NRAS Q61K

Two frontline BRAF inhibitors (BRAFi), vemurafenib and dabrafenib, are frequently used to treat unresectable or metastatic BRAF V600E melanoma. Our data support the feasibility of the development of CRISPR-Cas therapeutic approaches to the treatment of melanoma. Successful therapeutic CRISPR-directed gene editing would enable both specific and efficient editing of a mutation-specific targeting approach eliminate concern for on- and off-target damage to the genomes of healthy cells.

In older adolescents with ITN, the A firma GSC showed excellent performance when de fining a true negative result by histology or clinical follow-up. Our findings indicate that an A firma GSC-B result appears reassuring and may allow for a more conservative management strategy in younger patients with ITN.

This observation reveals a binding site that can potentially be exploited for development of inhibitors against mutant NRAS. Furthermore, the well-resolved catalytic site of this GTPase bound to native GTP provides insight into the stalled GTP hydrolysis observed for NRAS-Q61K.

Therefore, the seven SNPs were identified as high-risk SNPs. Conclusions Given that SNPs have the potential to be candidates for cellular alterations brought on by mutations that are associated with cancer, this study provides vital information about how SNPs might be utilized as a diagnostic marker for cancer.

CNS melanomas based on NCM in childhood are aggressive malignancies without curative treatment to date. Therapeutic approaches must be individualized. Genetic tumor sequencing is essential to improve understanding of tumorigenesis and potentially identify new therapeutic targets.

Demographic details, tumor characteristics, and 10-year outcome data were also obtained.Ten cases with BRAF V600E mutations (11.6%) and five (5.49%) NRAS mutations (4 at Q61R, 1 at Q61K) were detected. No statistically significant differences were noted between groups for age, gender, depth of invasion, nodal status, or recurrence status (p ≥ 0.05).These findings suggest that the Irish population has a markedly lower incidence of BRAF and NRAS mutations in melanoma than those reported in other cohorts.

In our Brazilian cohort of mCRC patients, frequencies of RAS and BRAF mutations were similar to worldwide data. However, we found lower than expected frequency of MSI-high tumors. KRAS G12C mutation was associated with early-onset mCRC, an emergent population in which KRAS G12C inhibitors might be particulary useful.

RMC-7977 is a potent, oral small molecule inhibitor of both wild-type and mutant GTP-bound RAS oncoproteins (RASMULTI) and is a preclinical tool compound representative of the clinical candidate RMC-6236, currently in clinical evaluation (NCT05379985)...Gilteritinib and the gilteritinib/venetoclax combination selected for survival of cells harboring NRAS mutations, but RMC-7977 inhibited outgrowth of all cell populations...In vivo studies investigating the tolerability and activity of RMC-7977 and RMC-7977 combinations in RAS mutant/FLT3i-resistant patient-derived xenograft models are ongoing and will be presented. Collectively, our data provide preclinical evidence that combination therapies leveraging RASMULTI(ON) inhibition are effective in suppressing RAS-mutant AML clones, a common mechanism of resistance to currently approved targeted therapies in AML and a current area of high unmet clinical need.

Compared to LDH and S100B, ctDNA levels in stage I to III MM display superior sensitivity to detect MRD and could complement regular FU in predicting tumor progression. In the currently initiated prospective study part (MeLB), we will evaluate ctDNA as marker for MRD identifying patients with stage IIB to III MM at risk for relapse. We will include 50 patients followed for two years quarterly and compare standard singleplex with novel multiplex ddPCR strategies (parallel detection of up to 10 ctDNA mutations) and a custom design NGS panel.

 A biopsy of a newly developed metastasis from the trunk showed an identical biphenotypic pattern and had a common mutational pattern with the same NRAS Q61K mutation and loss of CDKN2A.  The patient also developed metastases to the lung, thyroid, pancreas, axillary lymph nodes, liver, and kidney.  A biphenotypic epithelioid and spindle pattern of melanocytic tumors has been well reported in primary melanomas but our case is unique in that multiple metastases shared this distinct pattern.  In this report, we raise awareness that cutaneous metastases may also show a distinct biphenotypic patten with a nodular and desmoplastic melanoma component.  Our case is unique, showing multiple metastases with this same pattern.  Poster type: Poster Defense

Pulmonary thyroid tissue is uncommon. The presence of this should raise suspicion for thyroid cancer.

These findings argue against the development of 'early' resistance mechanisms after neratinib and pemetrexed exposure. Future studies will be required to understand how NSCLC cells become resistant to neratinib and pemetrexed.

UV-radiation and MC1R germline variants are risk factors in the development of conventional and spitzoid paediatric melanomas. Paediatric CMs share genomic similarities with adult CMs while the SMs differ genetically from the CM group. Consistent genetic characterization of all paediatric melanomas will potentially lead to better subtype differentiation, treatment, and prevention in the future.

Each OSUMMER cell line possesses distinct in vitro growth properties, trametinib sensitivity, mutational signatures, and predicted antigenicity. Analysis of OSUMMER allografts shows a correlation between strong, predicted antigenicity and poor tumor outgrowth. These data suggest that the OSUMMER lines will be a valuable tool for modeling the heterogeneous responses of human melanomas to targeted and immune-based therapies.

Activation of MAPK pathway via mutated NRAS, KRAS and BRAF genes seems to have a negative impact on outcome in ndMM patients receiving VRd therapy. VRd* - bortezomib (Velcade®), lenalidomide (Revlimid®) and dexamethasone.

Finally, we develop a mutation reporter to show that UVA induces a G > T reversion mutation in yeast that mimics the oncogenic NRAS Q61K mutation in melanoma. Taken together, these findings indicate that UVA and UVB exposure can induce many of the non-canonical mutation classes that cause driver mutations in melanoma.

Those with ctDNA detected were randomized 1 : 1 in a double-blind fashion to continue routine follow-up with the investigators’ choice of treatment if they developed disease recurrence or were unblinded and treated with nivolumab...CtDNA is a useful tool to monitor for MRD/molecular relapse. The DETECTION trial will assess whether it can be used to safely monitor patients and systemically treat only those at highest risk of melanoma progression.

The PFS and OS were not affected by NRAS mutational status in patients treated with anti-PD1-based ICI. Similar ORR was seen in NRASwt and NRASmut patients. Tumour PD-L1 expression did not correlate with NRAS mutational status.

Driver gene fusions were identified in 8.5% of PTCs and were clinically relevant given the emerging targeted kinase inhibitor therapy. Of the 1.6% of cases for which no driver alteration was detected, the specificity of drivers tested and tumor classification require further investigation.

PTC in MEN1 has been rarely reported in the literature [1]. However, per our knowledge, this is the first report of a PTC with second-hit in the MEN1 gene. Somatic MEN1 pathogenic variants have been reported in occasional cases of thyroid oncocytic tumors and NRAS is more frequently associated with follicular or oncocytic thyroid tumors.

In this cohort with population-based and real-world patients, no differences in patient characteristics or treatment modalities were seen between different RAS mt, except a higher frequency of right-colon primaries among KRAS mt compared with NRAS mt. KRAS -G12S conferred a worse OS compared with some other KRAS mt, whereas no other differences in OS were seen. It therefore seems as if different RAS mt behave quite similar.

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."

Adjuvant CPI therapy with nivolumab was started in 2019 with a total of 17 infusions... GCMN have a high risk to develop a melanoma and therefore a rigorous follow-up is required. This case demonstrates that CPI therapy can induce VLD in GCMN that persists and progresses years after CPI therapy is discontinued. A long term benefit might be possible.

P2/3, N=8, Terminated, The Christie NHS Foundation Trust | N=1050 --> 8 | Trial completion date: Oct 2030 --> Jan 2023 | Recruiting --> Terminated | Trial primary completion date: Oct 2030 --> Jan 2023; Closed earlier than expected due to the need for a redesign to reflect the recent change in standard of care guidelines. New design will include these treatments.

Combined alterations of two driver genes were detected in 28/8355 (0.3%) tumors (KRAS/NRAS: 8; KRAS/BRAF: 4; KRAS/HER2: 12; NRAS/HER2: 4). This study demonstrates that a substantial portion of RAS alterations is represented by atypical mutations, KRAS Q61K substitution is always accompanied by the second gene-rescuing mutation, BRAF mutation frequency is a subject to geographical variations, and a small fraction of CRCs has simultaneous alterations in more than one driver gene.

"Of 21 pts with paired plasma samples, 17 (81%) had ≥1 acquired genomic alteration. RTK alterations and secondary (2°) RAS alterations were most common; each occurred in 57% of pts (Table). KRAS amplification was the most common single alteration (43%)."

CD133 may therefore activate a survival pathway where (1) increased AKT phosphorylation and activation induces (2) BAD phosphorylation and inactivation, (3) decreases BAX activation, and (4) reduces caspases-3 and -9 activity and caspase-mediated PARP cleavage, leading to apoptosis suppression and drug resistance in melanoma. Targeting nodes of the AKT and MAPK survival pathways with both trametinib and AZD5363 highlights the potential for combination therapies for NRAS-mutant melanoma stem cells for the development of more effective treatments for patients with high-risk melanoma.

Long-term therapy with dabrafenib (BRAF inhibitor), cobimetinib or trametinib (MEK inhibitor) led to the establishment of the drug-resistant SK-MEL-3 (BRAF V600E) and SK-MEL-30 (NRAS Q61K) melanoma cell line. PHI-501 demonstrated potent growth inhibition (GI50 <1 µM) in seven melanoma cell lines harboring BRAF V600E or NRAS mutations. Melanoma cells resistant to RAF or MEK-targeted treatments or harboring NRAS mutation exhibited strong antiproliferative activity when treated with PHI-501, a highly potent pan-RAF/DDR dual inhibitor. The results of this study suggest that PHI-501, as a single agent, has the potential to overcome the restricted response in the treatment of melanoma.

In this post-2017 WHO classification cohort of 554 consecutive PTCs, BRAF V600E mutation is highly prevalent in 87% of the cases. RAS mutations account for only 1.1% of the cases and half of them are classified as encapsulated follicular variant of PTC. Kinase gene fusions are identified in 8.5% of the cases and are clinically relevant given the emerging targeted kinase inhibitor therapy.

Afirma XA detected abnormalities in approximately one-third of Afirma GSC suspicious nodules, of which RAS mutations were the most common finding (68%). Two-thirds of cases labeled suspicious by Afirma GSC did not reveal gene mutations or fusions by Afirma XA testing, suggesting other unknown genetic alterations requiring further investigation.

Beside established anti-CRC treatment, better understanding of the causality of CRC can be established by combining epidemiology and genetic/epigenetic on CRC etiology in Morocco. This approach may be able to significantly reduce the burden of disease in the country. Moreover, the Moroccan government should develop policy on CRC prevention and public health programs which may serve as a feasible setting to increase public awareness on lifestyle risk factors.

Complex and miscellaneous karyotypes showed KRAS mutations more often. KRASK117N mutations were consistently associated with TET2 and ASXL1 mutations and mutually exclusive with NPM1 and DNMT3A.

Interestingly, the KRAS G13D isogenic line displays elevated PD-L1 expression suggesting the KRAS G13D mutation could be a potential indication for immunotherapy. Overall, these three novel isogenic cell models with endogenous level RAS and MEK1 point mutations provide direct bio-functional evidence demonstrating that acquiring a drug-resistant gene drives tumor cell survival and may simultaneously introduce new indications for combo therapy or immunotherapy in the clinic.

Cobimetinib plus Dexamethasone were administered for two 28-day cycles followed by the addition of an Ixazomib, Pomalidomide and Dexamethasone (IPd) backbone therapy for all subsequent treatment cycles until disease progression. After exposure to Cobimetinib, the plasma cell clusters that expressed higher levels of this MAPK signature decreased in proportion relative to clusters with lower expression of MAPK. In summary, here we report on our initial observations of dynamic transcriptional changes in specific immune and myeloma cell compartments that are associated with targeting the MAPK pathway in the MyDrug C1 sub-protocol.