Susanne Crowe

VeriStrat® has a prognostic value for patients with advanced non-small cell lung cancer treated with erlotinib and bevacizumab in the first line: pooled analysis of SAKK19/05 and NTR528.

BACKGROUND VeriStrat(®) is a serum proteomic test used to determine whether patients with advanced non-small cell lung cancer (NSCLC) who have already received chemotherapy are likely to have good or poor outcomes from treatment with gefitinib or erlotinib. The main objective of our retrospective study was to evaluate the role of VS as a marker of overall survival (OS) in patients treated with erlotinib and bevacizumab in the first line. PATIENTS AND METHODS Patients were pooled from two phase II trials (SAKK19/05 and NTR528). For survival analyses, a log-rank test was used to determine if there was a statistically significant difference between groups. The hazard ratio (HR) of any separation was assessed using Cox proportional hazards models. RESULTS 117 patients were analyzed. VeriStrat classified patients into two groups which had a statistically significant difference in duration of OS (p = 0.0027, HR = 0.480, 95% confidence interval: 0.294-0.784). CONCLUSION VeriStrat has a prognostic role in patients with advanced, nonsquamous NSCLC treated with erlotinib and bevacizumab in the first line. Further work is needed to study the predictive role of VeriStrat for erlotinib and bevacizumab in chemotherapy-untreated patients.

Bevacizumab and erlotinib (BE) first-line therapy in advanced non-squamous non-small-cell lung cancer (NSCLC) (stage IIIB/IV) followed by platinum-based chemotherapy (CT) at disease progression: A multicenter phase II trial (SAKK 19/05).

PURPOSE This phase II trial aimed to evaluate feasibility and efficacy of a first-line combination of targeted therapies for advanced non-squamous NSCLC: bevacizumab (B) and erlotinib (E), followed by platinum-based CT at disease progression (PD). METHODS 103 patients with advanced non-squamous NSCLC were treated with B (15 mg/kg day 1 of each 21-day cycle) and E (150 mg daily) until PD or unacceptable toxicity. Upon PD patients received 6 cycles of CT (cisplatin/carboplatin and gemcitabine). The primary endpoint was disease stabilization rate (DSR) after 12 weeks of BE treatment. RESULTS 101 patients were evaluable. Under BE, DSR at week 12 was 54.5%. 73 patients had at least stable disease (SD), including 1 complete remission and 17 partial responses (PR). No unexpected toxicities were observed. Median time to progression (TTP) under BE was 4.1 months. 62 patients started CT; 35 received at least 4 cycles (6 PR, 32 SD). At a median follow-up of 36 months, median overall survival (OS) was 14.1 months. CONCLUSIONS First-line BE treatment followed by a fixed CT regimen at PD is feasible with acceptable toxicity and activity. In a non-squamous NSCLC population unselected for EGFR status, we found OS rates similar to standard CT.

Combination of trastuzumab and letrozole after resistance to sequential trastuzumab and aromatase inhibitor monotherapies in patients with estrogen receptor-positive, HER-2-positive advanced breast cancer: a proof-of-concept trial (SAKK 23/03)

A sequential treatment design was chosen in this trial to ensure complete resistance to single-agent non-steroidal aromatase inhibitor (AI) and trastuzumab both given as monotherapy before receiving the combination of a non-steroidal AI and trastuzumab. Key eligibility criteria included postmenopausal patients with advanced, measurable, human epidermal growth factor receptor-2 (HER-2)-positive disease (assessed by FISH, ratio (≥2)), hormone receptor (HR)-positive disease, and progression on prior treatment with a non-steroidal AI, e.g. letrozole or anastrozole, either in the adjuvant or in the advanced setting. Patients received standard dose trastuzumab monotherapy in step 1 and upon disease progression continued trastuzumab in combination with letrozole in step 2. The primary endpoint was clinical benefit rate (CBR) in step 2. Totally, 13 patients were enrolled. In step 1, six patients (46%) achieved CBR. Median time to progression (TTP) was 161 days (95% confidence interval (CI): 82-281). In step 2, CBR was observed in eight out of the 11 evaluable patients (73%), including one patient with partial response. Median TTP for all the 11 patients was 188 days (95% CI: 77-not reached). Results of this proof-of-concept trial suggest that complete resistance to both AI and trastuzumab can be overcome in a proportion of patients by combined treatment of AI and trastuzumab, as all patients served as their own control. Our results appear promising for a new treatment strategy that offers a chemotherapy-free option for at least a subset of patients with HR-positive, HER-2-positive breast cancer over a clinically relevant time period.

Expression of inhibitory Fc receptor (FcγRIIB) is a marker of poor response to rituximab monotherapy in follicular lymphoma

Abstract Background FcγRIIB promotes rituximab internalisation on various B-cell targets, including in follicular lymphoma, which may lead to reduced efficacy. We analysed diagnostic tumour samples from the SAKK 35/98 trial, which has follow-up data of nearly 10 years to determine the relation of FcγRIIB expression with responses and clinical outcomes after rituximab monotherapy in follicular lymphoma. Methods Available archived tissue samples were stained with an anti-human FcγRIIB antibody. Positive samples were graded into negative/low intensity staining (n=116) or medium/high staining (n=13) by a histopathologist masked to clinical outcomes. Failure-free survival (FFS) was defined as time from first rituximab infusion until failure to achieve complete/partial response at week 12, progression, relapse, a second cancer, or death from any cause. Objective response rate (ORR) was associated with intensity staining levels with Fishers exact test. All time-to-event endpoints were evaluated with the Kaplan-Meier method; groups were compared with the log-rank test. Hazard ratio (HR) was assessed with Cox proportional hazards models. Findings Patients expressing medium/high levels of FcγRIIB were less likely to respond to rituximab than were those with negative/low levels (ORR 23·1% [95% CI 7·5–50·9] vs 58·6% [49·5–67·2], p=0·02). FFS was higher in the negative/low staining group than in the medium/high staining group (median 8·3 months [95% CI 2·8–13·4, IQR 2·76–28·5] vs 2·8 [not calculable, 2·76–2·76], p=0·002; HR 0·43 [95% CI 0·23–0·78]). There was a non-significant trend towards better overall survival in the low/negative group compared with the medium/high group (median 140·0 months vs 50·0, p=0·13; HR 0·56 [95% CI 0·26–1·20]). Interpretation Elevated FcγRIIB expression level is associated with poor response to rituximab in patients with follicular lymphoma. This group may show better results with non-internalising type II antibodies, a hypothesis for validation in future prospective clinical trials. Funding Cancer Research UK.

EGFR exon-level biomarkers of the response to bevacizumab/erlotinib in non-small cell lung cancer.

Activating epidermal growth factor receptor (EGFR) mutations are recognized biomarkers for patients with metastatic non-small cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitors (TKIs). EGFR TKIs can also have activity against NSCLC without EGFR mutations, requiring the identification of additional relevant biomarkers. Previous studies on tumor EGFR protein levels and EGFR gene copy number revealed inconsistent results. The aim of the study was to identify novel biomarkers of the response to TKIs in NSCLC by investigating whole genome expression at the exon-level. We used exon arrays and clinical samples from a previous trial (SAKK19/05) to investigate the expression variations at the exon-level of 3 genes potentially playing a key role in modulating treatment response: EGFR, V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and vascular endothelial growth factor (VEGFA). We identified the expression of EGFR exon 18 as a new predictive marker for patients with untreated metastatic NSCLC treated with bevacizumab and erlotinib in the first line setting. The overexpression of EGFR exon 18 in tumor was significantly associated with tumor shrinkage, independently of EGFR mutation status. A similar significant association could be found in blood samples. In conclusion, exonic EGFR expression particularly in exon 18 was found to be a relevant predictive biomarker for response to bevacizumab and erlotinib. Based on these results, we propose a new model of EGFR testing in tumor and blood.

Abstract P3-14-16: Can Resistance to Trastuzumab Be Reversed by Endocrine Therapy? Results from a Proof-of-Principle Trial in Postmenopausal Patients with Hormonal Receptor (HR) Positive, HER-2 Positive Advanced Breast Cancer (SAKK 23/03)

Introduction: Trastuzumab (T) is a cornerstone in the treatment of patients with HER2-overexpressing advanced breast cancer and development of resistance to T is a major therapeutic problem. HER-2 is part of a highly interactive signaling network that may impair efficacy of endocrine therapy. A sequential treatment design was chosen in this trial to ensure complete resistance to single agent therapy before receiving both a non-steroidal aromatase inhibitor (AI) and T. Any kind of clinical activity with combined treatment of AI and T after progression of single agent treatments could indicate restoration of sensitivity as a consequence of cross-talking and networking between both pathways. Methods: Key eligibility criteria included postmenopausal patients (pts.) with advanced, measurable, HER-2 positive (assessed by FISH, ratio (≥2)), HR positive disease and progression on prior treatment with a non-steroidal AI, e.g. letrozole or anastrozole, either in an adjuvant or advanced setting. Pts. received standard dose T monotherapy either weekly or three-weekly in step 1 and upon disease progression, continued T in combination with letrozole in step 2. The primary endpoint was clinical benefit response (CBR: CR, PR or SD for at least 24 weeks (+/− 1 week) according to RECIST) in step 2. Results: Thirteen pts. were enrolled in five centers in Switzerland. In step 1, six pts. (46%) achieved CBR. Median time to progression (TTP) was 161 days (Range: 50 - 627). Based on data collected until the end of May 2010, CBR was observed in seven out of the eleven evaluable pts. (64%) in step 2, including one pt. with partial response. Four of the seven pts. within step 2 that achieved CBR also had CBR in step 1. Seven out of eleven pts. have documented tumor progression during step 2 treatment. Median TTP for all eleven pts. was 184 days (range 61 - 471). Mean time on study treatment (TTP in step 1 plus TTP in step 2) for pts. reaching step 2 was 380 days (range 174 - 864). Adverse events were generally mild. Conclusion: Results of this proof-of-principle trial suggest that complete resistance to both AI and T can be overcome in a proportion of pts. by combined treatment of AI and T, as all pts. served as their own control. Our results appear promising for a new treatment strategy which offers a chemotherapy-free and well-tolerated option for at least a subset of the pts. with HR positive, HER-2 positive breast cancer. Further trials will need to corroborate this finding. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-14-16.

Abstract P2-16-07: hMMP9 as Predictive Factor for Response and Progression Free Survival in Breast Cancer Patients Treated with Bevacizumab and Pegylated Liposomal Doxorubicin (PLD)

Background: The anti-angiogenic drug, bevacizumab (Bv), is currently used in the treatment of different malignancies including breast cancer. Many angiogenesis-associated molecules are found in the circulation of cancer patients. Until now, there are no prognostic or predictive factors identified in breast cancer patients treated with Bv. We present here the first results of the prospective monitoring of 6 angiogenesis-related molecules in the peripheral blood of breast cancer patients treated with a combination of Bv and PLD in the phase II trial, SAKK 24/06. Methods: Patients were treated with PLD (20 mg/m 2 ) and Bv (10 mg/kg) on days 1 and 15 of each 4-week cycle for a maximum of 6 cycles, followed by Bv monotherapy maintenance (10 mg/m 2 q2 weeks) until progression or severe toxicity. Plasma and serum samples were collected at baseline, after 2 months of therapy, then every 3 months and at treatment discontinuation. Enzyme-linked immunosorbent assays (Quantikine, RD70(24 Suppl):Abstract nr P2-16-07.