BRAF K601E

Nine patients received targeted therapy; dabrafenib/trametinib (6), pembrolizumab (2), and entrectinib (1), mostly upon tumor progression (7). Outsourcing of NGS testing was feasible; however, criteria for case selection are needed. In addition, local capacity-building in conducting the test, interpretation of the results, and access to "new drugs" continue to be a challenge in LMICs.

The BRAF mutation may represent important genetic alteration in a subset of IDC-P, highlighting the role of MAPK signaling pathway in this subtype of PCa. To the best of knowledge, this is the first description of non-V600 BRAF mutation in setting of IDC-P, which may in part explain the aggressive phenotype seen in IDC-P and could also bring more treatment options for PCa patients with IDC-P harboring such mutations.

Cobimetinib plus vemurafenib showed antitumor activity in patients with advanced solid tumors with BRAF V600E mutations; additional study is warranted to confirm the antitumor activity in tumors with non-V600E BRAF mutations.

Eight patients received targeted therapy; Dabrafenib/Trametinib (5), Pembrolizumab (2), Entrectinib (1), while radio-chemotherapy was used in the others. Sent abroad NGS testing was feasible, however local capacity building is necessary. In this highly selected tumor cohort, high percentage of targetable alterations were identified. NGS was helpful to characterize tumors more and to offer alternative therapies.

Patients with NSCLCs with BRAF non-V600E, especially class III, were associated with poorer therapeutic outcomes than those with V600E. Furthermore, patients with NSCLC with class IIa had distinct clinicogenomic features, and further preclinical and clinical studies are needed to evaluate class IIa mutations as a therapeutic target.

In recent years, the mutational landscape of thyroid tumors has been extensively described, and two molecular profiles have been identified: RAS-like (NRAS, HRAS, and KRAS mutations; EIF1AX mutations; BRAF K601E mutation; and PPARG and THADA fusions) and BRAF-like (including BRAF mutation and RET and BRAF fusions). The purpose of this review is to discuss the latest molecular findings in the context of indeterminate thyroid nodules, highlighting the role of molecular tests in patients' management.

We found an association of K601E mutants with follicular variants of thyroid cancer such as FV‐PTC, FA, and FTC. Our findings may also be consistent with K601E mutants having a more indolent course, but more data is needed to show significance and make clinical recommendations.

Furthermore, TP53, LRP1B, STK11, SPTA1and MAGI2 were significantly over-mutated in Class II and III (p<0.06) and SETD2 is over-mutated in Class I (p<0.001), might suggesting relatively poor prognosis in NSCLC patients. Conclusions The characteristics of Chinese NSCLC were further explored, including BRAF mutation types, the incidence of related co-mutations and TMB value, which is helpful to formulate targeted therapy strategies to adapt to different types of BRAF mutation functions according to their genomic and clinical characteristics.

However, the MRI acquired four weeks after adding capmatinib showed partial response (PR) of LM.Patients with ALK+ NSCLC switched from alectinib [n=2] or brigatinib [n=1] to lorlatinib following LP. Although we identified the primary driver in 26 out of 28 patients with EGFRm+ NSCLC, only seven CSF samples showed RM (ERBB2, EGFR and PIK3CA). Commonly identified RMs in systemic progression such as EGFR C797X and METamp were not identified in CSF or plasma. Identifying resistance mechanisms to targeted therapy in LM proves difficult.

Activating BRAF alterations were detected in ~3% of prostate cancers, and most were Class II mutations and rearrangements; BRAF V600 mutations were exceedingly rare. These findings suggest that BRAF activation in prostate cancer is unique from other cancers and supports further clinical investigation of therapeutics targeting the MAPK pathway.

RAS mutations were associated with the follicular variant, encapsulated tumor, and no extrathyroidal extension. HRAS-mutated PTC frequently exhibited tumor multifocality.

In this large cohort of consecutive DTC patients with prospective 7-gene molecular testing and long-term follow-up, 5- and 10-year DFS was higher in patients with RAS-like TC compared to those with BRAF-like TC. ~60% of recurrences occurred in the first 2 years, while most recurrences >5 years were locoregional or biochemical and only one patient developed distant metastatic disease. Further analysis with additional comprehensive genetic variables is ongoing to better identify patients who are at risk for long-term recurrence.*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation.

The study highlights the heterogeneity of patients with BRAF class II and class III regarding histology and co-mutational status, with both classes equally frequent. A more granular investigation of non-V600X alterations and their associated clinical outcomes under different treatment approaches is ongoing.

P2 | "According to liquid biopsy before second- and third-line therapies, treatment sequences are: FOLFIRI + cetuximab (first-line), FOLFOX + cetuximab (second-line); irinotecan + cetuximab (third-line) in patients with plasma ctDNA RAS/BRAFV600E WT tumors. In patients with RAS/BRAFV600E mutant tumors, second-line is FOLFOX + bevacizumab, while third-line is regorafenib or trifluridine/tipiracil (investigator's choice)... Both tumor tissue- and liquid biopsy-based comprehensive genomic profiling by NGS identify additional molecular alterations, that could be involved in resistance to anti-EGFR monoclonal antibodies, as compared to PCR-based tumor tissue analysis. CAPRI 2-GOIM trial will determine if NGS would allow better selection of RAS/BRAFV600E WT mCRC patients for the most appropriate treatments through three sequential lines of therapies."

A complex of methods for determination of the nucleotide sequence of the BRAF codons 592-601 and the algorithm for testing samples and analyzing mutations in the BRAF codons 600-601 was developed. The method provides sufficient sensitivity to detect frequent mutations in codons 600 and 601 and allows them to be precisely differentiated.

Subsequently, cells or xenograft-bearing mice were treated with trametinib, dabrafenib plus trametinib or sorafenib plus trametinib. Our preliminary results demonstrated the therapeutic values of MEK and BRAF/MEK inhibitors against BRAFK601E-mutated melanoma. As previous studies report the superior therapeutic effects of BRAF/MEK inhibitors over MEK inhibitor alone, phenotype characterization of the cells, as well as underlying mechanisms behind such response, worth further investigation.

The findings of this cohort study suggest that there are broad differences among organoids with different BRAF variant subtypes in sensitivity to BRAF or MEK inhibitors. Identifying and classifying BRAF variants may be able to help guide precise treatment for patients with ICC.

Indeed, we show that BRAF non-V600E mutations can be found in tumors with metastatic potential. However, in both aggressive cases, the BRAF mutations were concomitant with other molecular alterations, such as TERT promoter mutation.

P1/2, N=17, Active, not recruiting, Memorial Sloan Kettering Cancer Center | Trial completion date: Feb 2023 --> Feb 2024 | Trial primary completion date: Feb 2023 --> Feb 2024

This study presents the first large-scale genomic characterization of BRAF mutations in patients with prostate cancer using both tissue and ctDNA NGS analysis. Among thousands of samples from prostate cancer patients, K601E was the most common BRAF mutation. This confirms findings of smaller studies and has implications for developmental therapeutics.

Activating BRAF alterations are detected in ~3% of aPC, with frequent BRAF-SND1 fusions. BRAF RE represent almost half of aPC BRAF GA, the highest fraction observed across a pan-tumor dataset. In addition, we detected a higher incidence of concurrent CDK12 GA and a lower relative frequency of concurrent PTEN,APC, and TMPRSS2-ERG GA.

XA improved risk stratification and identification of malignant thyroid disease with a very high ROM in GSC “suspicious” nodules. Although a negative XA result was associated with lower RoM in our cohort, a negative XA result should not be used as a “rule-out” test.

The combination of dabrafenib plus trametinib was recently FDA-approved for use in these BRAF V600E altered unresectable or metastatic cancers. Analysis of whole-exome and whole transcriptome sequencing data found actionable BRAF mutations in 4.4% of GI cancer patients, 37.6% of whom had BRAF mutations not at V600. Several biomarkers were significantly associated with BRAF alterations. Assays that are limited to DNA sequencing, or to targeted gene panels, may not detect mutations and fusions that could aid in therapy selection and prognosis.

P1/2, N=17, Active, not recruiting, Memorial Sloan Kettering Cancer Center | Recruiting --> Active, not recruiting | N=38 --> 17

The combination of C + V has antitumor activity in heavily pretreated patients with CRC with BRAF mutations.

Four patients received combined BRAF/MEK inhibitors, two patients BRAF inhibitor monotherapy, and six patients were treated with ICI for advanced melanoma; four patients received adjuvant treatment with nivolumab. Given the few cases and the absence of randomized clinical trials, it is important to report clinical experiences, which can guide physicians in the treatment of melanomas harboring rare BRAF mutations.

Most nodules had RAS-like mutations and most were benign or low-risk neoplasms (NIFTP). This study supports the role of histologic examination in the distinction of malignancy in RAS-like thyroid neoplasms and underscores the role of molecular testing in risk stratification, patient counseling, and operative management.

In this large cohort of patients with NIFTP diagnosed at the time of surgery and managed typically by lobectomy with no radioiodine ablation, no evidence of tumor recurrence was identified on a limited follow-up. This finding supports indolent clinical course of NIFTP.

It also seems important to perform liquid biopsies, especially in patients in whom it is not possible to repeat a new tissue biopsy. Ongoing clinical trials continue to evaluate sorafenib in different settings, and in combination with other therapies in DTC and HCC.

This case serves as a great illustration of the pivotal role of molecular diagnostics in modern pathology in arriving at the correct diagnosis. Additionally, it is an excellent example of how clinical-radiologic-pathologic-molecular correlation plays into the landscape of molecular pathology to deliver optimal care for the patient.

C+Vdemonstrated evidence of anti-tumor activity in pts with advanced solid tumors with BRAF V600E and other muts.

This study found specific molecular features may explaining the efficacy difference of BRAF inhibitors in MM and TC, which requires further validation in patients treated with BRAF inhibitors.

In our retrospective study we found that among stage III BRAF-mutant patients monotherapy with aPD1 was the most common adjuvant treatment regimen. In some patients with stage III disease IFN-alfa is still given. More studies are needed to define best adjuvant treatment for BRAF mutant stage III melanoma pts.

The current study found that different miRNA signature profiles were linked to unique histological variants and BRAF mutations in PTC. Further studies focusing on the downstream pathogenetic functions of mRNAs in thyroid neoplasms are warranted.

The three instances of discordance pertained to monoclonal, topographically continuous tumors, which would have been considered as unique disease in routine practice. Overall, our results emphasize pathologic and molecular heterogeneity of primary PCa, and suggest that comprehensive IHC-assisted pathology review and genomic analysis are highly concordant in nominating the 'index' primary PCa area.

As such, melanoma patient-derived K601E oncogenic mutation mimics K601 acetylation to augment BRAF kinase activity. Our findings, therefore, uncover a layer of BRAF regulation and suggest p300 hyperactivation or SIRT1 deficiency as potential biomarkers to determine ERK activation in melanomas.

Our results demonstrate that the Idylla BRAF Mutation Assay produces accurate, precise results in less than 3 hours, with faster TAT compared to NGS. Single-use cartridges eliminate the need for manual sample preprocessing and the risk of PCR contamination. In addition, this sensitive assay correctly identifies BRAF V600 alterations in samples with necrosis and low tumor cell content.

Conclusion Our results - on a small number of patients - suggest that patients with rare BRAF mutations may have inferior survival outcomes with first line targeted treatment, compared with patients with classical BRAF mutations. Impact statement Our findings add to the limited clinical knowledge on rare BRAF mutations in melanoma and may help guide treatment decisions on this small subset of patients.

P2, N=40, Active, not recruiting, Gustave Roussy, Cancer Campus, Grand Paris | Recruiting --> Active, not recruiting | N=87 --> 40 | Trial primary completion date: Dec 2022 --> Nov 2021

Vemurafenib and dabrafenib have already been approved for the treatment of melanoma, NSCLC and colorectal carcinoma. BRAF gene mutations, especially BRAF non-V600, was extensively mutated in Chinese multiple cancer types. Our revealed the potential targeted therapeutic strategies among non-V600 population with solid tumors should be considered in further study.