AIO KRK Research Articles

Refining first-line treatment decision in RAS wildtype (RAS-WT) metastatic colorectal cancer (mCRC) by combining clinical biomarkers: Results of the randomized phase 3 trial FIRE-3 (AIO KRK0306).

13 Background: Optimal patient selection for first-line treatment targeting epithelial growth factor receptor (EGFR) in RAS-WT mCRC is based on primary tumor sidedness (PTS) with anti-EGFR being the preferred option for patients with left-sided mCRC (LC). Right-sided mCRCs (RC) are preferentially treated in combination with bevacizumab targeting vascular endothelial growth factor (VEGF). Here, improvement in patient selection was evaluated by combining clinical biomarkers beyond PTS using the randomized phase III trial FIRE-3. Methods: FIRE-3 evaluated first-line FOLFIRI (folinic acid, fluorouracil and irinotecan) plus cetuximab (FOLFIRI/Cet) versus FOLFIRI plus bevacizumab (FOLFIRI/Bev) in patients with RAS-WT mCRC. Besides PTS, further clinical biomarkers were evaluated in pairwise combinations using Cox regression models and model-based recursive partitioning with Weibull models to predict treatment benefit of either treatment arm regarding overall survival (OS): age, sex, liver-limited disease status (LLD) and baseline carcinoembryonic antigen serum level (CEA). The resulting P-values of second-order interactions were adjusted using Holm-Bonferroni correction. The model with the best test statistics and P-value was chosen for further evaluations. Results: In 400 patients with RAS-WT mCRC, a model combining PTS and LLD status best predicted treatment outcome of either treatment arm (c-index = 0.603, p=0.005). Here, a significant survival benefit of FOLFIRI/Cet over FOLFIRI/Bev was evident in patients with LC/non-LLD (HR 0.62, p=0.02) compared to LC/LLD (HR 0.83, p=0.40). In patients with RC, FOLFIRI/Bev was significantly associated with increased OS compared to FOLFIRI/Cet when patients suffered from non-LLD (HR 2.09, p=0.010). However, patients with RC/LLD rather had a benefit from FOLFIRI/Cet compared to FOLFIRI/Bev (HR 0.59, p=0.218). Conclusions: Combining clinical biomarkers PTS and LLD status might improve optimal patient selection for targeted first-line treatment in RAS-WT mCRC. Validation in further data sets is warranted. Clinical trial information: NCT00433927 .

Prognostic and predictive impact of metastatic organ involvement on maintenance therapy in advanced metastatic colorectal cancer: Subgroup analysis of patients treated within the PanaMa trial (AIO KRK 0212).

Despite molecular selection, patients (pts) with RAS wildtype mCRC represent a heterogeneous population including diversity in metastatic spread. We investigated metastatic patterns for their prognostic and predictive impact on maintenance therapy with 5-fluorouracil/folinic acid ± panitumumab. The study population was stratified according to (1) number of involved metastatic sites (single vs multiple organ metastasis), liver-limited disease vs (2) liver metastasis plus one additional site, and (3) vs liver metastasis plus ≥two additional sites. Kaplan-Meier method and Cox regressions were used to correlate efficacy endpoints. Single organ metastasis was observed in 133 pts (53.6%) with 102 pts (41.1%) presenting with liver-limited disease, while multiple organ metastases were reported in 114 pts (46.0). Multiple compared to single organ metastases were associated with less favorable PFS (HR 1.48, 95% CI 1.13-1.93; P = .004) and OS (HR 1.37, 95% CI 0.98-1.93; P = .068) of maintenance therapy. While metastatic spread involving one additional extrahepatic site was not associated with clearly impaired survival compared to liver-limited disease, pts with liver metastasis plus ≥two additional sites demonstrated less favorable PFS (HR 1.92, 95% CI 1.30-2.83; P < .001), and OS (HR 2.38, 95% CI 1.51-3.76; P < .001) of maintenance therapy. Pmab-containing maintenance therapy appeared active in both pts with multiple (HR 0.58; 95% CI, 0.39-0.86; P = .006) as well as to a lesser numerical extent in pts with single organ metastasis (HR 0.83; 95% CI, 0.57-1.21; P = .332; Interaction P = .183). These data may support clinical decisions when EGFR-based maintenance therapy is considered.

598P Influence of the early stoma closure after low rectal cancer resection on completeness of adjuvant chemotherapy (CoCStom): A randomized, controlled multicentre trial of the AIO (AIO KRK 0113)

598P Influence of the early stoma closure after low rectal cancer resection on completeness of adjuvant chemotherapy (CoCStom): A randomized, controlled multicentre trial of the AIO (AIO KRK 0113)

The Oncology Biomarker Discovery framework reveals cetuximab and bevacizumab response patterns in metastatic colorectal cancer

Precision medicine has revolutionised cancer treatments; however, actionable biomarkers remain scarce. To address this, we develop the Oncology Biomarker Discovery (OncoBird) framework for analysing the molecular and biomarker landscape of randomised controlled clinical trials. OncoBird identifies biomarkers based on single genes or mutually exclusive genetic alterations in isolation or in the context of tumour subtypes, and finally, assesses predictive components by their treatment interactions. Here, we utilise the open-label, randomised phase III trial (FIRE-3, AIO KRK-0306) in metastatic colorectal carcinoma patients, who received either cetuximab or bevacizumab in combination with 5-fluorouracil, folinic acid and irinotecan (FOLFIRI). We systematically identify five biomarkers with predictive components, e.g., patients with tumours that carry chr20q amplifications or lack mutually exclusive ERK signalling mutations benefited from cetuximab compared to bevacizumab. In summary, OncoBird characterises the molecular landscape and outlines actionable biomarkers, which generalises to any molecularly characterised randomised controlled trial.

Health-related quality of life in patients with RAS wild-type metastatic colorectal cancer treated with fluorouracil and folinic acid with or without panitumumab as maintenance therapy: a prespecified secondary analysis of the PanaMa (AIO KRK 0212) trial

BackgroundThe PanaMa trial demonstrated significant benefit in progression-free survival with the addition of panitumumab (Pmab) to fluorouracil and folinic acid (FU/FA) as maintenance therapy following first-line induction therapy with FOLFOX/Pmab in patients with RAS wild-type metastatic colorectal cancer. Here, we report health-related quality of life (HRQOL) analyses from the PanaMa trial. MethodsHRQOL outcomes were evaluated using European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) at every cycle of therapy until disease progression/death. HRQOL outcomes were mean and individual changes in EORTC QLQ-C30 from baselines (before induction therapy and before maintenance therapy) to each cycle of treatment. Comparative analyses were performed by randomisation status and treatment arm for induction- and maintenance-therapy, respectively. The trial is registered with clinicaltrials.gov (NCT01991873). ResultsAt least one HRQOL questionnaire was completed by a total of 349/377 (93%) patients who received induction therapy, and by 237/248 (96%) patients who were randomised and received maintenance therapy. During induction therapy, most HRQOL dimensions remained stable or showed improvement, while appetite loss and diarrhoea significantly deteriorated. During maintenance therapy, HRQOL dimensions remained stable, while those that deteriorated during induction therapy showed significant improvement, without significant differences between the treatment arms. ConclusionMaintenance therapy improves HRQOL dimensions that initially deteriorated during induction therapy while stabilising HRQOL in other dimensions. The addition of Pmab to FU/FA as maintenance therapy in patients with RAS wild-type metastatic colorectal cancer prolongs progression-free survival without negative impact on HRQOL.

Impact of number and size of colorectal metastases (CRM) on survival in patients with RAS wild-type metastatic colorectal cancer treated within the PanaMa trial (AIO KRK 0212).

3551 Background: In this exploratory analysis, we aim to evaluate surrogates of metastatic burden, namely number of CRMs and size of largest CRM, for their prognostic and predictive value on efficacy of maintenance therapy with 5-fluorouracil/leucovorin (FU/FA) plus panitumumab (pmab) or FU/FA alone in RAS wildtype mCRC patients treated within the PanaMa trial. Methods: Number of CRMs and size of largest CRM at baseline were determined taking into account target and non-target lesions measured by central radiological review. Median number of metastases was set as threshold (n≤/ &gt; 10) to assess the prognostic and predictive value of CRM count on PFS and OS of maintenance therapy. A threshold of ≤/ &gt; 50mm was set to evaluate the impact of the largest CRM on the above time-to-event endpoints. PFS and OS were expressed by Kaplan-Meier method and compared by log-rank testing. Hazard ratios (HR) with 95% CIs were estimated using Cox regression models. Results: Out of 248 patients receiving maintenance therapy, CT and MRI scans of 211 patients were centrally evaluable (FU/FA+ Pmab, n = 106; FU/FA alone, n = 105). At baseline, 50.1% of the patients were diagnosed with &gt; 10 CRM. Median size of the largest CRM was 45 mm. Number of CRMs n≤10 was associated with favorable PFS, while both, number n≤10, and size of largest CRM ≤50mm correlated with favorable OS compared to n &gt; 10 and size of largest CRM &gt; 50mm, respectively. In patients with &gt; 10 CRMs, and those with largest CRM sized &gt; 50mm, PFS of maintenance therapy was significantly superior with FU/FA+ Pmab compared to FU/FA alone (Table). Conclusions: Metastatic burden was found to be prognostic for PFS and OS of maintenance therapy. Additionally, number and largest size of CRMs proofed predictive of PFS of maintenance therapy with Pmab, the primary endpoint of the trial. Patients with high metastatic burden at baseline appear to benefit particularly from Pmab-containing maintenance therapy. Clinical trial information: NCT01991873 . [Table: see text]

Consensus Molecular Subtypes as Biomarkers of Fluorouracil and Folinic Acid Maintenance Therapy With or Without Panitumumab in RAS Wild-Type Metastatic Colorectal Cancer (PanaMa, AIO KRK 0212).

Consensus molecular subtypes (CMSs) were evaluated as prognostic and predictive biomarkers of patients with RAS wild-type metastatic colorectal cancer (mCRC) receiving fluorouracil and folinic acid (FU/FA) with or without panitumumab (Pmab) after Pmab + mFOLFOX6 induction within the randomized phase II PanaMa trial. CMSs were determined in the safety set (ie, patients that received induction) and full analysis set (FAS; ie, randomly assigned patients who received maintenance) and correlated with median progression-free survival (PFS) and overall survival (OS) since the start of induction or maintenance treatment and objective response rates (ORRs). Hazard ratios (HRs) and 95% CI were calculated by univariate/multivariate Cox regression analyses. Of 377 patients of the safety set, 296 (78.5%) had available CMS data: CMS1/2/3/4: 29 (9.8%)/122 (41.2%)/33 (11.2%)/112 (37.8%) and unclassifiable: 17 (5.7%). The CMSs were prognostic biomarkers in terms of PFS (P < .0001), OS (P < .0001), and ORR (P = .02) since the start of induction treatment. In FAS patients (n = 196), with CMS2/4 tumors, the addition of Pmab to FU/FA maintenance therapy was associated with longer PFS (CMS2: HR, 0.58 [95% CI, 0.36 to 0.95], P = .03; CMS4: HR, 0.63 [95% CI, 0.38 to 1.03], P = .07) and OS (CMS2: HR, 0.88 [95% CI, 0.52 to 1.52], P = .66; CMS4: HR, 0.54 [95% CI, 0.30 to 0.96], P = .04). The CMS interacted significantly with treatment in terms of PFS (CMS2 v CMS1/3: P = .02; CMS4 v CMS1/3: P = .03) and OS (CMS2 v CMS1/3: P = .03; CMS4 v CMS1/3: P < .001). The CMS had a prognostic impact on PFS, OS, and ORR in RAS wild-type mCRC. In PanaMa, Pmab + FU/FA maintenance was associated with beneficial outcomes in CMS2/4, whereas no benefit was observed in CMS1/3 tumors.

Prognostic and predictive impact of metastatic organ involvement on maintenance therapy in advanced metastatic CRC: Analysis of patients treated within the PanaMa trial (AIO KRK 0212).

127 Background: Despite molecular selection, patients with RAS wildtype mCRC represent a heterogeneous population, including different metastatic patterns and number of organs involved. We investigated metastatic patterns for their prognostic and predictive impact on maintenance therapy with (FU/FA plus Pmab or FU/FA alone) in patients treated within the PanaMa trial. Methods: The study population was stratified according to number of organs involved and also to different patterns including liver metastases alone or in combination with additional organs. Kaplan-Meier method and Cox regressions were used to correlate efficacy endpoints (i.e. progression-free survival (PFS) and overall survival (OS) of maintenance therapy) in the aforementioned populations. Results: Of 248 patients (pts) receiving maintenance therapy, 133 pts had a one-metastatic site disease (53.6%). Of those, 102 pts had liver-only metastases. Furthermore, liver metastases plus one additional involved organ was observed in 61/248 patients (24.6%), and liver metastases plus two or more organs in 40/248 patients (16.1%). In general, one organ disease was associated with favourable PFS of maintenance therapy compared to patients with ≥2 organs involved (HR 0.68, 95% CI 0.52–0.88; P = 0.004). A predictive impact of disease spread in terms of pmab-containing maintenance therapy was present for the PFS of maintenance therapy in patients with ≥ 2 organ disease (HR 0.58, 95% CI 0.39–0.86; P = 0.006) unlike in patients with only one-organ disease (HR 0.83, 95% CI, 0.57-1.21; P = 0.332) and also specifically in patients with a 2-organ disease including the liver (HR 0.57, 95% CI 0.33–0.99; P = 0.046). Conclusions: Consistent with previous reports, organ spread has prognostic impact in mCRC. The efficacy of more intensive maintenance therapy (including pmab and 5-FU/FA) is predominantly seen in patients with more than one organ involved in the metastatic spread, while less striking effects were seen in patients with only one organ disease. These data may support clinical decisions when EGFR-based maintenance therapy is considered. Clinical trial information: NCT01991873 .

EMT-Related Genes Have No Prognostic Relevance in Metastatic Colorectal Cancer as Opposed to Stage II/III: Analysis of the Randomised, Phase III Trial FIRE-3 (AIO KRK 0306; FIRE-3).

There is no standard treatment after resection of colorectal liver metastases and the role of systemic therapy remains controversial. To avoid over- or undertreatment, proper risk stratification with regard to postoperative treatment strategy is highly needed. We recently demonstrated the prognostic relevance of EMT-related (epithelial-mesenchymal transition) genes in stage II/III CRC. As EMT is a major step in CRC progression, we now aimed to analyse the prognostic relevance of EMT-related genes in stage IV CRC using the study cohort of the FIRE-3 trial, an open-label multi-centre randomised controlled phase III trial of patients with metastatic CRC. Overall and progression free survival were considered as endpoints (n = 350). To investigate the prognostic relevance of EMT-related genes on either endpoint, we compared predictive performance of different models using clinical data only to models using gene data in addition to clinical data, expecting better predictive performance if EMT-related genes have prognostic value. In addition to baseline models (Kaplan Meier (KM), (regularised) Cox), Random Survival Forest (RSF), and gradient boosted trees (GBT) were fit to the data. Repeated, nested five-fold cross-validation was used for hyperparameter optimisation and performance evaluation. Predictive performance was measured by the integrated Brier score (IBS). The baseline KM model showed the best performance (OS: 0.250, PFS: 0.251). None of the other models were able to outperform the KM when using clinical data only according to the IBS scores (OS: 0.253 (Cox), 0.256 (RSF), 0.284 (GBT); PFS: 0.254 (Cox), 0.256 (RSF), 0.276 (GBT)). When adding gene data, performance of GBT improved slightly (OS: 0.262 vs. 0.284; PFS: 0.268 vs. 0.276), however, none of the models performed better than the KM baseline. Overall, the results suggest that the prognostic relevance of EMT-related genes may be stage-dependent and that EMT-related genes have no prognostic relevance in stage IV CRC.

Depth of response of induction therapy and consecutive maintenance treatment in patients with RAS wild-type metastatic colorectal cancer: An analysis of the PanaMa trial (AIO KRK 0212)

BackgroundIn patients with RAS wild-type metastatic colorectal cancer, depth of response (DpR) has gained importance as a novel end-point in clinical trials. We investigated the overall DpR, as well as the prognostic and predictive impact of DpR to induction therapy (six cycles of 5-fluorouracil, leucovorin [FU/FA], oxaliplatin [FOLFOX] and panitumumab [Pmab]) on consecutive maintenance therapy (FU/FA plus Pmab or FU/FA alone) in patients treated within the PanaMa trial. MethodsCentral radiological assessment was performed according to RECIST 1.1. DpR was defined as percentage change in tumour diameter within defined time intervals (induction therapy, maintenance therapy, total course of therapy). For prognostic and predictive analyses, median DpR (</≥) served as threshold. ResultsOut of 248 patients receiving maintenance therapy, 211 were evaluable for DpR analyses (FU/FA + Pmab, n = 106; FU/FA alone, n = 105). The overall DpR in all patients was 56.5%. DpR of induction therapy (42.5%) accounted for the largest proportion (75.2%) of the overall DpR. While greater DpR to induction therapy was significantly associated with prolonged PFS (HR 0.70, 95% CI 0.52–0.93, p = 0.013) and OS (HR 0.38, 95% CI 0.28–0.51, p < 0.001), there was no significant correlation of DpR and maintenance treatment arm. ConclusionsIn the PanaMa trial, the overall DpR was similar to DpR achieved by other epidermal growth factor receptor-based regimens. DpR to induction therapy accounted for three quarters of the total tumour shrinkage potentially suggesting that FOLFOX plus Pmab can be de-escalated following induction without substantially compromising efficacy. DpR to induction therapy was prognostic but not predictive for efficacy of consecutive maintenance therapy. Clinical trial informationNCT01991873.

396P Impact of depth of response of induction therapy on consecutive maintenance therapy in patients with RAS wild-type metastatic colorectal cancer: An analysis of the PanaMa trial (AIO KRK 0212)

Depth of response (DpR) is associated with improved progression-free survival (PFS) and overall survival (OS) in patients with RAS wild-type (WT) metastatic colorectal cancer (mCRC). There are limited data on the relevance of DpR to induction therapy for consecutive maintenance treatment. Thus, the impact of DpR to induction with 6 cycles of 5-fluoruracil/leucovorin (FU/FA), oxaliplatin and panitumumab (pmab) on the efficacy of maintenance therapy with pmab-FU/FA vs. FU/FA alone was examined within the randomized PanaMa trial. Computed tomography and magnetic resonance imaging were used for central radiologic assessment. DpR was defined as change of tumor diameter from baseline 1 (pre-induction) to baseline 2 (post-induction). Cox regression models and log-rank tests estimated hazard ratios including 95% confidence intervals of DpR (grouped as DpR 1= <0-30%; DpR 2= >30-50%; DpR 3= >50-100%) on PFS and OS during maintenance therapy. Out of 248 patients in the full analysis set 211 were evaluable for central review and DpR analysis (arm A, n=106; arm B, n=105). Median DpR was similar in both treatment arms (42.7% [arm A] vs. 42.2% [arm B]). Cox regression analysis demonstrated a significant correlation of initial DpR with both consecutive PFS (p=0.023) and OS (p=0.046) in the pmab-arm while in patients receiving FU/FA alone this association was not observed. There was no predictive value of DpR groups on efficacy according to treatment arm.Table: 396PFU/FA+pmab (n=106)FU/FA (n=105)DpR 1<0-30%DpR 2>30-50%DpR 3>50-100%DpR 1<0-30%DpR 2>30-50%DpR 3>50-100%Patients (n)215233205233Median PFS, months (95% CI)8.1 (2.7-13.5)9.9 (6.8-13.1)9.5 (5.5-13.5)5.2 (4.6-5.8)5.8 (4.9-6.7)6.1 (4.2-8.1)HR (95% CI), p (log-rank)-0.57 (0.35-1.02)0.43 (0.24-0.80)-0.69 (0.40-1.18)0.60 (0.33-1.08)p=0.023p=0.213Median OS, months (95% CI)16.4 (12.2-20.6)28.2 (23.9-32.5)27.4 (21.1-33.8)17.1 (14.9-19.4)26.4 (22.4-30.5)28.1 (22.9-33.4)HR (95% CI), p (log-rank)-0.50 (0.26-0.94)0.46 (0.23-0.92)-0.52 (0.26-1.303)0.40 (0.18-0.87)p=0.046p=0.054 Open table in a new tab In RAS WT mCRC treated within in the PanaMa trial, DpR to induction therapy has a prognostic impact on subsequent maintenance treatment. This effect appears pronounced in patients receiving pmab-based maintenance therapy.

Standard diametric versus volumetric early tumor shrinkage as a predictor of survival in metastatic colorectal cancer: subgroup findings of the randomized, open-label phase III trial FIRE-3 / AIO KRK-0306

ObjectivesEarly tumor shrinkage (ETS) quantifies the objective response at the first assessment during systemic treatment. In metastatic colorectal cancer (mCRC), ETS gains relevance as an early available surrogate for patient survival. The aim of this study was to increase the predictive accuracy of ETS by using semi-automated volumetry instead of standard diametric measurements.MethodsDiametric and volumetric ETS were retrospectively calculated in 253 mCRC patients who received 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) combined with either cetuximab or bevacizumab. The association of diametric and volumetric ETS with overall survival (OS) and progression-free survival (PFS) was compared.ResultsContinuous diametric and volumetric ETS predicted survival similarly regarding concordance indices (p > .05). In receiver operating characteristics, a volumetric threshold of 45% optimally identified short-term survivors. For patients with volumetric ETS ≥ 45% (vs < 45%), median OS was longer (32.5 vs 19.0 months, p < .001) and the risk of death reduced for the first and second year (hazard ratio [HR] = 0.25, p < .001, and HR = 0.39, p < .001). Patients with ETS ≥ 45% had a reduced risk of progressive disease only for the first 6 months (HR = 0.26, p < .001). These survival times and risks were comparable to those of diametric ETS ≥ 20% (vs < 20%).ConclusionsThe accuracy of ETS in predicting survival was not increased by volumetric instead of diametric measurements. Continuous diametric and volumetric ETS similarly predicted survival, regardless of whether patients received cetuximab or bevacizumab. A volumetric ETS threshold of 45% and a diametric ETS threshold of 20% equally identified short-term survivors.Key Points• ETS based on volumetric measurements did not predict survival more accurately than ETS based on standard diametric measurements.• Continuous diametric and volumetric ETS predicted survival similarly in patients receiving FOLFIRI with cetuximab or bevacizumab.• A volumetric ETS threshold of 45% and a diametric ETS threshold of 20% equally identified short-term survivors.

FOLFOX plus panitumumab or FOLFOX alone as additive therapy following R0/1 resection of RAS wild-type colorectal cancer liver metastases – The PARLIM trial (AIO KRK 0314)

PurposeThis trial investigates the addition of panitumumab to chemotherapy with fluorouracil/folinic acid and oxaliplatin (FOLFOX) in a 2:1 randomised, controlled, open-label, phase II trial in RAS wild-type colorectal cancer patients with R0/1-resected liver metastases. Experimental designThe primary endpoint was progression-free survival (PFS) two years after randomisation. The experimental arm (12 weeks of biweekly mFOLFOX6 plus panitumumab followed by 12 weeks of panitumumab alone) was considered active if the two-year PFS rate was ≥65%. Based on historical data, a two-year PFS rate of 50% was estimated in the control arm (12 weeks of biweekly FOLFOX). The trial was performed with a power of 80% and an alpha of 0.05. Secondary endpoints included overall survival (OS) and toxicity. The trial is registered with ClinicalTrials.gov, NCT01384994. ResultsThe full analysis set consists of 70 patients (pts) in the experimental arm and 36 pts in the control arm. The primary endpoint was missed with a two-year PFS of 35.7% with FOLFOX plus panitumumab and 30.6% in the control arm. In comparative analyses, trends towards improved PFS (HR 0.83; 95%CI, 0.52–1.33; P = 0.44) and OS (HR 0.70; 95% CI, 0.34–1.46; P = 0.34) were observed in favour of the panitumumab-based study arm. No new or unexpected safety signals were observed with FOLFOX plus panitumumab following liver resection. ConclusionThe PARLIM trial failed to demonstrate a two-year PFS rate of 65% after resection of colorectal liver metastases. The positive trends in survival endpoints may support future trials evaluating treatment with anti-EGFR agents after resection of liver metastases.

First-line fluoropyrimidine plus bevacizumab followed by irinotecan-escalation versus initial fluoropyrimidine, irinotecan and bevacizumab in patients with metastatic colorectal cancer – Final survival and per-protocol analysis of the randomised XELAVIRI trial (AIO KRK 0110)

BackgroundThe randomised open-label phase III XELAVIRI trial failed to demonstrate non-inferiority of the sequential application of fluoropyrimidine plus bevacizumab followed by additional irinotecan at first progression (Arm A) versus initial combination of all agents (Arm B) for untreated metastatic colorectal cancer in the initial analysis of time-to-failure-of-strategy (TFS, 90% confidence boundary of 0.8). Here, we evaluate efficacy in the full analysis set (FAS), the per-protocol set, in addition to age-related and molecular subgroups. MethodsMedian TFS, overall survival (OS) and progression-free survival (PFS) were estimated by Kaplan–Meier method and log-rank test. Cox regression models assessed hazard ratios (HRs) and confidence intervals (CIs) (TFS: 90%; OS, PFS: 95%). ResultsOf 421 patients, 390 (92.6%), 391 (92.9%) and 357 (84.8%) events for TFS, OS and PFS were observed in the FAS with a median follow-up of 54.2 months (Arm A) versus 52.9 months (Arm B). Non-inferiority of sequential treatment for TFS was missed in the FAS (HR 0.93; 90% CI, 0.79–1.10; P = 0.482) and not shown in the per-protocol set (HR 0.93; 90% CI, 0.75–1.13, P = 0.433). Formal non-inferiority for TFS was observed for patients older than 70 years (HR 1.06; 90% CI, 0.80–1.41; P = 0.670) and patients with RAS mutant tumours (HR 1.12; 90% CI, 0.87–1.43; P = 0.465). In RAS/BRAF wild-type tumours, combination treatment was significantly superior to sequential therapy in all end-points. ConclusionsIn the overall population, XELAVIRI just missed to demonstrate the non-inferiority of sequential compared to combination therapy for TFS. However, the non-inferiority of sequential treatment was observed in elderly patients and RAS mutant tumours. Trial registrationTrial registration ID (clinicaltrials.gov) NCT01249638.

Mutational profiles of metastatic colorectal cancer treated with FOLFIRI plus cetuximab or bevacizumab before and after secondary resection (AIO KRK 0306; FIRE-3).

Secondary resection of metastases is recommended in metastatic colorectal cancer (mCRC). Data describing changes in mutational profiles of corresponding primary tumor and metastatic tissue after conversion treatment are limited. Next generation sequencing was performed in formalin-fixed mCRC samples from patients of the FIRE-3 trial (FOLFIRI plus cetuximab or bevacizumab) before treatment start (baseline) and after secondary resection of metastases (post baseline). Changes of mutational profiles and tumor mutational burden (TMB) were assessed within a post-hoc analysis. Median overall survival (OS), progression-free survival (PFS) and objective response rate (ORR) were compared between treatment arms. Paired tumor samples were obtained from 25 patients (19 RAS wild-type, 6 RAS mutant by pyrosequencing). ORR (92.0% vs 58.0%) and OS (60.8 vs 35.4months, hazard ratio = 0.39 [95% CI 0.14-1.12], P = .08) were higher for patients receiving cetuximab. After conversion therapy, 56 alterations (42 in the cetuximab and 14 in the bevacizumab arm) were newly observed in 18 patients (9 each treated with cetuximab or bevacizumab). Gains (n = 21) and losses (n = 21) of alterations occurred during cetuximab-based treatment, while mainly gains of alterations occurred during bevacizumab (n = 10). Three of nine patients treated with cetuximab that presented a change of mutational profiles, developed resistance to cetuximab. Mutational profiles were largely comparable before and after treatment with anti-VEGF or anti-EGFR directed monoclonal antibodies after secondary resection. Mutations associated with resistance to anti-EGFR antibodies were observed in only one-third of patients.

FOLFOX plus panitumumab or FOLFOX alone as additive therapy following R0/1 resection of RAS wild-type colorectal cancer liver metastases: The PARLIM trial (AIO KRK 0314).

3553 Background: This trial investigates the addition of panitumumab to chemotherapy with fluorouracil/ folinic acid and oxaliplatin (FOLFOX) in a 2:1 randomized, controlled, open label, phase II trial in RAS wild-type colorectal cancer patients with R0/1-resected liver metastases. Methods: The primary endpoint was progression-free survival (PFS) two years after randomisation. The experimental arm (12 wks of biweekly mFOLFOX6 plus panitumumab followed by 12 wks of panitumumab alone) was considered active if the 2-year-PFS rate was ≥65%. Based on historical data, a 2-year-PFS rate of 50% was estimated in the control arm (12 wks of biweekly FOLFOX). The trial was performed with a power of 80% and an alpha of 0.05. Secondary endpoints included overall survival (OS) and toxicity. The trial is registered with ClinicalTrials.gov, NCT01384994. Results: The full analysis set consists of 70 patients (pts) in the experimental arm and 36 pts in the control arm. The 2-year-PFS rate was 34.3% with FOLFOX plus panitumumab and failed to meet the primary endpoint. The 2-year-PFS rate in the control arm was 25%. In the experimental arm, a more favourable outcome was observed with regard to PFS (HR: 0.72, 95%CI 0.45-1.17; P = 0.18) and OS (HR: 0.76 (95% CI 0.34-1.71, P = 0.51) which did, however, not reach the level of significance. Updated data including toxicity and subgroup analyses might be presented at the meeting Conclusions: The PARLIM trial clearly failed to demonstrate a PFS rate of 65% after resection of colorectal liver metastases 2 years after randomisation, potentially indicating that the generally high frequency of recurrence and the choice of primary endpoint did not correspond in this study population. However, a trend for improved PFS and OS by the addition of panitumumab to 12 wks of FOLFOX followed by 12 wks panitumumab maintenance therapy may support future trials with ant-EGFR antibodies in this specific treatment setting. Clinical trial information: NCT01384994.

Consensus molecular subtypes and RAS status as biomarker of treatment intensity with fluoropyrimidine, bevacizumab, and irinotecan in metastatic colorectal cancer (XELAVIRI, AIO KRK 0110).

3552 Background: Prognostic biomarkers beside RAS/BRAF status are necessary to identify metastatic colorectal cancer (mCRC) patients who benefit from combined (COMB) versus sequential (SEQ) treatment with fluoropyrimidine, bevacizumab and irinotecan (randomized phase III XELAVIRI trial). Methods: mRNA was extracted from formalin-fixed paraffin embedded (FFPE) tumor tissue of 337 patients, gene expression was measured by the Nanostring PanCancer Progression Panel. Consensus molecular subtypes (CMS) classification was re-derived using a multinomial regression model. Data of Guinney et al. (Nat. Med. 2015. 21:1350-6) and FIRE-3 served as training and validation set. RAS/BRAF MUT were assessed by pyrosequencing. Median overall (OS) and progression free survival (PFS), hazard ratios (HR) and 95% confidence interval (CI) were estimated by Kaplan-Meier method and univariate Cox regression. Results: The multinomial regression model employed in the present analysis correctly predicted CMS labels in 98.3 % of the original Guinney- and 100.0 % of FIRE-3 population. In XELAVIRI, CMS subgroups were predicted as follows: CMS1: n = 62 (18.4 %); CMS2: n = 174 (51.6 %); CMS3: n = 9 (2.7 %); CMS4: n = 92 (27.3 %). A general prognostic impact of CMS was not observed when all patients were analysed. In RAS/BRAF WT mCRC patients, substantial benefit of COMB versus SEQ treatment was shown for OS and PFS in CMS2 and CMS4, but not in CMS1. Conversely, OS was significantly longer for COMB treatment in patients with RAS MUT and CMS1 mCRC, while SEQ treatment was not inferior in RAS MUT and CMS2 or CMS4 subgroups (see TABLE). Additional data for overall response rates, early tumor shrinkage and sidedness might be presented at the meeting. Conclusions: This retrospective analysis of XELAVIRI suggests that CMS may serve as biomarker that predicts response to initially combined versus less intensive sequential chemotherapy in patients with RAS/BRAF WT mCRC.[Table: see text]

Microsatellite instability (MSI-H) is associated with a high immunoscore but not with PD-L1 expression or increased survival in patients (pts.) with metastatic colorectal cancer (mCRC) treated with oxaliplatin (ox) and fluoropyrimidine (FP) with and without bevacizumab (bev): a pooled analysis of the AIO KRK 0207 and RO91 trials

IntroductionIn a retrospective analysis of two randomized phase III trials in mCRC patients treated first line with oxaliplatin, fluoropyrimidine with and without Bevacizumab (the AIO KRK 0207 and R091 trials) we evaluated the association of high microsatellite instability (MSI-H), immunoscore (IS) and PD-L1 expression in relation to overall survival (OS).MethodsIn total, 550 samples were analysed. Immunohistochemical analysis of the MMR proteins and additionally fragment length analysis was performed, molecular examinations via allele-discriminating PCR in combination with DNA sequencing. Furthermore PD-L1 and IS were assessed.ResultsMSI-H tumors were more frequent in right sided tumors (13.66% vs. 4.14%) and were correlated with mutant BRAF (p = 0.0032), but not with KRAS nor NRAS mutations (MT). 3.1% samples were found to be PD-L1 positive, there was no correlation of PDL1 expression with MSI-H status, but in a subgroup analysis of MSI-H tumors the percentage of PD-L1 positive tumors was higher than in MSS tumors (9.75% vs. 2.55%). 8.5% of samples showed a positive IS, MSI-H was associated with a high IS. The mean IS of the pooled population was 0.57 (SD 0.97), while the IS of MSI-H tumors was significantly higher (mean of 2.4; SD 1.4; p =< 0.0001).DiscussionRegarding OS in correlation with MSI-H, PD-L1 and IS status we did not find a significant difference. However, PD-L1 positive mCRC tended to exhibit a longer OS compared to PD-L1 negative cancers (28.9 vs. 22.1 months).

441P Evaluation of conversion therapy in patients undergoing secondary resection of metastases in curative intent within the FIRE-3 (AIO KRK-0306) study

441P Evaluation of conversion therapy in patients undergoing secondary resection of metastases in curative intent within the FIRE-3 (AIO KRK-0306) study

Impact of Size and Location of Metastases on Early Tumor Shrinkage and Depth of Response in Patients With Metastatic Colorectal Cancer: Subgroup Findings of the Randomized, Open-Label Phase 3 Trial FIRE-3/AIO KRK-0306

BackgroundThe Response Evaluation Criteria in Solid Tumors (RECIST) are used to define degrees of response to chemotherapy. For accelerated response evaluation, early tumor shrinkage (ETS) of ≥ 20% has been suggested as a predictor for outcome in metastatic colorectal cancer (mCRC). Together with depth of response (DpR), new alternative metrics have been provided, yielding promising outcome parameters. In this analysis, we aimed to further characterize ETS and DpR. Patients and MethodsThis analysis was based on FIRE-3, a randomized phase 3 trial comparing first-line FOLFIRI plus either cetuximab or bevacizumab in KRAS exon 2 wild-type mCRC. ETS and DpR were determined on the basis of RECIST 1.1 in a blinded radiologic review. ETS was evaluated as a categorized (≥ 20% shrinkage) and continuous parameter. The impact of baseline location and size of metastases on ETS and DpR were evaluated by univariate and multivariate analyses. ResultsOf 592 patients, 395 (66.7%) had data available for radiologic review. Median continuous ETS for lung, liver, and suspected lymph node metastases was 20%, 23%, and 30%, respectively. The median DpR was −32%, −44%, and −50%, respectively (all P < .01). In multivariate analysis, lung metastases were significantly associated with inferior DpR (P = .021), whereas hepatic metastases led to higher DpR (P = .024). Large metastases were associated with favorable ETS, whereas small metastases were correlated with higher DpR (P < .001). ConclusionETS and DpR depend on the location and size of metastases in mCRC. These associations may establish the basis for further research to optimize the predictive accuracy of both parameters. This may help basing treatment decisions on ETS and DpR.