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 35.4 months, 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.

Treatment of advanced gastrointestinal cancer with genetically modified autologous mesenchymal stem cells: Results from the phase 1/2 TREAT-ME-1 trial.

TREAT-ME-1, a Phase 1/2 open-label multicenter, first-in-human, first-in-class trial, evaluated the safety, tolerability and efficacy of treatment with genetically modified autologous mesenchymal stromal cells (MSC), MSC_ apceth_101, in combination with ganciclovir in patients with advanced gastrointestinal adenocarcinoma. Immunological and inflammatory markers were also assessed. All patients (3 in Phase 1; 7 in Phase 2) received three treatment cycles of MSC_apceth_101 at one dose level on Day 0, 7, and 14 followed by ganciclovir administration according to the manufacturer's instructions for 48─72 h after MSC_apceth_101 injection. Ten patients were treated with a total dose of 3.0 x 106 cells/kg MSC_apceth_101. 36 adverse events and six serious adverse events were reported. Five patients achieved stable disease (change in target lesions of -2 to +28%). For all patients, the median time to progression was 1.8 months (95% CI: 0.5, 3.9 months). Median overall survival could not be estimated as 8/10 patients were still alive at the end of the study (1 year) and therefore censored. Post-study observation of patients showed a median overall survival of 15.6 months (ranging from 2.2─27.0 months). Treatment with MSC_apceth_101 and ganciclovir did not induce a consistent increase or decrease in levels of any of the tumor markers analyzed. No clear trends in the immunological markers assessed were observed. MSC_apceth_101 in combination with ganciclovir was safe and tolerable in patients with advanced gastrointestinal adenocarcinoma, with preliminary signs of efficacy in terms of clinical stabilization of disease.

Relevance of liver-limited disease in metastatic colorectal cancer: Subgroup findings of the FIRE-3/AIO KRK0306 trial.

In metastatic colorectal cancer (mCRC), liver-limited disease (LLD) is associated with a higher chance of metastectomy leading to long-term survival. However, limited data describes the prognostic and predictive relevance of initially unresectable LLD with regard to targeted first-line therapy. The present analysis investigated the relevance of initially unresectable LLD in mCRC patients treated with targeted therapy against either the epidermal growth factor receptor (EGFR) or vascular epithelial growth factor (VEGF). The analysis was performed based on FIRE-3, a randomized phase III trial comparing first-line chemotherapy with FOLFIRI plus either cetuximab (anti-EGFR) or bevacizumab (anti-VEGF) in RAS wild-type (WT) mCRC. Of 400 patients, 133 (33.3%) had LLD and 267 (66.8%) had non-LLD. Median overall survival (OS) was significantly longer in LLD compared to non-LLD patients (36.0 vs. 25.4 months; hazard ratio [HR] = 0.66; 95% confidence interval [CI]: 0.51-0.87; p = 0.002). In a multivariate analysis also including secondary hepatic resection as time-dependent variable, LLD status was independently prognostic for OS (HR = 0.67; 95% CI: 0.50-0.91; p = 0.01). As assessed by interaction tests, treatment benefit from FOLFIRI plus cetuximab compared to FOLFIRI plus bevacizumab was independent of LLD status with regard to objective response rate (ORR), early tumour shrinkage ≥20% (ETS), depth of response (DpR) and OS (all p > 0.05). In conclusion, LLD could be identified as a prognostic factor in RAS-WT mCRC, which was independent of hepatic resection in patients treated with targeted therapy. LLD had no predictive relevance since benefit from FOLFIRI plus cetuximab over bevacizumab was independent of LLD status.

Exploring the effect of primary tumor sidedness on therapeutic efficacy across treatment lines in patients with metastatic colorectal cancer: analysis of FIRE-3 (AIOKRK0306).

PURPOSE: To assess the impact of primary tumor sidedness on outcome of patients with metastatic colorectal cancer (mCRC) across treatment lines. PATIENTS AND METHODS: Patients of the FIRE-3 trial (initial FOLFIRI plus either cetuximab or bevacizumab) were separately evaluated according to primary tumor site differentiating left-sided (LPT) from right-sided primary tumors (RPT). Efficacy (i.e. progression-free survival (PFS2nd) and overall survival (OS2nd) of second-line therapy) was evaluated by Kaplan-Meier method and compared by log rank test as well as Cox regression analyses. All analyses were also reported according to drug sequences. RESULTS: 411 of 592 patients (69%) with KRAS exon 2 wild-type tumors received 2nd-line therapy has and had available information on primary tumor location, of those 309 patients (75%) presented with LPT. In patients with LPT, PFS2nd was markedly longer than in patients with RPT (6.0 months [95% CI 5.5-6.5] versus 3.8 months [95% CI 2.5-5.2], hazard ratio: 0.61 [95% CI 0.47-0.78], P<0.001). Differences in PFS2nd between study-arms were evident in patients with LPT, but not in patients with RPT (Cox model interaction test, P=0.12). Consistent observations were also made for OS2nd. CONCLUSION: This retrospective analysis of FIRE-3 indicates that efficacy of second-line therapy was significantly greater in patients with left-sided tumors as compared to right-sided tumors. This difference was driven by superior activity of second-line regimens of the initial cetuximab-arm as compared to the initial bevacizumab-arm in left-sided tumors. Our observations confirm the strong prognostic value of primary tumor location in second-line therapy of mCRC.

Pattern and Dynamics of Distant Metastases in Metastatic Colorectal Cancer.

BACKGROUND: Few studies report the incidence of metastatic patterns in colorectal cancer. Furthermore, little is known about dynamic aspects of these metastases during the course of disease. METHODS: This retrospective cohort study involved 385 patients who received anti-tumor treatment at our institution (Department of Medical Oncology, University Hospital Grosshadern, Ludwig-Maximilians-University Munich, Germany) for metastatic colorectal adenocarcinoma between 2007 and 2014. We reviewed all available imaging results of these patients to document the presence and detailed localization of metastases. RESULTS: Most of the evaluated patients were initially diagnosed with metastases in the liver (70%), followed by the lungs (24%), distant lymph nodes (16%), and peritoneum (15%), besides rare anatomical sites (<5%). Colon and rectal cancer as well as synchronous and metachronous metastases differed with regard to the pattern of individual metastatic sites. The median time to first progressive disease (PD) with new metastases was 12.6 months. The time intervals between first and second as well as second and third PD with new metastases were comparable with 10.5 and 10.8 months, respectively. At initial diagnosis, the mean number of metastatic sites was 1.4 and increased to 2.6 at the third PD with new metastases. For patients with initially one metastatic site, the mean number increased to 2.2. CONCLUSION: The present analysis provides detailed information on the pattern and evolution of colorectal cancer metastases over time. Thus, it may establish the basis for prospective future research in this field.

Relation of early tumor shrinkage (ETS) observed in first-line treatment to efficacy parameters of subsequent treatment in FIRE-3 (AIOKRK0306).

We explored the association of early tumor shrinkage (ETS) and non-ETS with efficacy of first-line and consecutive second-line treatment in patients with KRAS wild-type metastatic colorectal cancer treated in FIRE-3. Assessment of tumor shrinkage was based on the sum of longest diameters of target lesions, evaluated after 6 weeks of treatment. Shrinkage was classified as ETS (shrinkage by ≥ 20%), mETS (shrinkage by 0 to <20%), mPD (minor progression >0 to <20%) and PD (progression ≥20%). Overall survival (OS) was 33.2 (95% CI 28.0-38.4) months in ETS patients, while non-ETS was associated with less favorable outcome (mETS 24.0 (95% CI 21.2-26.9) months, mPD 19.0 (95% CI 13.0-25.0) months, PD 12.8 (95% CI 11.1-14.5) months). Differences in PFS of first-line therapy were less pronounced. ETS subgroups defined in first-line therapy also correlated with efficacy of second-line therapy. Progression-free survival in second-line (PFS2nd) was 6.5 months (5.8-7.2) for ETS, and was 5.6 (95% CI 4.7-6.5) months for mETS, 4.9 (95% CI 3.7-6.1) months for mPD and 3.3 (95% CI 2.3-4.3) months for PD. PFS of first-line and PFS2nd showed a linear correlation (Bravais-Pearson coefficient: 0.16, p = 0.006). While ETS is associated with the most favorable outcome, non-ETS represents a heterogeneous subgroup with distinct characteristics of less favorable initial tumor response to treatment. This is the first analysis to demonstrate that early tumor response observed during first-line FOLFIRI-based therapy may also relate to efficacy of second-line treatment. Early response parameters may serve as stratification factors in trials recruiting pretreated patients.