FLOX Regimen Research Articles

First-line oxaliplatin-based chemotherapy and nivolumab for metastatic microsatellite-stable colorectal cancer—the randomised METIMMOX trial

BackgroundWe evaluated first-line treatment of metastatic microsatellite-stable colorectal cancer with short-course oxaliplatin-based chemotherapy alternating with immune checkpoint blockade.MethodsPatients were randomly assigned to chemotherapy (the FLOX regimen; control group) or alternating two cycles each of FLOX and nivolumab (experimental group). Radiographic response assessment was done every eight weeks with progression-free survival (PFS) as the primary endpoint. Cox proportional-hazards regression models estimated associations between PFS and relevant variables. A post hoc analysis explored C-reactive protein as signal of responsiveness to immune checkpoint blockade.ResultsEighty patients were randomised and 38 in each group received treatment. PFS was comparable—control group: median 9.2 months (95% confidence interval (CI), 6.3–12.7); experimental group: median 9.2 months (95% CI, 4.5–15.0). The adjusted Cox model revealed that experimental-group subjects aged ≥60 had significantly lowered progression risk (p = 0.021) with hazard ratio 0.17 (95% CI, 0.04–0.76). Experimental-group patients with C-reactive protein <5.0 mg/L when starting nivolumab (n = 17) reached median PFS 15.8 months (95% CI, 7.8–23.7). One-sixth of experimental-group cases (all KRAS/BRAF-mutant) achieved complete response.ConclusionsThe investigational regimen did not improve the primary outcome for the intention-to-treat population but might benefit small subgroups of patients with previously untreated, metastatic microsatellite-stable colorectal cancer.Trial registrationClinicalTrials.gov number, NCT03388190 (02/01/2018).

Enrichment of circulating helper-T (Th) and unswitched memory-B (NSwM-B) cell populations and responsiveness to immune checkpoint blockade (ICB) in microsatellite-stable (MSS)/mismatch repair-proficient (pMMR) colorectal cancer (CRC).

150 Background: The anti-tumor activity of ICB in MSS/pMMR-CRC is limited. However, recent studies have highlighted the possibility of inducing ICB responsiveness by oxaliplatin-based chemotherapy. The understanding of underlying mechanisms and identification of rational biomarkers are major focus areas in immuno-oncology. Methods: Patients with previously untreated, unresectable abdominal metastases from MSS/pMMR-CRC were randomly assigned to the oxaliplatin-based standard Nordic FLOX regimen (control arm) or 2 FLOX cycles followed by 2 ICB (nivolumab) cycles in a repeat sequential schedule (experimental arm). Radiologic response assessment was done every 8 weeks, and the study arms reached identical primary endpoint – median progression-free survival (PFS) 9.3 months. Experimental-arm patients at one study center had peripheral blood mononuclear cells (PBMC) prepared at study entry (V1), after the initial 2 FLOX cycles (V3), and after the succeeding 2 nivolumab cycles (V5). The PBMC were incubated with 19 cell-surface antibodies and analyzed by mass cytometry. Patients were categorized in PFS &gt;9.3 months (improved; n = 7) or PFS &lt;9.3 months (shortened; n = 6). Live cell clusters were identified by hierarchically applying automated 1D gates to the available lineage markers. After gating, all cells were assigned to soft clusters according to phenotypes. The cluster sizes were used to compute the differential abundance of immune-cell populations and a Peacock test assessed multivariate changes between the improved and shortened PFS groups. Results: Circulating CD4+ (Th) cells and CD27+IgD+ (NSwM-B) cells were concurrently enriched in the improved PFS group. After the initial 2 FLOX cycles (V3), median increase (from V1) was 2.89% (of lymphocyte count) for Th cells and 0.54% (of leukocyte count) for NSwM-B cells (p &lt; 0.001). Continued responses occurred over the succeeding 2 nivolumab cycles (until V5) with median increase of 1.19% for Th cells and 0.19% for NSwM-B cells (p &lt; 0.001). The association between the immune-cell alterations and PFS was validated by categorizing the cases in above or below the median increase in Th and NSwM-B cell populations from V1 to V5. The high-increase group achieved median PFS 15.0 months (95% CI, 10.8-19.2) compared to 4.0 months (95% CI, 1.9-22.1) for the low-increase group (log-rank; p = 0.002). Conclusions: This unsupervised analysis of high-dimensional PBMC data from a limited case number revealed that circulating Th and NSwM-B cell populations may mediate ICB responsiveness invoked by short-course oxaliplatin-based chemotherapy in patients with abdominal metastases from MSS/pMMR-CRC. Owing to weaknesses of such a post-hoc analysis, further studies are needed to confirm the generalizability of these findings. Clinical trial information: NCT003388190 .

Early radiologic signal of responsiveness to immune checkpoint blockade in microsatellite-stable/mismatch repair-proficient metastatic colorectal cancer

BackgroundImmune checkpoint blockade (ICB) results in radiologic tumour response dynamics that differ from chemotherapy efficacy measures and require an early signal of clinical utility.MethodsPreviously untreated, unresectable microsatellite-stable (MSS)/mismatch repair-proficient (pMMR) colorectal cancer (CRC) patients were randomly assigned to the oxaliplatin-based Nordic FLOX regimen (control arm) or repeat sequential two FLOX cycles and two ICB cycles (experimental arm). The radiologic response was assessed every 8 weeks. In this post hoc analysis, we explored early target lesion (TL) dynamics as indicator of ICB responsiveness. Progression-free survival (PFS) was the primary endpoint.ResultsUsing a landmark analysis approach, we categorised experimental-arm patients into ≥10% (N = 19) or <10% (N = 16) TL reduction at the first post-baseline response assessment. Median PFS for the groups was 16.0 (95% confidence interval (CI), 12.3–19.7) and 3.9 months (95% CI, 2.3–5.5), respectively, superior and inferior (both P < 0.01) to the median PFS of 9.8 months (95% CI, 4.9–14.7) for control arm patients (N = 31).ConclusionsRadiologic TL reduction of ≥10% at the first post-baseline response assessment identified patients with ICB-responsive metastatic MSS/pMMR-CRC. This pragmatic measure may be used to monitor patients in investigational ICB schedules, enabling early treatment adaptation for unresponsive cases.Trial registrationClinicalTrials.gov number, NCT03388190 (02/01/2018).

Abstract 522: Immunogenic chemotherapy and immune checkpoint inhibition (ICI) in microsatellite-stable (MSS) metastatic colorectal cancer (mCRC): Biomarkers indicative of durable treatment response

Abstract Purpose: Cancer immune therapy has revolutionized patient outcome for the small mCRC subgroup with highly immunogenic disease. The majority of mCRC cases, however, are MSS with inherently low susceptibility to immune therapy. In our ongoing METIMMOX study (NCT03388190), MSS-mCRC patients are randomized to oxaliplatin-based immunogenic chemotherapy followed by ICI (experimental study arm) or the oxaliplatin-based standard-of-care (control arm). A subgroup of experimental arm patients has obtained durable major partial or complete responses. Such remarkable outcomes call for biomarkers that may help identifying MSS-mCRC patients who will benefit from such sequential therapy. Experimental procedures: Study enrollment began August 2018. Patients with unresectable, previously untreated MSS-mCRC have been randomized to the Nordic FLOX regimen (standard-of-care) or repeat sequential 2 FLOX cycles and 2 cycles of nivolumab (240 mg Q2W). At analysis October 2020, 48 patients were evaluable for progression-free survival (PFS). Serum collected at baseline and after the first 2 FLOX and 2 nivolumab cycles were analyzed for 42 immune factors with the Luminex multiplex immunoassay. The Significance Analysis for Microarrays method was applied to select the most significant proteins. Diffusion-weighted magnetic resonance imaging (DW-MRI) of the liver was performed at baseline and after the first 2 FLOX cycles. Using a b-value of 1000 s/mm2, the intensity ratio of a representative metastatic lesion relative to normal parenchymal tissue in the liver was calculated at each recording. Results: At this early time of analysis, with median follow-up of 8.6 (range, 1-21) months, median PFS for the entire groups of control and experimental arm patients was identical (6.4 and 6.6 months, respectively). We selected 13 experimental arm patients with long (median 13.6 months) or short (median 5.6 months) PFS for the serum protein analysis and 9 patients with liver DW-MRI. High serum CD40L levels (&amp;gt; median 47.6 ng/ml) at baseline or CD23 levels (&amp;gt; median 15.7 ng/ml) after the first 2 FLOX and 2 nivolumab cycles were both associated with improved PFS (p &amp;lt; 0.001 and p &amp;lt; 0.007; log-rank test). The baseline DW-MRI intensity of the peripheral hyperintense rim of the metastatic lesion (2.0- to 2.8-fold higher than the corresponding parenchymal value) diminished towards the parenchymal intensity (1.2- to 1.6-fold higher) after the first 2 FLOX cycles in patients with longer PFS than the median for all study patients. The rim intensity did not change in patients with short PFS. Conclusions: Three potential response markers in serum or at DW-MRI (one at baseline, one following the induction immunogenic chemotherapy, and one following the subsequent ICI) were identified for MSS-mCRC at this early time of the METIMMOX study conduct. Citation Format: Anne Hansen Ree, Sebastian Meltzer, Kine M. Bakke, Hanne M. Hamre, Christian Kersten, Eva Hofsli, Marianne Grønlie Guren, Halfdan Sorbye, Christin Johansen, Anne Negård, Kathrine Røe Redalen, Kjersti Flatmark. Immunogenic chemotherapy and immune checkpoint inhibition (ICI) in microsatellite-stable (MSS) metastatic colorectal cancer (mCRC): Biomarkers indicative of durable treatment response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 522.

Electronic von Frey as an objective assessment tool for oxaliplatin-induced peripheral neuropathy: A prospective longitudinal study.

There is wide discrepancy on how to perform clinical assessment of oxaliplatin-induced peripheral neuropathy. In this scenario, the Electronic von Frey (EVF), which evaluates pain objectively based upon mechanical pain thresholds (MPTs), may be a valuable tool. The present study aims to quantify hyperalgesia in the hands and feet of patients treated with oxaliplatin and to propose a novel method to classify the degree of neurotoxicity using EVF-derived measures as cut-off points. This is a prospective cohort study including 46 patients treated for colorectal cancer with the FLOX regimen. Before each oxaliplatin administration, patients were evaluated with the Acute and Chronic Neuropathy Questionnaire, Oxaliplatin-Specific Neurotoxicity Scale and National Cancer Institute Common Terminology Criteria for Adverse Events scale. Also, objective pain assessment with the EVF was performed. For both upper and lower extremities, EVF was shown to correlate well with patients' symptoms and functional impairment, as assessed by subjective scales. Also, when cut-off MPT variations were determined for diagnosis of neurotoxicity grade 2 or 3, the method showed good sensitivity and specificity. Electronic von Frey is a noninvasive and easy-to-perform objective method with potential to supplement the current assessment tools for oxaliplatin-induced peripheral neuropathy, which are mostly subjective.

Abstract A43: Induction of systemic immune response by oxaliplatin-based neoadjuvant therapy and survival without metastatic progression in high-risk rectal cancer

Abstract In locally advanced rectal cancer (LARC), local recurrence rates are low due to contemporary multimodal treatment regimens involving neoadjuvant chemoradiotherapy (CRT) and surgery. Metastatic progression however, represents a major challenge and is reported by 30-40% of cases in recent trials. Ongoing effort to combine treatment modalities, including immunotherapy, to best target systemic progression of colorectal cancer, would benefit from a better understanding of the biological and immune responses invoked from the different treatment modalities. In this report we investigated systemic immune activity invoked in LARC patients undergoing neoadjuvant regimens containing oxaliplatin (an agent known to cause immunogenic cell death), by assessing circulating levels of the fms-related tyrosine kinase 3 ligand (Flt3L). Flt3L is a potent hematopoietic factor with proliferating effects on mature dendritic cells (DC), whose elevated levels have also been demonstrated to reflect therapy-induced myelosuppression. LARC patients with mainly T3-4 disease from two independent cohorts (Oslo and Copenhagen) received neoadjuvant chemotherapy (NACT) and sequential CRT. All of the Oslo cohort patients underwent NACT consisting of 4 weeks of the Nordic FLOX regimen (oxaliplatin 85 mg/m2 on day 1 and bolus fluorouracil 500 mg/m2 and folinic acid 100 mg on days 1 and 2 every second week) followed by long-course CRT (radiation to a total dose of 50 Gy and concomitant weekly oxaliplatin 50 mg/m2 and capecitabine 825 mg/m2 twice daily), and then surgery 8-12 weeks later. Eighty percent of Copenhagen cohort patients underwent NACT as 6-8 weeks of oxaliplatin 85 mg/m2 every second week and continuous capecitabine 650 mg/m2 twice daily. Less than 90% of patients had concomitant weekly oxaliplatin 50 mg/m2 during the long-course CRT to a total radiation dose of 54 Gy. Finally, 57% of patients received an additional 1-2 cycles of capecitabine with or without oxaliplatin following CRT completion. Patients had surgery 2-19 weeks after CRT completion. In both cohorts, Flt3L levels were measured in serum collected at baseline, following NACT and then the sequential CRT. Serum samples were stored at –80°C until analysis and Flt3L was quantified using ELISA or a customized Luminex Multiplex Assay (both from R&amp;D Systems). In 39 randomly chosen samples covering all three sampling points, a strong correlation (r=0.96, p&amp;lt;0.01) was found between Flt3L levels measured by the single-parameter and multiplex assays. We found that median serum Flt3L levels were elevated upon completion of each sequential modality in both cohorts (n=73 and n=65). In the principal cohort (Oslo), an increase in levels of Flt3L upon NACT completion was correlated with a decline in hemoglobin and neutrophil counts (r=–0.38, p&amp;lt;0.01 and r= –0.36, p=0.01), possibly reflecting the myelosuppressive effect. Progression-free survival (PFS), with the majority of events being metastatic progression, was 68% and 71% in the two cohorts. For T4 cases in the Oslo cohort, a high Flt3L level following NACT was associated with a low risk for a PFS event (HR=0.22, 95% CI=0.06-0.72, p=0.01). Additionally, oxaliplatin dose reduction during CRT, aimed at maintaining patient compliance to radiotherapy, was also associated with advantageous PFS (HR=0.40, 95% CI=0.17-0.92, p=0.03). In conclusion, the neoadjuvant regimens might have caused repetitive myelosuppression resulting in elevated circulating Flt3L levels, thereby enhancing proliferation of mature dendritic cells and mediation of systemic tumor-targeting effects. Oxaliplatin-containing neoadjuvant therapy that causes normal tissue toxicity but does not compromise patient compliance to the radiotherapy, may condition DC to present shed tumor antigens to cytotoxic T cells, and thus enable eradication of occult microscopic tumor at distant sites in LARC patients prone to develop metastatic disease. Citation Format: Erta Kalanxhi, Sebastian Meltzer, Jakob Vasehus Schou, Finn Ole Larsen, Svein Dueland, Kjersti Flatmark, Benny Vittrup Jensen, Knut Håkon Hole, Therese Seierstad, Kathrine Røe Redalen, Dorte Lisbet Nielsen, Anne Hansen Ree. Induction of systemic immune response by oxaliplatin-based neoadjuvant therapy and survival without metastatic progression in high-risk rectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A43.

Abstract 4006: Oxaliplatin-induced immune factors and long-term disease control in rectal cancer - a reflection of immunogenic tumor cell death

Abstract Purpose: In contemporary cancer therapy, the ability of the immune system to recognize and destroy tumor cells is increasingly acknowledged. Following cytotoxic damage of tumor cells, the priming of tumor-targeting T lymphocytes via presentation of shed tumor antigens by dendritic cells may ultimately result in systemic anti-tumor activity, a concept referred to as immunogenic cell death (ICD). Recent preclinical studies have highlighted oxaliplatin as an ICD-inducing agent. In a prospective study (NCT00278694) of curatively intended treatment of locally advanced rectal cancer (LARC), oxaliplatin-containing induction neoadjuvant chemotherapy (NACT; two cycles of the Nordic FLOX regimen) was administered prior to chemoradiotherapy (CRT) and surgery. Within the spectrum of possible ICD responses to NACT, we analyzed circulating osteoprotegerin (OPG) and fms-related tyrosine kinase 3 ligand (FLT3LG), both of which are factors implicated in activation of the antigen-specific interaction between dendritic cells and cytotoxic T lymphocytes. Experimental procedures: Immunoassay measurements of OPG and FLT3LG were performed in serum samples collected from study patients at baseline and following the induction NACT. Estimated 5-year progression-free survival (PFS) and overall survival (OS) were assessed using the log-rank test. Results: Fifty-six patients (38 T2-3 cases and 18 T4 cases) with median follow-up time of 65 months were included in the analysis. During follow-up, 18 patients (nine in each of the T2-3 and T4 groups) experienced metastatic progression as a PFS event. For the entire study population, significant increases in serum levels of both OPG and FLT3LG (from median baseline values of 46.1 pg/ml and 66.7 pg/ml to median post-NACT values of 53.6 pg/ml and 140 pg/ml, respectively) were observed. Patients were separated into cases with (n = 37) or without (n = 19) increase in circulating OPG levels and more (n = 30) or less (n = 26) than two-fold increase in circulating FLT3LG levels. When grouped together, patients with the designated increases in both factors (n = 25) or in either of OPG or FLT3LG values (n = 21) during NACT had significantly better PFS rates than the remaining cases (n = 10) (86%, 72%, and 20%, respectively; p &amp;lt; 0.001). Corresponding OS rates were 100%, 88%, and 60% (p &amp;lt; 0.001), suggesting that even patients who experienced metastatic progression had reasonably good OS. Conclusion: Increase in circulating OPG and FLT3LG following oxaliplatin-containing induction chemotherapy was associated with favorable long-term outcome in LARC patients given curatively intended neoadjuvant treatment consisting of CRT and surgery. These immune effectors may have mediated systemic anti-tumor immunity invoked by ICD-inducing oxaliplatin effects. Citation Format: Sebastian Meltzer, Erta Kalanxhi, Svein Dueland, Kjersti Flatmark, Kathrine Røe Redalen, Anne Hansen Ree. Oxaliplatin-induced immune factors and long-term disease control in rectal cancer - a reflection of immunogenic tumor cell death. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4006.

Oxaliplatin-containing Preoperative Therapy in Locally Advanced Rectal Cancer: Local Response, Toxicity and Long-term Outcome

AimsThis non-randomised study was undertaken to examine oxaliplatin as possibly an intensifying component of sequential neoadjuvant therapy in locally advanced rectal cancer for improved local and metastatic outcome. Materials and methodsNinety-seven patients (57 T2–3 cases, 40 T4 cases) received two cycles of the Nordic FLOX regimen (oxaliplatin 85 mg/m2 day 1 and bolus 5-fluorouracil 500 mg/m2 and folinic acid 100 mg days 1 and 2) before long-course chemoradiotherapy with concomitant oxaliplatin and capecitabine, followed by pelvic surgery. Treatment toxicity, local tumour response and long-term outcome were recorded. ResultsGood histologic tumour regression was obtained in 72% of patients. Implementing protocol-specific dose adjustments, tolerance was acceptable and 95% of patients received the total prescribed radiation dose. Estimated 5 year progression-free and overall survival were 61% and 83%, respectively. T4 stage was associated with an inferior local response rate, which again was highly associated with impaired long-term outcome. ConclusionsIn this cohort of rectal cancer patients dominated by T4 and advanced T3 cases given sequential oxaliplatin-containing preoperative therapy with acceptable toxicity, high tumour response rates and overall survival were obtained, consistent with both local and systemic effects. However, tumour response and long-term outcome remained inferior for a significant number of T4 cases, suggesting that the T4 entity is biologically heterogeneous with subgroups of patients eligible for further individualisation of therapy.

Abstract C101: Circulating tumor necrosis factor receptor (TNFR) proteins in systemic disease outcome to combined-modality radiotherapy in rectal cancer

Abstract Introduction: In colorectal cancer, the impact of the tumor microenvironment with its immune effectors for disease outcome is increasingly acknowledged. Following curatively intended combined-modality radiotherapy in locally advanced rectal cancer (LARC), metastatic disease still remains a dominant cause of failure. Therefore, within the frame of a prospective LARC study of intensified neoadjuvant therapy (NCT00278694), and in light of intriguing recent findings of radiation effects on systemic antitumor immunity, we investigated whether treatment toxicity and survival outcome might be reflected by circulating immune factors. Experimental procedures: Using antibody array technology, the profiling of approximately 500 proteins was performed in serial serum samples collected during neoadjuvant chemotherapy (NACT; two cycles of the Nordic FLOX regimen) followed by long-course chemoradiotherapy (CRT) before final pelvic surgery. Array data was analyzed in the Significance Analysis of Microarrays algorithm, and functional associations among proteins were explored using the Search Tool for the Retrieval of Interacting Genes and Proteins software. Clinical endpoints were progression-free survival (PFS; median follow-up of 59 months for 85 patients) and treatment toxicities as assessed by Common Terminology Criteria for Adverse Events (CTCAE) scoring. Results: Analysis of the array data revealed significant changes in levels (relative to baseline) of a number of serum proteins during the neoadjuvant treatment course, among which osteoprotegerin (OPG; TNFRSF11B) showed the strongest increase. Single-parameter immunoassay OPG assessment demonstrated significant correlations between its baseline serum levels (range 13.6-177 pg/ml) and patients' age as well as common markers of systemic inflammation, such as erythrocyte sedimentation rate (ESR) and neutrophil-to-lymphocyte ratio (NLR). In univariate Cox regression analysis, high values of these variables were associated with adverse PFS (age-adjusted baseline OPG levels: hazard ratio (HR) 3.33, 95% confidence interval (CI) 1.24-8.94, p = 0.02; baseline ESR: HR 1.85, 95% CI 1.10-3.11, p = 0.02; post-NACT NLR: HR 1.89, 95% CI 1.08-3.31, p = 0.03). Of further note, patients' serum levels of RANK (TNFRSF11A) paralleled OPG alterations during the neoadjuvant therapy. Specifically, the CRT-induced changes in OPG and RANK were associated with PFS – the higher the increase (fold-change from NACT completion), the lower risk of a PFS event following definitive surgery (OPG: HR 0.27, 95% CI 0.09-0.87, p = 0.03; RANK: HR 0.13, 95% CI 0.02-0.76, p = 0.02). Correspondingly, by one-way analysis of variance, decline in serum levels during CRT (fold-change from NACT completion) was associated with adverse CTCAE grade diarrhea, the clinical correlate of treatment toxicity (OPG: p&amp;lt;0.01; RANK: p&amp;lt;0.01). Conclusions: In this LARC study, elevated levels of systemic inflammation markers on commencement of neoadjuvant therapy were associated with adverse PFS. On the contrary, the association between strong increase in circulating TNFR proteins at CRT completion and favorable outcome in a patient population treated with curative intent but with metastatic disease as the main PFS event suggests that systemic antitumor immunity may be invoked by radiation. Citation Format: Sebastian Meltzer, Erta Kalanxhi, Helga Helseth Hektoen, Svein Dueland, Kjersti Flatmark, Kathrine Røe Redalen, Anne Hansen Ree. Circulating tumor necrosis factor receptor (TNFR) proteins in systemic disease outcome to combined-modality radiotherapy in rectal cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr C101.

Abstract 571: Circulating proteins in response to combined-modality therapy in locally advanced rectal cancer identified by antibody array screening

Abstract Background: In treatment of locally advanced rectal cancer (LARC) with chemoradiotherapy (CRT) followed by surgery, local recurrence rates are low but development of metastatic disease remains a dominant cause of failure. The attempt of improving survival outcome by increasingly complex multimodality programs is at the price of extended limits of treatment intensity and patient tolerance. Prediction biomarkers of efficacy and toxicity might therefore assist in achieving more individualized treatment in LARC. Methods: In a prospective LARC study (NCT00278694) composed of neoadjuvant chemotherapy (NACT; two cycles of the Nordic FLOX regimen) before long-course CRT in order to intensify treatment, serial serum samples were collected from 87 cases at baseline, following NACT (post-NACT), at CRT completion (post-CRT), and at evaluation of the neoadjuvant treatment 2-4 weeks before surgery. Anticipating that proteins were released into the circulation from the tumor as well as from other tissues as an adverse response to the combined-modality therapy, the serum samples were analyzed using an antibody array detecting a variety of 507 proteins (RayBiotech® AHH-BLG-1 array). Alterations in circulating protein profiles during the neoadjuvant treatment were correlated to progression-free survival (PFS) and treatment toxicities as assessed by Common Terminology Criteria for Adverse Events (CTCAE) scoring. Median follow-up was 63 months. Results: Significant changes in serum protein levels (as compared to baseline) were observed during the treatment course, with the numerically greater alterations found post-CRT. Gene ontology analysis of the altered proteins showed that the majority were involved in immune system processes and extracellular matrix organization. Interestingly, the levels of lipocalin-2 (LCN2) and matrix metalloproteinase-9 (MMP9) were significantly lowered during the entire treatment course with post-NACT median fold change decline to 0.46 and 0.38 for LCN2 and MMP9 respectively, followed by a gradual increase towards baseline values post-CRT and at evaluation before surgery. On univariate cox regression analysis, post-NACT values (fold change from baseline) of LCN2 and MMP9 were entered as continuous data, and for both factors, the lower the value the better PFS with a hazard ratio for a PFS event of 2.8 and 2.3, respectively. Both components (the Nordic FLOX regimen and pelvic CRT) of the neoadjuvant treatment protocol would cause intestinal toxicity, but the individual patient's post-NACT decline in LCN2 and MMP9 serum levels did not predict CTCAE grade 3 diarrhea at CRT completion when the highest incidence of treatment-induced enteropathy was recorded. Conclusion: Antibody array analysis of serial serum samples from the neoadjuvant treatment course represented a ‘liquid biopsy’ insight into systemic responses to intensified combined-modality therapy in LARC. Citation Format: Erta Kalanxhi, Helga Helseth Hektoen, Sebastian Meltzer, Svein Dueland, Kathrine Roe Redalen, Kjersti Flatmark, Anne Hansen Ree. Circulating proteins in response to combined-modality therapy in locally advanced rectal cancer identified by antibody array screening. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 571. doi:10.1158/1538-7445.AM2015-571

Effect of oxaliplatin-containing neoadjuvant chemotherapy on tumor volume in locally advanced rectal cancer and sensitivity of surviving tumor cells to radiotherapy.

3547 Background: The use of oxaliplatin (OXA) is well established in adjuvant and palliative treatment of colorectal cancer (CRC), but its role in neoadjuvant treatment of locally advanced rectal cancer (LARC) is controversial. Data from the ACCORD 12/0405, STAR-01 and NSABBP R-04 trials suggest no additional clinical benefit of adding OXA to fluoropyrimidine-based preoperative chemoradiotherapy (CRT) in LARC. However, the possibility of reducing risk of systemic recurrence and the use of OXA-containing neoadjuvant chemotherapy (NACT) in liver metastasis warrant further clarification of the role of OXA in neoadjuvant treatment of LARC. Methods: We report results from a non-randomized phase II trial of neoadjuvant treatment of 72 LARC patients, receiving two courses of the Nordic FLOX regimen prior to CRT (25 x 2 Gy; weekly OXA; daily capecitabine). Tumor volumes were calculated from MRI scans taken before and after NACT and 4 weeks after CRT completion. Using OXA resistant human CRC cell lines, the impact of previous OXA exposure on radiosensitivity (1-5 Gy) was examined. Results: Median baseline tumor volume was 16.6 cm3 (1.1-293 cm3). All tumors, except one, responded to NACT, leaving a median tumor volume of 5.3 cm3 (0.2-157 cm3), representing a median volume reduction of 63%. In all but three patients, additional tumor volume reduction was observed following subsequent CRT (median tumor volume 5.3 cm3; 0.02-119 cm3; median volume reduction of 68%). Exposure of cell lines to increasing concentrations of OXA resulted in resistance towards the drug. OXA resistant models exhibited increased radiosensitivity compared to OXA sensitive counterparts. Conclusions: OXA-containing NACT led to substantial tumor volume reduction. Additional tumor volume reduction was observed in almost all cases, suggesting that pretreatment with OXA-containing NACT did not preclude tumor response to CRT. Results from experimental models rather suggest that pretreatment with OXA might enhance radiosensitivity of surviving OXA resistant cells. Taken together, our results are in favor of continued exploration of OXA-containing NACT in LARC. Clinical trial information: NCT00278694.

Oxaliplatin and Bolus-Modulated 5-Fluorouracil as a Second-Line Treatment for Advanced Pancreatic Cancer: Can Bolus Regimens Replace FOLFOX When Considered for Second Line?

Objective. Comparing activity of 2 regimens combining oxaliplatin to bolus modulated fluorouracil as second line treatment in advanced pancreatic adenocarcinoma pretreated with gemcitabine-containing schedule. Methods. Forty eight patients with advanced pancreatic adenocarcinoma were randomly assigned to receive either FU 500 mg/m2 IV bolus weekly ×6 weeks plus leucovorin 500 mg/m2 IV weekly for 6 weeks during each 8-week cycle plus oxaliplatin 85 mg/m2 IV on weeks 1, 3, and 5 of each 8-week (FLOX) OR receive weekly intravenous infusions of oxaliplatin 40 mg/m2, 5-FU 500 mg/m2, and leucovorin 250 mg/m2 (3 weeks on, 1 week off). Results. Non progression(PR+SD) was found in 33.5% for first regimen and 29% for second regimen, and 37.5% had clinical benefit (FLOX regimen) compared to 50% in 3-weeks regimen. The median TTP was 3.9,4 months respectively. Median OS was 8, 9 months for both regimens. Only one case in 3-weeks arm suffered from grade IV diarrhea. Two cases > grade 2 neutropenia were observed; one in each treatment groups. Grade 3 anemia was recorded in 3 patients (2 in FLOX arm, one in 3-weeks arm). Conclusions. Both regimens showed encouraging efficacy, acceptable toxicity, and clinical benefit.

Plasma levels of TIMP-1 in chemo-naive patients with metastatic colorectal cancer treated with first-line FLOX with or without cetuximab: Results from the Nordic VII Study.

392 Background: KRAS status is presently the best known biomarker to select patients with metastatic colorectal cancer (mCRC) for therapy with EGFR inhibition. However, in NORDIC VII a survival benefit of adding cetuximab to the Nordic FLOX regimen could not be confirmed. Plasma Tissue Inhibitor of MetalloProteinases-1 (TIMP-1) is a promising biomarker in patients with mCRC, and has multiple actions including regulation of apoptosis, angiogenesis, cell growth and differentiation. High levels of TIMP-1 associate with reduced sensitivity to irinotecan-based treatment in patients with mCRC. We investigated whether high plasma TIMP-1 also correlates with response rate, progression-free survival (PFS) and overall survival (OS) in patients with mCRC treated in NORDIC VII. Methods: In NORCIC VII 571 patients with mCRC were randomized to: (A) Nordic FLOX; (B) Nordic FLOX + cetuximab or (C) Nordic FLOX intermittently + cetuximab continuously. Baseline plasma samples for TIMP-1 analysis were available from 426 patients (79%). Plasma TIMP-1 was determined using the MAC15 antibody in-house validated kinetic Enzyme Linked Immunosorbent Assay. Results: Median plasma TIMP-1 was 296 ng/mL. The tumor was KRAS mutated in 149 patients (35%). Best response did not correlate to TIMP-1 values (OR=1.16, 0.91-1.49, p=0.22). High plasma TIMP-1 was associated with short PFS (HR=1.22, 1.07-1.39, p=0.003) and OS (HR=1.55, 1.36-1.80, p&lt;0.0001). Multivariate analysis (TIMP-1, age, gender, KRAS, ALP, WBC, platelets, CRP, CEA, WHO PS, no. of metastatic sites) demonstrated that high plasma TIMP-1 was not an independent biomarker of PFS (HR=0.95, 0.76-1.18, p=0.65) or OS (HR=1.17, 0.91-1.50, p=0.22). Multivariate analysis retained CRP, PS and no. of metastatic sites in the final model for PFS and alkaline phosphates, PS and no. of metastatic sites for OS. Conclusions: Plasma TIMP-1 is a new prognostic biomarker in patients with mCRC treated with 1st line Nordic FLOX +/- cetuximab. Due to the design of NORDIC VII, a predictive effect of plasma TIMP-1 could only be estimated for cetuximab treatment and no significant treatment by marker intervention was observed.

Modified FLOX as first-line chemotherapy for metastatic colorectal cancer patients in the public health system in Brazil: Effectiveness and cost-utility analysis

Incorporation of new drugs for treatment of metastatic colorectal cancer (mCRC) has led to a clear improvement in overall patient survival, the added cost of treatment, however, is a major concern worldwide. The cost-effectiveness of using a modified FLOX (mFLOX) regimen for treating mCRC patients was delineated. In this study, 82 consecutive mCRC patients were treated with leucovorin (LV) at 20 mg/m2 in combination with weekly bolus of 5-fluorouracil (5-FU) (500 mg/m2) for 6 consecutive weeks and oxaliplatin (85 mg/m2) at weeks 1, 3 and 5, every 8 weeks. Overall survival (OS) and toxicity were evaluated. A Markov Model with a 2-year time horizon and 2-week cycles was developed, comparing mFLOX and mFOLFOX6 in a Brazilian environment. Health outcomes were measured in quality-ajusted life years (QALYs). The median overall period of survival was 19 months, while the estimated 1-year survival was 75%. Response by RECIST was assessed in 33 patients. Partial response was observed in 39.4% of patients, while 36.3% were stable. The mFLOX regimen cost was BRL 9,000, while the mFOLFOX6 BRL 22,000 (1 EUR=2.29 BRL), leading to an incremental costed of BRL 13,000, considering a 20-week period of first-line therapy. The incremental effect of the mFOLFOX was of 0,117 QALY. The incremental cost-effectiveness ratio of mFOLFOX6 was of BRL 110,344/QALY. The sensitivity analysis detected no differences in the outcome measures. In conclusion, the mFLOX is an active regimen in mCRC patients, possibly providing a cost-effective option in public health systems.

Plasma concentrations of YKL-40 in chemo-naive patients with metastatic colorectal cancer treated with FLOX with or without cetuximab: Results from the NORDIC VII study.

3548 Background: KRAS status is presently the best biomarker to select patients with metastatic colorectal cancer (mCRC) for therapy with EGFR inhibition even though not confirmed in all phase III studies. In the NORDIC VII study a survival benefit of adding cetuximab to the Nordic FLOX regimen could not be confirmed. Identification of new predictive and prognostic biomarkers is essential. Plasma concentration of YKL-40 is emerging as a new biomarker in patients with cancer and inflammatory diseases. We tested the hypothesis that high plasma YKL-40 associates with short progression free survival (PFS) and short overall survival (OS) in patients included in the NORDIC VII Study. Methods: 566 patients with mCRC were randomized to: A) Nordic FLOX; B) FLOX + cetuximab; and C) FLOX for 16 weeks + cetuximab continuously. Plasma samples were available from 510 patients (90%). Pretreatment plasma YKL-40 was determined by ELISA (Quidel), and the plasma YKL-40 concentration was dichotomized according to the age-corrected 95% YKL-40 level in 3130 healthy subjects. Results: Plasma YKL-40 was elevated in 204 patients (40%) and the median plasma YKL-40 was higher in the study group compared to healthy subjects (120 mg/l vs. 40 mg/l, p&lt;0.001). Elevated plasma YKL-40 was associated with short PFS (HR=1.25, 95% CI 1.04-1.51, p=0.02). This relationship was demonstrated only in patients treated with FLOX chemotherapy alone (HR=1.42, 1.02-1.98, p=0.04). High plasma YKL-40 was associated with short OS in all patients (HR=1.55, 1.25-1.92, p&lt;0.001) and in the different treatment groups (A: HR=1.54, 1.05-2.26, p=0.03; B: HR=1.40, 0.97-2.01, p=0.07; C: 1.79, 1.23-2.60, p=0.002). Multivariate analysis (YKL-40, performance status, number of metastatic sites) demonstrated that elevated plasma YKL-40 was an independent biomarker of short OS (HR=1.46, 1.17-1.81, p=0.001). Conclusions: Plasma YKL-40 may be a new prognostic biomarker in patients with mCRC treated with 1st line FLOX chemotherapy, with or without cetuximab. The predictive value of plasma YKL-40 is not yet clarified.

Phase III Trial of Cetuximab With Continuous or Intermittent Fluorouracil, Leucovorin, and Oxaliplatin (Nordic FLOX) Versus FLOX Alone in First-Line Treatment of Metastatic Colorectal Cancer: The NORDIC-VII Study

The NORDIC-VII multicenter phase III trial investigated the efficacy of cetuximab when added to bolus fluorouracil/folinic acid and oxaliplatin (Nordic FLOX), administered continuously or intermittently, in previously untreated metastatic colorectal cancer (mCRC). The influence of KRAS mutation status on treatment outcome was also investigated. Patients were randomly assigned to receive either standard Nordic FLOX (arm A), cetuximab and FLOX (arm B), or cetuximab combined with intermittent FLOX (arm C). Primary end point was progression-free survival (PFS). Overall survival (OS), response rate, R0 resection rate, and safety were secondary end points. Of the 571 patients randomly assigned, 566 were evaluable in intention-to-treat (ITT) analyses. KRAS and BRAF mutation analyses were obtained in 498 (88%) and 457 patients (81%), respectively. KRAS mutations were present in 39% of the tumors; 12% of tumors had BRAF mutations. The presence of BRAF mutations was a strong negative prognostic factor. In the ITT population, median PFS was 7.9, 8.3, and 7.3 months for the three arms, respectively (not significantly different). OS was almost identical for the three groups (20.4, 19.7, 20.3 months, respectively), and confirmed response rates were 41%, 49%, and 47%, respectively. In patients with KRAS wild-type tumors, cetuximab did not provide any additional benefit compared with FLOX alone. In patients with KRAS mutations, no significant difference was detected, although a trend toward improved PFS was observed in arm B. The regimens were well tolerated. Cetuximab did not add significant benefit to the Nordic FLOX regimen in first-line treatment of mCRC.

FLOX regimen (5-FU, folinic acid, oxaliplatin) and FLIRI regimen (5-FU, folinic acid, irinotecan) as first-line treatment in metastatic and locally advanced gastric cancer: A randomized phase II study.

71 Background: The Norwegian Gastrointestinal Cancer Group (NGICG) conducted a phase II randomized study comparing the efficacy and safety of FLOX and FLIRI as first line treatment in metastatic or locally advanced gastric cancer. At progression or unacceptable drug related toxicity, a crossover to the other treatment arm should be done, if second line chemotherapy was indicated. Methods: 66 patients from 6 treatment centers in Norway were randomized to FLOX (oxaliplatin 85 mg/m2 on day 1, bolus 5-FU 500 mg/m2 and FA 60 mg/m2 on day 1 and 2, or FLIRI (irinotecan 180 mg/m2 on day 1, bolus 5-FU 500 mg/m2 and FA 60 mg/m2 on day 1 and 2). Both treatments were repeated every second week. The primary endpoint was response rate (RR) and time to progression (TTP). Secondary endpoints were overall survival (OS) and safety data. Results: At the present time data from 63 patients are available for analysis. First-line treatment: FLOX (n = 32) versus (v.) FLIRI (n = 31): Complete response (CR) n = 0 in both arms, partial response (PR) n = 16 v. 9, stable disease (SD) n = 12 v. 13, progressive disease (PD) n = 3 v. 6, not assessable for evaluation n = 1 v. 3 patients. RR was 50 % in the FLOX arm v. 29 % in the FLIRI arm, p = not significant (n.s), Pearson Chi-Square test. Median TTP was 5 months (95 % CI 2.2-7.8) v. 4 months (95 % CI 2.2-5.8), p = n.s, median OS was 11 months (95 % CI 9.2-12.8 ) v. 10 months (95 % CI 5.7-14.3), p = n.s, Log Rank test. Patient characteristics were well balanced. Febrile neutropenia was present among 10 % of the patients in the FLOX arm versus 7 % in the FLIRI arm. Second line treatment: 30 patients received second line treatment with FLOX or FLIRI. Data regarding RR, TTP, OS and safety will be updated in December 2011. Conclusions: The FLOX and FLIRI regimens are well tolerated among patients with locally advanced and metastatic gastric cancer. As first line treatment the FLOX regime had a higher RR of 50% v. 29% for the FLIRI regime, longer TTP; 5 v. 4 months and longer OS 11 v. 10 months, but the difference did not reach statistical significance.

Oxaliplatin in the adjuvant treatment of colon cancer

Oxaliplatin in the adjuvant treatment of colon cancer

Randomized phase III study of 5-fluorouracil/folinate/oxaliplatin given continuously or intermittently with or without cetuximab, as first-line treatment of metastatic colorectal cancer: The NORDIC VII study (NCT00145314), by the Nordic Colorectal Cancer Biomodulation Group.

365 Background: The role of anti-EGFR therapy in first-line treatment of metastatic colorectal cancer (mCRC) is not established. In the present study pts were randomized to FLOX or FLOX + cetuximab until progression or FLOX intermittently + cetuximab continuously. Methods: Treatment arm A: Nordic FLOX (q2w): oxaliplatin 85 mg/m2day 1, 5-FU bolus 500 mg/m2 and FA 60 mg/m2 day 1-2; B: FLOX + cetuximab, initial dose 400 mg/m2, then 250 mg/m2/week; C: FLOX for 16 weeks + cetuximab continuously, with FLOX added at progression. Primary endpoint was progression-free survival (PFS). Results: Between May 05-Oct 07, 571 pts were randomized, 566 pts evaluable in intention to treat (ITT) analyses. Median age was 61 (24-74). ECOG status: 0=67%, 1=29%, 2=4%. KRAS and BRAF mutation (mut) analyses were obtained in 498 (87%) and 457 pts (81%), respectively. 40% of tumors had KRAS mut, 12% had BRAF mut. Cetuximab combined with Nordic FLOX did not significantly improve RR, PFS or OS compared to FLOX. KRAS mutation was not predictive for cetuximab effect. OS was similar for patients treated with FLOX intermittently and cetuximab continuously as for patients treated until progression. BRAF mutation was a strong negative prognostic factor (median OS 7.6 vs. 20.4 mo). Conclusions: Cetuximab did not add significant benefit to the Nordic FLOX regimen in first-line treatment of mCRC, irrespective of KRAS-mut. [Table: see text] [Table: see text]

Adjuvant chemotherapy in colon cancer – Is it worth it?

Two decades since the first demonstration that 5-fluorouracil (5-FU)-based adjuvant chemotherapy improves survival in resected colon cancer, the standard of care of adjuvant chemotherapy in this disease has been shaped by several pivotal phase III trials and meta-analyses. Adjuvant treatment still relies on a fluoropyrimidine backbone (5-FU/FA (folinic acid) or capecitabine) with the addition of oxaliplatin for stage III colon cancers and select stage II cancers to form the FOLFOX, XELOX, or – less utilised – the FLOX regimen. More recent data question the use of oxaliplatin in elderly patients over the age of 70, and so far no survival benefit has been established with oxaliplatin for patients with stage II disease, although patients with clinically ‘high-risk’ stage II cancers experience a longer disease-free survival when treated with FOLFOX compared with 5-FU/FA alone. The drugs used in the adjuvant treatment will likely not change over the next 5–10 years since 3 of 4 tested agents, irinotecan, cetuximab and bevacizumab, which all demonstrated activity in advanced colorectal cancer failed to provide significant benefit in phase III adjuvant trials. The goal of adjuvant therapy is primarily to increase cure rates in resectable colon cancer, but in order to perform a true value assessment, one has to take a more comprehensive ap-