PIK3CA H1047R

Mutational hotspots are a recurrent feature in both genes which, due to positive selection during tumorigenesis, can be potentially exploited by targeted treatments, as has been demonstrated by the US Food and Drug Administration (FDA)-approved PI3K inhibitor alpelisib in advanced hormone-receptor positive (HR+) breast cancer... The AGENA ClearSEEK PIK3CA and TP53 Panels combine low hands-on time requirements with accurate data assessment, and provide a reliable tool for clinical trial evaluation of known actionable PIK3CA mutations and response to PI3K inhibitors in breast cancer, as well as for investigating the oncogenic activities of TP53 hotspot mutations and patient selection e.g., for cell cycle targeting therapies.

Characterization of the two different approaches in terms of sensitivity results in comparable detection limits (229 copies μL-1 and 224 copies μL-1, respectively), though RPA followed by lambda exonuclease digestion yields significantly higher currents. Finally, this method, together with a designed wild-type blocking oligo that inhibits binding of the wild-type target DNA during probe-target hybridization, allows for detecting the PIK3CA point mutations H1047R, E545K, and E542K in the presence of wild-type target DNA when the proportion of mutant target DNA is >20%.

These results highlight the viability of liquid biopsy as a minimally invasive method for monitoring PIK3CA mutations in canine patients. The study suggests that liquid biopsy techniques hold significant promise for improving the early detection and monitoring of canine cancers, warranting further research to refine these methods and explore their applications in canine cancer diagnostics and treatment.

Background: Trastuzumab resistance is associated with overexpressing the human epidermal growth factor receptor 2 (HER-2), which results from the altered phosphoinositide 3-kinase (PI3K) pathway in breast cancer patients...However, single and double-point mutations in PI3K were significantly associated with the clinical stages of diagnosis and tumor size (p = 0.027 and p = 0.04, respectively). Single and double-point mutations in PI3K are related to tumor size and advanced clinical-pathological traits in Mexican patients with HER-2 overexpression, and future molecular studies are necessary to understand these findings.

Multi-hit mutations in PIK3CA are seen in 1.7% of advanced CRC, a meaningful prevalence given the high burden of CRC worldwide, and may represent a subset of patients that have enhanced sensitivity to PI3K inhibition. Future investigation regarding the clinical utility of PI3K inhibitors is warranted in multi-hit PIK3CA CRC.

The developed novel multi-marker liquid bead array assay for the simultaneous detection of PIK3CA and ESR1 hotspot mutations in single CTCs is highly specific, highly sensitive, high-throughput, and sample-, cost-, and time-saving. This multi-marker liquid bead array assay can be extended to detect up to 100 mutations in many genes at once and can be applied for bulk CTC and ctDNA analysis.

Our findings underscore the robust synergy between pyrotinib and trastuzumab in overcoming HER2 dependency and provide a rationale for pyrotinib, trastuzumab, and docetaxel as one of the optimal choices for patients with untreated HER2-positive metastatic breast cancer, who are dependent on the HER2 signalling cascade.

PIK3CA co-occurring mutations in other genes may represent distinct subsets of NSCLC. Further elucidation of the roles of PIK3CA hotspot mutations combined with other driver mutations, including EGFR and KRAS, is needed to guide effective treatment in patients with advanced NSCLC.

Moreover, we show that in the H1047R mutant, the cavity, where the allosteric ligands STX-478 and RLY-2608 bind, is more accessible contrary to the WT. This study provides insights into the molecular mechanisms underlying activation of oncogenic PI3Kα by C-terminal mutations and represents a valuable resource for continued efforts in the development of mutant selective inhibitors as therapeutics.

P1, N=193, Active, not recruiting, Eli Lilly and Company | Recruiting --> Active, not recruiting | N=400 --> 193

Considering the recent approval of capivasertib for HR+/HER2- metastatic breast cancer (MBC) harboring PI3K-AKT pathway alts based on tissue NGS, we assessed the concordance of tissue and ctDNA NGS for PIK3CA, AKT1, PTEN as well as ESR1. We identified 367 HR+/HER2- MBC pts treated at MSK with tissue NGS by MSK-IMPACT within 60 days of ctDNA NGS by either Guardant360 or MSK-ACCESS, without intervening therapy... Tissue-ctDNA concordance for the detection of any oncogenic alteration was high for PIK3CA, AKT1, moderate for ESR1, and low for PTEN. More alts were detected in ctDNA for ESR1 and in tissue for PTEN, reflecting acquired ESR1 alts after estrogen deprivation and the current lack of ctDNA assay PTEN copy number loss detection. Additional correlative analyses (e.g.

SSDH shows PI3K pathway alterations similar to those seen in other similar proliferative lesions of the breast (i.e., radial scar, infiltrating epitheliosis) and these lesions may possibly be classified as pre-neoplastic rather than hyperplastic. This finding may explain the rare association of SSDH with atypical hyperplasia/carcinoma.

These results demonstrate that the TCR repertoire is associated with characteristics, genetic alterations, and clinical outcomes. Monitoring changes in the TCR repertoire may serve as a prognostic biomarker for breast cancer patients.

Circulating levels of the chemokine CXCL1 were elevated only in animals with tumors containing HRASG12V mutation. Since RAS pathway aberrations are found in 19% of cancers, evaluating skeletal muscle defects in the context of genomic aberrations in cancers, particularly RAS pathway mutations, may accelerate development of therapeutic modalities to overcome cancer-induced systemic effects.

Gain-of-function mutation in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) catalytic subunit alpha gene (PIK3CA) is a significant factor in head and neck cancer (HNC). Salubrinal and N-acetyl-L-cysteine attenuated celecoxib-induced mitochondrial dysfunction. Collectively, our results suggest that celecoxib and SUS efficiently suppress activating PIK3CA mutation-harboring HNC progression by inducing ER and oxidative stress and mitochondrial dysfunction, leading to apoptotic cell death, further supporting NSAID treatment as a useful strategy for oncogenic PIK3CA-mutated HNC therapy.

However, the role of mutated PIK3CA in adenocarcinoma has not been discussed. In addition, mutations occurring in other main members of the PI3K-AKT-mTOR signaling pathway other than PIK3CA were also excluded.

Structural and MD simulation analyses show that the allosteric binding of QR-7909 and QR-8557 inhibit PI3KαH1047R hyper-activity by reducing the fluctuation and mobility of the activation loop. Our work provides a strong rational basis for a further optimization and development of highly selective drug candidates to treat PI3KαH1047R-driven cancers.

However, parity decreased the overall prevalence of tumors bearing Krasmut, and the magnitude of this decrease depended on both the number and timing of pregnancies. These multistage models may be useful for elucidating biological features of premalignant mammary neoplasia.

Alpelisib represents an active treatment option in patients with recurrent gynecological cancers harboring a PIK3CA mutation. These findings support the need of biomarker-driven randomized trials of PI3K inhibitors in gynecological cancers.

The genomic profiling performed using biopsies from young colorectal cancer patients provides a unique ability to identify the potential 'Å“genomic triggers' for the development and progression of cancer in these patients. In this study in addition to known colorectal cancer associated gene mutations we identified recurrent missense mutations in DDR oncogene. This information can be further used to develop not only targeted treatment options for these patients but also to design new screening protocols for identifying high risk patients for optimal surveillance.

When dosed in the HCC1954 tumor model in mice, 17 provided tumor regressions and a clear pharmacodynamic response. X-ray cocrystal structures from several PI3Kα inhibitors were obtained, revealing three distinct binding modes within PI3KαH1047R including a previously reported cryptic pocket in the C-terminus of the kinase domain wherein we observe a ligand-induced interaction with Arg1047.

The commercially available Oncolipsy PIK3CA CE-IVD kit is highly sensitive and specific for the detection of four PIK3CA hotspot mutations in primary tumors and plasma-cfDNA.

Here we reported two clinical cases of HER2-low MBC patients whose disease progressed after prior treatment with MTAs such as docetaxel and vincristine. The patients were treated with everolimus before being rechallenged with RC48, which may lead to a better response. This study further summarizes and analyzes the potential mechanism of the PI3K-AKT signaling pathway in MTA resistance and reveals that the PIK3CA H1047R mutation may be a potential molecular marker for the efficacy prediction of mTOR inhibitors, providing new insights and potential therapeutic strategies for the application of MTAs to MBC patients.

Combining targeted therapies may improve clinical outcomes in breast cancer. Moreover, implementing healthy lifestyle strategies in Latin America could enhance therapy effectiveness and clinical outcomes.

Intensive ctDNA quantification improves metastatic breast cancer surveillance and enables individualized risk-based scheduling of clinical care.

These findings provide important insights into the molecular genetics and clinicopathological characteristics of FM meningiomas. The identification of specific genetic alterations associated with tumor location, volume, calcification, histology, and sex at diagnosis may have implications for personalized treatment strategies in the future.

Background: PIK3CA mutations occur in ~40% of HR-positive breast cancers, where alpelisib, an orthosteric PI3Kα inhibitor, is FDA-approved in combination with fulvestrant... To identify on-target and off-target alterations potentially mediating resistance to PI3Kα inhibitors, we used a targeted next-generation sequencing assay (Guardant360; Guardant Health) to analyze ctDNA in serially collected plasma samples from 32 patients with PIK3CA-mutated advanced HR-positive, HER2-negative breast cancer treated with alpelisib and inavolisib...Some mutations had differential effects on PI3Kaselective vs. pan-PI3K inhibitors, but resistance induced by all mutations could be overcome by the novel allosteric pan-mutant-selective PI3Ka-inhibitor RLY-2608... In one of the largest patient cohorts analyzed to date, this study defines the clinical landscape of acquired resistance to PI3Ka inhibitors. Genomic alterations within the PI3K pathway represent a major mode of resistance and identify a novel class of secondary PIK3CA resistance mutations that can be overcome by an allosteric PI3Ka inhibitor. Together, these findings provide insights to guide strategies to overcome resistance in PIK3CA-mutated cancers.

We found that the prevalence of PIK3CA mutations in our patients was comparable to what has been reported in other nations. Our results suggest that PIK3CA mutational status has no bearing to ET efficacy in first-line setting.

Clinically, elevated expression of p110α/FBXO3/USP4/Twist1 is associated with poor overall survival (OS) and recurrence-free survival (RFS) of breast cancer patients. Taken together, this study reveals that the FBXO3-USP4-Twist1 axis is pivotal in PI3K-mediated breast tumor metastasis and that FBXO3/USP4 may be potential therapeutic targets for breast cancer treatment.

Participants received neoadjuvant paclitaxel with trastuzumab, lapatinib, or both. In ERBB2/HER2-positive EBC, PIK3CA mutations were associated with lower pCR rates and independently associated with worse long-term EFS. These findings appear to be associated with PIK3CA mutations in HR-positive and luminal EBC.

Thus, our studies provide a high-resolution transcriptome atlas of breast epithelial cells of BRCA1 and BRCA2 mutation carriers and reveal their susceptibility to PIK3CA mutation-driven transformation.  .

Alpelisib demonstrated a tolerable safety profile at a dose of 750mg/week and clinical and metabolic complete remission in a PIK3CA-mutated LCH patient. These data demonstrate PIK3CA as a targetable non-canonical driver of LCH and underscore the importance of mutational analysis-based personalized treatment in histiocytic neoplasms.

P2, N=66, Recruiting, Breast Cancer Trials | N=140 --> 66

Our findings suggest that targeting the p110αH1047R/L mutations in TNBC could be a promising strategy for developing transcriptional-based therapies. Restoring the interaction between ΔNp63α and the p110α kinase domain, which is disrupted by these mutations, may provide a new approach to treating TNBC.

At variant level, PIK3CA p.H1047R (22%) and RBM26 p.Q701Tfs*23 (10%) were the top two somatic variants identified...Conclusions ctDNA status and dynamics correlate well with clinical status of patients with mILC, as determined by conventional monitoring tools such as imaging and biopsy. Our results indicate that personalized, tumor-informed, longitudinal ctDNA testing may serve as a useful tool for detection of progression and monitoring treatment response in mILC patients.

This case report aims to warn of the possibility that other driver mutations may be associated with the diagnosis of TCCRP, such as IDH1 R132 and not just IDH2 R172, and that a comprehensive testing approach of the IDH1/2 genes might be more accurate in these cases.

Although targeting PI3Kα in cancer is a therapeutically proven strategy, with the currently approved drug alpelisib showing clinical efficacy alone or in combination with other therapies, treatment with non-mutant selective PI3Kα inhibitors such as alpelisib is associated with significant toxicities such as hyperglycemia, due to on-target inhibition of the wild-type enzyme...Moreover, OKI-219 dosed in combination with the selective estrogen receptor degraders (SERDs) fulvestrant, elacestrant or camizestrant showed significant combination benefit leading to tumor regressions of up to 100% in the ER+ H1047R mutant breast cancer model xxT47D, at doses where no regressions were observed with single agent treatment. Dosing OKI-219 in combination with HER2-inhibitors, such as tucatinib, led to tumor regressions in the ER-HER2+ and H1047R mutant breast cancer CDX model HCC1954, also at doses where no regressions were observed with single agent treatment. These data indicate that OKI-219 offers improved efficacy and a wider therapeutic window compared to non-mutant selective PI3Kα inhibitors. OKI-219 is advancing into clinical trials.

73 of 84 patients were treated with traditional neoadjuvant chemotherapy plus trastuzumab meanwhile 13 of 84 received neoadjuvant chemotherapy plus trastuzumab and pertuzumab. We would like to acknowledge the contribution of Multi-specialistic Biobank Research Core Facility G-STeP, Fondazione Policlinico Universitario "A. Gemelli" IRCCS (Biobank-FPG) who provided the bio-resources.

These findings strongly encourage further investigation into TCRs targeting driver mutations in MBC, with the aim of advancing neoantigen-targeted TCR-T therapies into clinical trials. Additionally, the PIK3CA_H1047L neoantigen holds great promise as a potential candidate for the development of effective cancer vaccines.

The approved PI3Kα inhibitor, alpelisib, shows promise for this targeted class with improvements in progression-free survival in HR+/Her2- breast cancer in combination with fulvestrant. These issues likely limit dose administration leading to exposure which is suboptimal for maximal efficacy and creates an opportunity to identify an inhibitor with an improved tolerability profile that targets oncogenic mutations while sparing wild type PI3Kα. Herein, we present preclinical in vitro and in vivo activity of a novel, wild type sparing PI3Kα inhibitor which is potent against the oncogenic H1047R mutation.