Maria Eugenia Vega-Villegas

Pharmacogenomic and Pharmacoproteomic Studies of Cetuximab in Metastatic Colorectal Cancer: Biomarker Analysis of a Phase I Dose-Escalation Study

PURPOSE This study assessed biomarkers for cetuximab efficacy in tissue samples collected during a phase I dose-escalation study exploring every second week administration of cetuximab as first-line therapy in patients with metastatic colorectal cancer (mCRC). PATIENTS AND METHODS Sixty-two patients received cetuximab monotherapy for 6 weeks, followed by cetuximab plus infusional fluorouracil, leucovorin, and irinotecan until disease progression. Patients in the control arm received cetuximab as a 400 mg/m(2) initial dose then 250 mg/m(2) per week; patients in the dose-escalation arms received 400 to 700 mg/m(2) every second week. Tumor and skin biopsies were taken for immunohistochemical and microarray expression analyses (tumor only) at baseline and week 4. Plasma was collected for proteomic analysis at baseline and week 4. KRAS tumor mutation status was assessed. RESULTS In subsets of paired skin samples from 35 patients, cetuximab treatment was associated with substantial downregulation of phospho(p)-EGFR, p-MAPK and proliferation and substantial upregulation of p27(Kip1) and p-STAT3 levels. No marked difference in these effects was noted for different schedules of administration and dose levels. In the cetuximab monotherapy phase, responses were seen only in patients whose tumors were wild-type for KRAS (eight of 29 v zero of 19 for KRAS mutant tumors; P = .015). Progression-free survival was longer for patients with KRAS wild-type compared with KRAS mutant tumors (log-rank P = .048). Genomics/proteomics analyses (42 and 45 patients, respectively) identified candidate biomarkers associated with response. CONCLUSION Biomarker analysis supported the functional equivalence of weekly and every second week administration of cetuximab and provided further confirmation that patients with KRAS wild-type mCRC were those most likely to benefit from cetuximab treatment.

Cetuximab in metastatic or recurrent head and neck cancer: the EXTREME trial

Expression of EGF receptor (EGFR) is frequently elevated in squamous cell carcinoma of the head and neck (SCCHN). Cetuximab is an anti-EGFR monoclonal antibody that has been shown to improve overall survival in patients with locally advanced SCCHN when combined with radiotherapy. Data from Phase II trials suggest an interesting activity of cetuximab in patients with recurrent or metastatic SCCHN who are refractory to cisplatin. The Erbitux in First-Line Treatment of Recurrent or Metastatic Head and Neck Cancer (EXTREME) Phase III trial compared platin-5-fluorouracil alone versus combined with cetuximab as first-line treatment in recurrent or metastatic SCCHN. In the cetuximab arm of this study, a significant improvement in the overall survival (the main objective), progression-free survival and response rate were observed. The quality of life analyses (QLQ-C30 and QLQ-H&N35) showed no significant differences in most of the studied scores between the two treatment arms. Nevertheless, patients in the cetuximab arm displayed significant improvements in pain, swallowing problems and scores for speech and social eating problems. The results of the EXTREME study (and other studies evaluating cetuximab for the treatment of SCCHN) suggest a lack of a predictive value for the expression of EGFR (determined by immunohistochemistry) by the tumor and other biomarkers need to be investigated. The role of other targeted drugs and of possible combinations of these new drugs with cetuximab should be investigated in properly designed preclinical studies and clinical trials.

Cetuximab, its clinical use and future perspectives.

Increase in the expression of epidermal growth factor receptors (EGFRs) has been observed in many tumours. EGFR overexpression usually correlates with a more advanced stage of the disease, a poorer prognosis and a worse chemotherapy response. For all the aforementioned reasons, EGFR inhibition can be considered an attractive approach in cancer treatment. One strategy has been extracellular domain receptor inhibition, using monoclonal antibodies. In this review, we summarize the current status as well as what is likely to be the future use of monoclonal antibodies directed against EGFR. We have focussed on cetuximab being the most developed one. It has been mainly studied in colorectal cancer, and the major portion of this review will focus on all the research that has been carried out on this tumour. Clinical development of cetuximab is also important in head and neck cancer and in lung cancer. Interesting studies have been carried out in pancreatic, gastric, oesophageal and ovarian tumours, as well as in malignant gliomas.

Cetuximab administered once every second week to patients with metastatic colorectal cancer: a two-part pharmacokinetic/pharmacodynamic phase I dose-escalation study

BACKGROUND This phase I dose-escalation study was designed to determine the maximum tolerated dose (MTD) and recommended dose of cetuximab administered on an every-second-week schedule to patients with metastatic colorectal cancer, on the basis of safety, pharmacokinetic and pharmacodynamic evaluation. PATIENTS AND METHODS The study comprised two parts: a 6-week cetuximab monotherapy dose-escalation phase and a subsequent combination therapy phase, during which patients received cetuximab, at the same dose/schedule as in the monotherapy phase, followed by irinotecan plus infusional 5-fluorouracil/folinic acid (FOLFIRI). Patients in the control group received cetuximab as a 400 mg/m(2) initial dose, then 250 mg/m(2)/week and in the dose-escalation group, at 400-700 mg/m(2), every second week. RESULTS Sixty-two patients were included in the study. The MTD of cetuximab administered on an every-second-week schedule was not reached. The safety profiles were similar across all groups. Response rates in the cetuximab monotherapy and combination therapy phases were 15% and 42%, respectively. Trough levels for the 500, 600 mg/m(2) and standard weekly regimens were comparable. CONCLUSION Cetuximab can be safely administered once every second week at doses between 400 and 700 mg/m(2), with 500 mg/m(2) being the most convenient and feasible dose for future studies.

Retrospective analysis of surgical resection after induction chemotherapy for patients with T4b squamous cell head and neck cancer

Background. Standard treatment of patients with T4b squamous cell head and neck cancer (T4b-SCHNC) is concomitant chemo-radiotherapy (CT-RT). Recent Phase III trials with Taxane containing induction chemotherapy (IC) suggest that IC could also play a role in this setting. The value of resecting the residual mass after IC and before RT is not yet clear in this context. Methods. We present the results of a retrospective analysis. Results. Between 1984 and 2001, 113 patients (patients) with T4b-SCHNC were treated at our institution with IC. Four patients dead during IC and 57 patients achieved a complete or a >90% partial response at primary and proceeded to definitive RT (or concomitant CT/RT). Surgical resection was reconsidered after IC and before RT in the other 52 patients. Surgery was performed in 13 of them: in 7 patients resection was R1, all of them had loco-regional progression (2 also developed systemic metastases) and median OS after surgery was 21 months, with no patient alive at 48 months. In the other 6 patients a R0 resection was performed: 3 of these patients had loco-regional relapses (1 also developed systemic metastases) and the other 3 patients remain alive and disease free 56, 62 and 72 months after surgery. Considering the 52 patients that achieved less than a 90% partial response at primary with IC, overall survival was equivalent when no Resection or an R1 resection was performed after IC (5 year OS 8 vs. 0%, lrk, p=0.74), but a statistically significant improvement in OS was observed when an R0 resection was obtained (5 years OS 50%, lrk, p=0.02). Conclusions: R0 resections after IC and before RT could indicate an improvement in OS in patients with T4b-SCHNC that obtain less than a 90% PR at primary after IC. We consider that this approach deserves further research in prospective clinical trials.

Prognostic factors for survival with primary site preservation (SPP) in patients with resectable locally advanced squamous cell carcinoma (R-LA-SCC) of larynx and hypopharynx treated with induction chemotherapy (IC) followed by radiotherapy (RT) in an organ preservation setting

5547 Background: IC followed by RT if complete or nearly complete response at primary is an alternative to laryngectomy in patients (pts) with R-LA-SCC of Larynx and Hypopharynx. To avoid the added morbidity and costs of unsuccessful intent of an organ preservation approach it could be interesting to describe prognostic factors or scores for SPP (time from initiation of IC to death or laryngectomy) such as TALK Score (ASCO 2003, Abst 1999). METHODS We have analized different prognostic factors for SPP, including TALK Score, in 156 pts treated in our institution between 1984 and 2001 with induction Cisplatin-5-FU based chemotherapy in an organ preservation setting. RESULTS Median follow-up: 62 months (25-183). Number of pts affected by each potential prognostic factor, 5 year actuarial SPP (in pts with and without the risk factor) and results of univariate (Lrk) and multivariate (Cox) analysis are given in the table below. When TALK Score (3-4 vs 0-2) was not included in the analysis, Cox regression only identified T4 as an independent poor prognostic factor (HR=2; 95% CI: 1.3-3). When TALK score was included, T4 was not selected and only TALK Score had independent prognostic value (HR=2.3; 95% CI: 1.3-4). [Figure: see text] Conclusions: In our analysis Albumin and Heavy Drinking do not have any prognostic value for SPP. Nevertheless, TALK Score has been validated as an independent prognostic factor for SPP in this study. No significant financial relationships to disclose.