Treatment of patients with BRAFV600E-mutated metastatic colorectal cancer after progression to encorafenib and cetuximab: data from a real-world nationwide dataset.

BACKGROUND: Targeted therapy (TT) with encorafenib and cetuximab is the current standard for patients with BRAFV600E-mutated metastatic colorectal cancer (mCRC) who received one or more prior systemic treatments. However, the median progression-free survival (mPFS) is ∼4 months, and little is known about the possibility of administering subsequent therapies, their efficacy, and clinicopathological determinants of outcome. METHODS: A real-world dataset including patients with BRAFV600E-mutated mCRC treated with TT at 21 Italian centers was retrospectively interrogated. We assessed treatments after progression, attrition rates, and outcomes. RESULTS: Of the 179 patients included, 85 (47%), 32 (18%), and 7 (4%) received one, two, or three lines of treatment after TT, respectively. Those receiving TT in the second line were more likely to receive at least one subsequent therapy (53%), as compared with those treated with TT in the third line or beyond (30%; P < 0.0001), and achieved longer postprogression survival (PPS), also in a multivariate model (P = 0.0001). Among 62 patients with proficient mismatch repair/microsatellite stable (pMMR/MSS) tumors receiving one or more lines of treatment after second-line TT, combinatory chemotherapy ± anti-vascular endothelial growth factor (anti-VEGF) was associated with longer PFS and PPS as compared with trifluridine-tipiracil or regorafenib (mPFS: 2.6 versus 2.0 months, P = 0.07; PPS: 6.5 versus 4.4 months, P = 0.04). CONCLUSIONS: Our real-world data suggest that TT should be initiated as soon as possible after the failure of first-line treatment in BRAFV600E-mutated mCRC. Among patients with pMMR/MSS tumors, combinatory chemotherapy ± anti-VEGF appears the preferred treatment choice after TT failure.

Phase II study of capecitabine-based concomitant chemoradiation followed by durvalumab as a neoadjuvant strategy in locally advanced rectal cancer: the PANDORA trial.

BACKGROUND: This study investigated the efficacy of chemoradiotherapy (CRT) followed by durvalumab as neoadjuvant therapy of locally advanced rectal cancer. PATIENTS AND METHODS: The PANDORA trial is a prospective, phase II, open-label, single-arm, multicenter study aimed at evaluating the efficacy and safety of preoperative treatment with durvalumab (1500 mg every 4 weeks for three administrations) following long-course radiotherapy (RT) plus concomitant capecitabine (5040 cGy RT in 25-28 fractions over 5 weeks and capecitabine administered at 825 mg/m2 twice daily). The primary endpoint was the pathological complete response (pCR) rate; secondary endpoints were the proportion of clinical complete remissions and safety. The sample size was estimated assuming a null pCR proportion of 0.15 and an alternative pCR proportion of 0.30 (α = 0.05, power = 0.80). The proposed treatment could be considered promising if ≥13 pCRs were observed in 55 patients (EudraCT: 2018-004758-39; NCT04083365). RESULTS: Between November 2019 and August 2021, 60 patients were accrued, of which 55 were assessable for the study's objectives. Two patients experienced disease progression during treatment. Nineteen out of 55 eligible patients achieved a pCR (34.5%, 95% confidence interval 22.2% to 48.6%). Regarding toxicity related to durvalumab, grade 3 adverse events (AEs) occurred in four patients (7.3%) (diarrhea, skin toxicity, transaminase increase, lipase increase, and pancolitis). Grade 4 toxicity was not observed. In 20 patients (36.4%), grade 1-2 AEs related to durvalumab were observed. The most common were endocrine toxicity (hyper/hypothyroidism), dermatologic toxicity (skin rash), and gastrointestinal toxicity (transaminase increase, nausea, diarrhea, constipation). CONCLUSION: This study met its primary endpoint showing that CRT followed by durvalumab could increase pCR with a safe toxicity profile. This combination is a promising, feasible strategy worthy of further investigation.

Plasmatic BRAF-V600E allele fraction as a prognostic factor in metastatic colorectal cancer treated with BRAF combinatorial treatments.

BACKGROUND: Combination of a BRAF inhibitor (BRAFi) and an anti-epidermal growth factor receptor (EGFR), with or without a MEK inhibitor (MEKi), improves survival in BRAF-V600E-mutant metastatic colorectal cancer (mCRC) over standard chemotherapy. However, responses are heterogeneous and there are no available biomarkers to assess patient prognosis or guide doublet- or triplet-based regimens. In order to better characterize the clinical heterogeneity observed, we assessed the prognostic and predictive role of the plasmatic BRAF allele fraction (AF) for these combinations. PATIENTS AND METHODS: A prospective discovery cohort including 47 BRAF-V600E-mutant patients treated with BRAFi-anti-EGFR ± MEKi in clinical trials and real-world practice was evaluated. Results were validated in an independent multicenter cohort (n= 29). Plasmatic BRAF-V600E AF cut-off at baseline was defined in the discovery cohort with droplet digital PCR (ddPCR). All patients had tissue-confirmed BRAF-V600E mutations. RESULTS: Patients with high AF have major frequency of liver metastases and more metastatic sites. In the discovery cohort, median progression-free survival (PFS) and overall survival (OS) were 4.4 and 10.1 months, respectively. Patients with high BRAF AF (≥2%, n = 23) showed worse PFS [hazard ratio (HR) 2.97, 95% confidence interval (CI) 1.55-5.69; P = 0.001] and worse OS (HR 3.28, 95% CI 1.58-6.81; P = 0.001) than low-BRAF AF patients (<2%, n = 24). In the multivariable analysis, BRAF AF levels maintained independent significance. In the validation cohort, high BRAF AF was associated with worse PFS (HR 3.83, 95% CI 1.60-9.17; P = 0.002) and a trend toward worse OS was observed (HR 1.86, 95% CI 0.80-4.34; P = 0.15). An exploratory analysis of predictive value showed that high-BRAF AF patients (n = 35) benefited more from triplet therapy than low-BRAF AF patients (n = 41; PFS and OS interaction tests, P < 0.01). CONCLUSIONS: Plasmatic BRAF AF determined by ddPCR is a reliable surrogate of tumor burden and aggressiveness in BRAF-V600E-mutant mCRC treated with a BRAFi plus an anti-EGFR with or without a MEKi and identifies patients who may benefit from treatment intensification. Our results warrant further validation of plasmatic BRAF AF to refine clinical stratification and guide treatment strategies.

Encorafenib plus cetuximab with or without binimetinib in patients with BRAF V600E-mutated metastatic colorectal cancer: real-life data from an Italian multicenter experience.

BACKGROUND: Encorafenib plus cetuximab with or without binimetinib showed increased objective response rate (ORR), progression-free survival (PFS), and overall survival (OS) compared with chemotherapy plus anti-EGFR in previously treated patients with BRAF V600E-mutated (mut) metastatic colorectal cancer (mCRC). Although no formal comparison was planned, addition of binimetinib to encorafenib plus cetuximab did not provide significant efficacy advantage. PATIENTS AND METHODS: This real-life study was aimed at evaluating safety, activity, and efficacy of encorafenib plus cetuximab with or without binimetinib in patients with BRAF V600E-mut mCRC treated at 21 Italian centers within a nominal use program launched in May 2019. RESULTS: Out of 133 patients included, 97 (73%) received encorafenib plus cetuximab (targeted doublet) and 36 (27%) the same therapy plus binimetinib (targeted triplet). Most patients had Eastern Cooperative Group Performance Status (ECOG-PS) of 0 or 1 (86%), right-sided primary tumor (69%), and synchronous disease (66%). Twenty (15%) tumors were DNA mismatch repair deficiency (dMMR)/microsatellite instability (MSI)-high. As many as 44 (34%) patients had received two or more prior lines of therapy, 122 (92%) were previously exposed to oxaliplatin, and 109 (82%) to anti-vascular endothelial growth factor (anti-VEGF). Most frequent adverse events were asthenia (62%) and anti-EGFR-related skin rash (52%). Any grade nausea (P = 0.03), vomiting (P = 0.04), and diarrhea (P = 0.07) were more frequent with the triplet therapy, while melanocytic nevi were less common (P = 0.06). Overall, ORR and disease control rate (DCR) were 23% and 69%, respectively, with numerically higher rates in the triplet group (ORR 31% versus 17%, P = 0.12; DCR 78% versus 65%, P = 0.23). Median PFS and OS were 4.5 and 7.2 months, respectively. Worse ECOG-PS, peritoneal metastases, and more than one prior treatment were independent poor prognostic factors for PFS and OS. Clonality of BRAF mutation measured as adjusted mutant allele fraction in tumor tissue was not associated with clinical outcome. CONCLUSIONS: Our real-life data are consistent with those from the BEACON trial in terms of safety, activity, and efficacy. Patients in good general condition and not heavily pretreated are those more likely to derive benefit from the targeted treatment.

Clinical impact of neutropenia and febrile neutropenia in metastatic colorectal cancer patients treated with FOLFOXIRI/bevacizumab: a pooled analysis of TRIBE and TRIBE2 studies by GONO.

BACKGROUND: TRIBE and TRIBE-2 studies demonstrated higher benefit from FOLFOXIRI (fluorouracil, leucovorin, oxaliplatin, and irinotecan)/bevacizumab compared with FOLFIRI (fluorouracil, leucovorin, and irinotecan) or FOLFOX/bevacizumab as an upfront option for metastatic colorectal cancer patients, with more toxicities. We focused on the incidence and longitudinal dynamics of neutropenia and febrile neutropenia (FN) in the two studies, to evaluate their clinical relevance, the magnitude of impact of FOLFOXIRI/bevacizumab, and the role of risk factors in predicting their occurrence. METHODS: The overall incidence of grade 3-4 (G3-4) neutropenia and FN, the time to their onset, the use of granulocyte colony-stimulating factor, and the association with risk factors were evaluated in the overall population and according to treatment arm. FN episodes were assessed by Multinational Association for Supportive Care in Cancer (MASCC) score. RESULTS: Among 1155 patients, 568 (49%) received FOLFOXIRI/bevacizumab. Overall, 410 (35%) experienced G3-4 neutropenia and 70 (6%) FN, 21 (2%) at high risk. FOLFOXIRI/bevacizumab was associated with higher incidence of neutropenia (51% versus 21%, P < 0.001), FN (8% versus 4%, P = 0.02), and high-risk FN [18 (3%) versus 3 (1%), P = 0.015]. No related deaths were observed. The first episode of G3-4 neutropenia and FN occurred mainly in the first 2 months in both arms. Longitudinal analysis showed different patterns of evolution over cycles between the arms (P < 0.001) G3-4 neutropenia being more frequent in the first cycles with FOLFOXIRI/bevacizumab. Older patients (P = 0.01) and females (P < 0.001) had a significantly higher risk of G3-4 neutropenia. No significant interaction effect between arm and analysed risk factors in terms of risk of G3-4 neutropenia or FN was observed. The incidence of FN among older females receiving FOLFOXIRI/bevacizumab was 12%. Neither G3-4 neutropenia nor FN impaired efficacy in terms of overall response rate, progression-free survival, and overall survival. CONCLUSIONS: FOLFOXIRI/bevacizumab has a higher risk of G3-4 neutropenia and FN than doublets/bevacizumab. FN occurred in <10% of patients, mostly as low-risk episodes. A closer monitoring during the first 2 months is recommended; prophylactic use of granulocyte colony-stimulating factor may be considered for older females.

Prognostic and predictive impact of consensus molecular subtypes and CRCAssigner classifications in metastatic colorectal cancer: a translational analysis of the TRIBE2 study.

INTRODUCTION: The consensus molecular subtypes (CMS) demonstrated prognostic value in metastatic colorectal cancer (mCRC). Similarly, a prognostic impact was suggested for the pre-consensus CRCAssigner (CRCA) classifier in early stages. The potential predictive role of these classifiers with regard to the choice of the first-line therapy has not been established. We investigated the prognostic and predictive impact of CMS and CRCA subtypes among mCRC patients treated in the TRIBE2 study. METHODS: Among 679 randomized patients, 426 and 428 (63%) samples were profiled according to CMS and CRCA classifications, respectively. The prognostic and predictive impact of both CMS and CRCA subtypes was investigated with univariate and multivariate analyses for progression-free survival (PFS), PFS 2 (PFS2), and overall survival (OS). RESULTS: Significant associations of CMS and CRCA subtypes with PFS, PFS2, and OS were demonstrated; the CMS classifier confirmed its independent prognostic value in the multivariable model (P value for PFS/PFS2/OS = 0.01/0.07/0.08). The effect of treatment intensification was independent of CMS subtypes (P value for interaction for PFS/PFS2/OS = 0.88/0.75/0.55). A significant interaction effect between CRCA subtypes and treatment arm was demonstrated in PFS (P = 0.02), PFS2 (P = 0.01), and OS (P = 0.008). The benefit of FOLFOXIRI seemed more relevant in the stem-like (PFS, hazard ratio = 0.60; P = 0.03) and mixed subtypes (hazard ratio = 0.44; P = 0.002). These findings were confirmed in a subgroup of patients of the previous TRIBE study. CONCLUSIONS: We confirmed the independent prognostic role of CMS classification in mCRC independently of RAS/BRAF status. CRCA classification may help identifying subgroups of patients who may derive more benefit from FOLFOXIRI/bevacizumab.

Impact of age and gender on the safety and efficacy of chemotherapy plus bevacizumab in metastatic colorectal cancer: a pooled analysis of TRIBE and TRIBE2 studies.

BACKGROUND: The phase III TRIBE and TRIBE2 studies randomized metastatic colorectal cancer patients to first-line FOLFOXIRI/bevacizumab or a doublet (FOLFIRI or FOLFOX)/bevacizumab. The studies demonstrated a significant benefit from the triplet at the price of an increased incidence of chemotherapy-related adverse events (AEs). In both trials, males and females aged between 18 and 70 years with ECOG PS ≤2 and between 71 and 75 years with ECOG PS = 0 were eligible. We investigated the effect of FOLFOXIRI/bevacizumab versus doublets/bevacizumab according to age and gender. PATIENTS AND METHODS: Subgroup analyses according to age (<70 versus 70-75 years) and gender were carried out for overall response rate (ORR), progression-free survival (PFS), and AE rates. RESULTS: Of 1187 patients, 1005 (85%) were aged <70 years and 182 (15%) 70-75 years; 693 (58%) were males and 494 (42%) females. There was no evidence of interaction between age or gender and the benefit provided by the intensification of the upfront chemotherapy in terms of ORR and PFS, or the increased risk of experiencing G3/4 AEs. Elderly patients and females experienced higher rates of overall G3/4 AEs (73% versus 60%, P < 0.01 and 69% versus 57%, P < 0.01, respectively). Notably, in the FOLFOXIRI/bevacizumab subgroup, G3/4 diarrhea and febrile neutropenia occurred in 27% and 16% of elderly patients, respectively, while females reported high incidences of any grade nausea (67%) and vomiting (50%). CONCLUSIONS: The improvements in terms of ORR and PFS of FOLFOXIRI/bevacizumab versus doublets/bevacizumab are independent of gender and age, with a similar relative increase in AEs among elderly patients and females. Initial dose reductions and possibly primary G-CSF prophylaxis should be recommended for patients between 70 and 75 years old treated with FOLFOXIRI/bevacizumab, and a careful management of antiemetic prophylaxis should be considered among females.