Treatment Of Refractory Metastatic Colorectal Cancer Research Articles

Feasibility and Tolerability of Anlotinib Plus PD-1 Blockades for Patients with Treatment-Refractory Metastatic Colorectal Cancer: A Retrospective Exploratory Study.

Therapeutic regimens are relatively scarce among patients with treatment-refractory metastatic colorectal cancer (CRC). This study aimed to determine the feasibility and tolerability of anlotinib plus PD-1 blockades in patients with treatment-refractory metastatic CRC retrospectively. A total of 68 patients with previously treated metastatic CRC who received anlotinib plus PD-1 blockades in clinical practice were included in this study retrospectively. Demographic and clinical characteristics of the patients, therapeutic outcomes and safety profile during administration were collected and briefly analyzed. All subjects were followed up regularly. Therapeutic outcomes, including drug response and prognosis, were presented, and a safety profile was depicted to illustrate the adverse reactions. A total of 68 patients with treatment-refractory metastatic CRC who received anlotinib plus PD-1 blockades in clinical practice were included in the final analysis. Best therapeutic response during treatment indicated that partial response was observed in 11 patients, stable disease was noted in 41 patients, and progressive disease was found in 16 patients, producing an objective response rate of 16.2% (95% CI: 8.4%-27.1%) and a disease control rate of 76.5% (95% CI: 64.6%-85.9%). Prognostic analysis suggested that the median progression-free survival (PFS) of the 68 patients was 5.3 months (95% CI: 3.01-7.59), and the median overall survival (OS) was 12.5 months (95% CI: 9.40-15.60). Of the 11 patients who responded, the median duration of response was 6.7 months (95% CI: 2.89-10.53). Safety profile during treatment showed that patients experienced adverse reactions regardless of grade, and grade ≥3 adverse reactions were found in 61 patients (89.7%) and 41 patients (60.3%), respectively. Common adverse reactions were hypertension, myelosuppression (including leukopenia, neutropenia, thrombocytopenia, and anemia), fatigue, and hand-foot syndrome. Anlotinib plus PD-1 blockades demonstrated encouraging efficacy and acceptable safety profile in patients with treatment-refractory metastatic CRC preliminarily in clinical practice. This conclusion should be confirmed in prospective clinical trials.

Effectiveness and Safety of Apatinib Plus Programmed Cell Death Protein 1 Blockades for Patients with Treatment-refractory Metastatic Colorectal Cancer: A Retrospective Exploratory Study.

This study aimed to investigate the efficacy and safety of apatinib plus programmed cell death protein 1 (PD-1) blockades for patients with metastatic colorectal cancer (CRC) who were refractory to the standard regimens. In this retrospective study, patients with metastatic CRC who received apatinib plus PD-1 blockades in clinical practice were included. The initial dosage of apatinib was 250 mg or 500 mg, and PD-1 blockades were comprised of camrelizumab, sintilimab and pembrolizumab. Efficacy and safety data were collected through the hospital's electronic medical record system. From October 2018 to March 2022, a total of 43 patients with metastatic CRC were evaluated for efficacy and safety. The results showed an objective response rate of 25.6% (95% CI, 13.5%-41.2%) and a disease control rate of 72.1% (95% CI, 56.3%-84.7%). The median progression-free survival (PFS) of the cohort was 5.8 months (95% CI, 3.81-7.79), and the median overall survival (OS) was 10.3 months (95% CI, 5.75-14.85). The most common adverse reactions were fatigue (76.7%), hypertension (72.1%), diarrhea (62.8%), and hand-foot syndrome (51.2%). Multivariate Cox regression analysis revealed that Eastern Cooperative Oncology Group (ECOG) performance status and location of CRC (left or right-side) were independent factors to predict PFS of patients with metastatic CRC treated with the combination regimen. Consequently, the combination of apatinib and PD-1 blockades demonstrated potential efficacy and acceptable safety for patients with treatment-refractory metastatic CRC. This conclusion should be confirmed in prospective clinical trials subsequently.

Cost-effectiveness analysis of pembrolizumab in patients with treatment-refractory metastatic colorectal cancer in Japan.

The immune checkpoint inhibitor pembrolizumab has recently been recognized as a standard treatment regimen for patients with metastatic colorectal cancer and the microsatellite-instability-high/mismatch repair-deficient mutation. However, its cost-effectiveness in late-line treatment remains unclear. The aim of this study was to assess the cost-effectiveness of pembrolizumab for patients with microsatellite-instability-high/mismatch repair-deficient metastatic colorectal cancer. Markov decision modeling using treatment costs, disease-free survival and overall survival was performed to examine the cost-effectiveness of pembrolizumab monotherapy compared with chemotherapy, and best supportive care. The Japanese healthcare payer's perspective was adopted. The outcomes were modeled on the basis of published literature. The primary outcome was the incremental cost-effectiveness ratio between the strategies. Sensitivity analyses were performed and the effects of uncertainty on the model parameters were investigated. Pembrolizumab monotherapy had incremental cost-effectiveness ratios of $408204.3 per quality-adjusted life-year gained compared with best supportive care and $489123.4 per quality-adjusted life-year gained compared with chemotherapy. Given a Japanese willingness-to-pay threshold of $69560.38 per quality-adjusted life-year, the base case results suggested that pembrolizumab monotherapy was not cost-effective. The sensitivity analysis results were in line with the base case results. Pembrolizumab monotherapy is not a cost-effective option in late-line treatment for patients with metastatic colorectal cancer and microsatellite-instability-high/mismatch repair-deficient mutation in the Japanese healthcare system. Further studies on its cost-effectiveness in first-line treatment are warranted.

Phase 1b study to assess the safety of neoadjuvant trifluridine/tipiracil with concurrent radiation in resectable stage II/III rectal cancer.

TPS274 Background: Treatment of locally advanced rectal cancer currently involves tri-modal therapy with pre-operative chemo-radiation (CRT), surgery, and combination chemotherapy. Total neoadjuvant therapy (TNT) is emerging as an important treatment pathway that can increase rates of complete response (CR) leading to better overall outcomes. Novel radio-sensitizing agents may improve rates of CR. Trifluridine/tipiracil (TFD/TPI) is a novel fluoropyrimidine that has demonstrated clinical efficacy in patients with treatment-refractory metastatic colorectal cancer. Importantly, TFD/TPI has superior radio-sensitization in vitro compared to 5-fluorouracil, and we hypothesize that this can improve the tumor response of patients. This phase 1 study assesses the safety and preliminary efficacy of using TFD/TPI for long-course CRT for rectal cancer followed by FOLFOX chemotherapy in the TNT setting. Methods: NCT04104139 is a prospective, dose-finding phase I study using Bayesian Optimal Interval (BOIN) design to determine the maximum tolerated dose (MTD) of TFD/TPI with concurrent standard dose/fractionation radiation for resectable rectal cancer. Adults with previously untreated rectal adenocarcinoma, with clinical stage II (T3-4aN0) and stage III (T1-4aN1+) by MRI and endoscopy are eligible. Patients must first receive CRT with standard radiation (45-50 Gy over 25-28 fractions) followed by up to 8 cycles of standard FOLFOX, or alternatively 5 cycles of CAPOX chemotherapy. During CRT, the first dose level of TFD/TPI is PO 25mg/m2 twice a day from Mon to Fri (5 weekdays) alternating on weeks 1, 3, and 5 concurrent with 5-6 weeks of radiation. The second dose level is 30mg/m2, and third dose level is 35mg/m2. The MTD of TFD/TPI in combination with radiation is the dose corresponding to a dose limiting toxicity (DLT) probability of 30% using the BOIN design with escalation/de-escalation of each dose level occurring in cohorts of 3 participants until a maximum total of 18 participants, sub-total of 12 patients within one dose level, or another stopping rule based on serious toxicities. The primary endpoint is proportion of DLTs for TFD/TPI at MTD. Secondary endpoints include overall tolerability profile, delayed toxicities during FOLFOX, rates of clinical CR, rates of pathologic CR, and correlative biomarkers. The study was activated December 2019 and has accrued 8 of intended 18 patients. Clinical trial information: NCT04104139 .

Thrombotic Microangiopathy in the Setting of Colorectal Cancer: A Therapeutic Challenge with a Bad Prognosis

While most cases of thrombotic microangiopathic hemolytic anemias are idiopathic, some can occur in the setting of a malignancy. Differentiating both conditions is crucial to initiate the appropriate treatment. In this case report and literature review, we discuss the occurrence of a thrombotic microangiopathy in a 61-year-old male patient with a treatment-refractory metastatic colorectal cancer invading his bone marrow. Plasmapheresis does not constitute the mainstay of treatment in this setting, as targeting the primary disease is the ultimate management. Treating the condition of our patient has been challenging as multiple lines of treatments of his primary disease had been exhausted. The discrepancy in KRAs status obtained between PCR and later NGS offered a new treatment line with Cetuximab. In this article, we will discuss the different factors that differentiate between idiopathic and cancer-induced microangiopathy. We will emphasize on the fact that the treatment of the primary disease constitutes the most important step in the treatment of cancer-induced thrombotic microangiopathy. We will also raise several explanations to target the disagreement in KRAS status obtained by the different technical modalities.

Circulating Tumor DNA Identifies Diverse Landscape of Acquired Resistance to Anti-Epidermal Growth Factor Receptor Therapy in Metastatic Colorectal Cancer.

Anti-epidermal growth factor receptor (EGFR) antibodies are effective treatments for metastatic colorectal cancer. Improved understanding of acquired resistance mechanisms may facilitate circulating tumor DNA (ctDNA) monitoring, anti-EGFR rechallenge, and combinatorial strategies to delay resistance. Patients with treatment-refractory metastatic colorectal cancer (n = 169) enrolled on the CO.26 trial had pre-anti-EGFR tissue whole-exome sequencing (WES) compared with baseline and week 8 ctDNA assessments with the GuardantOMNI assay. Acquired alterations were compared between patients with prior anti-EGFR therapy (n = 66) and those without. Anti-EGFR therapy occurred a median of 111 days before ctDNA assessment. ctDNA identified 12 genes with increased mutation frequency after anti-EGFR therapy, including EGFR (P = .0007), KRAS (P = .0017), LRP1B (P = .0046), ZNF217 (P = .0086), MAP2K1 (P = .018), PIK3CG (P = .018), BRAF (P = .048), and NRAS (P = .048). Acquired mutations appeared as multiple concurrent subclonal alterations, with most showing decay over time. Significant increases in copy-gain frequency were noted in 29 genes after anti-EGFR exposure, with notable alterations including EGFR (P < .0001), SMO (P < .0001), BRAF (P < .0001), MET (P = .0002), FLT3 (P = .0002), NOTCH4 (P = .0006), ERBB2 (P = .004), and FGFR1 (P = .006). Copy gains appeared stable without decay 8 weeks later. There were 13 gene fusions noted among 11 patients, all but one of which was associated with prior anti-EGFR therapy. Polyclonal resistance was common with acquisition of ≥ 10 resistance related alterations noted in 21% of patients with previous anti-EGFR therapy compared with 5% in those without (P = .010). Although tumor mutation burden (TMB) did not differ pretreatment (P = .63), anti-EGFR exposure increased TMB (P = .028), whereas lack of anti-EGFR exposure resulted in declining TMB (P = .014). Paired tissue and ctDNA sequencing identified multiple novel mutations, copy gains, and fusions associated with anti-EGFR therapy that frequently co-occur as subclonal alterations in the same patient.

Abstract 5157: ctDNA change predicts treatment outcome of regorafenib in metastatic colorectal cancer

Abstract Introduction: Regorafenib is a multikinase inhibitor which showed clinical benefit in patients with treatment refractory metastatic colorectal cancer. However, as only a subset of patients derives clinical benefit from regorafenib, it is essential to identify biomarker to predict therapeutic response. Circulating tumor DNA (ctDNA) is emerging as a valuable non-invasive tool to identify tumor heterogeneity and tumor burden. This study investigated ctDNA dynamics in patients with metastatic colorectal cancer treated with regorafenib. Methods: This is a prospective biomarker study including patients with refractory metastatic colorectal cancer treated with regorafenib (ClinicalTrial.gov Identifier: NCT01996969). Patients with metastatic colorectal cancer who were refractory to standard therapies (fluoropyrimidine, oxaliplatin, and irinotecan) were eligible for the current study. Patients received oral regorafenib 160 mg once daily for the first 3 weeks of each 4-week cycle and were treated until disease progression, death, unacceptable toxicity, or decision by the treating physicians. Blood samples were obtained prior to regorafenib treatment and after every two cycles of regorafenib treatment until disease progression. ctDNA was detected by AlphaLiquid® 100 target capture panel (IMBdx, Inc., Seoul, South Korea). Alphaliquid® 100 is a tumor agnostic panel consist of 106 genes, including 10 gene fusion and MSI. Variant allele frequency (VAF) amount was calculated by adding the VAF value of all altered genes. Results: A total of 110 patients were included in the present study. Baseline blood samples were successfully acquired in 107 patients (97.3%) with a total of 713 genetic alteration. Mutation was most frequently found in TP53 (76.6%) followed by APC (75.7%), KRAS (43.0%), PIK3CA (17.8%), and SMAD4 (17.8%). BRAF mutation was found in 8.4% of patients and NRAS was detected in 3.7% of patients. Blood samples after two cycle of regorafenib was acquired in 106 patients, and was acquired in 95 patients after disease progression. Among 104 patients with baseline and follow-up cfDNA, the mean VAF at baseline was 12.8% and 7.2% in follow-up. This resulted in a mean VAF change of -5.61% (absolute value) and -43.7% (relative change). VAF decreased markedly after 2 cycles of regorafenib in several genes, including CSF1R, JAK3, KIT, ROS1, and TERT. Although, VAF change of specific gene was not associated with regorafenib outcome, VAF change of whole gene was an early predictive marker for regorafenib. Reduction in VAF amount of ≥ 50% after two cycles of regorafenib were associated with a significantly improved PFS (6.1 vs. 2.7 months, p = 0.002), OS (11.3 vs. 5.9 months, p = 0.001), and higher disease control rate (86.3% vs. 51.1%, p &amp;lt; 0.001). Conclusions: Serial ctDNA could be used as an early predictive biomarker in metastatic colorectal cancer treated with regorafenib. Citation Format: Dae-Won Lee, Sae-Won Han, Yoojoo Lim, Hwang-Phill Kim, Hanseong Roh, Min Jung Kim, Seung-Bum Ryoo, Ji Won Park, Seung-Yong Jeong, Kyu Joo Park, Gyeong Hoon Kang, Tae-You Kim. ctDNA change predicts treatment outcome of regorafenib in metastatic colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5157.

Comparative analysis of overall survival in patients with HER2-amplified treatment-refractory metastatic colorectal cancer treated with pertuzumab plus trastuzumab in Mypathway and patients treated in the real-world.

36 Background: ML28897 (MyPathway) is a multi-basket trial evaluating the efficacy and safety of targeted therapies in non-indicated tumor types harboring relevant genetic alterations. In MyPathway, patients with treatment-refractory HER2-amplified metastatic colorectal cancer (mCRC) were enrolled and received pertuzumab plus trastuzumab. In order to facilitate contextualization of the outcome of pertuzumab plus trastuzumab in MyPathway, we conducted a retrospective study to compare with the outcome in real-world HER2-amplified mCRC patients. Methods: Overall survival (OS) was used as the endpoint to compare outcomes from MyPathway (PER/HER arm) and the external control of HER2-amplified mCRC patients treated with any therapy except anti-HER2 therapy in the refractory setting (EC arm) from the US-based de-identified Flatiron Health-Foundation Medicine Clinico-Genomic Database (CGDB). The de-identified data originated from approximately 280 US cancer clinics (̃800 sites of care). OS was defined as time from first treatment to death in the PER/HER arm and from index date (initiation of treatment in the refractory setting) to death in the EC arm. For patients in the CGDB who had met study eligibility criteria at multiple index dates, all eligible index dates were used for the analysis. Standardized mortality ratio weighting based on propensity score was used for deriving the pseudo-population (post-weighting population). In the post-weighting population, multivariate Cox regression models and Kaplan-Meier analyses were used to compare between the arms. A series of sensitivity analyses were conducted to investigate the robustness and consistency of the primary analysis results. Results: The PER/HER arm consisted of 57 patients who had treatment-refractory mCRC with HER2 amplification and enrolled in the MyPathway by August 1, 2017 data cutoff. For the EC arm, 64 HER2-amplified mCRC patients were selected from CGDB collected between January 1, 2011 and December 31, 2019. After applying the predefined inclusion/exclusion criteria set to be similar to those in the MyPathway, 27 eligible index dates were selected from 18 eligible patients and used for primary analysis. In the post-weighting population, the hazard ratio (HR) for OS estimated by multivariate Cox regression model was 0.729 (95% CI: 0.184-3.900) and median survival in the PER/HER arm and the EC arm were 11.47 months (95% CI: 7.72-22.11) and 9.72 months (95% CI: 7.43-22.21), respectively. The results of the all sensitivity analyses were consistent with those in the primary analysis in terms of the point estimate of HR. Conclusions: Despite a small sample size, the totality of findings suggests that the combination of pertuzumab and trastuzumab could have a potential benefit in OS for this population.

Genomic landscape of treatment refractory metastatic colorectal cancer

Background Metastatic colorectal cancer (mCRC) is a complex and heterogeneous disease with few standard and targeted treatment options. Next-generation sequencing of tumor tissue was performed to identify cancer driver mutations to discover possible personalized treatment options, as targeted treatment possibilities are limited for this patient population. Results of genomic sequencing in patients with treatment-refractory mCRC are described in this retrospective analysis. Material and methods Clinico-pathological characteristics and genomic sequence results of consecutive patients with refractory mCRC, referred to the Experimental Cancer Therapy Unit (ECTU) at Department of Oncology, Herlev & Gentofte Hospital in the period from 1 October 2015 to 14 December 2018 were reviewed in this retrospective analysis. Tumor tissue from the patients was analyzed by next-generation sequencing using the Oncomine Comprehensive primer panel to detect actionable variants of cancer driver mutations and microsatellite instability status. From August 2018 tumor mutational burden was also analyzed. Results A total of 80 patients with treatment-refractory mCRC and in a fairly good performance were referred to the ECTU during this period. Genomic sequencing of tumor tissue was performed for all 80 patients and a cancer driver mutation was identified in 90% (n = 72) of the patients. A total of 31.3% (n = 25) of the patients received therapy either as targetable therapy outside an available trial (n = 2), FDA approved therapy (n = 2), or treatment in phase 1 or 2 trials, independent of the genomic signature 26.3% (n = 21). Conclusion Most mCRC patients refractory to standard anti-neoplastic therapies, presented with a cancer driver mutation, however, only a few of these mutations gave rise to matched therapies as only 2.5% of the patients from this period received targeted therapy.

Pertuzumab plus trastuzumab and real-world standard of care (SOC) for patients (pts) with treatment refractory metastatic colorectal cancer (mCRC) with HER2 (ERBB2) amplification (amp) confirmed by tumor tissue or ctDNA analysis (TRIUMPH, EPOC1602).

3555 Background: HER2 amp occurs in 1-4% of mCRC pts. Two single arm phase 2 studies, HERACLES and MyPathway, showed efficacy for dual HER2-targeted therapy in pts with RAS wild type ( RAS wt) mCRC with HER2 amp detected in tumor tissue; however, efficacy for pts prospectively enrolled with HER2 amp identified in ctDNA is unknown. Furthermore, the efficacy of real-world non-HER2-targeted SOC for HER2 amplified RASwt mCRC pts is not clear. Methods: We conducted a phase 2 trial to evaluate the efficacy of pertuzumab (P) plus trastuzumab (T) in RASwt mCRC pts with HER2 amp centrally confirmed by tissue (IHC and/or FISH) and/or ctDNA (Guardant360) who had progressed on SOC including EGFR blockade. Pts received intravenous P (840 mg loading dose followed by 420 mg) and T (8 mg/kg loading dose followed by 6 mg/kg) every 3 weeks. The primary endpoint was confirmed objective response rate (ORR) by investigator assessment, analyzed for two primary populations: pts with HER2 amp in tissue (tissue+) or in ctDNA (ctDNA+). Efficacy of real-world non-HER2-targeted SOC for HER2 amplified RASwt mCRC pts was prospectively assessed in a concurrent registry: the SCRUM-Japan registry. Results: Among 75 pts screened, concordance of HER2 amp between tissue and ctDNA was 83%. The primary endpoint was met in each cohort of TRIUMPH, with confirmed ORR of 30% (95% CI 14-50%) in 27 tissue+ pts and 28% (12-49%) in 25 ctDNA+ pts. In contrast, ORR in first salvage SOC after EGFR blockade was 0% (0.0-24.7%) in the real-world cohort. Median progression free and overall survival were 4.0 months (1.4-5.6) and 10.1 months (4.5-16.5) in the tissue+ pts and 3.1 months (1.4-5.6) and 8.8 months (4.3-12.9) in the ctDNA+ pts. One pt withdrew due to an adverse event (grade 3 decreased ejection fraction), but no treatment related deaths occurred. In exploratory analyses, pts without ctDNA mutations of RAS/ BRAFV600/ PIK3CA/ HER2 were more likely to respond to P+T than those with a ctDNA mutation in at least one of these genes (ORR 44% vs. 0% in tissue+ and 37% vs. 0% in ctDNA+). Decreased ctDNA fraction and HER2 plasma copy number at 3 weeks after treatment initiation corresponded to P+T response. At least one actionable alteration emerged after progression in 16 (62%) of 26 pts with ctDNA results at both baseline and progression. Among 5 pts who achieved response and had ctDNA results at both time points, 4 pts acquired actionable alteration at progression. Conclusions: We demonstrate promising efficacy and safety of P+T for RASwt mCRC pts with HER2 amp in either tumor tissue or ctDNA. Our results show that complete ctDNA genotyping identifies pts most likely to benefit from dual HER2 blockade and can be used to monitor response and detect actionable resistance biomarkers. Clinical trial information: UMIN000027887 and UMIN000028058.

Phase II trial of nivolumab and metformin in patients with treatment refractory microsatellite stable metastatic colorectal cancer.

95 Background: Preclinical data suggests metformin can improve immune exhaustion of tumor infiltrating lymphocytes and potentiate the effects of PD-1 blockade. By normalizing the hypoxic TME, metformin was shown to improve cytotoxic T cell function and efficacy of anti-PD-1 antibody in highly aggressive B16 melanoma and MC38 colon adenocarcinoma tumor models. Based on this preclinical rationale we conducted a phase II study with nivolumab and metformin combination in treatment refractory MSS metastatic colorectal cancer (mCRC). Methods: Nivolumab 480 mg IV every 4 weeks and Metformin 1000 mg po twice daily was administered in 28-day cycles following a 14-day metformin only lead-in phase.Eligible patients included stage IV metastatic treatment refractory MSS mCRC (patients must have received oxaliplatin, irinotecan, and fluoropyrimidine), age ≥18 years, ECOG PS 0-1, adequate organ function, no prior anti PD-1 agent. The primary endpoint was overall response rate (ORR). Secondary endpoints included overall survival (OS) and progression free survival (PFS). Simon’s two-stage Minimax design was employed (H0: ORR =4%; H1: ORR=15%; alpha = 0.1; power =80%). If ≥1 objective response was observed in the first evaluable 18 patients, 10 additional patients would be included in the cohort. ≥3 objective responders in 28 patients would be required to be considered positive study. Pre-treatment and on-treatment research biopsies and correlative peripheral blood specimens were collected. Results: A total of 24 patients were enrolled, 6 patients were replaced per protocol, and 18 patients had evaluable disease. Of the 18 evaluable patients 11/18 (61%) were female, median age 58 [IQR 50-67]. 2 patients had prolonged stable disease (4 and 10 cycles). No patients had objective response based on RECIST 1.1. Median OS and PFS was 5.1 months [95% CI (2-11.7)] and 2.3 months [95% CI (1.7-2.4)], respectively. Most common grade 3 and 4 toxicities were anemia (n=2) and diarrhea (n=2). Conclusions: In treatment refractory MSS mCRCnivolumab and metformin combination was well tolerated. Two patients achieved stable disease, but no objective response was seen; therefore, the study did not proceed with the second stage of enrollment. Immunologic correlative analysis of this study is ongoing. Clinical trial information: NCT03800602.

Safety and efficacy of regorafenib in patients with treatment-refractory metastatic colorectal cancer in Turkey: the single-arm, open-label REGARD study

ObjectivesRegorafenib improved overall survival in patients with metastatic colorectal cancer (mCRC) refractory to standard therapies in two randomised, phase III trials, but has not been evaluated in Turkey. REGARD evaluated...

Safety and effectiveness of regorafenib in patients with metastatic colorectal cancer in routine clinical practice in the prospective, observational CORRELATE study

BackgroundRegorafenib prolonged overall survival (OS) versus placebo in patients with treatment-refractory metastatic colorectal cancer (mCRC) in phase III trials. We conducted an observational study of regorafenib for patients with mCRC in real-world clinical practice. MethodsThe international, prospective, CORRELATE study recruited patients with mCRC previously treated with approved therapies, for whom the decision to treat with regorafenib was made by the treating physician according to the local health authority approved label. The primary objective was safety, assessed by treatment-emergent adverse events (TEAEs; National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.03). ResultsA total of 1037 patients were treated. The median age was 65 years (range: 24–93); 87% of patients had Eastern Cooperative Oncology Group performance status 0–1, 56% of patients had KRAS, 7% had NRAS and 4% had BRAF mutations. The initial regorafenib dose was 160 mg/day in 57% of patients. The most common grade III or IV drug-related TEAEs were fatigue (9%), hand–foot skin reaction (7%) and hypertension (6%). Drug-related grade V (fatal) TEAEs occurred in 1% of patients. Dose reductions for drug-related TEAEs occurred in 24% of patients. Median OS was 7.7 months (95% confidence interval [CI]: 7.2–8.3), and median progression-free survival (PFS) was 2.9 months (95% CI: 2.8–3.0). ConclusionsIn this real-world, observational study of patients with mCRC, the regorafenib toxicity profile was similar to that reported in phase III trials. The starting dose for almost half of patients was less than the approved 160-mg dose, and the median OS and PFS were in the range observed in phase III trials.Trial registration: NCT02042144.

Fruquintinib or regorafenib as the third-line treatments for metastatic colorectal cancer based on CONCUR and FRESCO trials: A cost-effectiveness analysis.

e15011 Background: Survival benefit of regorafenib and fruquintinib as third-line agents have been respectively demonstrated in patients with treatment-refractory metastatic colorectal cancer. This study tries to explore the cost-effectiveness of the two agents. Methods: A Markov model was performed based on two phase 3 trials, FRESCO and CONCUR. Health outcomes were measured with quality-adjusted life-years (QALYs). The key outcome was incremental cost-effectiveness ratio (ICER). Probabilistic sensitivity and one-way sensitivity analysis were performed to estimate the impact of essential variables on the results of the analysis. Results: No statistical differences were observed in the baseline patient characteristics, except that the CONCUR trial enrolled older patients and higher ratios of prior use of VEGF or EGFR antibodies in comparison with the FRESCO trial.Treatment with fruquintinib was estimated to cost $25,550.15 with an effectiveness gain of 0.54 QALYs, whereas regorafenib resulted in 0.53 QALY at a mean cost of $29,681.52, yielding ICER of $-413,137.00 per QALY. By using treble the Chinese Gross Domestic Product per Capita as willingness-to-pay threshold, the probability for fruquintinib being cost-effective was higher than regorafenib in the probabilistic sensitivity analysis. Conclusions: Fruquintinib provides a more cost-effective option for metastatic colorectal patients compared with regorafenib in the third line treatment.[Table: see text]

Dual HER2 inhibition strategies in the management of treatment-refractory metastatic colorectal cancer: History and status.

Human epidermal growth factor receptor 2 (HER2) signaling pathway activation has been identified as a contributor to de novo or acquired resistance to epidermal growth factor receptor (EGFR) inhibitors in a small subset of patients with metastatic colorectal cancer (mCRC). Dual anti-HER2-targeted treatment exhibits strong antitumor activity in preclinical models of HER2-positive mCRC, supporting its testing in clinical trials. The HERACLES trial at four Italian academic cancer centers has confirmed the effectiveness of dual blockage of HER2 with trastuzumab plus lapatinib in patients with heavily pretreated HER2-positive mCRC, refractory to the anti-EGFR antibodies cetuximab or panitumumab. Here, we reviewed the preclinical studies exploring the role of HER2 signaling in the development of anti-EGFR therapy resistance and discussed the status of clinical trials assessing the activity of HER2 inhibitors in this setting.

A meta-analysis of safety and efficacy of regorafenib for refractory metastatic colorectal cancer.

Background:Patients with metastatic colorectal cancer (mCRC) often suffer from progressive disease despite previous therapy. It has been a great challenge for those patients. In 2012, regorafenib was approved for mCRC. In this meta-analysis, we aimed to collect and present existing data to explorethe clinical use of regorafenib.Methods:The online electronic databases, such as PubMed, Embase, and the Cochrane library, updated to November 2017 were systematically searched. Trials on the effectiveness of regorafenib in patients who suffer from treatment-refractory metastatic colorectal cancer were included, of which the main outcomes included 3 parameters: overall survival (OS), progression-free survival (PFS), and grade 3/4 AE.Results:Totally, 4 trials were included in this meta-analysis. The OD was significantly better with the use of regorafenib (OR = 0.78, 95%CI = 0.65–0.94, I2 = 69%, P = .008), and PFS (OR = 0.52, 95%CI = 0.34–0.79, I2 = 97%, P = .002). However, the most common toxicities occurred more frequently in the regorafenib group than the control group (OR = 3.73, 95%CI = 1.68–8.28, I2 = 79%, P = .001).Conclusion:Regorafenib demonstrates better efficacy and has manageable adverse-event profile for treatment-refractory mCRC. Considering the safety feature of regorafenib, further studies and clinical trials are warranted to investigate the dosing of regorafenib and alternative approaches are needed to explore predictive biomarker fortherapy selection.

Tumor bulk to predict clinical outcomes of anti-EGFR therapy in treatment refractory metastatic colorectal cancer independent of sidedness.

795 Background: Epidermal growth factor receptor (EGFR) antibodies, cetuximab (C) and panitumumab (P) have shown improvement in clinical outcomes for distinct molecular profiles in metastatic colorectal cancer (mCRC). In the first line setting, EGFR targeting of left-sided tumors has shown favorable clinical outcomes when compared to right-sided tumors. Here we examined the efficacy of EGFR therapy in the treatment refractory setting as well as the impact of tumor bulk on clinical outcomes. Methods: A retrospective cohort of 72 patients (pts) with KRAS wild-type mCRC were identified who received either C or P in the late-line setting. Tumor measurements were performed per RECIST v1.1. Disease bulk was defined as single lesion with longest diameter or lymph node with short axis &gt; 3.5 cm. Right colon primary was defined proximal to splenic flexure. Results: In pts with treatment refractory right-sided disease the response rate (RR) was 16.7%, progression free survival (PFS) was 3.7 months (mo), and overall survival (OS) was 14.0 mo. This was compared to left sided disease with RR of 26.0%, PFS 6.2 mo (p &lt; 0.05), and OS 15.0 mo. In the non-bulky cohort the RR was 32.4%, PFS 7.9 mo, and OS 18.4 mo. In the bulky cohort the RR was 5.3% (p &lt; 0.01), PFS 4.0 mo (p &lt; 0.02), and OS 6.6 mo. In the right-sided non-bulky cohort there was a RR of 33% v. 0% in the right-sided bulky cohort. In the left-sided non-bulky cohort there was a RR of 32.3% v. 7.7% in the bulky cohort (p &lt; 0.05). Conclusions: These data indicate that tumor bulk can predict clinical outcomes for anti-EGFR targeting. In the late line setting, pts with left-sided cancers overall trended towards improvements in clinical outcomes, consistent with prior understanding in first line setting. Despite a limited cohort size, response was observed in pts with non-bulky right-sided disease. There was limited-to-no benefit of anti-EGFR targeting with right-sided bulky disease. Left-sided non-bulky patient received the greatest benefit from anti-EGFR targeting. Future prospective studies of targeted therapeutics should incorporate tumor bulk and sidedness when assessing clinical outcomes and tumor biology.

Functional imaging and circulating biomarkers of response to regorafenib in treatment-refractory metastatic colorectal cancer patients in a prospective phase II study

ObjectiveRegorafenib demonstrated efficacy in patients with metastatic colorectal cancer (mCRC). Lack of predictive biomarkers, potential toxicities and cost-effectiveness concerns highlight the unmet need for better patient selection.DesignPatients with RAS mutant...

Avelumab and cetuximab in combination with FOLFOX in patients with previously untreated metastatic colorectal cancer (MCRC): The phase II AVETUX-CRC trial (AIO KRK 0216).

TPS3620 Background: Inhibition of the PD-1/L1 axis has shown to improve survival as single agent in a variety of tumor types. The efficacy of single agent PD-1/L1 inhibition in patients with treatment refractory MCRC seems to be limited to hypermutated tumors characterized by mismatch repair deficiency. 1st line chemotherapy (e.g. FOLFOX) with cetuximab for patients with RAS/BRAF wildtype MCRC result in objective response rates of about 60%, thus substantial antigen release will likely occur triggering immune control. Furthermore, the induction of immunogenic cell death has been recently shown for cetuximab-based regimen. Thus, the evaluation of FOLFOX and cetuximab in combination with avelumab in 1st line MCRC is of particular interest. Methods: AVETUX is a single arm exploratory phase II investigator initiated trial. Patients with RAS/BRAF wildtype MCRC will be included independent of mismatch repair status to receive mFOLFOX6 and cetuximab in combination with avelumab (10mg/kg from day 1 of cycle 2 onwards). Treatment with avelumab is limited to a maximum of 18 months. Primary endpoint is 12month progression-free survival rate, which should be increased from 40% to 57%, with type I error of 10% and 80% power, leading to a sample size of 43 patients. An early stopping rule will be applied in case of an increase in toxicity after the first 15 patients received at least two months of treatment. The trial is flanked by a large translational program including immunoprofiling to determine and correlate the respective immune response signatures with clonal dynamics (RAS/EGFR). Recruitment will start in 11 German sites early 2017. Clinical trial information: EudraCT No 2016-004434-26. Conclusion: The AVETUX trial will determine the feasibility and early efficacy of FOLFOX and cetuximab combined with avelumab in 1st line MCRC. The translational research program will shed light on the potential mode of action of this novel combination. Clinical trial information: 2016-004434-26.

TAS 102 in refractory metastatic colorectal cancer: UK Expanded Access Programme experience.

e15043 Background: Trifluridine/tipiracil (TAS-102), an oral combination of a nucleoside analogue and thymidine phosphorylase inhibitor, showed significant survival benefit in the RECOURSE study. We assessed TAS-102 clinical activity in an unselected patient population with refractory metastatic colorectal cancer in the UK Expanded Access Programme (EAP). Methods: Pharmacy databases were used to identify patients treated with TAS-102 on the UK EAP at three tertiary referral Cancer Centres (Manchester, Cardiff and Southampton) between December 2015 and December 2016. Case notes, laboratory tests and histopathology were reviewed to ascertain survival data and prognostic variables. Results: Of the 78 patients treated with TAS-102, median ECOG PS was 1, 56% of patients were male and median age was 64 years (range 27- 80 years). 31 patients had 3 or more metastatic sites of disease. 26 patients were RAS mutant and 1 patient was B-RAFmutant. Median number of cycles of TAS-102 was 2 cycles (range 1-11 cycles) with one third of patients requiring a dose reduction due to toxicity. 39% of patients developed grade 3 or 4 neutropenia and 12% febrile neutropenia. Response assessment was not performed in 12 patients due to death prior to assessment (6 patients) or withdrawal of patient consent for TAS-102 treatment (6 patients). Where best disease response was assessed by RECIST 1.1 criteria, 26.6% patient showed clinical benefit (stable disease or partial response) whereas 73.3% of patients had confirmed progressive disease. Median follow-up period was 5.2 months with 45 deaths in the study period. Median overall survival (OS) was 6.6 months. OS was significantly worse for patients with hypoalbuminemia (Albumin &lt; 30g/dl) at cycle 1 day 1 TAS-102 (p = 0.028). Anaemia, renal or liver impairment and number of metastatic sites of disease had no impact on patient survival. RAS mutant colorectal cancer patients showed a trend to improved outcome on TAS-102 which did not reach statistical significance within the study follow-up period. Conclusions: TAS-102 shows modest clinical benefit in treatment refractory metastatic colorectal cancer patients on the UK expanded access programme.