BRAF Wt Research Articles

Interaction of DisBa01 peptide from Bothrops alternatus venom with BRAF melanoma receptors: Modeling and molecular docking

Metastatic melanoma is highly aggressive and challenging, often leading to a grim prognosis. Its progression is swift, especially when mutations like BRAFV600E continuously activate pathways vital for cell growth and survival. Although several treatments target this mutation, resistance typically emerges over time. In recent decades, research has underscored the potential of snake venoms and peptides as bioactive substances for innovative drugs, including anti-coagulants, anti-microbial, and anti-cancer agents. Leveraging this knowledge, we propose employing a bioinformatics simulation approach to: a) Predict how well a peptide (DisBa01) from Bothrops alternatus snake venom binds to the melanoma receptor BRAFV600E via Molecular Docking. b) Identify the specific peptide binding sites on receptors and analyze their proximity to active receptor sites. c) Evaluate the behavior of resulting complexes through molecular dynamics simulations. d) Assess whether this peptide qualifies as a candidate for anti-melanoma therapy. Our findings reveal that DisBa01 enhances stability in the BRAFV600E melanoma receptor structure by binding to its RGD motif, an interaction absent in the BRAF WT model. Consequently, both docking and molecular dynamics simulations suggest that DisBa01 shows promise as a BRAFV600E inhibitor.

Monitoring ctDNA RAS Mutational Status in Metastatic Colorectal Cancer: A Trial Protocol of RAS-trace and RAS-trace-2 Studies.

Spatial and temporal heterogeneities of RAS and other molecular genes should be considered in the treatment of metastatic colorectal cancer (mCRC) treated with anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs); acquired RAS mutation is sometimes observed at disease progression of treatment with the anti-EGFR mAb. At the same time, discrepancy of RAS status from tissues and circulating tumor DNA (ctDNA) in the same patient is sometimes observed. Based on this, we commenced two observational studies to clarify these heterogeneities of RAS and BRAF in mCRC, using next generation sequencing from liquid biopsy. RAS-trace study is an observational study to monitor ctDNA RAS/BRAF/PIK3CA status every 4-12 weeks using the Plasma-SeqSensei™ CRC RUO Kit (Sysmex Inostics GmbH) in mCRC with RAS/BRAF wild-type (wt) on tumor tissue. The primary endpoint was the time to the acquired RAS mutations. A total of 42 patients has been accrued. RAS-trace-2 study is also an observational study aimed at comparing the efficacy of the anti-EGFR mAb in ctDNA RAS/BRAF wt with ctDNA RAS or BRAF mutant mCRC patients, whose RAS/BRAF are wt in tumor tissue. The primary endpoint was progression-free survival in patients with ctDNA RAS/BRAF wt and RAS or BRAF mutant. A total of 240 patients will be accrued over 2 years. These trials will help us understanding the clinical significance of spatial and temporal heterogeneities of RAS, BRAF and other genes, while optimizing the anti-EGFR mAb treatment strategies in mCRC.

Abstract 5063: Exploring the mutational landscape of KRAS and NRAS in tumors with non-V600 BRAF mutations

Abstract Background: BRAF, a key modulator of the Mitogen-Activated Protein Kinase (MAPK) pathway, is observed in 7% of all cancers. Therapeutic response to MAPK inhibition (MAPKi) often relies on molecular distinctions between members of varying classes: Class 1 (V600), Class 2 and 3 (non-V600) BRAF mutants. Preliminary data indicates that co-occurring RAS mutations in non-V600 BRAF mutant cancers are less responsive to MAPKi treatment. This emphasizes the need to investigate the characteristics of RAS co-mutations in non-V600 BRAF mutant tumors. Methods: Genomic data was obtained from a cohort of 183,292 patients provided by the AACR GENIE database (v14.1). Patient samples were clustered according to their BRAF mutation status and co-occurring K/NRAS mutations: WT BRAF (n=60,845) vs. non-V600 BRAF (n=1009). Samples were grouped based on cancer type: melanoma (n=3841), colorectal (n=15,434), and non-small cell lung cancer (n=14640) and were further categorized according to key biochemical features of RAS GTPase function and overall GTPase activity. Results: This dataset revealed a diverse array of allelic variants of K/NRAS between cancer types and their underlying BRAF mutation status (Table 1). Non-V600 BRAF mutant cancers showed an enrichment for KRAS mutations linked to amplified nucleotide exchange (37.9% vs. 13.4%; p<0.0001) and hydrolysis-impairing NRAS mutations (41.9% vs. 23%; p<0.0001), compared to WT BRAF cancers. Rare allelic variants including KRAS L19F, KRAS A146T, and NRAS G60E were seen in Class 2/3 BRAF mutants. Conclusion: This data suggests that non-V600 BRAF mutant tumors are characterized by a unique distribution of RAS mutations. More research into the difference in downstream effectors of RAS mutants overrepresented in non-V600 BRAF mutant tumors could provide important insights into how these tumors develop and resist targeted therapies. Table 1. Classification of KRAS and NRAS mutations in WT BRAF vs. non-V600 BRAF mutant tumors GTPase Function Cancer Type All cancers NSCLC Colorectal Melanoma BRAF mutation WT non-V600 p-value WT non-V600 p-value WT non-V600 p-value WT non-V600 p-value KRASmutation class Impaired hydrolysis n=20731 (79.8%) n=167 (51.9%) <0.0001 n=6068 (86.1%) n=60 (56.6%) <0.0001 n=4799 (68.2%) n=16 (29.1%) <0.0001 n=38 (48.1%) n=13 (50.0%) 0.4047 Nucleotide Exchange n=3475 (13.4%) n=122 (37.9%) n=530 (7.5%) n=36 (34.0%) n=1842 (26.2%) n=36 (65.5%) n=30 (38.0%) n=12 (46.2%) Hybrid n=1765 (6.8%) n=33 (10.2%) n=446 (6.3%) n=10 (9.4%) n=395 (5.6%) n=3 (5.5%) n=11 (13.9%) n=1 (3.8%) NRAS mutation class Impaired hydrolysis n = 974 (23.0%) n=78 (41.9%) <0.0001 n=29 (18.7%) n=9 (39.1%) 0.0196 n=188 (32.6%) n=17 (68.0%) <0.0001 n=86 (5.5%) n=22 (27.8%) <0.0001 Nucleotide Exchange n=459 (10.8%) n=22 (11.8%) n=5 (3.2%) n=2 (8.7%) n=48 (8.3%) n=4 (16.0%) n=93 (5.9%) n=10 (12.7%) Hybrid n=2811 (66.2%) n=86 (46.2%) n=121 (78.1%) n=12 (52.2%) n=341 (59.1%) n=4 (16.0%) n=1385 (88.6%) n=47 (59.5%) GTPase Activity BRAF mutation WT non-V600 p-value WT non-V600 p-value WT non-V600 p-value WT non-V600 p-value KRASmutation class Intermediate activity n=14408 (55.3%) n=142 (44.4%) 0.0001 n=5082 (72.3%) n=54 (50.5%) <0.0001 n=3540 (49.9%) n=17 (31.5%) 0.0089 n=46 (56.8%) n=13 (50.0%) 0.6516 High activity n=11630 (44.7%) n=178 (55.6%) n=1947 (27.7%) n=53 (49.5%) n=3552 (50.1%) n=37 (68.5%) n=35 (43.2%) n=13 (50.0%) NRAS mutation class Intermediate activity n=1364 (32.2%) n=101 (55.8%) <0.0001 n=36 (23.4%) n=12 (54.5%) 0.0041 n=239 (41.8%) n=20 (87.0%) <0.0001 n=190 (12.3%) n=34 (43.0%) <0.0001 High activity n=2868 (67.8%) n=80 (44.2%) n=118 (76.6%) n=10 (45.5%) n=333 (58.2%) n=3 (13.0%) n=1357 (87.7%) n=45 (57.0%) Citation Format: Chantel L. Mukonoweshuro, Emmanuelle Rousselle, April A. Rose. Exploring the mutational landscape of KRAS and NRAS in tumors with non-V600 BRAF mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5063.

Abstract 7273: Small molecule activation of PP2A in the treatment of melanoma

Abstract Protein phosphatase 2A (PP2A) is a heterotrimeric holoenzyme functioning as a serine/threonine phosphatase, where it accounts for about 50-70% of all serine/threonine phosphorylation in the cell. Yet, PP2A is commonly inactivated in cancer, likely due to its role as a tumor suppressor. Due to the important role PP2A plays in many cellular processes, including those involved with tumor progression, there is a current need for novel therapeutics capable of targeting PP2A in cancer. Currently, none of the current PP2A modulators have made it into approved clinical use. As such, we have recently synthesized the PP2A activators, PPA24 and PPA27, using molecular docking and fragment-based drug design based on the structures of recently reported PP2A activators, iHAP1 and NSC49L. We were previously able to establish PPA24 as the lead compound in treating colorectal cancer (CRC) in vitro, compared to PPA27 and the parent compounds. Nevertheless, a single dose NCI-60 screen of both PPA24 and PPA27 indicated the cell selectivity present in both compounds and revealed the potential effect these compounds could have in other cancers. Further evaluation with an extended NCI-60 5-dose screen of PPA24 and PPA27 demonstrated a strong potential for both compounds in treating melanoma. Overall, the NCI-60 screen displayed PPA27 as most effective in melanoma across all cell lines screened, while PPA24 was found to be effective in both CRC and melanoma cell lines, agreeing with our previous findings. A cell viability screening of PPA24 and PPA27 in our laboratory across 5 melanoma cell lines (SK-MEL-2, SK-MEL-28, A375, Mel1241, and 451Lu) identified IC50 values in the range of 3.45-8.94 µM for PPA27 and 5.99-14.45 µM for PPA24. The parent compounds, iHAP1 and NSC49L, were also evaluated and NSC49L was found to be less effective in melanoma than previously found in CRC cells. Both PPA24 and PPA27 were found to be effective in cell lines with and without BRAFV600E mutation, though it appears the metastatic cell line, 451Lu, required an increased concentration for all compounds as compared to the IC50 values found in the other melanoma cell lines. Further evaluation revealed PPA24 and PPA27 as dose-dependently inducing apoptosis in cells with BRAFV600E (A375) and BRAF WT (SK-MEL-2). Together, these findings show the potential of PPA24 and PPA27 as therapeutic treatments for melanoma with or without BRAF mutations and are currently being further evaluated in several in vitro and in vivo melanoma models in our laboratory. Citation Format: Hannah Johnson, Amandeep Singh, Asif Raza, Satya Narayan, Arun K. Sharma. Small molecule activation of PP2A in the treatment of melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7273.

Augmenting MEK inhibitor efficacy in BRAF wild-type melanoma: synergistic effects of disulfiram combination therapy

BackgroundMEK inhibitors (MEKi) were shown to be clinically insufficiently effective in patients suffering from BRAF wild-type (BRAF WT) melanoma, even if the MAPK pathway was constitutively activated due to mutations in NRAS or NF-1. Thus, novel combinations are needed to increase the efficacy and duration of response to MEKi in BRAF WT melanoma. Disulfiram and its metabolite diethyldithiocarbamate are known to have antitumor effects related to cellular stress, and induction of endoplasmic reticulum (ER) stress was found to synergize with MEK inhibitors in NRAS-mutated melanoma cells. Therefore, we investigated the combination of both therapeutics to test their effects on BRAF-WT melanoma cells and compared them with monotherapy using the MEKi trametinib.MethodsThe effects of combined therapy with disulfiram or its metabolite diethyldithiocarbamate and the MEKi trametinib were evaluated in a series of BRAF-WT melanoma cell lines by measuring cell viability and apoptosis induction. Cytotoxicity was additionally assessed in 3D spheroids, ex vivo melanoma slice cultures, and in vivo xenograft mouse models. The response of melanoma cells to treatment was studied at the RNA and protein levels to decipher the mode of action. Intracellular and intratumoral copper measurements were performed to investigate the role of copper ions in the antitumor cytotoxicity of disulfiram and its combination with the MEKi.ResultsDiethyldithiocarbamate enhanced trametinib-induced cytotoxicity and apoptosis induction in 2D and 3D melanoma culture models. Mechanistically, copper-dependent induction of oxidative stress and ER stress led to Janus kinase (JNK)-mediated apoptosis in melanoma cells. This mechanism was also detectable in patient-derived xenograft melanoma models and resulted in a significantly improved therapeutic effect compared to monotherapy with the MEKi trametinib.ConclusionsDisulfiram and its metabolite represent an attractive pharmaceutical approach to induce ER stress in melanoma cells that potentiates the antitumor effect of MEK inhibition and may be an interesting candidate for combination therapy of BRAF WT melanoma.

Streamlining the diagnostic pathway for Lynch syndrome in colorectal cancer patients: a 10-year experience in a single Italian Cancer Center.

Universal screening of colorectal cancer (CRC) patients for Lynch syndrome (LS) through MisMatch Repair (MMR) testing is recommended. BRAF V600E mutation and/or MLH1 promoter methylation (Reflex Testing, RefT)generally rule out LS in MLH1-deficient (dMLH1) patients. We estimated the impact of RefTon genetic counseling (GC) and on the diagnostic yield of genetic testing (GT). Overall, 3199 CRC patients were referred to our center between 2011 and 2021. Patients referred until January 2019 (n=2536) underwent universal MMR testing and were termed 'Cohort A'; among patients after February 2019 (n=663), 'Cohort B', RefT was also performed in dMLH1 patients. Overall, 401/3199 patients (12.5%) were MMR-deficient (dMMR); 312 (77.8%) in cohort A and 89 (22.2%) inB; 346/401 were dMLH1 (86.3%), 262/312 (83.9%) in cohort A and 84/89 (94.3%) in B. In Cohort A, 91/312 (29.1%) dMMR patients were referred to GC, 69/91 (75.8%) were in the dMLH1 group; 57/69 (82.6%) dMLH1 patients underwent GT and 1/57 (1.7%) had LS. In Cohort B, 3/84 dMLH1 patients did not undergo BRAF testing. Three BRAF wt and not hypermethylated of the remaining 81 dMLH1 patients were referred to GC and GT, and one had LS. This diagnostic pathway reduced GC referrals by 96% (78/81) in Cohort B and increased the diagnostic yield of GT by about 20 times. Our findings support RefT in dMLH1 CRC patients within the LS diagnostic pathway, as it reduces the number of GC sessions needed and increases the diagnostic yield of GT.

PD-L1 is a biomarker of real-world clinical outcomes for anti-CTLA-4 plus anti-PD-1 or anti-PD-1 monotherapy in metastatic melanoma

BackgroundMetastatic melanoma (MM) is commonly treated with a combination of nivolumab and ipilimumab, regardless of tumor PD-L1 expression. MethodsWe conducted a population-based study including all patients with MM (except ocular melanoma) treated in Denmark with first-line combination therapy or anti-PD-1 monotherapy since January 2017. Baseline data including known prognostic characteristics were used in multivariable and propensity-matched score (PMS) analyses to assess progression-free survival (PFS), melanoma-specific survival (MSS), and overall survival (OS) according to PD-L1 expression. ResultsWe identified 1341 eligible patients, with known PD-L1 status for 1081 patients (43% PD-L1 ≥ 1%, 57% PD-L1 < 1%). PD-L1 ≥ 1% was an independent positive prognostic biomarker for survival in the overall cohort (MSS: HR 0.66, CI 0.52–0.83, p < 0.001). In the PMS PD-L1 ≥ 1% cohort, combination therapy showed similar clinical outcomes to monotherapy (PFS: HR 1.41, CI 0.94–2.11, p = 0.101; MSS: HR 1.21, CI 0.70–2.11, p = 0.49; OS: HR 1.17, CI 0.68–2.00, p = 0.567). In contrast, in the PMS PD-L1 < 1% and in the PMS PD-L1 < 1% BRAF WT cohorts, combination therapy improved PFS (respectively with HR 0.70, CI 0.53–0.93, p = 0.013; and HR 0.54, CI 0.37–0.78, p = 0.001), but did not reach statistically significant improvements of MSS (HR 0.72, CI 0.50–1.02, p = 0.065; and HR 0.79, CI 0.51–1.21, p = 0.278) or OS (HR 0.78, CI 0.56–1.08, p = 0.135; and HR 0.81, CI 0.54–1.21, p = 0.305) compared to monotherapy. ConclusionOur findings support previous exploratory analyses of Checkmate-067, highlighting that improved clinical outcomes with combination therapy are not established in unselected patients with high (≥1%) tumor PD-L1 expression.

Abstract C141: Targeting SHP2-dependent adaptive resistance to BRAF and MEK inhibition in gliomas

Abstract Introduction: BRAF-mutant gliomas, common in children, are sensitive to MEK and/or BRAF inhibitors. However, responses are incomplete and can be short-lived, due to poorly understood mechanisms of resistance that are likely to involve kinome re-programming, treatment-emergent resistance mutations, and adaptive resistance, by which upstream signaling components become activated due to release of negative feedback. Based on the critical role of SHP2 upstream of RAS pathway, we postulated that the combination of SHP2i and BRAFi/MEKi would maintain superior ERK pathway inhibition in gliomas. Here, we demonstrate that combined SHP2i+BRAFi can be efficacious in BRAFV600E mutant gliomas, potentially without the toxicity posed by SHP2i+MEKi in human participants. Methods: Using a panel of BRAFV600E mutant and wild-type glioma cell lines, we examined cell growth with Incucyte live-cell imaging, RAS activity with pull-down assay, and immunoblots of ERK signaling activity in response to MEKi (Trametinib), BRAFi (Dabrafenib), and/or SHP2i (TNO155). NSG immune-deficient mice were implanted subcutaneously with human-derived glioma lines and patient-derived xenografts (PDXs), then treated via oral gavage for ≤28 days while recording tumor volume and weight. Results: In BRAFV600E glioma cells, we observed ERK reactivation and increased RAS activity in response to BRAFi or MEKi. SHP2 knockdown using PTPN11 pooled siRNA partially inhibited cell growth, while the addition of BRAFi/MEKi enhanced growth inhibition compared with either intervention alone. BRAFV600E cells showed insensitivity to small molecule SHP2i monotherapy, but augmented growth inhibition upon the combination with either BRAFi or MEKi due to prolonged ERK pathway suppression. BRAF wt glioma cell lines exhibit sensitivity to TNO155 monotherapy, and combination with MEKi demonstrates sustained pERK suppression in NF1-mut and NF1 wt cell lines. Additionally, we evaluated the effect of combined BRAFi+SHP2i in heterotopic xenografts using human-derived glioma lines and PDXs. In both models, tumor growth was significantly slower in the combined treatment group than either monotherapy. Moreover, mice tolerated the combination well with no weight loss or lethargy. Conclusion. Combined MEKi and SHP2i attenuate RAS reactivation in response to MEKi and demonstrates additive effects in glioma cell lines that are resistant to MEKi monotherapy. Moreover, SHP2i in combination with BRAFi in BRAFV600E mutant glioma cells synergistically attenuated tumor growth in vitro and shows superior preclinical activity to BRAFi or SHP2i alone in BRAFV600E models of gliomas. Citation Format: Abiola Abdulrahman Ayanlaja, Kriti Lalwani, Maria Ioannou, Christine Pratilas, Karisa Schreck. Targeting SHP2-dependent adaptive resistance to BRAF and MEK inhibition in gliomas [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr C141.

Postoperative circulating tumor DNA-based molecular residual disease in patients with BRAF V600E and MSI-H colorectal cancer: Updated results from GALAXY study in the CIRCULATE-Japan.

32 Background: Postoperative circulating tumor DNA (ctDNA)-based molecular residual disease (MRD) is reported to be associated with a high risk of recurrence. Here, we present an updated analysis of MRD detection and correlations with BRAF and MSI status in radically resected, stage II-IV colorectal cancer (CRC) from the observational GALAXY study (UMIN000039205). Methods: Serial ctDNA was analyzed using personalized tumor-informed assay (Signatera bespoke multiplex-PCR NGS assay) at 1 (4-week MRD time point), 3, 6, 9, 12, 18, and 24 months after surgery or until recurrence (whichever comes first). CT scans were conducted every 6 months. BRAF and MSI status were determined by central assessment until September 2021 and per the standard of care after October 2021. The primary endpoint was disease-free survival (DFS), defined as the time between the date of surgery and date of diagnosis with relapse or death due to any cause. Results: Among 3,615 CRC patients (pts) who were enrolled between May 2020 and April 2022 in GALAXY study, 2,083 pts that met the inclusion criteria were analyzed. The median follow-up period was 16.3 months. Of 2,083 pts included in the analysis, 60 pts (2.9%) had BRAF V600E mutant and MSS tumors, 100 pts (4.8%) had BRAF wt and MSI-H tumors, and 115 patients (5.5%) had BRAF V600E mutant and MSI-H tumors. In the overall population, 286 (14%) were ctDNA-positive at the 4-week MRD time point and 1,797 (86%) were ctDNA-negative. Pts with ctDNA-positivity at the 4-week demonstrated inferior DFS and were 12 times more likely to recur, compared to ctDNA-negative pts (HR: 12, 95%CI: 9.1-15%; p&lt;0.001). Pts with BRAF wt and MSI-H tumors had significantly better DFS compared to pts with BRAF wt and MSS tumors (HR: 4.14, 95 %CI: 1.3-12.9, p=0.015). Pts with BRAF V600E mutant and MSI-H tumors had significantly better DFS compared to pts with BRAF wt and MSS tumors (HR: 4.80, 95 %CI: 1.5-15, p=0.007). On the other hand, ctDNA-positivity was associated with significantly shorter DFS in pts with BRAF V600E mutant and MSS tumors (HR: 2.33, 95%CI: 1.03-5.3, p=0.043) and BRAF V600E mutant and MSI-H tumors (HR:7.54, 95%CI:2.37-24, p&lt;0.001) compared to pts with BRAF wt and MSS tumors. Multivariate analysis in DFS showed that ctDNA positivity was significantly associated with poor prognosis (HR: 11.68, 95%CI: 8.61-15.85, p&lt;0.001), outperforming other clinicopathologic factors such as BRAF and MSI status. Conclusions: ctDNA status at the postoperative MRD time point is the most prognostic risk factor of DFS regardless of BRAF V600E or MSI-H status. Pts with positive postoperative ctDNA should be examined carefully due to a high risk of recurrence. ctDNA-guided adjuvant strategies will further be established by the ongoing randomized VEGA and ALTAIR studies in CIRCULATE-Japan. Clinical trial information: UMIN000039205 .

Dual detection system for cancer-associated point mutations assisted by a multiplexed LNA-based amperometric bioplatform coupled with rolling circle amplification

DNA point mutation in a BRAF proto-oncogene, V600E, is considered an important prognostic and predictive biomarker in various types of cancer, such as melanoma or colorectal cancer. We report here a novel electrochemical (EC) bioplatform for the analysis of BRAF V600E mutation coupled with rolling circle amplification (RCA) and locked nucleic acid (LNA) capture probes. A dual detection system was implemented, whereby two padlock probes complementary to either wild-type (wt) BRAF gene or DNA with V600E mutation (mut) led to amplification of wt or mut variant, respectively. Hybridization with specific LNA capture probes then increased the assay specificity, while EC detection provided rapid measurement times. The bioplatform was applied to analyze BRAF V600E mutation of cancer cells and tumor tissues from patients with melanoma or colorectal cancer. This is the first RCA-based EC bioplatform for BRAF analysis in a dual format without using PCR or sophisticated instrumentation.

Optimal molecular-targeted therapies as first-line treatment for RAS wild-type, right-sided metastatic colorectal cancer from the Analysis and Research in Cancers of the Digestive System (ARCAD) database.

3588 Background: Although anti-EGFR antibody plus doublet chemotherapy has become the standard of first-line treatment for RAS wild-type (wt), left sided metastatic colorectal cancer (mCRC), the optimal molecular-targeted therapy for RAS wt, right-sided mCRC is not clear. Methods: To evaluate the efficacy between anti-EGFR antibody vs. bevacizumab combination therapy, from 40,889 Individual patient (pt) data from 59 studies in ARCAD mCRC database, 723 pts with RAS wt, right-sided mCRC who received a first-line molecular-targeted therapy with backbone chemotherapy (FOLFOX/FOLFIRI when anti-EGFR antibody combination, and FOLFOX/FOLFIRI/CAPOX/FOLFOXIRI when bevacizumab combination) were selected from 10 randomized studies (FIRE-3, CALGB80495, CRYSTAL, PRIME, CAIRO2, OPUS, TRIBE, TRIBE2, ATOM, and CCOG1201). Primary objective was overall survival (OS), and secondary objectives were progression-free survival (PFS) and overall response rate (ORR); Hazard ratio (HR) and Odds ratio (OR) were adjusted for ECOG-PS, age, and gender. Propensity score matching (PSM) and inverse probability treatment weighting (IPTW) as sensitivity analysis were also performed. Secondary analyses were limited to BRAF wt pts. Results: Anti-EGFR antibody and bevacizumab were administrated in 329 and 394 pts, respectively, of whom 162 and 151 pts were BRAF wt, respectively. Baseline characteristics were as follows (anti-EGFR antibody/bevacizumab): median age, 63.0 years both; female, 47.1/46.4%; and ECOG-PS 0, 53.2/65.2%. The OS and PFS were significantly prolonged in pts receiving bevacizumab combination therapy compared to those receiving anti-EGFR antibody combination therapy (Table). These trends were more pronounced when limited to BRAF wt pts (Table). There were no significant differences in ORR for both overall and BRAF wt pts. These results were similar in the sensitivity analysis (Table). Conclusions: For patients with RAS wt or RAS/ BRAF wt, right-sided mCRC, bevacizumab combination therapy is preferred first-line treatment. [Table: see text]

Impact of adjuvant immunotherapy in resected stage II/III/IV melanoma: A single center experience.

e21565 Background: The incidence of malignant melanoma (MM) in Mediterranean countries is estimated at 3- 5/100.000 inhabitants/year with a predicted rising trend. MM is responsible for over 90% skin cancer deaths due to its tendency to metastasize early. Surgical excision is the treatment of choice for early-stage melanoma, however, 40-60% of patients with high recurrence risk melanoma, thick ulcerated primary melanomas (Stage IIC) and those with lymph node involvement (Stage III), experience a tumor relapse. Adjuvant therapy in resected high-risk melanomas has shown improved Relapse-Free-Survival (RFS), although no Overall Survival (OS) benefit has been observed to date. This retrospective observational study, conducted in one center, aims to evaluate effectiveness and safety of adjuvant therapies for resected high-risk melanoma. Methods: Single center cross-sectional study that included patients with a resected high-risk melanoma candidate for adjuvant treatment, at 2015-2022 period. Convenience sampling 48 patients recruited. Median follow up 55,4 months. Results: Median age was 54y, 52% were male and 93’6 is cutaneous melanoma. 53% were BRAF WT. Median Breslow (mm) was 3’85, median num/mm2 mitosis are 4 and 62’5% had ulceration. 15% presented satelosis or intransit metastasis and 55% had a lymphadenectomy. Melanoma stage: 9%IIB, 11%IIC, 11%IIIA, 25%IIIB, 38%IIIC, 2% IIID and 2% IV. Adjuvant treatment: 22% nivolumab, 20% ipilimumab+nivolumab, 12% ipilimumab, 16% interferon.75% of patients completed adjuvant treatment, 14% stopped for toxicity and 9% presented disease relapse (21% loca, 64% systemic). Best treatment response in relapse was 12% partial response, 37% progression. Toxicity: 18% presented grad ¾ toxicity. Efficacy: median RFS was 78’8m and median OS was NR. Conclusions: Adjuvant treatment is associated with an increased DFI in resected high risk melanoma patients. Adjuvant therapy was generally well tolerated, with manageable adverse events, consistent in type and incidence to those seen in clinical trials that allowed the approval for these compounds in adjuvant and metastatic scenarios. Prospective studies are needed to determine new biomarkers for the selection of those patients who could benefit to a greater extent from adjuvant therapies in resected high-risk melanoma.

Modified FOLFOXIRI plus cetuximab and avelumab as initial therapy in RAS wild-type unresectable metastatic colorectal cancer: Results of the phase II AVETRIC trial by GONO.

3575 Background: The modified schedule of FOLFOXIRI (mFOLFOXIRI) in combination with an anti-EGFR agent showed a manageable safety profile and remarkable activity in RAS wild-type (wt) metastatic colorectal cancer (mCRC). The association of an active cytotoxic regimen with cetuximab (cet) may increase the exposure of tumour-associated neoantigens and induce immunogenic cell death and antibody-dependent cell-mediated cytotoxicity thus enabling the effect of immune checkpoint inhibitors. The AVETRIC study aimed at exploring the efficacy and safety of first-line mFOLFOXIRI plus cet and avelumab (ave) in RAS wt mCRC patients (pts). Methods: AVETRIC is a prospective, open label, multicenter, phase II, single arm trial in which initially unresectable and previously untreated RAS wt mCRC pts received mFOLFOXIRI (irinotecan 150 mg/sqm, oxaliplatin 85 mg/sqm, folinate 200 mg/sqm leucovorin [LV], and 5-fluorouracil [5FU] 2400 mg/sqm) plus cet (500 mg/sqm) and ave (800 mg) every 2 weeks up to 12 cycles followed by maintenance with 5FU/LV plus cet and ave until disease progression. A safety run-in phase including the first 6 enrolled pts was planned. Due to the occurrence of grade 3-4 diarrhoea in 2 (33%) pts, the protocol study was amended to reduce the irinotecan dose to 130 mg/sqm. Primary endpoint was Progression Free Survival (PFS). Fifty-eight pts were needed to detect an increase in median PFS (mPFS) from 10.0 to 19.4 months (mos), setting one-sided α and β errors at 0.05 and 0.10, respectively. The trial is registered at Clinicaltrial.gov, NCT04513951. Results: Between Jun 2020 and Dec 2021, 62 pts were enrolled in 16 Italian centres. Main pts' characteristics were: median age 56 yrs, ECOG PS 0 87%, synchronous metastases 94%, liver-only disease 42%, left-sided primary tumour 89%; all pts had BRAF wt and proficient MMR (pMMR) tumours. The primary endpoint was met. At a median follow-up of 16.0 months, 39 (63%) events were recorded and mPFS was 14.1 months (90% CI 12.0-16.7, Brookmeyer-Crowley test p &lt; 0.001). Response rate and disease control rate were 82% and 98%, respectively, and R0 resection rate was 21% (27% in liver-only subgroup). Early tumour shrinkage was achieved in 74% pts and median deepness of response was 56%. In pts treated after study amendment (n = 56), main grade 3-4 adverse events were neutropenia (27%), diarrhoea (27%), skin rash (14%), asthenia (14%), nausea (11%), stomatitis (7%), febrile neutropenia (2%). Grade 3-4 immune-related adverse events occurred in 6% of pts. Overall survival results are still immature. Conclusions: AVETRIC study met its primary endpoint, showing that combining mFOLFOXIRI plus cet and ave achieves promising results in terms of PFS as well as response rate, in pts with pMMR RAS and BRAF wt mCRC. Translational analyses to evaluate the impact of immune-related biomarkers are ongoing. Clinical trial information: NCT04513951 .

A phase 1/2 study of CFT1946, a novel, bifunctional degradation activating compound (BIDAC) degrader, of mutant BRAF V600 as monotherapy and in combination with trametinib, in mutant BRAF V600 solid tumors.

TPS3163 Background: BRAF is a protein kinase that acts as a signal transducer in the MAPK pathway. Mutant BRAF V600 is capable of uncontrolled signaling and is constitutively active and signals as a monomer, leading to hyperactivation of MEK, ERK, and dysregulation of cellular proliferation. Mutant BRAF V600 is a clinically-validated target in a variety of cancers including melanoma, colorectal cancer (CRC), non-small cell lung cancer (NSCLC), and anaplastic thyroid carcinoma (ATC). Currently approved BRAF inhibitors (BRAFi) result in paradoxical RAF activation as the mutant BRAF protein is still able to dimerize with WT BRAF, resulting in a dimeric signaling complex. CFT1946 is a novel, orally bioavailable BiDAC degrader that inhibits and degrades mutant BRAF V600 protein. Distinct from approved BRAFi, CFT1946 avoids paradoxical RAF activation as the degraded BRAF V600 mutant protein can no longer incorporate into a dimeric signaling complex. CFT1946 is selective for the mutant protein and spares WT BRAF V600. CFT1946 has demonstrated preclinical activity in BRAF V600 mutant in vitro and in vivo models, including models resistant to BRAFi. These preclinical data provide rationale for a first-in-human (FIH) study to evaluate CFT1946 in BRAF V600 mutant solid tumors. Methods: This is a FIH, open-label, multicenter, Phase 1/2 clinical trial to characterize the initial safety, tolerability, and preliminary efficacy of CFT1946 and CFT1946+trametinib in BRAF V600 mutant melanoma, NSCLC, CRC, ATC, and other non-CNS BRAF V600 mutant solid tumors. This study includes 2 phases: dose escalation Phase 1 comprising CFT1946 (Arm A) with a starting oral dose of 20 mg twice daily and CFT1946+trametinib (Arm B) as well as dose expansion Phase 2 comprising CFT1946 (Arm A1) and CFT1946+trametinib (Arms B1 and B2). Arm A1 and B1 will include BRAF V600 mutant melanoma and NSCLC with prior BRAFi therapy while Arm B2 will enroll BRAF V600 mutant NSCLC who are BRAFi-naïve. Phase 2 will be initiated once the RP2D has been identified. Eligible subjects are ≥18yo with documented BRAF V600 mutant cancers who have received ≥1 prior therapy. CFT1946 will be administered orally in 28-day cycles until disease progression or intolerable toxicity. Primary objectives include safety, tolerability, RP2D and preliminary antitumor activity of CFT1946 monotherapy and in combination with trametinib. Secondary objectives include assessment of pharmacokinetics and pharmacodynamics. Key inclusion criteria include documented evidence of a BRAF V600 mutation obtained from tumor tissue or liquid biopsy; at least 1 prior line of standard-of-care therapy for locally advanced or metastatic disease. The study is anticipated to enroll 101-122 patients across 11 participating US and European sites and is currently open to enrollment (NCT05668585). Clinical trial information: NCT05668585 .

Comprehensive analysis of the mutational status of early colon cancer: Real world data from the AIO ColoPredict registry study.

e15535 Background: The comprehensive analysis of the mutational status of colon cancer (CC) may identify targetable alterations also in early stages. This may open up potential beneficial treatment choices, e.g. immunotherapy in microsatellite instable (MSI) tumors. So far, there is few data regarding the distribution of molecular alterations in CC in a real world setting in Germany. Methods: We analyzed clinical and molecular data from our Colopredict Plus (CPP) registry trial including CC patients (pts.) stage I-III. Samples were tested for MS status by immunohistochemistry and for gene mutations (MT) using a 71 gene panel comprised for CC. Molecular data was correlated with clinicopathologic parameters. Disease free Survival (DFS) was estimated by the Kaplan-Meier method. Results: Data from 2746 pts. was included. Female: 1476/2746 (53,8 %), median age: 72 yrs (range: 22-100 yrs), right sided tumor: 1607/2746 (58,5 %), stage distribution I/II/III/NA: 414 (15,1 %)/1198 (43,6 %)/1076 (39,2 %)/58 (2,1 %). MSI/MSS: 544(19,8%)/2202/ (80,2%). A KRAS mutation was observed in 846/2746 (30,8 %). The most frequent hotspot MT were codon 12 KRAS MT with p.G12D (27%), p.G12V (19%), p.G12A (6%), and p.G12C (6%) followed by codon 13 MT with p.G13D (18%). The subtypes p.G12D, p.G12V, and p.Q61K were significantly more frequent in the right colon. BRAF MT was seen in 560/2746 (20,4%). Observed rare MT were: POLE (76/2746 (2,8 %), PTEN 188/2746 (6,8 %), and EGFR (21/2746; 0,8%). MSI CC were more frequent in the right colon and associated with BRAF MT (346/560; 61,8 %), and also MT in BRCA1 (35/53; 66 %), BRCA2 (119/171; 69,6 %), POLE (45/76 (59,2 %), PTEN 107/188 (56,9 %), and EGFR (18/21, 85,7%). In contrast, TP53 MT (1223/2746 (44,5 %)) were associated with MSS (1090/2746 (49,5 %)). 3 yrs DFS in MSI BRAF WT vs. MSS BRAF MT pts. was 0,75 (0,67 – 0,81 vs 0,52 (0,36 – 0,65) (p =0,11). DFS did not differ in specific KRAS MT variants. Conclusions: We here show a comprehensive analysis of genetic alterations in early CC in a prospective real world cohort. As expected, MSI was correlated with female sex, right sided primary tumor and BRAF MT. Interestingly, we also found a strong correlation of BRCA1 MT, BRCA2 MT, EGFR MT, POLE MT, and PTEN MT with presence of MSI while MSS was associated with TP53 MT. Broad molecular characterization of early CC may help individualize treatment strategies in the future.

Early tumor shrinkage (ETS) as clinical factor to select maintenance with cetuximab (cet) monotherapy in patients (pts) with RAS/BRAF wild-type (wt) metastatic colorectal cancer (mCRC): A secondary endpoint analysis of the ERMES study.

3603 Background: ERMES study aimed to demonstrate non-inferior PFS of maintenance with cetuximab (cet) monotherapy (arm B) compared to FOLFIRI+cet until progression (arm A) in RAS and BRAF wt mCRC pts. Although study did not meet its primary endpoint it showed better toxicity profile and OS for cet alone and comparable ORR between arms. Here we present results of ETS, a secondary endpoint. Methods: ETS was defined as ≥20% reduction of the sum of target lesions at 8 weeks from the start of treatment, and was assessed by blinded independent central review. PFS and OS were compared between ETS+ and ETS- pts according to treatment arm in the modified Per-Protocol (mPP) population. Results: 327 of 337 (97%) pts were evaluable for ETS. In arm A, no statistically significant differences were observed between ETS+ and ETS- cohort for PFS (11.9 m, 95%CI 11.28-13.19, vs 12.2 m, 95%CI 10.82-14.93; HR 1.05, 95%CI 0.73-1.50; p 0.77) and OS (30.75 m, 95%CI 25.09-37.73, vs 25.46 m, 95%CI 19.96-34.63; HR: 0.79, 95%CI 0.50-1.24; p 0.29). In arm B, a statistically significant difference was observed between ETS+ and ETS- cohort for PFS (10.62 m, 95%CI 9.86-13.09, vs 8.52 m, 95%CI 7.89-9.37; HR 0.70, 95%CI 0.49-1.00; p 0.036) and for OS (38.88 m, 95%CI 34.53-43.25, vs27.43 m, 95%CI 20.59-36.64; HR 0.60, 95%CI 0.38-0.93; p 0.019). ETS+ pts reported no statistically significant difference between arm B and arm A in terms of PFS (HR 1.12, 95%CI 0.83-1.49; p 0.43) while experiencing a better OS for arm B compared to arm A (HR 0.72, 95%CI 0.50-1.05; p 0,08). Conclusions: In pts achieving ETS, induction treatment with FOLFIRI+cet may be de-escalated to cet alone without detrimental effect on PFS, resulting in less toxicity and better OS. These data support the hypothesis that ETS might be a clinical dynamic predictor of efficacy of a less intensive maintenance strategy, allowing to plan de-escalation to cet alone after 4 months of FOLFIRI+cet induction. Clinical trial information: NCT02484833 .

Abstract ND05: The discovery and characterization of CFT1946: A potent, selective, and orally bioavailable degrader of mutant BRAF for the treatment of BRAF-driven cancers

Abstract The BRAF kinase plays a critical role in the MAPK signaling pathway and is mutated in ~8% of all human cancers including melanoma (~60%), thyroid (~60%), and lung adenocarcinoma (~10%). The most common mutation in BRAF is V600E (Class I), which is found in &amp;gt;70% in these cancers. Despite the clinical success of approved small molecule inhibitors of BRAF V600E (vemurafenib, dabrafenib and encorafenib), this remains an area of unmet medical need because nearly all patients progress, due to either primary or acquired resistance. A bifunctional degradation activating compound (or BiDACTM degrader) may address the liabilities of approved drugs by overcoming, or preventing the emergence of, resistance to BRAF inhibitors. Here we describe CFT1946, an orally bioavailable cereblon-based BiDAC degrader of BRAF V600 mutant proteins, and provide an overview of the medicinal chemistry path leading to its discovery. CFT1946 degrades BRAF V600 mutant proteins, while maintaining exquisite selectivity against the proteome, sparing wild type BRAF (BRAF-WT), ARAF, and CRAF. In A375 cells, CFT1946 potently degraded BRAF V600E and inhibited ERK phosphorylation and cell growth while having no effect in the mutant KRAS, BRAF-WT driven cell line HCT116. In the A375 xenograft model, oral delivery of CFT1946 at 10 mg/kg PO BID resulted in deeper and more durable tumor regression compared to a clinically relevant dose of encorafenib. Further evaluation of CFT1946 in an engineered, clinically relevant BRAFi-resistant A375 cell line (endogenous BRAF V600E + engineered expression of NRAS Q61K) demonstrated that CFT1946 both degraded BRAF V600E and caused a loss of viability in these cells, while treatment with encorafenib had no effect. In xenografts derived from this BRAFi-resistant cell line, oral dosing of CFT1946 as a single agent led to tumor growth inhibition, while treatment with a clinically relevant dose of encorafenib had no effect on tumor growth. Furthermore, dosing CFT1946 in combination with the MEK inhibitor, trametinib, resulted in significant tumor regression, whereas combining encorafenib with the same dose of trametinib had no effect. The medicinal chemistry campaign resulting in CFT1946 focused on the improvement of in vivo pharmacokinetics and rational linker design to achieve high oral bioavailability in a beyond Rule of 5 heterobifunctional degrader. The preclinical data presented herein support the planned Phase 1/2 clinical trial of CFT1946 for the treatment of BRAF-V600 mutant solid tumors. Citation Format: Yanke Liang, Mathew E. Sowa, Katrina L. Jackson, Jeffrey R. Simard, Bridget Kreger, Ping Li, Laura Poling, Joelle Baddour, Andrew Good, Hongwei Huang, Scott Eron, Christopher G. Nasveschuk, Robert Yu, Mark Fitzgerald, Victoria Garza, Morgan W. O’Shea, Gesine Veits, Jeremy L. Yap, Moses Moustakim, Ashley Hart, Roman V. Agafonov, Grace Sarkissian, Joe S. Patel, Richard Deibler, Kyle S. Cole, David Cocozziello, Fazlur Rahman, Andrew J. Phillips, Elizabeth Norton, Adam S. Crystal, Roy M. Pollock, Stewart L. Fisher. The discovery and characterization of CFT1946: A potent, selective, and orally bioavailable degrader of mutant BRAF for the treatment of BRAF-driven cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr ND05.

Design, synthesis, biological evaluation, in silico ADME prediction and molecular docking of pyrazole-benzamides as multitargeting protien kinase inhibitors

In the present study, N-(1-(2-bromobenzoyl)-4-cyano-1H-pyrazol-5-yl) halogenated benzamides (5a-h) were prepared and evaluated for their in vitro anticancer activity against three cancer cell lines, namely hepatic cancer (HepG-2), breast cancer (MCF-7) and colon cancer (HCT-116). The derivatives 5a-d and 5 h revealed the most promising growth inhibition effect, with IC50 values ranging from 0.005133 ± 0.000042 to 0.022249 ± 0.000069 μM, compared to doxorubicin, which had IC50 values of 0.004635 ± 0.000002, 0.004587 ± 0.000029, and 0.004064 ± 0.000002 µM respectively. The potential ADME properties of 5a-h were investigated using calculations. Compounds 5a-h have good oral bioavailability and gastrointestinal absorption but cannot penetrate the blood-brain barrier. According to ADME results, 5b has a tumorigenic and reproductive effect. Furthermore, the derivatives 5a, 5b, and 5d produced promising safety profiles on the WI-38 normal cell line with IC50 values of 0.045374 ± 0.002593, 0.115714 ± 0.006732, and 0.058241 ± 0.003411 μM, respectively, compared to doxorubicin, which had IC50 value of 0.038234 ± 0.00223 µM. Moreover, utilizing afatinib and sorafenib as positive controls, compounds 5a, 5b, and 5d were further assessed as in vitro multitargeting candidates towards EGFRWT, VEGFR-2, and B-RAFWT. For the purpose of figuring out potential ligand-protien interactions and stability, in silico molecular docking simulations against VEGFR-2, EGFRWT, and B-RAFWT were run. The results exhibited that compound 5b was the most potent compound, producing an inhibition effect on EGFRWT and B-RAF WT kinases that was approximately equipotent to that obtained by the reference drugs afatinib and sorafenib with IC50 values of 0.000140 ± 0.000009 and 0.000158 ± 0.000009 µM, respectively (IC50 Afatinib: 0.000086 ± 0.000004, IC50 Sorafenib: 0.000097 ± 0.000006) The molecular docking study confirmed the biological result. Moreover, compound 5b arrested the HCT-116 cell cycle at the G1/S phase and showed a good early and late apoptotic induction effect within HCT-116 cells.

Abstract 3425: The discovery and characterization of CFT1946: A potent, selective, and orally bioavailable degrader of mutant BRAF for the treatment of BRAF-driven cancers

Abstract The BRAF kinase plays a critical role in the MAPK signaling pathway and is mutated in ~8% of all human cancers including melanoma (~60%), thyroid (~60%), and lung adenocarcinoma (~10%). The most common mutation in BRAF is V600E (Class I), which is found in &amp;gt;70% in these cancers. Despite the clinical success of approved small molecule inhibitors of BRAF V600E (vemurafenib, dabrafenib and encorafenib), this remains an area of unmet medical need because nearly all patients progress, due to either primary or acquired resistance. A bifunctional degradation activating compound (or BiDACTM degrader) may address the liabilities of approved drugs by overcoming, or preventing the emergence of, resistance to BRAF inhibitors. Here we describe CFT1946, an orally bioavailable cereblon-based BiDAC degrader of BRAF V600 mutant proteins, and provide an overview of the medicinal chemistry path leading to its discovery. CFT1946 degrades BRAF V600 mutant proteins, while maintaining exquisite selectivity against the proteome, sparing wild type BRAF (BRAF-WT), ARAF, and CRAF. In A375 cells, CFT1946 potently degraded BRAF V600E and inhibited ERK phosphorylation and cell growth while having no effect in the mutant KRAS, BRAF-WT driven cell line HCT116. In the A375 xenograft model, oral delivery of CFT1946 at 10 mg/kg PO BID resulted in deeper and more durable tumor regression compared to a clinically relevant dose of encorafenib. Further evaluation of CFT1946 in an engineered, clinically relevant BRAFi-resistant A375 cell line (endogenous BRAF V600E + engineered expression of NRAS Q61K) demonstrated that CFT1946 both degraded BRAF V600E and caused a loss of viability in these cells, while treatment with encorafenib had no effect. In xenografts derived from this BRAFi-resistant cell line, oral dosing of CFT1946 as a single agent led to tumor growth inhibition, while treatment with a clinically relevant dose of encorafenib had no effect on tumor growth. Furthermore, dosing CFT1946 in combination with the MEK inhibitor, trametinib, resulted in significant tumor regression, whereas combining encorafenib with the same dose of trametinib had no effect. The medicinal chemistry campaign resulting in CFT1946 focused on the improvement of in vivo pharmacokinetics and rational linker design to achieve high oral bioavailability in a beyond Rule of 5 heterobifunctional degrader. The preclinical data presented herein support the planned Phase 1/2 clinical trial of CFT1946 for the treatment of BRAF-V600 mutant solid tumors. Citation Format: Yanke Liang, Mathew E. Sowa, Katrina L. Jackson, Jeffrey R. Simard, Bridget Kreger, Ping Li, Laura Poling, Joelle Baddour, Andrew Good, Hongwei Huang, Scott Eron, Christopher G. Nasveschuk, Robert Yu, Mark Fitzgerald, Victoria Garza, Morgan W. O’Shea, Gesine Veits, Jeremy Y. Yap, Moses Moustakim, Ashley Hart, Roman V. Agafonov, Grace Sarkissian, Joe S. Patel, Richard Deibler, Kyle S. Cole, David Cocozziello, Fazlur Rahman, Andrew J. Phillips, Elizabeth Norton, Adam S. Crystal, Roy M. Pollock, Stewart L. Fisher. The discovery and characterization of CFT1946: A potent, selective, and orally bioavailable degrader of mutant BRAF for the treatment of BRAF-driven cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3425.

The five-year KRAS, NRAS and BRAF analysis results and treatment patterns in daily clinical practice in Slovenia in 1st line treatment of metastatic colorectal (mCRC) patients with RAS wild-type tumour (wtRAS) - a real- life data report 2013-2018.

We preformed a Phase IV non-interventional study to assess KRAS, NRAS and BRAF status in metastatic colorectal cancer (mCRC) patients suitable for 1st line treatment and to evaluate the decisions for 1st line treatment considering the treatment goals in the RAS wild type (wt) patients. The aim of our study was also to evaluate the influence of a waiting period for biomarkers analysis on the start of first-line treatment. Patients with histologically confirmed mCRC adenocarcinoma suitable for first-line treatment fulfilling all inclusion criteria were included in the study. The KRAS, NRAS and BRAF analysis was performed from tissue samples of primary tumor site or metastatic site. All included patients have given consent to participate in the study by signing the informed consent form. From April 2013 to March 2018 at the Institute of Oncology Ljubljana 650 patients were included, 637 of them were treated with first- line systemic treatment according to RAS and BRAF status. Remaining 13 patients with mCRC did not receive systemic first-line treatment. The distribution of patients with KRAS mutated and wild-type tumors, was almost equal, 48.8% and 47.9% respectively, 89 % of the patients had wt NRAS tumours and 86.1% had wt BRAF tumours. The most frequently prescribed treatment was bevacizumab-based therapy (53.1%), either in combination with doublet chemotherapy or with mono-chemotherapy. EGFR inhibitors cetuximab and panitumumab were prescribed in wt RAS mCRC patients (30.9%). The waiting period for biomarkers analysis was two weeks. Our real-world data, single centre 5-year analysis showed that the distribution between wild type and mutated type tumors of the patients with mCRC was approximately the same, as worldwide, so the Slovenian population with mCRC has the same ratio distribution of KRAS, NRAS and BRAF wild and mutated genes. We concluded that a two-week waiting period for biomarkers analysis did not influence the first line treatment decision, so it was in the accordance with the worldwide treatment guidelines based on evidence-based medicine.