The association of healthcare contact days with physical function and survival in CCTG/AGITG CO.17

INTRODUCTION

While contact days-days with healthcare contact outside home-are increasingly adopted as a measure of time toxicity and treatment burden, they could also serve as a surrogate of treatment-related harm. We sought to assess the association between contact days and patient-reported outcomes, and the prognostic ability of contact days.

METHODS

We conducted a secondary analysis of CO.17 that evaluated cetuximab vs supportive care in patients with advanced colorectal cancer. CO.17 collected EORTC-QLQ-C30 instrument data. We assessed the association between number of contact days in a window and changes in physical function and global health status, and the association between number of contact days in the first 4 weeks with overall survival (OS).

RESULTS

There was a negative association between the number of contact days and change in physical function (per each additional contact day at 4 weeks, 1.50 point decrease; and 8 weeks, 1.06 point decrease, p < .0001 for both), but not with global health status. This negative association was seen in patients receiving cetuximab, but not supportive care. More contact days in the first 4 weeks was associated with worse OS for all comers and patients receiving cetuximab (per each additional contact day; all comers, aHR 1.07, 95% CI, 1.05- 1.10; and cetuximab, aHR 1.08, 95%CI 1.05- 1.11, p < .0001 for both).

CONCLUSIONS

In this secondary analysis of a clinical trial, more contact days early in the course was associated with declines in physical function and worse survival in all-comers and in participants receiving cancer-directed treatment.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT00079066.

Plasma Cetuximab Concentrations Correlate With Survival in Patients With Advanced KRAS Wild Type Colorectal Cancer

BACKGROUND

Cetuximab is a standard of care therapy for patients with RAS wild-type (WT) advanced colorectal cancer. Limited data suggest a wide variation in cetuximab plasma concentrations after standard dosing regimens. We correlated cetuximab plasma concentrations with survival and toxicity.

METHODS

The CO. 20 study randomized patients with RAS WT advanced colorectal cancer in a 1:1 ratio to cetuximab 400 mg/m2 intravenously followed by weekly maintenance of 250 mg/m2, plus brivanib 800 mg orally daily or placebo. Blood samples obtained at week 5 precetuximab treatment were analyzed by ELISA. Patients were grouped into tertiles based on plasma cetuximab concentrations. Cetuximab concentration tertiles were correlated with survival outcomes and toxicity. Patient demographic and biochemical parameters were evaluated as co-variables.

RESULTS

Week 5 plasma cetuximab concentrations were available for 591 patients (78.8%). The median overall survival (OS) was 11.4 months and 7.8 months for patients in the highest (T3) and lowest tertiles (T1) respectively. On multivariable analysis, plasma cetuximab concentration was associated with OS (HR 0.66, 95% confidence interval [CI]: 0.53-0.83, P < .001, T3 vs. T1), and a trend towards progression-free survival (HR 0.82, 95% CI: 0.66-1.02, P = .07, T3 vs. T1). There was no association between cetuximab concentration and skin toxicity or diarrhea.

CONCLUSION

The standard cetuximab dosing regimen may not be optimal for all patients. Further pharmacokinetic studies are needed to optimize cetuximab dosing given the potential improvement in OS.

Clinical and metabolomic characterization of Brivanib-Induced hypertension in metastatic colorectal cancer

BACKGROUND

Trials of tyrosine kinase inhibitors (TKI) have not demonstrated dramatic benefits in advanced colorectal cancer (CRC), and this may be a function of poor patient selection. TKI-induced hypertension is reportedly a surrogate marker for treatment benefit for some tumor types. Our objective was to determine whether hypertension was associated with benefit in the context of CRC treatment, and also to gain insight on the pathogenesis of TKI-induced hypertension by monitoring associated changes in the circulating metabolome.

PATIENTS AND METHODS

Clinical data were acquired from clinical trial patients with metastatic CRC randomized to cetuximab ± the TKI brivanib (N = 750). Outcomes were evaluated as a function of treatment-induced hypertension. For metabolomic studies, plasma samples were taken at baseline, as well as at 1, 4, and 12 weeks after treatment initiation. Samples were submitted to gas chromatography-mass spectrometry to identify treatment-related metabolomic changes associated with TKI-induced hypertension, compared to pre-treatment baseline. A model based on changes in metabolite concentrations was generated using orthogonal partial least squares discriminant analysis (OPLS-DA).

RESULTS

In the brivanib treated group, 95 patients had treatment-related hypertension within 12 weeks of initiating treatment. TKI-induced hypertension was not associated with a significantly higher response rate, nor was it associated with improved progression-free or overall survival. In metabolomic studies, 386 metabolites were identified. There were 29 metabolites that changed with treatment and distinguished patients with and without TKI-induced hypertension. The OPLS-DA model for brivanib-induced hypertension was significant and robust (R2 Y score = 0.89, Q2 Y score = 0.70, CV-ANOVA = 2.01 e-7). Notable metabolomic features previously reported in pre-eclampsia and associated with vasoconstriction were found.

CONCLUSION

TKI-induced hypertension was not associated with clinical benefit in metastatic CRC. We have identified changes in the metabolome that are associated with the development of worsening brivanib-induced hypertension that may be useful in future efforts of characterizing this toxicity.

Evaluating the Time Toxicity of Cancer Treatment in the CCTG CO.17 Trial

PURPOSE

The time spent in pursuing treatments for advanced cancer can be substantial. We have previously proposed a pragmatic and patient-centered metric of these time costs-which we term time toxicity-as any day with physical health care system contact. This includes outpatient visits (eg, bloodwork, scans, etc), emergency department visits, and overnight stays in a health care facility. Herein, we sought to assess time toxicity in a completed randomized controlled trial (RCT).

METHODS

We conducted a secondary analysis of the Canadian Cancer Trials Group CO.17 RCT that evaluated weekly cetuximab infusions versus supportive care alone in 572 patients with advanced colorectal cancer. Initial results reported a 6-week improvement in median overall survival (OS) with cetuximab (6.1 v 4.6 months). Subsequent analyses reported that benefit was restricted to patients with K-ras wild-type tumors. We calculated patient-level time toxicity by analyzing trial forms. We considered days without health care contact as home days. We compared medians of time measures across arms and stratified results by K-ras status.

RESULTS

In the overall population, median time toxic days were higher in the cetuximab arm (28 v 10, P < .001) although median home days were not statistically different between arms (140 v 121, P = .09). In patients with K-ras-mutated tumors, cetuximab was associated with almost numerically equal home days (114 days v 112 days, P = .571) and higher time toxicity (23 days v 11 days, P < .001). In patients with K-ras wild-type tumors, cetuximab was associated with more home days (186 v 132, P < .001).

CONCLUSION

This proof-of-concept feasibility study demonstrates that measures of time toxicity can be extracted through secondary analyses of RCTs. In CO.17, despite an overall OS benefit with cetuximab, home days were statistically similar across arms. Such data can supplement traditional survival end points in RCTs. Further work should refine and validate the measure prospectively.

Early detection of treatment futility in patients with metastatic colorectal cancer

PURPOSE

Chemotherapy options for treating CRC have rapidly expanded in recent years, and few have predictive biomarkers. Oncologists are challenged with evidence-based selection of treatments, and response is evaluated retrospectively based on serial imaging beginning after 2-3 months. As a result, cumulative toxicities may appear in patients who will not benefit. Early recognition of non-benefit would reduce cumulative toxicities. Our objective was to determine treatment-related changes in the circulating metabolome corresponding to treatment futility.

METHODS

Metabolomic studies were performed on serial plasma samples from patients with CRC in a randomized controlled trial of cetuximab vs. cetuximab + brivanib (N = 188). GC-MS quantified named 94 metabolites and concentrations were evaluated at baseline, Weeks 1, 4 and 12 after treatment initiation. In a discovery cohort (N = 68), a model distinguishing changes in metabolites associated with radiographic disease progression and response was generated using OPLS-DA. A cohort of 120 patients was used for validation of the model.

RESULTS

By one week after treatment, a stable model of 21 metabolites could distinguish between progression and partial response (R2Y = 0.859; Q2Y = 0.605; P = 5e-4). In the validation cohort, patients with the biomarker had a significantly shorter OS (P < 0.0001). In a separate cohort of patients with HCC on axitinib, appearance of the biomarker also signified a shorter PFS (1.7 months vs. 9.2 months, P = 0.001).

CONCLUSION

We have identified changes in the metabolome that appear within 1 week of starting treatment associated with treatment futility. The novel approach described is applicable to future efforts in developing a biomarker for early assessment of treatment efficacy.

Initial experience of TAS-102 chemotherapy in Australian patients with Chemo-refractory metastatic colorectal cancer

For patients with refractory metastatic colorectal cancer (mCRC) treatment with Trifluridine/Tipiracil, also known as TAS-102, improves overall survival. This study aims to investigate the efficacy and safety of TAS-102 in a real-world population from Victoria, Australia. A retrospective analysis of prospectively collected data from the Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) registry was undertaken. The characteristics and outcomes of patients receiving TAS-102 were assessed and compared to those enrolled in the registration study (RECOURSE). Across 13 sites, 107 patients were treated with TAS-102. The median age was 60 years (range: 31-83), compared to 63 for RECOURSE. Comparing registry TAS-102-treated and RECOURSE patients, 75% vs 100% were ECOG performance status 0-1, 74% vs 79% had initiated treatment more than 18 months from diagnosis of metastatic disease and 36% vs 49% were RAS wild-type. Median time on treatment was 10.4 weeks (range: 1.7-32). Median progression-free survival (PFS) was 3.3 months compared to 2 months in RECOURSE, while median overall survival was the same at 7.1 months. Two patients (2.3%) had febrile neutropenia and there were no treatment-related deaths, where TAS-102 dose at treatment initiation was at clinician discretion.TRACC registry patients treated with TAS-102 were younger than those from the RECOURSE trial, with similar overall survival observed. Less strict application of RECIST criteria and less frequent imaging may have contributed to an apparently longer PFS.

Intratumoral Transcriptome Heterogeneity Is Associated With Patient Prognosis and Sidedness in Patients With Colorectal Cancer Treated With Anti-EGFR Therapy From the CO.20 Trial

PURPOSE

Metastatic colorectal cancers (mCRCs) assigned to the transit-amplifying (TA) CRCAssigner subtype are more sensitive to anti-epidermal growth factor receptor (EGFR) therapy. We evaluated the association between the intratumoral presence of TA signature (TA-high/TA-low, dubbed as TA-ness classification) and outcomes in CRCs treated with anti-EGFR therapy.

PATIENTS AND METHODS

The TA-ness classes were defined in a discovery cohort (n = 84) and independently validated in a clinical trial (CO.20; cetuximab monotherapy arm; n = 121) and other samples using an established NanoString-based gene expression assay. Progression-free survival (PFS), overall survival (OS), and disease control rate (DCR) according to TA-ness classification were assessed by univariate and multivariate analyses.

RESULTS

The TA-ness was measured in 772 samples from 712 patients. Patients (treated with anti-EGFR therapy) with TA-high tumors had significantly longer PFS (discovery hazard ratio [HR], 0.40; 95% CI, 0.25 to 0.64; P < .001; validation HR, 0.65; 95% CI, 0.45 to 0.93; P = .018), longer OS (discovery HR, 0.48; 95% CI, 0.29 to 0.78; P = .003; validation HR, 0.67; 95% CI, 0.46 to 0.98; P = .04), and higher DCR (discovery odds ratio [OR]; 14.8; 95% CI, 4.30 to 59.54; P < .001; validation OR, 4.35; 95% CI, 2.00 to 9.09; P < .001). TA-ness classification and its association with anti-EGFR therapy outcomes were further confirmed using publicly available data (n = 80) from metastatic samples (PFS P < .001) and patient-derived xenografts (P = .042). In an exploratory analysis of 55 patients with RAS/BRAF wild-type and left-sided tumors, TA-high class was significantly associated with longer PFS and trend toward higher response rate (PFS HR, 0.53; 95% CI, 0.28 to 1.00; P = .049; OR, 5.88; 95% CI, 0.71 to 4.55; P = .09; response rate 33% in TA-high and 7.7% in TA-low).

CONCLUSION

TA-ness classification is associated with prognosis in patients with mCRC treated with anti-EGFR therapy and may further help understanding the value of sidedness in patients with RAS/BRAF wild-type tumors.

Update on optimal treatment for metastatic colorectal cancer from the AGITG expert meeting: ESMO congress 2019

Introduction: Outcomes in metastatic colorectal cancer are improving, due to the tailoring of therapy enabled by better understanding of clinical behavior according to molecular subtype.Areas covered: A review of the literature and recent conference presentations was undertaken on the topic of systemic treatment of metastatic colorectal cancer. This review summarizes expert discussion of the current evidence for therapies in metastatic colorectal cancer (mCRC) based on molecular subgrouping.Expert opinion: EGFR-targeted and VEGF-targeted antibodies are now routinely incorporated into treatment strategies for mCRC. EGFR-targeted antibodies are restricted to patients with extended RAS wild-type profiles, with evidence that they should be further restricted to patients with left-sided tumors. Clinically distinct treatment pathways based on tumor RAS, BRAF, HER2 and MMR status, are now clinically applicable. Evidence suggests therapy for additional subgroups will soon be defined; the most advanced being for patients with KRAS G12 C mutation and gene TRK fusion defects.

Personalized Medicine-Current and Emerging Predictive and Prognostic Biomarkers in Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer diagnosed worldwide and is heterogeneous both morphologically and molecularly. In an era of personalized medicine, the greatest challenge is to predict individual response to therapy and distinguish patients likely to be cured with surgical resection of tumors and systemic therapy from those resistant or non-responsive to treatment. Patients would avoid futile treatments, including clinical trial regimes and ultimately this would prevent under- and over-treatment and reduce unnecessary adverse side effects. In this review, the potential of specific biomarkers will be explored to address two key questions—1) Can the prognosis of patients that will fare well or poorly be determined beyond currently recognized prognostic indicators? and 2) Can an individual patient’s response to therapy be predicted and those who will most likely benefit from treatment/s be identified? Identifying and validating key prognostic and predictive biomarkers and an understanding of the underlying mechanisms of drug resistance and toxicity in CRC are important steps in order to personalize treatment. This review addresses recent data on biological prognostic and predictive biomarkers in CRC. In addition, patient cohorts most likely to benefit from currently available systemic treatments and/or targeted therapies are discussed in this review.

Non-BRCA DNA Damage Repair Gene Alterations and Response to the PARP Inhibitor Rucaparib in Metastatic Castration-Resistant Prostate Cancer: Analysis From the Phase II TRITON2 Study

PURPOSE

Genomic alterations in DNA damage repair (DDR) genes other than BRCA may confer synthetic lethality with PARP inhibition in metastatic castration-resistant prostate cancer (mCRPC). To test this hypothesis, the phase II TRITON2 study of rucaparib included patients with mCRPC and deleterious non-BRCA DDR gene alterations.

PATIENTS AND METHODS

TRITON2 enrolled patients who had progressed on one or two lines of next-generation androgen receptor-directed therapy and one taxane-based chemotherapy for mCRPC. Key endpoints were investigator-assessed radiographic response per modified RECIST/PCWG3 and PSA response (≥50% decrease from baseline).

RESULTS

TRITON2 enrolled 78 patients with a non-BRCA DDR gene alteration [ATM (n = 49), CDK12 (n = 15), CHEK2 (n = 12), and other DDR genes (n = 14)]. Among patients evaluable for each endpoint, radiographic and PSA responses were observed in a limited number of patients with an alteration in ATM [2/19 (10.5%) and 2/49 (4.1%), respectively], CDK12 [0/10 (0%) and 1/15 (6.7%), respectively], or CHEK2 [1/9 (11.1%) and 2/12 (16.7%), respectively], including no radiographic or PSA responses in 11 patients with confirmed biallelic ATM loss or 11 patients with ATM germline mutations. Responses were observed in patients with alterations in the DDR genes PALB2, FANCA, BRIP1, and RAD51B.

CONCLUSIONS

In this prospective, genomics-driven study of rucaparib in mCRPC, we found limited radiographic/PSA responses to PARP inhibition in men with alterations in ATM, CDK12, or CHEK2. However, patients with alterations in other DDR-associated genes (e.g., PALB2) may benefit from PARP inhibition.See related commentary by Sokolova et al., p. 2439.

Abstract 727: Comprehensive genomic profiling of &gt;1000 plasma and tumor tissue samples from metastatic castration-resistant prostate cancer (mCRPC) patients gives insight into targeted treatment strategies

Background: The phase 2 TRITON2 (NCT02952534) study is evaluating the poly(ADP-ribose) polymerase inhibitor rucaparib in mCRPC patients with a deleterious germline or somatic mutation in BRCA1, BRCA2, ATM, or 1 of 12 other DNA damage repair (DDR) genes who have progressed on prior androgen receptor-directed therapy and 1 taxane-based therapy. Here we present results from central genomic screening of plasma and tissue samples for TRITON2.

Methods: Plasma samples were profiled for genomic alterations (GAs) in 70 genes and tumor tissue FFPE samples for GAs in 395 genes by Foundation Medicine, Inc., using next-generation sequencing (NGS) assays. Deleterious alterations included frameshift, nonsense, and deleterious missense mutations, protein-truncating rearrangements, and (for tissue samples) homozygous loss. Tissue samples included both archival and more recent specimens, whereas plasma samples were collected at the time of disease progression on prior therapy.

Results: As of July 2, 2018, 359 plasma samples from patients with mCRPC were screened for deleterious GAs in a DDR gene. Of the plasma samples, 96% (343/359) were successfully sequenced for a comprehensive genomic profile. The most commonly altered genes were AR (49%) and TP53 (48%). Deleterious GAs were detected in BRCA1 (2%), BRCA2 (10%), ATM (15%), CDK12 (6%), or other DDR genes (6%). GAs in the MAPK pathway were observed in 5% of plasma samples. Additionally, 738 tissue samples from primary prostate cancer tumors (78%) or metastases (22%) were profiled. Only 66% of tissue samples (487/738) were sequenced successfully, highlighting the challenges associated with NGS of predominantly archival prostate tissues (median sample age, 2.5 years [range, 4 days to 21 years]). The most commonly altered genes were TP53 (38%), PTEN (33%), ERG-TEMPRSS2 fusions (28%), AR (15%), and MYC (9%). Deleterious GAs were observed in BRCA1(2%), BRCA2 (9%), ATM (7%), CDK12 (7%), or other DDR genes (5%), as well as in the PI3K/AKT (41%), Wnt (11%), MAPK (5%), and mismatch repair (3%) pathways. Further, GAs in the DDR, PI3K/AKT, and Wnt pathways were observed at a higher rate in metastatic (42%, 40%, and 15%, respectively) than in primary prostate tissues (32%, 34%, and 12%, respectively). Updated and expanded genomic analyses and plasma-tissue concordance analyses will be presented.

Conclusions: Genomic NGS profiling of plasma and FFPE tumor tissue samples successfully identified patients with GAs in a DDR gene for the evaluation of rucaparib in mCRPC. The plasma assay is convenient for patients and has a low NGS failure rate, whereas the tumor tissue assay has a higher failure rate but can detect more alteration types. Taken together, these data highlight the strengths and limitations of tissue and plasma testing to identify GAs for targeted therapies in mCRPC.

Citation Format: Foad Green, Jeremy D. Shapiro, Ray McDermott, Josep Maria Piulats, Alison Reid, Peter Ostler, Jingsong Zhang, David Campbell, Dominique Spaeth, Ivor Percent, Arif Hussain, Andrew D. Simmons, Tony Golsorkhi, Simon P. Watkins, Andrea Loehr, Simon Chowdhury, Wassim Abida. Comprehensive genomic profiling of &gt;1000 plasma and tumor tissue samples from metastatic castration-resistant prostate cancer (mCRPC) patients gives insight into targeted treatment strategies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 727.

Fc-γ Receptor Polymorphisms, Cetuximab Therapy, and Survival in the NCIC CTG CO.17 Trial of Colorectal Cancer

PURPOSE

Two germline Fc-γ receptor (FCGR) polymorphisms, rs1801274 [FCGR2A;His(H)131Arg(R)] and rs396991 [FCGR3A;Phe(F)158Val(V)] produce altered proteins through amino acid substitutions; both are reported to be associated with cetuximab-related outcomes. We performed a validation of these polymorphisms in NCIC CTG CO.17, a randomized trial of cetuximab monotherapy in refractory, metastatic colorectal cancer expressing EGFR.

EXPERIMENTAL DESIGN

DNA extracted from formalin-fixed paraffin-embedded tissue was genotyped. In addition to log-rank tests, Cox proportional hazard models assessed their relationships with overall (OS) and progression-free survival (PFS), adjusting for clinically important prognostic factors, along with a polymorphism-treatment arm interaction term.

RESULTS

Somatic KRAS status was wild-type for exon 2 in 153 (52%) of 293 patients, from whom tumor DNA was available. For FCGR2A H/H, a genotype-treatment interaction for KRAS wild-type patients was observed for OS (P = 0.03). In KRAS wild-type patients carrying FCGR2A H/H, cetuximab (vs. no cetuximab) improved survival substantially, with adjusted HRs (aHR) of 0.36 (OS) and 0.19 (PFS) and absolute benefits of 5.5 months (OS; P = 0.003) and 3.7 months (PFS; P = 0.02). In contrast, patients carrying FCGR2A R alleles (H/R or R/R) had aHRs of only 0.78 (OS; 2.8-month benefit) and 0.53 (PFS; 1.6-month benefit). No relationships were found for rs396991 (FCGR3A).

CONCLUSIONS

In the CO.17 trial, cetuximab worked best for patients with KRAS wild-type colorectal cancers carrying FCGR2A H/H genotypes. Significantly lower benefits were observed in patients carrying germline FCGR2A R alleles. Clin Cancer Res; 22(10); 2435-44. ©2016 AACR.

Quality and impact of eviQ Cancer Treatments Online (www.eviq.org.au): the medical oncologist's perspective

INTRODUCTION

eviQ Cancer Treatments Online is a free, web-based resource providing access to over 600 evidence-based treatment protocols in medical oncology, radiation oncology, hematology and cancer genetics. With over 60 000 registrants from 148 countries, eviQ is widely used by cancer clinicians globally. The aim of this study was to examine the perceived quality of eviQ by Australian medical oncologists, the impact it had on their knowledge and practice, and the effect it had on their patients.

METHODS

A web-based survey was administered to members of the Medical Oncology Group of Australia by email. Two reminders emails were sent to encourage participation.

RESULTS

Of the 97 respondents (15%), all but one, were practicing in Australia, with varying years of oncology experience (<2 years: 25%, 2-10 years: 36%, >10 years: 39%). eviQ was most frequently used as a source for providing patient information sheets on chemotherapy side effects, with 57% of respondents using eviQ for this purpose. Other uses included accessing side effect information (27%), checking drug doses (26%) and guiding dose adjustments (22%). The majority of respondents rated eviQ as current, accurate and relevant with over 90% agreeing that eviQ was of a high quality. Most of the respondents reported that they provided better care with enhanced patient experiences as a result of using eviQ.

CONCLUSIONS

eviQ was highly regarded by Australian medical oncologists who responded to our survey. The results suggested that usage of eviQ had a positive impact on individual knowledge, practice and promoted better patient-centered care.

Update on optimal treatment for metastatic colorectal cancer from the ACTG/AGITG expert meeting: ECCO 2015

The treatment of metastatic CRC (mCRC) has evolved over the last 20 years, from fluoropyrimidines alone to combination chemotherapy and new biologic agents. Median overall survival is now over 24 months for RAS mutated (MT) patients and over 30 months for RAS wild-type (WT) patients. However, there are subgroups of patients with BRAF V600E MT CRC who have a significantly poorer outlook. Newer treatment options are also being explored in select subgroups of patients (anti-HER 2 in HER2 positive mCRC and immunotherapy in patients with defective mismatch repair (dMMR)). The best use of these systemic treatment options, as well as surgery in well-selected patients requires careful consideration of predictive biomarkers and importantly, the optimal sequence in which therapies should be given to derive maximal benefit. A group of colorectal subspecialty medical oncologists from Australia, USA, The Netherlands and Germany met during ECCO 2015 in Vienna to review current practice.

Response to Cetuximab With or Without Irinotecan in Patients With Refractory Metastatic Colorectal Cancer Harboring the KRAS G13D Mutation: Australasian Gastro-Intestinal Trials Group ICECREAM Study

Purpose

RAS mutations predict lack of response to epidermal growth factor receptor monoclonal antibody therapy in patients with metastatic colorectal cancer (mCRC), but preclinical studies and retrospective clinical data suggest that patients with tumors harboring the exon 2 KRAS G13D mutation may benefit from cetuximab. We aimed to assess cetuximab monotherapy and cetuximab plus irinotecan in patients with molecularly selected (G13D mutation) chemotherapy-refractory mCRC in a randomized phase II trial of this rare molecular subtype.

Patients and Methods

Patients with chemotherapy-refractory KRAS G13D mutation–positive mCRC who had progressed within 6 months of irinotecan therapy were randomly assigned to cetuximab 400 mg/m2 loading dose and then 250 mg/m2 once per week with or without irinotecan 180 mg/m2 once every 2 weeks. The primary end point was 6-month progression-free survival; secondary end points were response rate, overall survival, quality of life, and toxicity.

Results

Fifty-one of 53 patients recruited over 2 years were eligible. The 6-month progression-free survival rate was 10% (95% CI, 2% to 26%) for cetuximab versus 23% (95% CI, 9% to 40%) for cetuximab plus irinotecan with a hazard ratio of 0.74 (95% CI, 0.42 to 1.32). Response and stable disease rates were 0% and 58% for monotherapy versus 9% and 70% for combination treatment, respectively. Overall survival and quality of life were similar; toxicities were higher with combination therapy.

Conclusion

In patients with G13D-mutated chemotherapy-refractory mCRC, there was no statistically significant improvement in disease control at 6 months with either cetuximab monotherapy or cetuximab plus irinotecan. No responses were seen with single-agent cetuximab. The responses observed with the combination of cetuximab and irinotecan may reflect true drug synergy or persistent irinotecan sensitivity. The ICECREAM (Irinotecan Cetuximab Evaluation and Cetuximab Response Evaluation Among Patients with a G13D Mutation) study demonstrates the need to prospectively evaluate hypotheses that were previously supported by retrospective analyses and exemplifies the value of international collaboration in trials of rare molecular subtypes.

Current opinion on optimal systemic treatment for metastatic colorectal cancer: outcome of the ACTG/AGITG expert meeting ECCO 2013

The treatment of metastatic colorectal cancer has evolved greatly in the last 15 years, involving combined chemotherapy protocols and, in more recent times, new biologic agents. Clinical benefit from the use of targeted therapy with bevacizumab, aflibercept, cetuximab, panitumumab and regorafenib in the treatment of metastatic colorectal cancer is now well established with median overall survival accepted as over 24 months, and with super selection for extended RAS patients higher again. The optimal timing of treatment options requires careful consideration of predictive biomarkers, and importantly the potential for interactions, to derive the maximal benefit. A group of colorectal subspecialty medical oncologists from Australia, the USA, the Netherlands and Germany met during ECCO 2013 to discuss current practice. Subsequent new data from the American Society of Clinical Oncology were also reviewed. This article reviews the evidence discussed in support of modern treatments for colorectal cancer and the decision-making behind the treatment choices, with their benefits and risks.

PIK3CA, BRAF, and PTEN status and benefit from cetuximab in the treatment of advanced colorectal cancer--results from NCIC CTG/AGITG CO.17

PURPOSE

Cetuximab improves survival in patients with K-ras wild-type advanced colorectal cancer. We examined the predictive and prognostic significance of additional biomarkers in this setting, in particular BRAF, PIK3CA, and PTEN.

EXPERIMENTAL DESIGN

Available colorectal tumor samples were analyzed from the CO.17 study. BRAF mutations were identified in tumor-derived DNA by direct sequencing and PIK3CA mutations were identified using a high-resolution melting screen with confirmation by sequencing. PTEN expression by immunohistochemistry (IHC) was performed on tissue microarrays. For each biomarker, prognostic and predictive effects were examined using a Cox model with tests for treatment-biomarker interaction.

RESULTS

A total of 572 patients with pretreated colorectal cancer were randomly assigned to receive cetuximab or best supportive care (BSC). Of 401 patients assessed for BRAF status, 13 (3.2%) had mutations. Of 407 patients assessed for PIK3CA status, 61 (15%) had mutations. Of 205 patients assessed for PTEN, 148 (72%) were negative for IHC expression. None of BRAF, PIK3CA, or PTEN was prognostic for overall or progression-free survival in the BSC arm. None was predictive of benefit from cetuximab, either in the whole study population or the K-ras wild-type subset. In the K-ras wild-type subgroup, the overall survival adjusted HR according to BRAF mutation status was 1.39 (interaction P = 0.69), PIK3CA mutation status HR = 0.79 (interaction P = 0.63), and PTEN expression HR = 0.75 (interaction P = 0.61).

CONCLUSIONS

In chemotherapy-refractory colorectal cancer, neither PIK3CA mutation status nor PTEN expression were prognostic, nor were they predictive of benefit from cetuximab. Evaluation of predictive significance of BRAF mutations requires a larger sample size.

Current opinion on optimal treatment for colorectal cancer

The medical treatment of colorectal cancer (CRC) has evolved greatly in the last 10 years, involving complex combined chemotherapy protocols and, in more recent times, new biologic agents. Advances in adjuvant therapy have been limited to the addition of oxaliplatin and the substitution of oral fluoropyrimidine (e.g., capecitabine) for intravenous 5-fluorouracil with no evidence for improved outcome with biological agents. Clinical benefit from the use of the targeted monoclonal antibodies, bevacizumab, cetuximab and panitumumab, in the treatment of metastatic CRC is now well established, but the optimal timing of their use requires careful consideration to derive the maximal benefit. Evidence to date suggests potentially distinct roles for bevacizumab and EGF receptor-targeted biological agents (cetuximab and panitumumab) in the treatment of metastatic CRC. This article reviews the evidence in support of modern treatments for CRC and the decision-making behind the treatment choices, their benefits and toxicities.

Quality of life in patients with K-RAS wild-type colorectal cancer: the CO.20 phase 3 randomized trial

BACKGROUND

The CO.20 trial randomized patients with K-RAS wild-type, chemotherapy-refractory, metastatic colorectal cancer to receive cetuximab (CET) plus brivanib alaninate (BRIV) or CET plus placebo (CET/placebo).

METHODS

Quality of life (QoL) was assessed using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30 at baseline and at 2, 4, 6, 8, 12, 16, and 24 weeks until disease progression. Predefined coprimary QoL endpoints were time to deterioration (first worsening from baseline of ≥ 10 points) on the Physical Function (PF) and Global (GHS) scales.

RESULTS

Of 750 randomized patients, 721 (358 of whom received CET/BRIV) were assessable for QoL. QoL compliance and baseline PF and GHS scores did not differ by treatment arm. The median time to deterioration was 1.6 months versus 1.1 months for GHS (P =.02) and 5.6 months versus 1.7 months for PF (P <.0001) favoring CET/placebo. Secondary analysis favored CET/placebo for QOL response on the PF, Cognitive Function, Fatigue, Nausea, Appetite, and Diarrhea scales. A greater percentage of patients on the CET/BRIV arm had PF worsening at 6 weeks (31% vs 17%). Clinical adverse events of ≥ grade 3 were more common with CET/BRIV than with CET/placebo, including fatigue (25% vs 11%), hypertension, rash, diarrhea, abdominal pain, dehydration, and anorexia.

CONCLUSIONS

Compared with CET/placebo, the combination of CET/BRIV worsened time to QoL deterioration for patients with K-RAS wild-type, chemotherapy-refractory, metastatic colorectal cancer on the PF and GHS scales of European Organization for Research and Treatment of Cancer Quality of Life Questionnaire C30. This result may be due to higher rates of fatigue and gastrointestinal adverse events.

Phase III randomized, placebo-controlled study of cetuximab plus brivanib alaninate versus cetuximab plus placebo in patients with metastatic, chemotherapy-refractory, wild-type K-RAS colorectal carcinoma: the NCIC Clinical Trials Group and AGITG CO.20 Trial

PURPOSE

The antiepidermal growth factor receptor monoclonal antibody cetuximab has improved survival in patients with metastatic, chemotherapy-refractory, wild-type K-RAS colorectal cancer. The addition of brivanib, a tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor and fibroblast growth factor receptor, to cetuximab has shown encouraging early clinical activity.

PATIENTS AND METHODS

Patients with metastatic colorectal cancer previously treated with combination chemotherapy were randomly assigned 1:1 to receive cetuximab 400 mg/m(2) intravenous loading dose followed by weekly maintenance of 250 mg/m(2) plus either brivanib 800 mg orally daily (arm A) or placebo (arm B). The primary end point was overall survival (OS).

RESULTS

A total of 750 patients were randomly assigned (376 in arm A and 374 in arm B). Median OS in the intent-to-treat population was 8.8 months in arm A and 8.1 months in arm B (hazard ratio [HR], 0.88; 95% CI, 0.74 to 1.03; P = .12). Median progression-free survival (PFS) was 5.0 months in arm A and 3.4 months in arm B (HR, 0.72; 95% CI, 0.62 to 0.84; P < .001). Partial responses observed (13.6% v 7.2%; P = .004) were higher in arm A. Incidence of any grade ≥ 3 adverse events was 78% in arm A and 53% in arm B. Fewer patients received ≥ 90% dose-intensity of both cetuximab (57% v 83%) and brivanib/placebo (48% v 87%) in arm A versus arm B, respectively.

CONCLUSION

Despite positive effects on PFS and objective response, cetuximab plus brivanib increased toxicity and did not significantly improve OS in patients with metastatic, chemotherapy-refractory, wild-type K-RAS colorectal cancer.

Association of hypomagnesemia with inferior survival in a phase III, randomized study of cetuximab plus best supportive care versus best supportive care alone: NCIC CTG/AGITG CO.17

BACKGROUND

Cetuximab-induced hypomagnesemia has been associated with improved clinical outcomes in advanced colorectal cancer (CRC). We explored this relationship from a randomized clinical trial of cetuximab plus best supportive care (BSC) versus BSC alone in patients with pretreated advanced CRC.

PATIENTS AND METHODS

Day 28 hypomagnesemia grade (0 versus ≥1) and percent reduction (<20% versus ≥20%) of Mg from baseline was correlated with outcome.

RESULTS

The median percentage Mg reduction at day 28 was 10% (-42.4% to 63.0%) for cetuximab (N = 260) versus 0% (-21.1% to 25%) for BSC (N = 251) [P < 0.0001]. Grade ≥1 hypomagnesemia and ≥20% reduction from baseline at day 28 were associated with worse overall survival (OS) [hazard ratio, HR 1.61 (95% CI 1.12-2.33), P = 0.01 and 2.08 (95% CI 1.32-3.29), P = 0.002, respectively] in multivariate analysis including grade of rash (0-1 versus 2+). Dyspnea (grade ≥3) was more common in patients with ≥20% versus < 20% Mg reduction (68% versus 45%; P = 0.02) and grade 3/4 anorexia were higher in patients with grade ≥1 hypomagnesemia (81% versus 63%; P = 0.02).

CONCLUSIONS

In contrast to prior reports, cetuximab-induced hypomagnesemia was associated with poor OS, even after adjustment for grade of rash.

Management of advanced gastric cancer

The management of advanced gastric cancer has only evolved a little over the last 15 years: platinum and fluoropyrimidine chemotherapy remains the backbone of therapy with ongoing debate as to the benefit of triplet therapy with either an anthracycline or taxane. Recently published trials of biological agents, in particular those targeting the Her2 receptor, have provided some signs of improvement. This article summarizes the relevant literature, discusses the role of these agents, as well as geographical variations in use, and provides recommendations regarding both 'standard chemotherapy' and the role of biological agents in advanced gastric cancer. Given the relative lack of progress for gastric cancer over the last 15 years, the focus for the next 5 years should be on an improved understanding of the molecular basis of gastric cancer, thus allowing rational integration of new molecular agents.

Quality of life (QoL) assessment in patients (pts) with K-RAS wild-type (WT) chemotherapy refractory metastatic colorectal cancer (mCRC) treated with cetuximab (CET) plus brivanib alaninate (BRIV) or placebo: Results of the NCIC Clinical Trials Group and AGITG CO.20 trial

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Background: The CO.20 trial randomized pts with K-RAS WT chemotherapy refractory mCRC to receive CET + BRIV (Arm A) or CET + placebo (Arm B). Although overall survival (primary endpoint) was not significantly improved (HR=0.88, p=0.12) in this heavily pre-treated population, progression free survival (PFS) favoured Arm A (HR=0.72 p<0.0001).

Methods: Patients with K-RAS WT mCRC previously treated with or with contraindications to a fluoropyrimidine, irinotecan, and oxaliplatin were randomized to a loading dose of IV CET followed by weekly IV CET + BRIV 800 mg PO daily or CET + placebo daily. QoL, a secondary endpoint, was assessed using the EORTC QLQ-C30 at baseline and at 2, 4, 6, 8, 12, 16 and 24 weeks until progression or clinical deterioration. Co-primary QoL endpoints were defined a priori as definitive deterioration (first worsening from baseline of ≥10 points) on the physical function (PF) and Global scales. Time to QoL deterioration (DET) was measured from randomization using the Hochberg procedure to adjust for multiple testing.

Results: 721 (358 Arm A) of 750 randomized pts were assessable for QoL. QoL compliance did not differ by arm and declined in follow-up from 87% to 47% over time. Baseline Global and PF scores did not differ by arm. Median time to QoL DET was 1.6 vs 1.1 mo for Global (p=0.02) and 5.6 vs 1.7 mo. for PF (p<0.0001) in Arm B vs A, respectively. Secondary QoL response evaluation showed a greater proportion of patients on Arm A to have worsening on the PF (31 vs 17% at 6 wks) and cognitive functioning scales, and on the fatigue, nausea, appetite and diarrhea symptom scales. Clinical adverse events ≥ Grade 3 were more common on Arm A than B including fatigue (25 vs 10%), hypertension, rash, diarrhea, abdominal pain, dehydration and anorexia.

Conclusions: Despite a PFS benefit, the combination of CET + BRIV worsened time to QoL DET on the PF and Global scales of EORTC QLQ-C30 in pts with chemotherapy refractory K-RAS WT mCRC. This result may be due to higher rates of fatigue and gastrointestinal adverse events observed with the combination.

Phase III randomized trial of cetuximab (CET) plus either brivanib alaninate (BRIV) or placebo in patients (pts) with metastatic (MET) chemotherapy refractory K-RAS wild-type (WT) colorectal carcinoma (CRC): The NCIC Clinical Trials Group and AGITG CO.20 trial

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Background: The anti-EGFR monoclonal antibody CET has improved survival in pts with MET, chemotherapy refractory, K-RAS wild type (WT) CRC. The addition of BRIV, a tyrosine kinase inhibitor targeting vascular endothelial and fibroblast growth factor receptors (VEGFR/FGFR), to CET has shown encouraging activity in an early phase clinical trial.

Methods: Pts with MET CRC previously treated with combination chemotherapy were randomized 1:1 to receive CET 400 mg/m2 IV loading dose followed by weekly maintenance of 250 mg/m2 plus either BRIV 800 mg PO daily (Arm A) or placebo (Arm B). Pts may have had 1 prior anti-VEGF, but no prior anti-EGFR therapy. The trial was amended shortly after opening to enrol K-RAS WT pts. Primary endpoint was overall survival (OS).

Results: From 02/2008 to 02/2011, 750 pts were randomized (376 in Arm A and 374 in Arm B). Demographics: median age=64 (range 27-88); male=64%; ECOG 0:1:2 (%)=32:58:10; >3 prior chemotherapy regimens=92%; prior anti-VEGF therapy=41%; K-RAS WT=97%. Median OS in the intent-to-treat population was 8.8 months in Arm A and 8.1 months in Arm B, hazard ratio (HR)=0.88; 95% CI=0.74 to 1.03; p=0.12. Median progression-free survival (PFS) was 5.0 months in Arm A and 3.4 months in Arm B, HR=0.72; 95% CI=0.62 to 0.84; p<0.0001. Both partial responses (13.6% vs 7.2%, p=0.004) and stable disease (50% vs 44%) were higher in Arm A. Incidence of any ≥grade 3 adverse event (AE) was 78% in Arm A and 53% in Arm B. Most frequent ≥grade 3 AEs were fatigue (25%), hypertension (11%) and rash (10%) in Arm A, vs fatigue (11%), rash (5%) and dyspnea (5%) in Arm B. Time to deterioration of physical function was shorter and global quality of life scores were lower in Arm A vs Arm B. Pts received ≥90% dose intensity of CET=57% in Arm A vs 83% in Arm B; of BRIV/placebo=48% in Arm A vs 87% in Arm B.

Conclusions: Despite positive effects on PFS and objective response, the combination of CET+BRIV did not significantly improve OS in pts with MET, chemotherapy refractory, K-RAS WT CRC. AEs were consistent with those reported for each drug given as monotherapy.

Health-related quality of life in patients with advanced colorectal cancer treated with cetuximab: overall and KRAS-specific results of the NCIC CTG and AGITG CO.17 Trial

PURPOSE

National Cancer Institute of Canada Clinical Trials Group CO.17 demonstrated the antiepidermal growth factor receptor (anti-EGFR) monoclonal antibody cetuximab improves overall and progression-free survival in patients with advanced, chemotherapy-refractory colorectal cancer (CRC), particularly in patients with wild-type KRAS tumors. This article reports the health-related quality-of-life (HRQL) outcomes from CO.17.

PATIENTS AND METHODS

Patients (N = 572) with pretreated EGFR-detectable advanced CRC were randomly assigned to cetuximab and best supportive care (BSC) or to BSC alone. HRQL primary end points assessed by the EORTC QLQ-C30 were physical function (PF) and global health status (GHS); mean changes from baseline to 8 and 16 weeks were assessed. Post hoc analysis by KRAS mutation status was performed.

RESULTS

Questionnaire compliance was 94% at baseline, but it declined differentially (67% v 47% for cetuximab v BSC at 16 weeks). PF change scores were -3.9 for cetuximab and -8.6 for BSC (P = .046) at 8 weeks and were -5.9 and -12.5 for cetuximab and BSC, respectively, (P = .027) at 16 weeks. GHS change scores were -0.5 and -7.1 (P = .008) at 8 weeks and were -3.6 and -15.2 (P = .008) at 16 weeks for cetuximab and BSC, respectively. In patients who had tumors with wild-type KRAS status, cetuximab resulted in less PF deterioration at 8 weeks (-0.7 v -7.2; P = .11) and 16 weeks (-3.4 v -13.8; P = .008) compared with BSC. Patients with wild-type status who received cetuximab experienced improved GHS at 8 weeks, whereas patients who received BSC alone deteriorated (3.2 v -7.7; P = .002). Cetuximab preserved GHS at 16 weeks (-0.2 v -18.1; P < .001). No significant differences were noted between study arms for patients with mutated KRAS tumors.

CONCLUSION

Cetuximab offers important HRQL and survival benefits for pretreated patients with advanced, wild-type KRAS CRC.

K-ras mutations and benefit from cetuximab in advanced colorectal cancer

BACKGROUND

Treatment with cetuximab, a monoclonal antibody directed against the epidermal growth factor receptor, improves overall and progression-free survival and preserves the quality of life in patients with colorectal cancer that has not responded to chemotherapy. The mutation status of the K-ras gene in the tumor may affect the response to cetuximab and have treatment-independent prognostic value.

METHODS

We analyzed tumor samples, obtained from 394 of 572 patients (68.9%) with colorectal cancer who were randomly assigned to receive cetuximab plus best supportive care or best supportive care alone, to look for activating mutations in exon 2 of the K-ras gene. We assessed whether the mutation status of the K-ras gene was associated with survival in the cetuximab and supportive-care groups.

RESULTS

Of the tumors evaluated for K-ras mutations, 42.3% had at least one mutation in exon 2 of the gene. The effectiveness of cetuximab was significantly associated with K-ras mutation status (P=0.01 and P<0.001 for the interaction of K-ras mutation status with overall survival and progression-free survival, respectively). In patients with wild-type K-ras tumors, treatment with cetuximab as compared with supportive care alone significantly improved overall survival (median, 9.5 vs. 4.8 months; hazard ratio for death, 0.55; 95% confidence interval [CI], 0.41 to 0.74; P<0.001) and progression-free survival (median, 3.7 months vs. 1.9 months; hazard ratio for progression or death, 0.40; 95% CI, 0.30 to 0.54; P<0.001). Among patients with mutated K-ras tumors, there was no significant difference between those who were treated with cetuximab and those who received supportive care alone with respect to overall survival (hazard ratio, 0.98; P=0.89) or progression-free survival (hazard ratio, 0.99; P=0.96). In the group of patients receiving best supportive care alone, the mutation status of the K-ras gene was not significantly associated with overall survival (hazard ratio for death, 1.01; P=0.97).

CONCLUSIONS

Patients with a colorectal tumor bearing mutated K-ras did not benefit from cetuximab, whereas patients with a tumor bearing wild-type K-ras did benefit from cetuximab. The mutation status of the K-ras gene had no influence on survival among patients treated with best supportive care alone. (ClinicalTrials.gov number, NCT00079066.)

A prospective evaluation of treatment with Selective Internal Radiation Therapy (SIR-spheres) in patients with unresectable liver metastases from colorectal cancer previously treated with 5-FU based chemotherapy

BACKGROUND

To prospectively evaluate the efficacy and safety of Selective Internal Radiation (SIR) spheres in patients with inoperable liver metastases from colorectal cancer who have failed 5FU based chemotherapy.

METHODS

Patients were prospectively enrolled at three Australian centres. All patients had previously received 5-FU based chemotherapy for metastatic colorectal cancer. Patients were ECOG 0-2 and had liver dominant or liver only disease. Concurrent 5-FU was given at investigator discretion.

RESULTS

Thirty patients were treated between January 2002 and March 2004. As of July 2004 the median follow-up is 18.3 months. Median patient age was 61.7 years (range 36-77). Twenty-nine patients are evaluable for toxicity and response. There were 10 partial responses (33%), with the median duration of response being 8.3 months (range 2-18) and median time to progression of 5.3 mths. Response rates were lower (21%) and progression free survival shorter (3.9 mths) in patients that had received all standard chemotherapy options (n = 14). No responses were seen in patients with a poor performance status (n = 3) or extrahepatic disease (n = 6). Overall treatment related toxicity was acceptable, however significant late toxicity included 4 cases of gastric ulceration.

CONCLUSION

In patients with metastatic colorectal cancer that have previously received treatment with 5-FU based chemotherapy, treatment with SIR-spheres has demonstrated encouraging activity. Further studies are required to better define the subsets of patients most likely to respond.

Prospective study of treatment with selective internal radiation therapy spheres in patients with unresectable primary or secondary hepatic malignancies

AIM

To prospectively evaluate the efficacy and safety of Selective Internal Radiation (SIR) Spheres (Sirtex Medical, Sydney, NSW, Australia) in patients with unresectable primary or secondary hepatic malignancies.

METHODS

We report our experience of SIR sphere therapy at three Australian centres. Patients with previously untreated colorectal cancer (CRC) received concurrent 5FU, other patients with CRC received 5-FU at investigator discretion and all other patients received SIR spheres alone.

RESULTS

Forty-six patients were enrolled between January 2002 and June 2003. The majority (32 patients) had metastatic colorectal cancer and five patients had hepatocellular carcinoma. The median age of patients was 64 years (range 46-78 years). Forty-three patients were evaluable for response. There were 12 partial responses, of which 10 were in patients with CRC. The median duration of response for all patients was 8.6 months (range 2-21 months). Overall treatment related toxicity was acceptable. Significant late toxicity included four cases of severe gastric ulceration, despite standard work-up and treatment by experienced interventional radiologists.

CONCLUSION

In this series of patients, treatment with SIR-spheres has demonstrated modest activity, mostly observed in patients with CRC. Toxicity was substantial in a small number of patients.

A phase I and pharmacologic study of 9-aminocamptothecin administered as a 120-h infusion weekly to adult cancer patients

PURPOSE

To define the toxicity profile and the recommended phase II doses of 9-aminocamptothecin (9-AC) administered as a weekly 120-h infusion.

METHODS

9-AC was administered over 120 h weekly to 55 adult cancer patients with solid tumors over doses ranging from 0.41 to 0.77 mg/m2 per day in a phase I and pharmacologic study. 9-AC formulated in dimethylacetamide/polyethylene glycol (DMA) was administered on a 3 of 4-week schedule, and the newer colloidal dispersion (CD) formulation was given on a 2 of 3-week schedule.

RESULTS

Overall, 193 courses of therapy were administered over 122 dose levels. On the 3 of 4-week schedule, 9-AC DMA infused at > or = 0.6 mg/m2 per day for 120 h weekly produced dose-limiting neutropenia, thrombocytopenia, and diarrhea, or resulted in 1-2-week treatment delays. Shortening treatments to 2 of 3 weeks resulted in dose-limiting neutropenia and fatigue at infusion rates > 0.72 mg/m2 per day. The ratio of 9-AC lactone to total (carboxylate + lactone) drug plasma concentrations at steady-state was 0.15 +/- 0.07. Clinical toxicities and drug pharmacokinetics were not substantially different between the DMA and CD formulations. One objective response was observed in a patient with bladder cancer and minor responses were observed in patients with lung and colon cancers. Plasma area under the concentration versus time curve for 9-AC lactone modestly correlated with the degree of thrombocytopenia (r=0.51) using a sigmoid Emax pharmacodynamic model.

CONCLUSION

The recommended phase II dose for the 9-AC DMA formulation is 0.48 mg/m2 per h over 120 h for 3 of 4 weeks and for the 9-AC CD formulation is 0.6 mg/m2 per day over 120 h for 2 of 3 weeks. Both regimens were well tolerated and feasible to administer.

Phase I and pharmacologic study of irinotecan administered as a 96-hour infusion weekly to adult cancer patients

PURPOSE

We conducted a phase I and pharmacologic study of a weekly 96-hour infusion of irinotecan to determine the maximum-tolerated dose, define the toxicity profile, and characterize the clinical pharmacology of irinotecan and its metabolites.

PATIENTS AND METHODS

In 26 adult patients with solid tumors, the duration and dose rate of infusion were escalated in new patients until toxicity was observed.

RESULTS

In 11 patients who were treated with irinotecan at 12.5 mg/m(2)/d for 4 days weekly for 2 of 3 weeks, dose-limiting grade 3 diarrhea occurred in three patients and grade 3 thrombocytopenia occurred in two patients. The recommended phase II dose is 10 mg/m(2)/d for 4 days given weekly for 2 of 3 weeks. At this dose, the steady-state plasma concentration (Css) of total SN-38 (the active metabolite of irinotecan) was 6.42 +/- 1.10 nmol/L, and the Css of total irinotecan was 28.60 +/- 17.78 nmol/L. No patient experienced grade 3 or 4 neutropenia during any cycle. All other toxicities were mild to moderate. The systemic exposure to SN-38 relative to irinotecan was greater than anticipated, with a molar ratio of the area under the concentration curve (AUC) of SN-38 to irinotecan of 0.24 +/- 0.08. One objective response lasting 12 months in duration was observed in a patient with metastatic colon cancer.

CONCLUSION

The recommended phase II dose of irinotecan of 10 mg/m(2)/d for 4 days weekly for 2 of 3 weeks was extremely well tolerated. Further efficacy testing of this pharmacologic strategy of administering intermittent low doses of irinotecan is warranted.

A pilot study of interferon alpha-2a, fluorouracil, and leucovorin given with granulocyte-macrophage colony stimulating factor in advanced gastrointestinal adenocarcinoma

We reported previously that the addition of recombinant Escherichia coli human granulocyte-macrophage colony stimulating factor (GM-CSF) to a 5-fluorouracil (5-FU) and leucovorin (LV) regimen seemed to ameliorate diarrhea and permit increased 5-FU dose intensity (J. L. Grem et al., J. Clin. Oncol., 12: 560-568, 1994). We then tested the effect of GM-CSF given with a more toxic regimen of 5-FU/LV/IFN-alpha (IFN alpha-2a). Thirty-one patients with a good performance status and no prior chemotherapy for systemic disease received IFN alpha(-2a (5 MU/m2 s.c., days 1-7), 5-FU (370 mg/m2 i.v., days 2-6), LV (500 mg/m2 i.v., days 2-6), and GM-CSF (Saccharomyces cerevisiae 250 microg/m2 s.c., days 7-18) every 3 weeks. Toxicities and 5-FU dose intensity were compared with that observed in our prior Phase II trial with 5-FU/LV/IFN alpha-2a (J. L. Grem et al., J. Clin. Oncol., 11: 1737-1745, 1993). In comparison with the prior Phase II study, the WBC and granulocyte nadirs in the present trial were significantly higher. When trends in toxicity grades for all cycles were compared, stratifying for 5-FU dose, the incidence and severity of mucositis, skin rash, WBC toxicity, and granulocyte toxicity were significantly lower in the present trial, whereas nausea/vomiting and fatigue were significantly worse. The delivered 5-FU dose intensity for all cycles of therapy appeared to be significantly higher in the present trial. Six of 28 evaluable patients had a partial response (21.4%), and 13 (46%) had stable disease for > or =12 weeks. Despite treatment-related toxicity, patient quality of life did not worsen during the study. No correlation was observed between thymidylate synthase content in primary tumor specimens and response, time to treatment failure, or survival. The addition of GM-CSF appeared to decrease the severity of leukopenia, granulocytopenia, mucositis, and skin rash when compared with our prior experience with this regimen of 5-FU/LV/IFN alpha-2a, at the cost of greater nausea/vomiting and fatigue. The potential impact of increased 5-FU dose intensity on clinical response, however, remains to be determined.

Low-dose versus standard-dose lenograstim prophylaxis after chemotherapy: a randomized, crossover comparison

PURPOSE

Granulocyte colony-stimulating factor (G-CSF) administered prophylactically after chemotherapy reduces the duration and severity of neutropenia. This randomized crossover study was designed to assess whether a lower dose of G-CSF is as effective as a standard dose of 5 microg/kg daily.

PATIENTS AND METHODS

Patients who received standard-dose chemotherapy regimens expected to cause neutropenia received G-CSF (lenograstim) that started the day after chemotherapy for 14 days or until the absolute neutrophil count (ANC) recovered to greater than 10 x 10(9)/L. The lenograstim dose was randomly allocated to be 2 or 5 microg/kg daily in the first cycle of chemotherapy and crossed over to the alternate dose for the second cycle. The study was designed to accrue 40 assessable patients to provide a power of 80% to detect a difference in duration of neutropenia of 1 day. Fifty-two patients were randomized to treatment and 43 patients completed two cycles of identical chemotherapy.

RESULTS

There was little neutropenia irrespective of the dose used. Twenty-three patients (53%) had no grade III or IV neutropenia and 30 patients (70%) had no grade IV neutropenia. Crossover trial methodology was used to assess the difference in outcome caused by the lower dose compared with the standard dose (estimated treatment effect). There was no significant difference in the measures of neutropenia, hospitalization, or other clinical outcomes. The 95% confidence interval (one-sided) for the additional duration of neutropenia caused by the lower dose of lenograstim was 0.43 days or less for grade III or IV neutropenia and 0.34 days or less for grade IV neutropenia.

CONCLUSION

Lenograstim 2 microg/kg provides similar protection to 5 microg/kg against neutropenia that complicates standard-dose chemotherapy. The use of a lower dose has important implications for the cost-effectiveness of prophylactic G-CSF therapy.

Dose intensive combination platinum and cyclophosphamide in the treatment of patients with advanced untreated epithelial ovarian cancer

BACKGROUND

The authors combined cisplatin and carboplatin together with cyclophosphamide to maximize platinum dose intensity in patients with advanced epithelial ovarian cancer (AOC).

METHODS

The authors treated 26 consecutive, newly diagnosed patients with International Federation of Gynecology and Obstetrics (FIGO) Stage III/IV AOC with carboplatin, 600 mg/m2, on Day 1; cyclophosphamide, 250 mg/m2, on Day 1; and cisplatin, 100 mg/m2, on Day 8 every 4 weeks with or without pretreatment with amifostine (range, 740-1140 mg/m2). Platinum dose intensity was estimated using a 4:1 conversion for equipotent doses of cisplatin and carboplatin for expression as cisplatin dose equivalents (CDE).

RESULTS

The mean administered CDE was 49.4 mg/m2/week, which was 79% of the planned dose. Hematologic toxicity was severe, with FIGO Grade 3-4 anemia in 81% of patients, Grade 3-4 neutropenia in 92% of patients, and Grade 4 thrombocytopenia in 96% of patients. Eleven patients (42%) were admitted to the hospital for febrile neutropenia and there was 1 toxic death. Sensory neuropathy > or = Grade 2 occurred in 10 patients (38%), ototoxicity > or = Grade 2 occurred in 18 patients (69%), and 6 patients (23%) required long term hearing aids. Elevations in serum creatinine > or = Grade 2 occurred in 7 patients (27%) and > or = Grade 2 hypomagnesemia was noted in 23 patients (88%). Other Grade 3 toxicities were nausea (42%), emesis (38%), fatigue (15%), mucositis (4%), and respiratory toxicities (4%). Twenty-two of 26 patients (85%) had a clinical response (19 with a complete response [CR] and 3 with a partial response). Pathologic CR was demonstrated in 10 of 26 patients (38%) and residual microscopic disease in 4 of 26 patients (15%) for a total pathologic response rate of 53%. The median progression free survival was 13.5 months and the median overall survival was 37.2 months at a median potential follow-up of 79.3 months. Three of 26 patients remained free of disease at 66, 71, and 103 months, respectively.

CONCLUSIONS

Although dose intensive combination platinum treatment combined with cyclophosphamide in patients with AOC is active, it also is associated with substantial toxicity.

Activity and toxicity of docetaxel (Taxotere) in women with previously treated metastatic breast cancer

BACKGROUND

Metastatic breast cancer is a major cause of cancer death in Australian women. Docetaxel is a new cytotoxic drug that has shown promise in the treatment of metastatic breast cancer in patients who have previously received other chemotherapy, particularly an anthracycline, and has recently been approved for marketing in Australia.

AIM

To report the first Australian experience with docetaxel in a group of women with metastatic breast cancer.

METHODS

Patients with progressive metastatic breast cancer who had previously received other chemotherapy were treated with docetaxel 75 mg/m2 or 100 mg/m2 given as a one hour infusion every three weeks. All patients received oral dexamethasone for five days starting 24 hours prior to docetaxel as prophylaxis against fluid retention. The patients' response to docetaxel and toxicity were assessed by standard criteria.

RESULTS

Twenty-six patients were treated. The major toxicity was neutropenia with 92% of patients experiencing at least one episode of grade 4 (absolute neutrophil count < 0.5 x 10(9)/L) neutropenia. Hospital admission for febrile neutropenia occurred in 44% of patients with one death from sepsis. Cumulative fluid retention was observed but in only one patient was it dose-limiting. Apart from alopecia, other toxicities were infrequent and rarely serious. In 23 patients assessable for response, there were 11 partial responses (48%). Three other patients whose disease could not be assessed for response had clinical improvement. The median survival of all patients treated was eight months.

CONCLUSIONS

The response rate observed with docetaxel is comparable to that seen in trials in the United States and Europe and confirms the high activity of this new cytotoxic agent. Neutropenia is the major toxicity, and consideration should be given to the use of prophylactic oral antibiotics or colony stimulating factors to try and prevent febrile episodes. Clinicians will need to balance the benefits, toxicities, and cost of docetaxel in determining the appropriateness of its use in their patients.

Activity of gemcitabine in patients with advanced ovarian cancer: responses seen following platinum and paclitaxel

Thirty-eight women with epithelial ovarian cancer were treated with gemcitabine, a new antimetabolite. All had previously received platinum, and 27 had also received paclitaxel. Four patients had a partial response giving a response rate of 13% in assessable patients (n = 31) and 11% for all patients entered. Additionally, 6 patients had stable disease with >50% reduction in CA-125 for at least 3 months. Activity was seen in patients resistant to both platinum and paclitaxel. Gemcitabine was well tolerated, with uncomplicated neutropenia the main hematological toxicity. Nonhematological toxicities were generally mild and included fatigue, myalgias, and skin rash. Gemcitabine has some activity in heavily pretreated ovarian cancer patients and deserves further investigation in this malignancy.

Comparison of pullout strength for seven- and nine-millimeter diameter interference screw size as used in anterior cruciate ligament reconstruction

This study compares biomechanical properties of 7- and 9-mm diameter screws providing interference fixation in anterior cruciate ligament reconstruction. Sixteen pairs of fresh-frozen bovine knees were evaluated. Uniaxial load to failure was performed at a deformation rate of 30 mm/s along the mechanical axis of the ligament graft with the knees secured at 45 degrees of flexion in a custom jig. A video analyzer was used to measure ligament strain and bone-to-bone deformation. Ultimate force, deformation, and failure mode were recorded and compared. The 7-mm screws provided 98% yield strength, and 95% ultimate force compared with the 9-mm screws. The average femoral pullout strength was 1161 +/- 93 N in the 7-mm group and 1198 +/- 142 N in the 9-mm group. Failure mode was similar in both groups. Clinically, the usage of 7-mm screws may reduce iatrogenic injuries to the patellar tendon graft compared with larger screws. This study shows that the biomechanical advantages of 9-mm screws compared with 7-mm screws are minimal.

The biomechanical effects of geometric configuration of bone-tendon-bone autografts in anterior cruciate ligament reconstruction

This study provides biomechanical support for a new technique of autograft anterior cruciate ligament reconstruction featuring circular bone plugs and endosteal interference fit fixation. Six matched pairs of fresh frozen human knees were utilized. Femoral interference fit pull-out strength was determined from material-testing-machine-generated oscillograph recordings at a strain rate of 100%/s. Circular bone plugs, obtained with a circular oscillating saw, provided 19.9% greater interference fit pull-out strength compared with identically fixed trapezoidal bone plugs. Different geometric defects were compared in three- and four-point bending on an Instron machine with frozen patellae and an artificial bone composite. Circular defects have 107% greater strength than matched trapezoidal patellar defects in three-point bending. In a bone composite, circular defects are 53% stronger than triangular and 25% stronger in four-point bending than trapezoidal defects. A new technique of harvesting bone plugs with endosteal interference fit fixation is described and biomechanically supported. To date, this technique has been performed on over 500 cases clinically without evidence of patellar fracture or fixation failure. This study demonstrates the efficacy of this simple and reproducible technique compared with previously reported procedures.

Augmented external fixation of unstable distal radius fractures

The technique of "augmentation" of external fixation employs the use of percutaneous Kirschner wires to secure the radial styloid fragment as a lateral buttress, elevate and fix in place the depressed lunate fossa fragment, and, when necessary, add support to the elevated articular surface by means of subarticular bone grafting. A series of 51 cases of comminuted, unstable intraarticular distal radius fractures has been managed using this technique. Detailed evaluation has demonstrated precise articular reconstitution with an overall satisfactory result rate of 92%.

Arthroscopy update #3. Chronic impingement syndrome. The role of ultrasonography and arthroscopic anterior acromioplasty

Diagnosis of advanced rotator cuff impingement syndrome has been difficult due to dependence on plain radiographs and arthrography, which in the absence of complete tears are frequently inconclusive. Advances in ultrasonography have enabled accurate diagnosis of the more enigmatic partial thickness tears of the rotator cuff. Until recently, advanced impingement syndrome resistant to conservative therapy has been managed by open anterior acromioplasty as described by Neer. This has required a prolonged postoperative rehabilitation program before return to normal activities of daily living and athletic participation. Precise diagnosis with ultrasonography and refined arthroscopic techniques have enabled us to identify 50 patients with resistant impingement syndrome and partial thickness tears of the rotator cuff, and surgically decompress the subacromial space via arthroscopic resection of the coracoacromial ligament and anterior-inferior leading edge of the acromion. Postoperatively there has been minimal pain. Return of nearly full passive range of motion has been achieved in all but two patients within the first week. Active range of motion exercises are begun on the first postoperative day and resistive exercises commence two weeks after surgery. Mean return of normal functioning in activities of daily living has been two months, while return to prior level of athletic activity has averaged five months.

Angiomyoma in the hand

Angiomyoma of the upper extremities is not commonly encountered by the orthopedic surgeon. A case of a vascular leiomyoma developing in a 79-year-old woman is discussed along with a review of the literature.

Midazolam-sufentanil anaesthesia for phaeochromocytoma resection

This is a case report of a 66-year-old patient to whom a combined infusion of midazolam and sufentanil was administered for phaeochromocytoma resection. With the exception of a drop in blood pressure immediately after tumour removal, significant intraoperative haemodynamic stability was observed. There was no need for the intraoperative administration of hypotensive or anti-arrhythmic drugs, nor was any prolonged postoperative anaesthetic effect noted. In this case, the combination of midazolam and sufentanil with N2O:O2 was successful in maintaining cardiovascular stability until the tumour was removed. The consequent drop in blood pressure responded to fluid infusion, a not uncommon event in phaeochromocytoma surgery. Although a prospective randomized study for resection of phaeochromocytoma showed that the choice of the anaesthetic technique is not a crucial factor in determining the patient outcome, we feel this technique of midazolam sufentanil is a worthy alternative to the use of inhalational anaesthetics. The lack of significant myocardial depressive effect of the two drugs, coupled with its simple administration, makes it a useful technique in the anaesthetic management of phaeochromocytoma resection.