Liver Metastases and Immune Checkpoint Inhibitor Efficacy in Patients With Refractory Metastatic Colorectal Cancer: A Secondary Analysis of a Randomized Clinical Trial

Importance

Immune checkpoint inhibitors (ICIs) have limited activity in microsatellite-stable (MSS) or mismatch repair-proficient (pMMR) colorectal cancer. Recent findings suggest the efficacy of ICIs may be modulated by the presence of liver metastases (LM).

Objective

To investigate the association between the presence of LM and ICI activity in advanced MSS colorectal cancer.

Design, Setting, and Participants

In this secondary analysis of the Canadian Cancer Trials Group CO26 (CCTG CO.26) randomized clinical trial, patients with treatment-refractory colorectal cancer were randomized in a 2:1 fashion to durvalumab plus tremelimumab or best supportive care alone between August 10, 2016, and June 15, 2017. The primary end point was overall survival (OS) with 80% power and 2-sided α = .10. The median follow-up was 15.2 (0.2-22.0) months. In this post hoc analysis performed from February 11 to 14, 2022, subgroups were defined based on the presence or absence of LM and study treatments.

Intervention

Durvalumab plus tremelimumab or best supportive care.

Main Outcomes and Measures

Hazard ratios (HRs) and 90% CIs were calculated based on a stratified Cox proportional hazards regression model. Plasma tumor mutation burden at study entry was determined using a circulating tumor DNA assay. The primary end point of the study was OS, defined as the time from randomization to death due to any cause; secondary end points included progression-free survival (PFS) and disease control rate (DCR).

Results

Of 180 patients enrolled (median age, 65 [IQR, 36-87] years; 121 [67.2%] men; 19 [10.6%] Asian, 151 [83.9%] White, and 10 [5.6%] other race or ethnicity), LM were present in 127 (70.6%). For patients with LM, there was a higher proportion of male patients (94 of 127 [74.0%] vs 27 of 53 [50.9%]; P = .005), and the time from initial cancer diagnosis to study entry was shorter (median, 40 [range, 8-153] vs 56 [range, 14-181] months; P = .001). Plasma tumor mutation burden was significantly higher in patients with LM. Patients without LM had significantly improved PFS with durvalumab plus tremelimumab (HR, 0.54 [90% CI, 0.35-0.96]; P = .08; P = .02 for interaction). Disease control rate was 49% (90% CI, 36%-62%) in patients without LM treated with durvalumab plus tremelimumab, compared with 14% (90% CI, 6%-38%) in those with LM (odds ratio, 5.70 [90% CI, 1.46-22.25]; P = .03). On multivariable analysis, patients without LM had significantly improved OS and PFS compared with patients with LM.

Conclusions and Relevance

In this secondary analysis of the CCTG CO.26 study, the presence of LM was associated with worse outcomes for patients with advanced colorectal cancer. Patients without LM had improved PFS and higher DCR with durvalumab plus tremelimumab. Liver metastases may be associated with poor outcomes of ICI treatment in advanced colorectal cancer and should be considered in the design and interpretation of future clinical studies evaluating this therapy.

Plasma phosphocreatine (PC) as a predictive biomarker for immune checkpoint inhibition in patients with refractory metastatic colorectal cancer (mCRC): Analysis of the CCTG CO.26 trial

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Background: In response to energetic stress, colorectal cancer cells secrete creatine kinase brain-type (CKB). CKB converts creatine and ATP from the extracellular matrix to PC, which is imported intracellularly to sustain survival and metastatic spread. In addition, PC modulates immune cell functions and may play a role in mediating responses to immune checkpoint inhibition. CO.26 was a phase II trial (NCT02870920) that randomized patients (pts) with refractory mCRC to durvalumab plus tremelimumab (D+T) versus best supportive care (BSC). In an exploratory, post-hoc analysis, we investigated the role of plasma PC as a predictive biomarker for response to D+T. Methods: PC concentrations were determined from pre-treatment blood samples with HPLC-tandem mass spectrometer. A minimum p-value approach was used to select an optimum cut-off value which dichotomized patients into low (< 95.6 ng/ml) versus high (≥ 95.6 ng/ml) groups predictive for benefit. Cox proportional hazard models were used to analyze predictive impacts of PC on progression free survival (PFS) and overall survival (OS). Results: Of 180 pts enrolled, pre-treatment blood samples were available for 162 pts (N =115 for D+T; 47 BSC). Pre-treatment PC was low in 15% (N=24) and high in 85% (N=138). There were no differences in baseline characteristics between pts included in this analysis and the total study pts, or PC low and high pts. D+T improved OS significantly in PC low pts (median OS 4.7 months vs 2.3 months; Hazard Ratio (HR) 0.32, 95% confidence interval (CI): 0.11 – 0.95, p = 0.03). There was no improvement in PC high pts with D+T (median OS 6.8 vs 5.2 months; HR 0.80, 95% CI: 0.55 – 1.17, p = 0.24. Interaction p < 0.0001). Plasma PC values had no impact on PFS and rates of disease control. Conclusions: Pts with low plasma PC derived more benefit from immune checkpoint inhibition with D+T in pts with refractory mCRC. Further prospective validation studies are needed. Predictive analysis for OS with pre-treatment PC levels dichotomized by minimum p approach. [Table: see text]

Effects of liver metastases on efficacy of immune checkpoint blockade in treatment refractory, metastatic colorectal cancer (CRC): CCTG CO.26

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Background: Immune checkpoint blockade has limited activity in microsatellite-stable (MSS) or mis-match repair proficient (pMMR) CRC. Recent findings suggest that immunotherapy efficacy may be modulated by the presence of liver metastases. We conducted a retrospective analysis of the Canadian Cancer Trials Group (CCTG) CO.26 study to investigate the relationship between the presence of liver metastases and activity of immune checkpoint blockade. Methods: The CCTG CO.26 study was a randomized phase II study (NCT02870920). Pts with treatment refractory CRC were randomized to durvalumab, tremelimumab and best supportive care (BSC) or BSC alone in a 2:1 fashion. Treatment consisted of durvalumab (1500 mg) q 28 days and tremelimumab (75 mg) q 28 days for the first 4 cycles. The primary endpoint was overall survival (OS) and a two-sided p-value <0.10 was considered significant. Results: Between 08/20106-06/2017, 180 pts were enrolled and 179 treated as randomized. Pt baseline characteristics were balanced between groups. With a median follow-up of 15.2 months, the median OS was 6.6 months for durvalumab and tremelimumab and 4.1 months for BSC (p = 0.07; Hazard ratio (HR): 0.72, 90% confidence interval (CI): 0.54 – 0.97). Progression free survival (PFS) was 1.8 months and 1.9 months respectively (HR 1.01, 90% CI: 0.76 – 1.34). Disease control rate (DCR) was 22.6% for durvalumab and tremelimumab and 6.6% for BSC (p = 0.006). At study entry, liver metastases were absent in 29.4% pts. Pts without liver metastases had improved OS compared to those with liver metastases, irrespective of treatments. PFS was significantly longer in those without liver metastases on durvalumab and tremelimumab (HR: 0.55, 90% CI: 0.31 – 0.97, p = 0.08, interaction p = 0.02). DCR was 49% in patients without liver metastases with durvalumab and tremelimumab, compared to 10% in those with liver metastases (Odds Ratio: 0.12, 90% CI: 0.05 – 0.26). Conclusions: Pts without liver metastases had improved OS and PFS, and higher DCR. Absence of liver metastases may be an indicator for improved efficacy of immune checkpoint blockade and should be investigated in future studies. [Table: see text]

Predictive value of germline ATM mutations in the CCTG PA.7 trial: Gemcitabine (GEM) and nab-paclitaxel (Nab-P) versus GEM, nab-P, durvalumab (D) and tremelimumab (T) as first-line therapy in metastatic pancreatic ductal adenocarcinoma (mPDAC)

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Background: PA.7 evaluated whether combining PD-L1 and CTLA-4 inhibition with GEM and Nab-P increases efficacy. A previous analysis of the PA.7 data demonstrated high plasma based TMB (≥9 mut/Mb) was associated with improved OS in the Gem, Nab-P, D+T arm. DNA repair pathway aberrations beyond mismatch repair have been associated with potential immune sensitivity. We assessed the predictive value of germline ATM mutations in the PA.7 trial. Methods: This randomized phase II study (ClinicalTrials.gov NCT02879318) assessed the efficacy and safety of GEM, Nab-P, D, and T (arm A) vs. GEM and Nab-P (arm B) in patients (pts) with mPDAC (n = 180). The primary endpoint was overall survival (OS). Pre-treatment plasma was sequenced with the Predicine ATLAS next generation assay (600 gene, 2.4 Mb panel). 2-sided alpha set at 0.1. Results: 180 pts were randomized (119 to arm A and 61 to arm B) There was no significant difference in OS (9.8 months in arm A vs. 8.8 months in arm B, p-value 0.72) or PFS (5.5 months and 5.4 months respectively, HR 0.98, p-value 0.91). Plasma analysis was performed on 174/180 pts with available samples. 16/174 (9.2%) pts had germline ATM mutations, 12 in arm A and 4 in arm B. GEM, Nab-P, D+T was associated with improved OS in patients with ATM mutations (HR 0.10, 90% CI 0.03-0.37; median OS 13.9 months vs. 4.9 months) while no activity was seen in pts with ATM Wild Type (HR 0.99, 90% CI 0.73-1.33; median OS 9.79 months vs. 10.2 months); interaction p = 0.014. Germline ATM mutation status was independent of plasma TMB levels (Wilcoxon p = 0.76). Conclusions: Germline ATM mutation appeared predictive of benefit from the addition of dual immune checkpoint inhibitors (D and T) to Gem and Nab-P, with a significant interaction p-value. In addition to previous data from this trial regarding the predictive value of high plasma TMB (≥9 mut/Mb), this data further supports that there may be independent subgroups of PDAC, beyond MSI-H, that may benefit from immunotherapy, and trials evaluating immunotherapy in subgroups of PDAC with these profiles are warranted. Clinical trial information: NCT02879318.

Predictive value of plasma tumor mutation burden (TMB) in the CCTG PA.7 trial: Gemcitabine (GEM) and nab-paclitaxel (Nab-P) vs. GEM, nab-P, durvalumab (D) and tremelimumab (T) as first line therapy in metastatic pancreatic ductal adenocarcinoma (mPDAC)

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Background: PA.7 evaluated whether combining PD-L1 and CTLA-4 inhibition with GEM and Nab-P increases efficacy as first line therapy in mPDAC. High TMB is associated with immunotherapy sensitivity, with a threshold of ≥10 mut/Mb receiving FDA accelerated approved for pembrolizumab in a tissue agnostic setting. We assessed the predictive value of plasma TMB in the PA.7 trial. Methods: This randomized phase II study (ClinicalTrials.gov NCT02879318) assessed the efficacy and safety of GEM, Nab-P, D, and T (arm A) vs. GEM and Nab-P (arm B) in patients (pts) with mPDAC (n = 180). The primary endpoint was overall survival (OS). Pre-treatment plasma was sequenced with the CLIA-certified PredicineATLAS cfDNA next generation assay (600 genes, 2.4 Mb panel). A pre-specified cut point of 5 mut/MB was selected based on distribution of TMB in the trial. 2-sided alpha set at 0.1. Results: 180 pts were randomized (119 to arm A and 61 to arm B). There was no significant difference in OS (9.8 months in arm A vs. 8.8 months in arm B, p-value 0.72) or PFS (5.5 months and 5.4 months respectively, HR 0.98, p-value 0.91). Plasma TMB analysis was performed on 174/180 pts with available samples, and tumor derived variants were detected in 173/174 pts (99.4%). 172 pts were microsatellite stable and 1 pt was microsatellite high (MSI-H) (plasma TMB 52.9 muts/Mb). Using the pre-specified cut-point of 5 mut/Mb there was no significant predictive value from plasma TMB (interaction p = 0.91). Using a minimum p-value approach, a cut-point of 9 mut/MB appeared predictive (p-interaction = 0.064; significant at pre-specified p = 0.1). 8/174 (4.6%) pts had a plasma TMB ≥9 mut/Mb (5/115 (4.4%) in arm A and 3/59 (5%) in arm B). GEM, Nab-P, D+T was associated with improved OS in patients with plasma TMB ≥9 mut/Mb (HR 0.30, 90% CI 0.06-1.37) while no activity was seen in pts with < 9 mut/Mb, (HR 0.97, 90% CI 0.73-1.29). TMB cut-point analysis revealed a clear trend for a decreasing HR favoring the GEM, Nab-P, D and T arm above the selected cut point, with no benefit in the low TMB group. Conclusions: Plasma TMB analysis was successful in over 99% of pts with available samples. Plasma TMB ≥9 mut/Mb was predictive of benefit from the addition of dual immune checkpoint inhibitors (D and T) to Gem and Nab-P, with a significant interaction p-value. While only present in a subgroup of pts (4.6%), this data defines a group beyond MSI-H PDAC that may benefit from immunotherapy. The optimal cut-point for high TMB in this setting requires validation. A clinical trial specifically assessing the role of chemotherapy combined with immune checkpoint inhibition in high TMB mPDAC is warranted. Clinical trial information: NCT02879318.

Effect of Combined Immune Checkpoint Inhibition vs Best Supportive Care Alone in Patients With Advanced Colorectal Cancer: The Canadian Cancer Trials Group CO.26 Study

Importance

Single-agent immune checkpoint inhibition has not shown activities in advanced refractory colorectal cancer (CRC), other than in those patients who are microsatellite-instability high (MSI-H).

Objective

To evaluate whether combining programmed death-ligand 1 (PD-L1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibition improved patient survival in metastatic refractory CRC.

Design, Setting, and Participants

A randomized phase 2 study was conducted in 27 cancer centers across Canada between August 2016 and June 2017, and data were analyzed on October 18, 2018. Eligible patients had histologically confirmed adenocarcinoma of the colon or rectum; received all available standard systemic therapies (fluoropyrimidines, oxaliplatin, irinotecan, and bevacizumab if appropriate; cetuximab or panitumumab if RAS wild-type tumors; regorafenib if available); were aged 18 years or older; had adequate organ function; had Eastern Cooperative Oncology Group performance status of 0 or 1, and measurable disease.

Interventions

We randomly assigned patients to receive either 75 mg of tremelimumab every 28 days for the first 4 cycles plus 1500 mg durvalumab every 28 days, or best supportive care alone (BSC) in a 2:1 ratio.

Main Outcomes and Measures

The primary end point was overall survival (OS) and a 2-sided P<.10 was considered statistically significant. Circulating cell-free DNA from baseline plasma was used to determine microsatellite instability (MSI) and tumor mutation burden (TMB).

Results

Of 180 patients enrolled (121 men [67.2%] and 59 women [32.8%]; median [range] age, 65 [36-87] years), 179 were treated. With a median follow-up of 15.2 months, the median OS was 6.6 months for durvalumab and tremelimumab and 4.1 months for BSC (hazard ratio [HR], 0.72; 90% CI, 0.54-0.97; P = .07). Progression-free survival was 1.8 months and 1.9 months respectively (HR, 1.01; 90% CI, 0.76-1.34). Grade 3 or 4 adverse events were significantly more frequent with immunotherapy (75 [64%] patients in the treatment group had at least 1 grade 3 or higher adverse event vs 12 [20%] in the BSC group). Circulating cell-free DNA analysis was successful in 168 of 169 patients with available samples. In patients who were microsatellite stable (MSS), OS was significantly improved with durvalumab and tremelimumab (HR, 0.66; 90% CI, 0.49-0.89; P = .02). Patients who were MSS with plasma TMB of 28 variants per megabase or more (21% of MSS patients) had the greatest OS benefit (HR, 0.34; 90% CI, 0.18-0.63; P = .004).

Conclusions and Relevance

This phase 2 study suggests that combined immune checkpoint inhibition with durvalumab plus tremelimumab may be associated with prolonged OS in patients with advanced refractory CRC. Elevated plasma TMB may select patients most likely to benefit from durvalumab and tremelimumab. Further confirmation studies are warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT02870920.

A retrospective observational study to estimate the attrition of patients across lines of systemic treatment for metastatic colorectal cancer in Canada

Background

Selection and sequencing of treatment regimens for individual patients with metastatic colorectal cancer (mcrc) is driven by maintaining reasonable quality of life and extending survival, as well as by access to and cost of therapies. The objectives of the present study were to describe, for patients with mcrc, attrition across lines of systemic therapy, patterns of therapy and their timing, and KRAS status.

Methods

A retrospective chart review at 6 Canadian academic centres included sequential patients who were diagnosed with mcrc from 1 January 2009 onward and who initiated first-line systemic treatment for mcrc between 1 January and 31 December 2009. Death was included as a competing risk in the analysis.

Results

The analysis included 200 patients who started first-line therapy. The proportions of patients who started second-, third-, and fourth-line systemic therapy were 70%, 30%, and 15% respectively. Chemotherapy plus bevacizumab was the most common first-line combination (66%). The most common first-line regimen was folfiri plus bevacizumab. KRAS testing was performed in 103 patients (52%), and 38 of 68 patients (56%, 19% overall) with confirmed KRAS wild-type tumours received an epidermal growth factor receptor inhibitor (egfri), which was more common in later lines. Most KRAS testing occurred after initiation of second-line therapy.

Conclusions

In the modern treatment era, a high proportion of patients receive at least two lines of therapy for mcrc, but only 19% receive egfri therapy. Earlier KRAS testing and therapy with an egfri might allow a greater proportion of patients to access all 5 active treatment agents.

Tucatinib Combined With Ado-Trastuzumab Emtansine in Advanced ERBB2/HER2-Positive Metastatic Breast Cancer: A Phase 1b Clinical Trial

Importance

Treatment options for patients with disease progression after treatment with trastuzumab, pertuzumab, and ado-trastuzumab emtansine (T-DM1) are limited. Tucatinib is an oral, potent, human epidermal growth factor receptor 2 (HER2)-specific tyrosine kinase inhibitor (TKI) being developed as a novel treatment for ERBB2/HER2-positive breast cancer.

Objective

To determine the maximum tolerated dosage of tucatinib in combination with T-DM1 in the treatment of patients with ERBB2/HER2-positive metastatic breast cancer with and without brain metastases.

Design, Setting, and Participants

In this phase 1b open-label, multicenter, clinical trial, 57 participants enrolled between January 22, 2014, and June 22, 2015, were 18 years of age or older with ERBB2/HER2-positive metastatic breast cancer previously treated with trastuzumab and a taxane. Data were analyzed between January and March 2018.

Interventions

Tucatinib 300 mg or 350 mg administered orally twice per day for 21 days and T-DM1 3.6 mg/kg administered intravenously once every 21 days.

Main Outcomes and Measures

Safety assessments, pharmacokinetics, and response were assessed using RECIST 1.1 every 2 cycles for 6 cycles, followed by every 3 cycles.

Results

Fifty-seven T-DM1-naive patients (median [IQR] 51 [44.0-63.0] years of age) who had undergone a median of 2 earlier HER2 therapies (range, 1-3) were treated. The tucatinib maximum tolerated dosage was determined to be 300 mg administered twice per day with dose-limiting toxic reactions seen at 350 mg twice per day. Pharmacokinetic analysis showed that there was no drug-drug interaction with T-DM1. Adverse events seen among the 50 patients treated at the maximum tolerated dosage regardless of causality included nausea (36 patients; 72%), diarrhea (30 patients; 60%), fatigue (28 patients; 56%), epistaxis (22 patients; 44%), headache (22 patients; 44%), vomiting (21 patients; 42%), constipation (21 patients; 42%), and decreased appetite (20 patients; 40%); the majority of adverse events were grade 1 or 2. Tucatinib-related toxic reactions that were grade 3 and above included thrombocytopenia (7 patients; 14%) and hepatic transaminitis (6 patients; 12%).

Conclusions and Relevance

In this study, tucatinib in combination with T-DM1 appeared to have acceptable toxicity and to show preliminary antitumor activity among heavily pretreated patients with ERBB2/HER2-positive metastatic breast cancer with and without brain metastases.

Trial Registration

ClinicalTrials.gov Identifier: NCT01983501.

CCTG CO.26: Updated analysis and impact of plasma-detected microsatellite stability (MSS) and tumor mutation burden (TMB) in a phase II trial of durvalumab (D) plus tremelimumab (T) and best supportive care (BSC) versus BSC alone in patients (pts) with refractory metastatic colorectal carcinoma (rmCRC)

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Background: Targeting both PD-L1 and CTLA-4 may be synergistic immunotherapy approaches. CO.26 evaluated if dual inhibition leads to improved pt survival vs BSC alone in rmCRC. Methods: rmCRC pts were randomized 2:1 to D+T vs BSC. Treatment consisted of D (1500 mg) D1 q 28 days and T (75 mg) D1 for first 4 cycles, and supportive measures. Primary endpoint was overall survival (OS). Two-sided p < 0.10 was considered statistically significant. Cell-free (cf)DNA sequencing for MSI and TMB used GuardantOMNI panel and baseline plasma. Results: From 08/2016-06/2017, 180 pts were enrolled. Pt characteristics were balanced between arms. At median follow-up of 15.2 months (mos), median OS was 6.6 mos for D+T and 4.1 mos for BSC (p = 0.07; Hazard ratio (HR): 0.72, 90% confidence interval (CI): 0.54 – 0.97). Progression free survival (PFS) was 1.8 mos vs 1.9 mos, respectively (HR 1.01, 90% CI 0.76 – 1.34). Disease control rate (DCR) was 22.6% for D+T and 6.6% for BSC (p = 0.006). cfDNA analysis was successful in 168/169 pts (99.4%). Two pts were MSI-high. In 166 MSS pts, OS HR was 0.66 (p=0.024; 90% CI 0.49-0.89). Excluding the MSI-H cases (TMB of 74.7 and 247.1 mts/Mb), mean TMB was 20.4 ± 16.3 mts/Mb (range: 0.96 – 114.0). In MSS pts, a pre-specified cutpoint of 20 mts/Mb stratified pts into high and low TMB groups but was not predictive for OS , PFS, or DCR (interaction p-values > 0.7). Using a minimum p-value approach, pts with TMB >28 mts/Mb (21% of MSS pts) had the greatest OS benefit (HR 0.34, 90% CI 0.18-0.63) for D+T (interaction p = 0.07). High TMB was associated with a trend in worse prognosis for OS in the BSC arm using both 20 mts/Mb (HR 1.26, 90% CI 0.76-2.12) and 28 mts/Mb (HR 2.59 90% CI 1.46-4.62) cutpoints. Conclusions: D+T significantly prolonged OS in pts with rmCRC. High TMB may select a group of MSS pts who benefit from D+T. Plasma TMB appeared prognostic in the BSC arm. This is the first study showing combined PD-L1 and CTLA-4 inhibition prolongs survival in pts with MSS rmCRC. Updated results based on deaths in more than 90% of pts will be presented. Clinical trial information: NCT02870920.

CCTG CO.26 trial: A phase II randomized study of durvalumab (D) plus tremelimumab (T) and best supportive care (BSC) versus BSC alone in patients (pts) with advanced refractory colorectal carcinoma (rCRC)

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Background: D is a human monoclonal antibody (mAb) that inhibits binding of programmed cell death ligand 1 (PD-L1) to its receptor. T is a mAb against the cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Targeting both PD-L1 and CTLA-4 may have additive/synergistic activity as the mechanisms of action of CTLA-4 and PD-L1 inhibition are non-redundant. This study evaluated whether combining PD-L1 and CTLA-4 inhibition would lead to improved pt survival vs BSC alone in rCRC. Methods: Pts with rCRC were randomized 2:1 to D+T vs BSC . Pts were eligible if they failed all standard regimens; containing a fluoropyrimidine, irinotecan and oxaliplatin (and an EGFR inhibitor if Ras wild type). Prior treatment (Tx) with anti-VEGF agents or TAS-102 was permitted but not mandatory. Tx consisted of D (1500 mg) D1 q 28 days and T (75 mg) D1 for first 4 cycles, and all appropriate supportive measures. Primary endpoint was overall survival (OS) and a two-sided p-value < 0.10 was considered statistically significant. Results: Between August 2016 and June 2017, 180 pts were enrolled and 179 treated as randomized. Pt baseline characteristics were balanced. 85% of pts received ≥ 90% of planned doses of D and T. No pts with known defective mismatch repair (dMMR) tumors were enrolled. With a median (med) follow-up of 15.2 months (mo), the med OS was 6.6 mo for D+T and 4.1 mo for BSC (p = 0.07; Hazard ratio (HR): 0.72, 90% confidence interval (CI): 0.54–0.97). Med progression free survival was 1.8 mo and 1.9 mo respectively (HR 1.01, 90% CI 0.76–1.34; p=0.97). Disease control rate was 22.7% for D+T and 6.6% for BSC (p = 0.006). Grade 3/4 abdominal pain, fatigue, lymphocytosis and eosinophilia were significantly higher in D+T. At 16 weeks, there was significantly less deterioration on EORTC QLQ-C30 physical function for D+T. Confirmation of MMR status is ongoing. Conclusions: D+T significantly prolonged OS in pts with rCRC and preserved quality of life. Adverse events were more frequent with D+T. This is the first study showing that combined PD-L1 and CTLA-4 inhibition prolongs survival in pts with advanced refractory CRC not selected for dMMR. Clinical trial information: NCT02870920.

Impact of primary tumor sidedness on erlotinib efficacy in patients with metastatic colorectal cancer treated with bevacizumab maintenance: Results from the DREAM phase III trial

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Background: Primary tumor sidedness (PTS) could be a predictive maker for treatment efficacy of EGFR inhibitors monoclonal antibodies in patients with wild-type (WT) RAS metastatic colorectal cancer (MCRC), cetuximab having limited efficacy in patients with WT-RAS right-sided tumors. DREAM study demonstrated that adding erlotinib, an oral EGFR tyrosine kinase inhibitor (TKI) to bevacizumab during maintenance therapy improved clinical outcomes (RR, PFS, OS) in patients with MCRC, whatever KRAS status. The aim of this post-hoc analysis is to evaluate the clinical outcomes according to KRAS mutational status and PTS when adding erlotinib to bevacizumab maintenance therapy. Methods: PTS was retrospectively collected in patients from the DREAM phase III trial treated with bevacizumab with or without erlotinib as maintenance therapy for MCRC who have been controlled by induction therapy. The limit for the definition of PTS was splenic flexure, and rectal tumors were considered as left-sided tumors. The primary endpoint was overall survival (OS). Results: Among 452 patients who received maintenance therapy, PTS ascertainment was 84.7% (n = 383) with 265 (71.0%) patients having left-sided primary tumor and 108 (28.9%) having right-sided primary tumors (3 patients had both and tumor location was unknown in 7 patients). Median OS and treatment effect are presented in table 1. Conclusions: The greatest OS benefit of adding erlotinib to bevacizumab maintenance therapy was observed in patients with WT-KRAS and right-sided MCRC, suggesting a clinical impact of the different mechanism of action between EGFR TKI and monoclonal antibodies. Clinical trial information: NCT00265824. [Table: see text]

Corrigendum: Eastern Canadian Gastrointestinal Cancer Consensus Conference 2014

[This corrects the article DOI: 10.3747/co.22.2603.].

Efficacy, quality of life, and safety of cabazitaxel in Canadian metastatic castration-resistant prostate cancer patients treated or not with prior abiraterone

INTRODUCTION

In the TROPIC study, cabazitaxel improved overall survival in abiraterone-naïve metastatic castration-resistant prostate cancer (mCRPC) patients post-docetaxel. To evaluate cabazitaxel in routine clinical practice, an international, single-arm trial was conducted. Efficacy, safety, and quality of life (QoL) data were collected from Canadian patients enrolled. Overall survival and progression-free survival were not collected as part of this study. Importantly, prior abiraterone use was obtained and its impact on clinical parameters was examined.

METHODS

Sixty-one patients from nine Canadian centres were enrolled, with prior abiraterone use known for 60 patients. Prostate-specific antigen (PSA) response rate, safety, and impact on QoL life were analyzed as a function of prior abiraterone use.

RESULTS

Overall, 92% of patients were ECOG 0/1, 88% had bone metastases, and 25% visceral metastases. Patients treated without prior abiraterone (NoPriorAbi) (n=35, 58%) and with prior abiraterone (PriorAbi) (n=25, 42%) had similar baseline characteristics, except for age and prior cumulative docetaxel dose. Median number of cabazitaxel cycles received was similar between groups (NoPriorAbi=6, PriorAbi=7), as was PSA response rate (NoPriorAbi=36.4%, PriorAbi=45.0%, p=0.54). Almost one-third (31%) of patients received prophylactic granulocyte colony-stimulating factors. Most frequent Grade 3/4 toxicities were neutropenia (14.8%); anemia, febrile neutropenia, fatigue (each at 9.8%); and diarrhea (8.2%). No treatment-related adverse event leading to death was observed. QoL and pain were improved with no difference seen between groups. Treatment discontinuation was mainly due to disease progression (45.9%) and adverse events (32.8%).

CONCLUSIONS

In routine clinical practice, cabazitaxel's risk-benefit ratio in mCRPC patients previously treated with docetaxel seems to be maintained independent of prior abiraterone use.

Eastern Canadian Colorectal Cancer Consensus Conference 2013: Emerging Therapies in the Treatment of Pancreatic, Rectal, and Colorectal Cancers

The annual Eastern Canadian Colorectal Cancer Consensus Conference held in Montreal, Quebec, 17–19 October 2013, marked the 10-year anniversary of this meeting that is attended by leaders in medical, radiation, and surgical oncology. The goal of the attendees is to improve the care of patients affected by gastrointestinal malignancies. Topics discussed during the conference included pancreatic cancer, rectal cancer, and metastatic colorectal cancer.

Patterns in KRAS testing and EGFRi therapy across lines of treatment for metastatic colorectal cancer in Canada: A retrospective analysis

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Background: Selection and sequencing of treatment regimens for individual metastatic colorectal cancer (mCRC) patients is governed by the goals of maintaining reasonable quality of life while extending survival. The timing of KRAS testing and its effect on EGFRi therapy is poorly described. The goals of this analysis wereto describe rates and timing of KRAS testing relative to EGFRi therapy for Canadian patients diagnosed with mCRC. Methods: A retrospective chart review conducted at 6 Canadian centres included patients diagnosed with mCRC from Jan 1, 2009 onwards, who commenced 1st-line systemic treatment for mCRC between Jan 1–Dec 31, 2009. Information on the proportion of patients who received 2nd, 3rd, or subsequent lines of systemic therapy for mCRC was determined and the rates and timing of KRAS testing was ascertained. Results: 200 patients commenced 1st-line therapy and the median age was 62 yr; 78% had mCRC at the time of diagnosis. The proportions of patients who started 2nd, 3rd, and 4th lines of systemic therapy were 70%, 30%, and 15%, respectively. 103 (52%) patients had KRAS testing; 6%, 18%, 57%, 16%, 2%, and 1% of patients were tested at diagnosis or before the 2nd, 3rd, 4th, 5th and 6th lines of therapy, respectively. Median time from testing to EGFRi treatment was 105 (range, 7–1192) days, and varied by site. The frequency of KRAS testing for patients ranged from 30%–70% across study sites; across provinces, the frequency of testing ranged from 46%–60%. 38/68 (56%) of patients with wt KRAS tumors received EGFRi; 31 (46%) patients received EGFRi therapy as next therapy following KRAS testing. 19 (28%) died and 4 were lost to follow-up within 120 days of KRAS testing with no other therapy. 2 additional patients with unknown KRAS status received EGFRi (1 without KRAS testing; 1 undetermined). Conclusions: KRAS testing occurred after starting 2nd line in 76% of cases and varied by site and province. About half of patients underwent KRAS testing and 56% of those patients with wt KRAS tumors received an EGFRi. The short time interval between (K)RAS testing and EGFRi therapy may point to the need for earlier testing if EGFRi therapy is to be used in earlier lines of therapy.

Eastern Canadian Gastrointestinal Cancer Consensus Conference 2014

The annual Eastern Canadian Colorectal Cancer Consensus Conference was held in Montreal, Quebec, 23-25 October 2014. Expert radiation, medical, and surgical oncologists and pathologists involved in the management of patients with gastrointestinal malignancies participated in presentations and discussions resulting in consensus statements on such hot topics as management of neuroendocrine tumours, advanced and metastatic pancreatic cancer, and metastatic colorectal cancer.

Abstract P4-15-08: A phase 1b study of ONT-380, an oral HER2-specific inhibitor, combined with ado-trastuzumab emtansine (T-DM1), in HER2+ metastatic breast cancer (MBC)

Background: ONT-380 (also known as ARRY-380) is a potent, selective small molecule inhibitor of HER2 with 500-fold selectivity compared to EGFR. Preclinical studies have demonstrated synergistic activity with ONT-380 and chemotherapy or trastuzumab, as well as superior activity compared to lapatinib and neratinib in models of HER2+ CNS metastases. In a Phase 1 single agent study in HER2+ MBC, ONT-380 was well tolerated and provided clinical benefit with minimal EGFR-type toxicities, with an MTD of 600 mg BID using an API-in-capsule formulation. Based on the potential for dual blockade of HER2 to lead to clinical benefit, ONT-380 is being evaluated in combination with T-DM1 in patients previously treated with a taxane and trastuzumab for metastatic disease.

Methods: This 3+3 dose escalation study evaluates escalating doses of ONT-380 in a new tablet formulation combined with T-DM1 at 3.6 mg/kg IV once every 21 days. Prior treatment with trastuzumab and a taxane are required. Prior lapatinib or neratinib therapy and asymptomatic brain metastases (treated or untreated) are allowed. Previous T-DM1 is not permitted. Normal left ventricular ejection fraction and anthracycline exposure ≤ 360 mg/m2 is required. Study assessments include safety, ONT-380 and T-DM1 PK, tumor response by RECIST 1.1, and CNS response by both modified RECIST and volumetric criteria. Dose escalation will be followed by enrollment of expansion cohorts in patients with and without CNS disease.

Results: As of 21 May 2014, 7 patients have been treated with ONT-380 at 300 mg BID for 1–5 cycles. One dose limiting toxicity (DLT) of Grade 3 ALT/AST elevation was seen in the ONT-380 300 mg BID cohort, requiring a dose reduction for both agents with subsequent cohort expansion to 6 patients. No further DLTs have been seen in this cohort, and no other dose reductions have been required. Most toxicities have been Grade 1 or 2, with the most common regardless of attribution being nausea, fatigue, diarrhea, and thrombocytopenia. Two Grade 3 AEs have been reported, including the DLT of ALT/AST elevation, and one event of thrombocytopenia, considered related to T-DM1 but not ONT-380. There has been no Grade 3 diarrhea and no SAEs. In the four patients evaluable for response to date, best response has been 1PR, 2 SD, and 1 PD. Three patients with prior CNS radiation have had continued reduction in CNS lesions on study. Initial PK data indicate greater ONT-380 exposure is achieved with the new tablet formulation compared to the earlier capsule formulation with no evidence of drug interaction with T-DM1.

Conclusions: Treatment with ONT-380 and T-DM1 has been associated with an acceptable safety profile, with only one DLT and minimal Grade 3 toxicity, including no Grade 3 diarrhea or rash. Early evidence of disease control has been seen, including in patients with CNS metastases. Dose escalation continues, and updated results will be presented for additional cohorts.

Citation Format: Virginia F Borges, Erika Hamilton, Denise A Yardley, Jorge Chaves, Nathalie Aucoin, Cristiano Ferrario, Luke Walker, Ian Krop. A phase 1b study of ONT-380, an oral HER2-specific inhibitor, combined with ado-trastuzumab emtansine (T-DM1), in HER2+ metastatic breast cancer (MBC) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-15-08.

Improving safety in first-line metastatic colorectal cancer (MCRC) therapy with bevacizumab: Modified FOLFOX7 versus XELOX2—Results of the induction phase of the GERCOR DREAM randomized phase III study

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Background: FOLFOX7 is an oxaliplatin FOLFOX regimen without 5FU bolus, first used in the OPTIMOX1 MCRC study (Tournigand, JCO 2006). Modified (m) FOLFOX7 has a reduced dose of oxaliplatin (100 mg/m²) and has been used in the OPTIMOX2 trial (Chibaudel, JCO 2009). XELOX2 derived from the bi-weekly XELOX regimen with oxaliplatin 85 mg/m² (Scheithauer, JCO 2003). Methods: First-line induction therapy (IT) allocation was randomized in unresectable MCRC patients with performance status (PS) 0-1 between 6 cycles of mFOLFOX7 with bevacizumab (B) or 6 cycles of XELOX2 with B. Stratification criteria were: center, age, ECOG PS, number of metastatic sites and LDH level. After 3-month IT, a second randomization for maintenance therapy allocation was done in non-progressive patients between B or B-erlotinib. mFOLFOX7-B consisted in B 5 mg/kg followed by folinic acid (FA) 400 mg/m² and oxaliplatin 100 mg/m² followed by 5-flurouracil (5FU) 2,400 mg/m² 46h-infusion. XELOX2-B consisted in B 5 mg/kg followed by oxaliplatin 100 mg/m² followed by capecitabine 1,250 mg/m² twice daily for seven days. Cycles were repeated every two weeks. The objective was to compare the safety and efficacy of XELOX2-B to mFOLFOX7-B (secondary objective of the study). Results: 156 patients were randomized to mFOLFOX7-B and 154 to XELOX2-B. Medians (mFOLFOX7/XELOX2) were: PFS 7.9/8.7 months (HR 0.98, CI 0.74-1.31; p=0.918), OS 26.6/23.4 months (HR 1.24, CI 0.98-1.59; p=0.075). RR (mFOLFOX7/XELOX2) was 50.0%/49.3%. Main grade 3/4 toxicities (mFOLFOX7/XELOX2) were neutropenia 9.2%/2.6% (p=0.018), diarrhea 5.2%/18.3% (p<0.001), asthenia 2.6%/11.8% (p=0.003), all 27.5%/37.6% (p=0.068). Conclusions: Both regimens have the same activity as the parent regimens with a reduced toxicity, especially mFOLFOX7-B. These regimens could be good backbones for future combinations with other agents and are well suited for frail and elderly patients. Clinical trial information: NCT00265824.

Cabazitaxel in docetaxel-pretreated metastatic castration resistant prostate cancer (mCRPC): Canadian experience

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Background: Cabazitaxel/prednisone (CbzP) improves survival in docetaxel resistant mCRPC. Canadian investigators collected safety, QoL and efficacy data in patients (pts) from a global Expanded Access Program. Methods: Following progression on or after docetaxel, all pts received cabazitaxel 25 mg/m² IV q3wkly and prednisone 10 mg daily. Safety and QoL were collected at baseline and at each cycle. Adverse events were graded according to NCI CTCAE v 4.0. Present pain intensity (PPI) and analgesic scores were assessed using the McGill-Melzack questionnaire. QoL was assessed using FACT-P and EQ 5D-3L. PSA was done at the investigator's discretion at each cycle and at the end of treatment. Results: 61 pts were enrolled at 9 centers. Median age was 65 (18% ≥ 75); 92% were ECOG 0/1; 89% had bone metastases and 21% had visceral metastases. Pts had a median of 9 cycles (median cumulative dose 675 mg/m2) of prior docetaxel, and 38% had progressed on or within 3 months of it. Notably 26 pts (43%) had also received and progressed on prior Abiraterone Acetate (AA) given before (5pts), or after docetaxel (21 pts). Half the patients (51%) received >6 cycles of CbzP. Median relative dose intensity was 99%. At cycle 1, 31% received prophylactic G-CSF. Main grade 3+ toxicities were anemia 9.8%, diarrhea 8.2%, fatigue 8.2% and febrile neutropenia 6.6%. Peripheral neuropathy was uncommon (4.9% ; no grade 3+). There was 1 treatment related death (1.6%) due to abdominal sepsis. Compared to baseline, PPI scores improved despite stable analgesic use and were significant at cycles 2, 4, 9 (p<0.05). The FACT-P prostate specific questions showed significant improvements in the first 4 cycles (p<0.05). On the EQ-5D-3L the percentage of patients reporting “no problem” for the pain domain by the last cycle increased. The PSA response rate (≥50% decrease) was 48.7% in 39 evaluable pts and was similar in AA pretreated and non-pretreated pts (47.1% and 50.0% respectively). Conclusions: In routine clinical practice, CbzP treatment was clinically manageable and toxicities were similar to the TROPIC study. PPI and QoL data support a palliative benefit of CbzP. PSA response rate was 48.7% and similar in AA pretreated and non-pretreated pts.

Quality of life (QoL) of patients with metastatic castration resistant prostate cancer (mCRPC) treated with cabazitaxel

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Background: The effects of cabazitaxel on QoL, pain response and preference/utility data have not been well studied in men with CRPC treated post-docetaxel. As part of a single-arm multicenter Sanofi-funded Early Access Program (EAP) for cabazitaxel, QoL data were collected on Canadian patients. Methods: Between May 2011 and February 2012, 61 patients (pts) were enrolled at 9 centers. QoL was assessed at the start of each cycle using the FACT-P and its subscales, and the EQ 5D-3L. EQ 5D-3L health state index (HIS) data were converted into utility values (Canadian tariff, Bansback 2011). Present pain intensity (PPI) and analgesic scores were assessed using the McGill-Melzack questionnaire. Results: QoL data were evaluable in 55 pts. Baseline pt characteristics were: median age 65 years (range, 42-79), 92.7% of pts were ECOG PS 0 or 1, 87% had bone metastases, and 56% (31/55) received at least 6 cycles of cabazitaxel. Statistically significant changes from baseline in mean QoL scores were observed on FACT-P total score at cycle 2, and prostate cancer specific subscale (PCS) at cycles 1 to 4. As a measure of QoL response, increases were observed and maintained for > 2 consecutive cycles in 9% (>16 points) and 25% (≥10) of pts for FACT-P total score. Improvements to the level of Minimal Important Differences (MID) (Cella 2009) maintained for > 2 consecutive cycles were observed in 36% of pts for FACT-P total score (MID=6), 49% for PCS subscale (MID=2), and 26% for PCS-Pain subscale (MID=2), respectively. The percentage of pts reporting "no problem" in the EQ-5D pain/discomfort domain were above baseline levels at every cycle and improved from baseline to end of treatment from 19% to 29% (p < 0.05). Other EQ-5D dimensions (anxiety/depression, mobility, self-care and usual activities) remained stable over the course of treatment. Improvement from baseline in utility value (HIS) was observed at cycle 4 with a utility value of 0.769 (vs 0.713 at baseline). PPI scores improved despite stable analgesic use and were significantly different from baseline at cycles 2, 4 and 9. Conclusions: Data from this EAP suggest improvements in QoL, pain and prostate cancer specific symptoms with second-line cabazitaxel treatment. Clinical trial information: NCT01254279.

Maintenance therapy with bevacizumab with or without erlotinib in metastatic colorectal cancer (mCRC) according to KRAS: Results of the GERCOR DREAM phase III trial

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Background: The primary analysis of DREAM demonstrated that a maintenance therapy (MT) with bevacizumab (Bev) + EGFR TKI erlotinib (E) significantly improved progression-free survival (PFS) after a 1st-line Bev-based induction therapy (IT) in patients (pts) with unresectable mCRC. Methods: Pts were randomized to MT after an IT with FOLFOX-bev or XELOX-bev or FOLFIRI-bev between Bev alone (Bev 7.5 mg/kg q3w; arm A) or Bev+E (Bev 7.5 mg/kg q3w, E 150 mg/d ; arm B) until PD or unacceptable toxicity. Primary endpoint was PFS on MT. Secondary endpoints included PFS from inclusion, overall survival (OS) and safety. The impact of KRAS tumor status on treatment efficacy was evaluated in an exploratory analysis. Results: 700 pts were registered and 452 pts were randomized (228 in arm A, 224 in arm B). KRAS status was available for 413/452 (91%) pts. The median duration of MT was 3.6 m. Results for MT are presented below (Table). In the registered population, median OS was 24.9m (22.5 – 27.3). Conclusions: Maintenance treatment with bev + erlotinib increases PFS over maintenance with bev alone in pts with mCRC but does not prolong OS. Further follow-up will determine the impact of 2nd or 3rd line anti-EGFR Mabs in this study. Contrasting with anti-EGFR Mabs, KRAS tumor status is not mandatory to select pts with mCRC for treatment with erlotinib. Clinical trial information: NCT00265824. [Table: see text]

Induction treatment in first-line with chemotherapy + bevacizumab (bev) in metastatic colorectal cancer: Results from the gercor-DREAM phase III study

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Background: the DREAM study compares a maintenance therapy with bevacizumab (bev) alone or with the erlotinib after a bev-based induction therapy with FOLFOX, or biweekly XELOX or FOLFIRI. Efficacy of the induction treatment is reported here. Methods: Patients (pts) with previously untreated metastatic colorectal cancer received one of the following regimen (investigator’s choice): mFOLFOX7-bev, biweekly mXELOX-bev or FOLFIRI-bev. Oxaliplatin was administered no more than 6 cycles. In the 1st cohort, pts received 3 months (m) of FOLFOX-bev or mXELOX-bev before randomization. In the 2nd cohort, pts received 3m of FOLFOX-bev or mXELOX-bev then 3 m of fluoropyrimidine-bev, or 6 m of FOLFIRI-bev before randomization. Pts with disease control were then randomized between bev alone or with erlotinib until progression. Results: FOLFOX-bev was administered in 424 pts, mXELOX-bev in 203 pts and FOLFIRI-bev in 67 pts. Pts characteristics for the whole population are: median age 63 yrs (26-80), male/female 59.8%/40.2%, synchronous mets/metachronous 82.6%/17.4%, PS 0/1/2 58%/39%/3%, LDH>UNL 53%, platelets >400000/mm3 27%. Patients received a median nb of 6 cycles of oxaliplatin for FOLFOX-bev and mXELOX-bev, and a median nb of 12 cycles of irinotecan with FOLFIRI-bev. Response rates are respectively 48%, 50% and 63%. Median PFS are respectively 8.61m, 8.97m and 9m. Severe toxicity profiles (grade 3-4) appear to be different according to the schedule : more neutropenia and diarrhea with FOLFIRI-bev, HFS and diarrhea with mXELOX-bev and neuropathy with FOLFOX-bev. Conclusions: Modified biweekly XELOX-bev provides similar efficacy results with FOLFOX-bev, and FOLFIRI-bev as induction therapy in first-line. Clinical trial information: NCT00265824.

Bevacizumab (Bev) with or without erlotinib as maintenance therapy, in patients (pts) with metastatic colorectal cancer (mCRC): Exploratory analysis according to KRAS status in the gercor DREAM phase III trial

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Background: In the GERCOR-DREAM trial, maintenance therapy (MT) with bev + EGFR tyrosine kinase inhibitor erlotinib (E) after a first-line Bev-based induction therapy (IT) in pts with mCRC significantly improved PFS compared with bev alone. Here we explore the influence of KRAS status on erlotinib efficacy. Methods: Pts with previously untreated and unresectable mCRC were eligible. After a Bev-based IT with FOLFOX or XELOX or FOLFIRI, pts without disease progression were randomized to MT between Bev alone (Bev 7.5 mg/kg q3w; arm A) or Bev+E (Bev 7.5 mg/kg q3w, E 150 mg/day continuously; arm B). KRAS determination was established by local assessment in each center. Results: Among the 452 randomized patients, KRAS status was available in 403 pts (89%): 234 pts (58%) KRAS wt and 169 pts (42%) KRAS mut. Clinical characteristics were similar between both populations. For the whole population of randomized patients (n=452), median PFS from inclusion were 9.33m and 10.55m in arm A and B, respectively (HR=0.76 [0.61-0.94], p=0.011). For KRAS wt population, median PFS from inclusion was 9.66 m and 10.94 m in arm A and B, respectively (HR=0.80 [0.59-1.08], p=0.141). For KRAS mut population, median PFS from inclusion was 9.79 m and 9.79 m in arm A and B, respectively (HR=0.86 [0.61-1.22], p=0.393). In KRAS wt pts treated with erlotinib, cutaneous toxicity was predictive of PFS: mPFS was 9.66m in pts with grade 0 (n=101) and 10.91m in pts with grade ≥1 (n=114) (HR=0.69 [0.51-0.95], p=0.0186). Conclusions: The addition of erlotinib to bevacizumab as maintenance treatment in first-line metastatic colorectal cancer significantly improves progression-free survival from inclusion. However, in both wt and mut KRAS pts, difference was not statistically significant. Unlike anti-EGFR monoclonal antibodies, the addition of erlotinib to bevacizumab does not appear to be antagonist in KRAS mutant patients. Clinical trial information: NCT00265824.

Bevacizumab (Bev) with or without erlotinib as maintenance therapy, following induction first-line chemotherapy plus Bev, in patients (pts) with metastatic colorectal cancer (mCRC): Efficacy and safety results of the International GERCOR DREAM phase III trial

LBA3500^

Background: Therapy targeting VEGF or EGFR demonstrated clinical activity in combination with chemotherapy (CT) in mCRC but monoclonal antibodies cannot be associated. The DREAM trial compares a maintenance therapy (MT) with bev +/- EGFR tyrosine kinase inhibitor erlotinib (E) after a first-line Bev-based induction therapy (IT) in pts with mCRC. Methods: Pts with previously untreated and unresectable mCRC were eligible. After a Bev-based IT with FOLFOX or XELOX or FOLFIRI, pts without disease progression were randomized to MT between Bev alone (Bev 7.5 mg/kg q3w; arm A) or Bev+E (B 7.5 mg/kg q3w, E 150 mg/day continuously; arm B). Pts were treated until progression or unacceptable toxicity. The primary endpoint was PFS on MT. Results: The study enrolled 700 pts from 01/2007 to 11/2011 in 3 countries (France, Canada, Austria). 446 (63.7%) pts were randomized for MT (arm A, N=224; arm B, N=222). Among the 446 randomized pts, IT regimen was FOLFOX-Bev in 265 pts (59.4%), XELOX-Bev in 135 pts (30.3%), and FOLFIRI-Bev in 46 pts (10.3%). Baseline characteristics of randomized pts were (arm A/B): ECOG PS 0, 60% in both arms; normal LDH level 47%/49%; normal alkaline phosphatase level 48%/50%; synchronous metastasis 83%/82%. The median no of MT cycles was 6 in both arms. With a median follow-up of 31.0 months, 327 PFS events were observed. Median MT-PFS were 4.6 m in arm A vs 5.8 m in arm B (HR 0.73 [95%CI: 0.59-0.91], P=.005). Median PFS from inclusion were 9.2 m vs 10.2 m. During MT, in arm A vs arm B, grade 3-4 diarrhea (<1% vs 9%) and grade 3 skin toxicity (0% vs 19%) were the main differences in toxicity. Severe adverse events from randomization related to B or E were 6 in arm A and 7 in arm B. Overall survival is not mature. Conclusions: The addition of erlotinib to bevacizumab after induction therapy significantly improves the duration of maintenance PFS, following induction with first-line chemotherapy plus bevacizumab, in patients with unresectable metastatic colorectal cancer.

Bevacizumab (Bev) with or without erlotinib as maintenance therapy, following induction first-line chemotherapy plus Bev, in patients with metastatic colorectal cancer (mCRC): Efficacy and safety results of the international GERCOR DREAM phase III trial

LBA3500^

The full, final text of this abstract will be available at abstract.asco.org at 12:01 AM (EDT) on Sunday, June 3, 2012, and in the Annual Meeting Proceedings online supplement to the June 20, 2012, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Sunday edition of ASCO Daily News.

Forearm vasoreactivity in type 1diabetic subjects

This study compared forearm vasoreactivity in 15 Type I diabetic subjects with 15 healthy controls. The groups were matched for age, exercise capacity, and the absence of other cardiovascular risk factors. Vasoreactivity was measured using strain gauge plethysmography, at rest, after arterial occlusion (OCC), and following OCC coupled with handgrip exercise (ROCC). Forearm blood flows were significantly elevated between conditions 2.58 +/- 0.37ml/100mltissue at rest to 26.80 +/- 6.56 after OCC and 32.80 +/- 8.26ml/100mltissue following ROCC in Type I diabetic subjects. There were no differences in forearm blood flow between groups for any of the conditions. These data indicate the degree of forearm blood flow is directly related to the intensity of the vasodilatory stimulus. However, our study did not reveal evidence of impaired vasodilatory capacity in Type I diabetic subjects compared to controls in the absence of other risk factors.