completely understood. Here, we have investigated the role of the family of p90 Ribosomal S6 kinases (RSK), important downstream mediators of ERK1/2, in the response to cisplatin chemotherapy. Strikingly, whereas treatment with cisplatin did not alter the levels of RSK1 in response to cisplatin treatment, the structurally related RSK2 protein was downregulated in an ovarian cancer cell line (A2780). Furthermore, we found that knockdown of RSK2, in contrast to knockdown of RSK1, gave rise to enhanced cisplatin sensitivity in a cisplatin sensitive as well as a cisplatin-resistant A2780 cell line. These results indicate that RSK2 is regulated in response to cisplatin treatment, and this downregulation may contribute to the cytotoxic action of cisplatin. Since RSK2 is frequently amplified in a growing number of cancers, this may have implications for the sensitivity of these tumours to platinum-based cytotoxics.

Adjuvant chemotherapy with doxorubicin, ifosfamide, and lenograstim for resected soft-tissue sarcoma (EORTC 62931): a multicentre randomised controlled trial

BACKGROUND

The effect of adjuvant chemotherapy on survival for resected soft-tissue sarcoma remains unknown. We investigated the effect of intensive adjuvant chemotherapy on survival in patients after resection of high-risk soft-tissue sarcomas.

METHODS

In this multicentre randomised trial, patients with macroscopically resected, Trojani grade II-III soft-tissue sarcomas at any site, no metastases, performance status lower than 2 and aged between 16 and 70 years were eligible within 4 weeks of definitive surgery. Patients were randomly assigned to receive adjuvant chemotherapy or no chemotherapy (control group). Randomisation was done with a minimisation technique, stratified by hospital, site of primary tumour, tumour size, planned radiotherapy, and isolated limb perfusion therapy. Chemotherapy consisted of five cycles of doxorubicin 75 mg/m(2), ifosfamide 5 g/m(2), and lenograstim every 3 weeks. Patients in both groups received radiotherapy if the resection was marginal or the tumour recurrent. The primary endpoint was overall survival and analyses were done by intention to treat. The final results are presented. This trial is registered with ClinicalTrials.gov, NCT00002641.

FINDINGS

Between February, 1995, and December, 2003, 351 patients were randomly assigned to the adjuvant chemotherapy group (175 patients) or to the control group (176). 258 (73%) of 351 patients received radiotherapy, 129 in each group. Overall survival did not differ significantly between groups (hazard ratio [HR] 0·94 [95% CI 0·68-1·31], p=0·72) nor did relapse-free survival (HR 0·91 [0·67-1·22], p=0·51). 5-year overall survival rate was 66·5% (58·8-73·0) in the chemotherapy group and 67·8% (60·3-74·2) in the control group. Chemotherapy was well tolerated, with 130 (80%) of 163 patients who started it completing all five cycles. 16 (10%) patients had grade 3 or 4 fever or infection, but no deaths due to toxic effects were recorded.

INTERPRETATION

Adjuvant chemotherapy with doxorubicin and ifosfamide in resected soft-tissue sarcoma showed no benefit in relapse-free survival or overall survival. Future studies should focus on patients with larger, grade III, and extremity sarcomas.

A phase I pharmacokinetic and pharmacodynamic study of CHR-3996, an oral class I selective histone deacetylase inhibitor in refractory solid tumors

PURPOSE

This clinical trial investigated the safety, tolerability, pharmacokinetic (PK), and pharmacodynamic (PD) profile of CHR-3996, a selective class I histone deacetylase inhibitor.

PATIENTS AND METHODS

CHR-3996 was administered orally once a day. This phase I trial used a 3+3 dose-escalation design. PK profiles were analyzed by liquid chromatography-tandem mass spectroscopic methods and PD studies were conducted using ELISA studying histone H3 acetylation in peripheral blood mononuclear cells.

RESULTS

Thirty-nine patients were treated at dose levels of 5 mg (n = 3), 10 mg (n = 4), 20 mg (n = 3), 40 mg (n = 10), 80 mg (n = 10), 120 mg (n = 4), and 160 mg (n = 5) administered orally once daily. The dose-limiting toxicities seen were thrombocytopenia (160 mg), fatigue (80 and 120 mg), plasma creatinine elevation (80 and 120 mg), and atrial fibrillation (40 mg). The area under the curve was proportional to the administered dose and a maximal plasma concentration of 259 ng/mL at a dose of 40 mg exceeded the concentrations required for antitumor efficacy in preclinical models. Target inhibition measured by quantification of histone acetylation was shown at doses of 10 mg/d and was maximal at 40 mg. A partial response was seen in one patient with metastatic acinar pancreatic carcinoma.

CONCLUSIONS

Taking the toxicity and PK/PD profile into consideration, the recommended phase II dose (RP2D) is 40 mg/d. At this dose, CHR-3996 has a favorable toxicologic, PK, and PD profile. CHR-3996 has shown preliminary clinical activity and should be evaluated in further clinical trials.

Prediction of early death among patients enrolled in phase I trials: development and validation of a new model based on platelet count and albumin

Background:

Selecting patients with ‘sufficient life expectancy’ for Phase I oncology trials remains challenging. The Royal Marsden Hospital Score (RMS) previously identified high-risk patients as those with ⩾2 of the following: albumin <35 g l⁻¹; LDH > upper limit of normal; >2 metastatic sites. This study developed an alternative prognostic model, and compared its performance with that of the RMS.

Methods:

The primary end point was the 90-day mortality rate. The new model was developed from the same database as RMS, but it used Chi-squared Automatic Interaction Detection (CHAID). The ROC characteristics of both methods were then validated in an independent database of 324 patients enrolled in European Organization on Research and Treatment of Cancer Phase I trials of cytotoxic agents between 2000 and 2009.

Results:

The CHAID method identified high-risk patients as those with albumin <33 g l⁻¹ or ⩾33 g l⁻¹, but platelet counts ⩾400.000 mm⁻³. In the validation data set, the rates of correctly classified patients were 0.79 vs 0.67 for the CHAID model and RMS, respectively. The negative predictive values (NPV) were similar for the CHAID model and RMS.

Conclusion:

The CHAID model and RMS provided a similarly high level of NPV, but the CHAID model gave a better accuracy in the validation set. Both CHAID model and RMS may improve the screening process in phase I trials.