Efficacy and safety of buparlisib, a PI3K inhibitor, in patients with malignancies harboring a PI3K pathway activation: a phase 2, open-label, single-arm study

What Do German Molecular Tumor Boards Recommend in Patients with PIK3CA-Mutated Tumors? Launch and First Results from the German Transsectoral Molecular Tumor Board Exchange Platform Deutschland

INTRODUCTION

Comprehensive molecular tumor profiling is widely used in the management of patients with cancer. Molecular tumor boards devise treatment strategies based on testing results. In this setting, the Transsectoral Molecular Tumor Board exchange platform Deutschland (TEAM-D) aims to drive peer-to-peer exchange to connect experts in the field.

METHODS

During the first virtual TEAM-D meeting, participants from 16 German universities and 5 nonacademic institutions discussed five cases with PIK3CA hotspot mutations. Furthermore, an illustrative case vignette was presented.

RESULTS

Overall, German caregivers show restraint in administering off-label PIK3CA inhibitor and favor clinical trials in this setting.

CONCLUSION

In the setting of precision oncology, TEAM-D enables virtual case discussion across the different sectors of the German healthcare system. Based on the example of PIK3CA hotspot mutations, TEAM-D demonstrated the value of integrating knowledge from different healthcare professionals.

Current and Future Therapeutic Targets for Directed Molecular Therapies in Cholangiocarcinoma

We conducted a comprehensive review of the current literature of published data, clinical trials (MEDLINE; ncbi.pubmed.com), congress contributions (asco.org; esmo.org), and active recruiting clinical trains (clinicaltrial.gov) on targeted therapies in cholangiocarcinoma. Palliative treatment regimens were analyzed as well as preoperative and perioperative treatment options. We summarized the current knowledge for each mutation and molecular pathway that is or has been under clinical evaluation and discussed the results on the background of current treatment guidelines. We established and recommended targeted treatment options that already exist for second-line settings, including IDH-, BRAF-, and NTRK-mutated tumors, as well as for FGFR2 fusion, HER2/neu-overexpression, and microsatellite instable tumors. Other options for targeted treatment include EGFR- or VEGF-dependent pathways, which are known to be overexpressed or dysregulated in this cancer type and are currently under clinical investigation. Targeted therapy in CCA is a hallmark of individualized medicine as these therapies aim to specifically block pathways that promote cancer cell growth and survival, leading to tumor shrinkage and improved patient outcomes based on the molecular profile of the tumor.

Cetuximab as a Key Partner in Personalized Targeted Therapy for Metastatic Colorectal Cancer

Cetuximab, a chimeric IgG1 monoclonal antibody targeting the epidermal growth factor receptor (EGFR), has revolutionized personalized treatment of metastatic colorectal cancer (mCRC) patients. This review highlights the mechanism of action, characteristics, and optimal indications for cetuximab in mCRC. Cetuximab has emerged as a pivotal partner for novel therapies in specific molecular subgroups, including BRAF V600E, KRAS G12C, and HER2-altered mCRC. Combining cetuximab with immunotherapy and other targeted agents further expands the therapeutic landscape, offering renewed hope for mCRC patients who face the development of resistance to conventional therapies. Ongoing clinical trials have continued to uncover innovative cetuximab-based treatment strategies, promising a brighter future for mCRC patients. This review provides a comprehensive overview of cetuximab's role and its evolving importance in personalized targeted therapy of mCRC patients, offering valuable insights into the evolving landscape of colorectal cancer treatment.

A systematic review of recent phase-II trials in refractory or recurrent osteosarcoma: Can we inform future trial design?

BACKGROUND/OBJECTIVE

To analyze changes in recurrent/refractory osteosarcoma phase II trials over time to inform future trials in this population with poor prognosis.

METHODS

A systematic review of trials registered on trial registries between 01/01/2017-14/02/2022. Comparison of 98 trials identified between 2003 and 2016. Publication search/analysis for both periods, last update on 01/12/2022.

RESULTS

Between 2017 and 2022, 71 phase-II trials met our selection criteria (19 osteosarcoma-specific trials, 14 solid tumor trials with and 38 trials without an osteosarcoma-specific stratum). The trial number increased over time: 13.9 versus 7 trials/year (p = 0.06). Monotherapy remained the predominant treatment (62% vs. 62%, p = 1). Targeted therapies were increasingly evaluated (66% vs. 41%, P = 0.001). Heterogeneity persisted in the trial characteristics. The inclusion criteria were measurable disease (75%), evaluable disease (14%), and surgical remission (11%). 82% of the trials included pediatric or adolescent patients. Biomarker-driven trials accounted for 25% of the total trials. The survival endpoint use (rather than response) slightly increased (40% versus 31%), but the study H1/H0 hypotheses remained heterogeneous. Single-arm designs predominated over multiarm trials (n = 7). Available efficacy data on 1361 osteosarcoma patients in 58 trials remained disappointing, even though 21% of these trials were considered positive, predominantly those evaluating multi-targeted kinase inhibitors.

CONCLUSION

Despite observed changes in trial design and an increased number of trials investigating new therapies, high heterogeneity remained with respect to patient selection, study design, primary endpoints, and statistical hypotheses in recently registered phase II trials for osteosarcoma. Continued optimization of trial design informed by a deeper biological understanding should strengthen the development of new therapies.

Update on Emerging Therapies for Advanced Colorectal Cancer

Colorectal cancer (CRC) is the third most common malignancy worldwide. It is projected to increase by 3.2 million new cases and account for 1.6 million deaths by 2040. Mortality is largely due to limited treatment options for patients who present with advanced disease. Thus, the development of effective and tolerable therapies is crucial. Chemotherapy has been the backbone of systemic treatment of advanced CRC, but utility has been limited because of invariable resistance to therapy, narrow mechanisms of action, and unfavorable toxicity profile. Tumors that are mismatch repair-deficient have demonstrated remarkable response to immune checkpoint inhibitor therapy. However, most CRC tumors are mismatch repair-proficient and represent an unmet medical need. Although ERBB2 amplification occurs only in a few cases, it is associated with left-sided tumors and a higher incidence of brain metastasis. Numerous combinations of HER2 inhibitors have demonstrated efficacy, and antibody-drug conjugates against HER2 represent innovative strategies in this area. The KRAS protein has been classically considered undruggable. Fortunately, new agents targeting KRAS G12C mutation represent a paradigm shift in the management of affected patients and could lead the advancement in drug development for the more common KRAS mutations. Furthermore, aberrant DNA damage response is present in 15%-20% of CRCs, and emerging innovative combinations with poly (ADP-ribose) polymerase (PARP) inhibitors could improve the current therapeutic landscape. Multiple novel biomarker-driven approaches in the management of patients with advanced CRC tumors are reviewed in this article.

High-throughput organo-on-pillar (high-TOP) array system for three-dimensional ex vivo drug testing

The development of organoid culture technologies has triggered industrial interest in ex vivo drug test-guided clinical response prediction for precision cancer therapy. The three-dimensional culture encapsulated with basement membrane (BM) components is extremely important in establishing ex vivo organoids and drug sensitivity tests because the BM components confer essential structures resembling tumor histopathology. Although numerous studies have demonstrated three-dimensional culture-based drug screening methods, establishing a large-scale drug-screening platform with matrix-encapsulated tumor cells is challenging because the arrangement of microspots of a matrix-cell droplet onto each well of a microwell plate is inconsistent and difficult to standardize. In addition, relatively low scales and lack of reproducibility discourage the application of three-dimensional organoid-based drug screening data for precision treatment or drug discovery. To overcome these limitations, we manufactured an automated organospotter-integrated high-throughput organo-on-pillar (high-TOP) drug-screening platform. Our system is compatible with various extracellular matrices, including BM extract, Matrigel, collagen, and hydrogel. In addition, it can be readily utilized for high-content analyses by simply exchanging the bottom plates without disrupting the domes. Our system demonstrated considerable robustness, consistency, reproducibility, and biological relevancy in three-dimensional drug sensitivity analyses using Matrigel-encapsulated ovarian cancer cell lines. We also demonstrated proof-of-concept cases representing the clinical feasibility of high-TOP-assisted ex vivo drug tests linked to clinical chemo-response in ovarian cancer patients. In conclusion, our platform provides an automated and standardized method for ex vivo drug-sensitivity-guided clinical response prediction, suggesting effective chemotherapy regimens for patients with cancer.

Addressing the Reciprocal Crosstalk between the AR and the PI3K/AKT/mTOR Signaling Pathways for Prostate Cancer Treatment

The reduction in androgen synthesis and the blockade of the androgen receptor (AR) function by chemical castration and AR signaling inhibitors represent the main treatment lines for the initial stages of prostate cancer. Unfortunately, resistance mechanisms ultimately develop due to alterations in the AR pathway, such as gene amplification or mutations, and also the emergence of alternative pathways that render the tumor less or, more rarely, completely independent of androgen activation. An essential oncogenic axis activated in prostate cancer is the phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway, as evidenced by the frequent alterations of the negative regulator phosphatase and tensin homolog (PTEN) and by the activating mutations in PI3K subunits. Additionally, crosstalk and reciprocal feedback loops between androgen signaling and the PI3K/AKT/mTOR signaling cascade that activate pro-survival signals and play an essential role in disease recurrence and progression have been evidenced. Inhibitors addressing different players of the PI3K/AKT/mTOR pathway have been evaluated in the clinic. Only a limited benefit has been reported in prostate cancer up to now due to the associated side effects, so novel combination approaches and biomarkers predictive of patient response are urgently needed. Here, we reviewed recent data on the crosstalk between AR signaling and the PI3K/AKT/mTOR pathway, the selective inhibitors identified, and the most advanced clinical studies, with a focus on combination treatments. A deeper understanding of the complex molecular mechanisms involved in disease progression and treatment resistance is essential to further guide therapeutic approaches with improved outcomes.

Targeting the PI3K/AKT/mTOR pathway in epithelial ovarian cancer, therapeutic treatment options for platinum-resistant ovarian cancer

The survival rates for women with ovarian cancer have shown scant improvement in recent years, with a 5-year survival rate of less than 40% for women diagnosed with advanced ovarian cancer. High-grade serous ovarian cancer (HGSOC) is the most lethal subtype where the majority of women develop recurrent disease and chemotherapy resistance, despite over 70%-80% of patients initially responding to platinum-based chemotherapy. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway regulates many vital processes such as cell growth, survival and metabolism. However, this pathway is frequently dysregulated in cancers including different subtypes of ovarian cancer, through amplification or somatic mutations of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA), amplification of AKT isoforms, or deletion or inactivation of PTEN. Further evidence indicates a role for the PI3K/AKT/mTOR pathway in the development of chemotherapy resistance in ovarian cancer. Thus, targeting key nodes of the PI3K/AKT/mTOR pathway is a potential therapeutic prospect. In this review, we outline dysregulation of PI3K signaling in ovarian cancer, with a particular emphasis on HGSOC and platinum-resistant disease. We review pre-clinical evidence for inhibitors of the main components of the PI3K pathway and highlight past, current and upcoming trials in ovarian cancers for different inhibitors of the pathway. Whilst no inhibitors of the PI3K/AKT/mTOR pathway have thus far advanced to the clinic for the treatment of ovarian cancer, several promising compounds which have the potential to restore platinum sensitivity and improve clinical outcomes for patients are under evaluation and in various phases of clinical trials.

PI3K/AKT Signaling Tips the Balance of Cytoskeletal Forces for Cancer Progression

The PI3K/AKT signaling pathway plays essential roles in multiple cellular processes, which include cell growth, survival, metabolism, and motility. In response to internal and external stimuli, the PI3K/AKT signaling pathway co-opts other signaling pathways, cellular components, and cytoskeletal proteins to reshape individual cells. The cytoskeletal network comprises three main components, which are namely the microfilaments, microtubules, and intermediate filaments. Collectively, they are essential for many fundamental structures and cellular processes. In cancer, aberrant activation of the PI3K/AKT signaling cascade and alteration of cytoskeletal structures have been observed to be highly prevalent, and eventually contribute to many cancer hallmarks. Due to their critical roles in tumor progression, pharmacological agents targeting PI3K/AKT, along with cytoskeletal components, have been developed for better intervention strategies against cancer. In our review, we first discuss existing evidence in-depth and then build on recent advances to propose new directions for therapeutic intervention.

The effectiveness of monotherapy with PI3K/AKT/mTOR pathway inhibitors in ovarian cancer: A meta-analysis

OBJECTIVE

To determine the clinical benefit of monotherapy with PI3K/AKT/mTOR inhibitors in patients diagnosed with advanced or recurrent ovarian cancer and to investigate the predictive value of current PI3K/AKT/mTOR biomarkers on therapy response.

METHODS

A systematic search was conducted in PubMed, Embase and the Cochrane Library for articles reporting on treatment with PI3K/AKT/mTOR inhibitors in ovarian cancer. The primary endpoint was defined as the clinical benefit rate (CBR), including the proportion of patients with complete (CR) and partial response (PR) and stable disease (SD). Secondary endpoints included the overall response rate (ORR, including CR and PR) and drug-related grade 3 and 4 adverse events.

RESULTS

We included 233 patients from 19 studies and observed a pooled CBR of 32% (95% CI 20-44%) and ORR of 3% (95% CI 0-6%) in advanced or recurrent ovarian cancer patients treated with PI3K/AKT/mTOR inhibitors. Subgroup analysis tended to favor the studies who selected patients based on current PI3K/AKT/mTOR biomarker criteria (e.g. genomic alterations or loss of PTEN protein expression), but the difference in CBR was not statistically significant from studies with unselected populations (respectively, CBR of 42% (95% CI 23-62%) and 27% (95% CI 14-42%), P = 0.217). To better reflect true patient benefit, we excluded SD <6 months as a beneficial outcome which resulted in a pooled CBR of 7% (95% CI 2-13%). The overall proportion of patients with drug-related grade 3 and 4 adverse events was 36%.

CONCLUSIONS

The efficacy of monotherapy with PI3K/AKT/mTOR inhibitors in advanced recurrent ovarian cancer patients is limited to a small subgroup and selection of patients with the use of current biomarkers did not improved the CBR significantly. Given the toxicity profile, we suggest that current treatment with PI3K/AKT/mTOR inhibitors should not be initiated unless in clinical trials. Furthermore, improved biomarkers to measure functional PI3K/AKT/mTOR pathway activity are needed to optimize patient selection.

Genetic alterations and their therapeutic implications in epithelial ovarian cancer

BACKGROUND

Genetic alterations for epithelial ovarian cancer are insufficiently characterized. Previous studies are limited regarding included histologies, gene numbers, copy number variant (CNV) detection, and interpretation of pathway alteration patterns of individual patients.

METHODS

We sequenced 410 genes to analyze mutations and CNV of 82 ovarian carcinomas, including high-grade serous (n = 37), endometrioid (n = 22) and clear cell (n = 23) histologies. Eligibility for targeted therapy was determined for each patient by a pathway-based approach. The analysis covered DNA repair, receptor tyrosine kinase, PI3K/AKT/MTOR, RAS/MAPK, cell cycle, and hedgehog pathways, and included 14 drug targets.

RESULTS

Postulated PARP, MTOR, and CDK4/6 inhibition sensitivity were most common. BRCA1/2 alterations, PTEN loss, and gain of PIK3CA and CCND1 were characteristic for high-grade serous carcinomas. Mutations of ARID1A, PIK3CA, and KRAS, and ERBB2 gain were enriched in the other histologies. PTEN mutations and high tumor mutational burden were characteristic for endometrioid carcinomas. Drug target downstream alterations impaired actionability in all histologies, and many alterations would not have been discovered by key gene mutational analysis. Individual patients often had more than one actionable drug target.

CONCLUSIONS

Genetic alterations in ovarian carcinomas are complex and differ among histologies. Our results aid the personalization of therapy and biomarker analysis for clinical studies, and indicate a high potential for combinations of targeted therapies.

PI3K Inhibitors in Cancer: Clinical Implications and Adverse Effects

The phospatidylinositol-3 kinase (PI3K) pathway is a crucial intracellular signaling pathway which is mutated or amplified in a wide variety of cancers including breast, gastric, ovarian, colorectal, prostate, glioblastoma and endometrial cancers. PI3K signaling plays an important role in cancer cell survival, angiogenesis and metastasis, making it a promising therapeutic target. There are several ongoing and completed clinical trials involving PI3K inhibitors (pan, isoform-specific and dual PI3K/mTOR) with the goal to find efficient PI3K inhibitors that could overcome resistance to current therapies. This review focuses on the current landscape of various PI3K inhibitors either as monotherapy or in combination therapies and the treatment outcomes involved in various phases of clinical trials in different cancer types. There is a discussion of the drug-related toxicities, challenges associated with these PI3K inhibitors and the adverse events leading to treatment failure. In addition, novel PI3K drugs that have potential to be translated in the clinic are highlighted.

Cardiovascular toxicity of PI3Kα inhibitors

The phosphoinositide 3-kinases (PI3Ks) are a family of intracellular lipid kinases that phosphorylate the 3'-hydroxyl group of inositol membrane lipids, resulting in the production of phosphatidylinositol 3,4,5-trisphosphate from phosphatidylinositol 4,5-bisphosphate. This results in downstream effects, including cell growth, proliferation, and migration. The heart expresses three PI3K class I enzyme isoforms (α, β, and γ), and these enzymes play a role in cardiac cellular survival, myocardial hypertrophy, myocardial contractility, excitation, and mechanotransduction. The PI3K pathway is associated with various disease processes but is particularly important to human cancers since many gain-of-function mutations in this pathway occur in various cancers. Despite the development, testing, and regulatory approval of PI3K inhibitors in recent years, there are still significant challenges when creating and utilizing these drugs, including concerns of adverse effects on the heart. There is a growing body of evidence from preclinical studies revealing that PI3Ks play a crucial cardioprotective role, and thus inhibition of this pathway could lead to cardiac dysfunction, electrical remodeling, vascular damage, and ultimately, cardiovascular disease. This review will focus on PI3Kα, including the mechanisms underlying the adverse cardiovascular effects resulting from PI3Kα inhibition and the potential clinical implications of treating patients with these drugs, such as increased arrhythmia burden, biventricular cardiac dysfunction, and impaired recovery from cardiotoxicity. Recommendations for future directions for preclinical and clinical work are made, highlighting the possible role of PI3Kα inhibition in the progression of cancer-related cachexia and female sex and pre-existing comorbidities as independent risk factors for cardiac abnormalities after cancer treatment.

The Landscape of PIK3CA Mutations in Colorectal Cancer

BACKGROUND

Colorectal cancer is one of the most common malignancies in both men and women. Despite progress in the treatment of the disease, metastatic colorectal cancer remains lethal with a median survival slightly surpassing 2 years and commonly for some cases a more aggressive course. New therapies are urgently needed based on a better understanding of the molecular pathogenesis of the disease.

METHODS

The focus of this investigation is the PIK3CA gene, encoding the alpha catalytic subunit of the enzyme phosphatidylinositol-3 kinase (PI3K). Publicly available data from 3 extensive published series of colorectal carcinomas were analyzed to define the molecular landscape of colorectal adenocarcinomas with and without mutations of PIK3CA. An analysis for discovery of associations with alterations in other critical genes and pathways involved in colorectal cancer was performed. The total mutation burden (TMB) and copy number alteration burden of colorectal cancers with and without mutations of PIK3CA, as well as prognostic implications of alterations of the gene for survival, were examined.

RESULTS

Mutations in PIK3CA are observed in 20% to 25% of colorectal cancers. PIK3CA represents one of the most frequently mutated oncogenes in these cancers. Mutations in PIK3CA are associated with higher rates of mutations in other genes of important cancer-associated pathways such as the tyrosine kinase receptors/K-Ras/BRAF/MAPK and the Wnt/β-catenin pathway. In addition, PIK3CA mutated colorectal cancers display a higher TMB than nonmutated cancers.

CONCLUSION

Frequent mutations of PIK3CA gene in colorectal carcinomas may represent an opportunity for targeted therapy combination development inhibiting both the PI3K kinase itself and associated pathway defects. Increased TMB may additionally confer immunotherapy sensitivity, which could be augmented by other targeted therapies.

Which Is the Most Appropriate PI3K Inhibitor for Breast Cancer Patients with or without PIK3CA Status Mutant? A Systematic Review and Network Meta-Analysis

Objective

The phosphatidylinositol 3-kinase (PI3K) signaling pathway is a promising treatment target for patients with breast cancer (BC). Our study aimed to evaluate the most effective and safe PI3K inhibitor for patients with BC, especially in PIK3CA mutation.

Methods

Electronics databases were systematically searched from their inception to June 2020 for published randomized controlled trials (RCTs) comparing PI3K inhibitor therapy versus non-PI3K inhibitor therapy in patients with BC that mentioned or reported data of PIK3CA-mutated patient subgroups. Eligible RCTs had to report at least one of the following clinical outcomes: objective response rate (ORR), progression-free survival (PFS), or adverse events (AE).

Results

Nine eligible RCTs involving 3872 BC patients and four PI3K inhibitor therapy arms (i.e., alpelisib, buparlisib, pictilisib, and taselisib) were included. In evaluating ORR, beneficial significant results of PI3K inhibitors could be found in the PIK3CA mutated group (1.952, 1.012 to 3.766); analogous results could also be found in 6m-PFS (1.519, 1.144 to 2.018) and PFS from HR data (-0.346, -0.525 to -0.168). From pairwise and network meta-analyses, buparlisib showed the most favorable ORR, as it was significantly different from fulvestrant in the PIK3CA-mutated patient group (2.80, 1.56 to 5.03). Alpelisib ranked first in the assessment of 6m-PFS and was significantly different from fulvestrant in the PIK3CA-mutated group (2.33, 1.45 to 3.44). The above PI3K inhibitors had good safety with few serious AEs. PROSPERO registration CRD42020193932.

Conclusion

The PI3K inhibitors alpelisib and buparlisib appear to have superior efficacy and safety therapeutic choices for patients with BC, especially in PIK3CA-mutated patients.

An evaluation of buparlisib for the treatment of head and neck squamous cell carcinoma

INTRODUCTION

Five-year overall survival for head and neck squamous cell carcinoma (HNSCC) is relatively poor at around 50-66%, and there has been little improvement over the past several decades. PIK3CA alterations are common in HNSCC and offer a promising therapeutic target.

AREAS COVERED

The authors discuss the PIK3 pathway and the use of PIK3 inhibitors in cancer, with a particular focus on HNSCC. A summary of the safety and efficacy of buparlisib, a class I pan-PI3K inhibitor, from several phase I and phase II HNSCC trials is provided.

EXPERT OPINION

With a maximum tolerated dose of 100 mg/day and an acceptable toxicity profile, buparlisib may be effective in HNSCC, irrespective of PIK3CA mutational status. On-going clinical trials will help determine the developmental strategy of buparlisib while novel combinatory strategies including combination with immune checkpoint inhibitors should be considered. Importantly, biomarker strategies, including wider use of tumor sequencing and circulating tumor DNA, should be utilized to improve patient selection.

An open-label, single-arm, phase II trial of buparlisib in patients with melanoma brain metastases not eligible for surgery or radiosurgery-the BUMPER study

Background

Patients with melanoma brain metastasis (MBM) still carry a dismal prognosis. Preclinical data originated in xenograft models showed that buparlisib therapy was highly effective in therapy-naïve MBM.

Patients and Methods

In this open-label, phase II trial, we investigate the safety and efficacy of monotherapy with buparlisib, a PI3K inhibitor, in patients with asymptomatic MBM who were not candidates for local therapy. These patients had also progressed under immunotherapy if BRAF wild-type or under targeted therapy with BRAF/MEK inhibitors if carrying a BRAFV600E/K mutation. The primary endpoint was the intracranial disease control rate assessed by the investigators. The secondary endpoints were overall response rate, duration of response (DOR) of intracranial disease, overall response, progression-free survival (PFS), overall survival (OS), safety, and tolerability of buparlisib.

Results

A total of 20 patients were screened and 17 patients were treated with buparlisib. Twelve patients had progressed under more than 2 systemic therapy lines and 17 had received at least 1 previous local therapy. There were no intracranial responses. Three patients achieved intracranial stable disease; the median DOR was 117 days. The median PFS was 42 days (95% confidence interval [CI]: 23–61 days) and the median OS was 5.0 months (95% CI: 2.24–7.76 months). No new safety signs were observed.

Conclusions

Buparlisib was well tolerated but no intracranial responses were observed. These results might be explained in part by the inclusion of only heavily pretreated patients. However, preclinical data strongly support the rationale to explore PI3K inhibitor-based combinations in patients with MBM displaying hyperactivation of the PI3K–AKT pathway.