Phase III trial of gemcitabine plus tipifarnib compared with gemcitabine plus placebo in advanced pancreatic cancer

Functional-proteomics-based investigation of the cellular response to farnesyltransferase inhibition in lung cancer

Farnesylation is a lipid post-translational modification of proteins crucial for protein membrane anchoring and cellular signaling. Farnesyltransferase inhibitors (FTIs), such as tipifarnib, are being tested in cancer therapy. However, the full impact of FTIs on farnesylation substrates remains poorly understood, thus limiting their use in precision medicine. In this study, we performed a global proteomics analysis to investigate farnesylation and the effects of tipifarnib in lung cancer cell lines. Using metabolic labeling and mass spectrometry, we identified farnesylated proteins and mapped their subcellular localization. We also analyzed tipifarnib-dependent protein relocalization and proteome-wide changes. Key findings include the potential therapeutic value of FTIs for NRAS-mutated melanoma and GNAQ/GNA11-mutated uveal melanoma by inhibiting INPP5A farnesylation. Additionally, we identified a synergistic drug combination involving tipifarnib and a ferroptosis inducer and discovered PTP4A1 as a regulator of interferon signaling. Our data, covering 15,080 proteins, offer valuable insights for future studies of farnesylation and FTIs.

Identification and validation the predictive biomarkers based on risk-adjusted control chart in gemcitabine with or without erlotinib for pancreatic cancer therapy

Background

In a randomized clinical controlled trial (PA.3) conducted by the Canadian Cancer Trials Group, the effects of gemcitabine combined with the targeted drug erlotinib (GEM-E) versus gemcitabine alone (GEM) on patients with unresectable, locally advanced, or metastatic pancreatic cancer were studied. This trial statistically demonstrated that the GEM-E combination therapy moderately improves overall survival (OS) of patients. However, real-world analysis suggested that GEM-E for pancreatic cancer was not more effective than GEM. The heterogeneity in outcomes or treatment effect exist. Thus, we tried to find predictive biomarkers to identifying the heterogeneous patients.

Methods

Of the 569 eligible patients, 480 patients had plasma samples. Univariate and multivariate Cox proportional hazards model were used to identify baseline characteristics related to OS, and a risk adjusted Exponentially Weighted Moving Average (EWMA) control chart based on a weighted score test from the Cox model was constructed to monitor patients' survival risk. Maximally selected rank statistics were constructed to identifying the predictive biomarkers, in addition, a risk adjusted control chart based on a weighted score test from the Cox model was constructed to validating the predictive biomarkers, discover the patients who sensitive to the GEM-E or GEM.

Results

Three baseline characteristics (ECOG performance status, extent of disease, and pain intensity) were identified related to prognosis. A risk-adjusted EWMA control chart was constructed and showed that GEM-E did improve OS in a few patients. Three biomarkers (BMP2, CXCL6, and HER2) were identified as predictive biomarkers based on maximum selected rank test, and using the risk-adjusted EWMA control chart to validate the reality and discover some patients who are sensitive to the GEM-E therapy.

Conclusion

In reality, GEM-E has not shown a significant advantage over GEM in the treatment of pancreatic cancer. However, we discovered some patients who are sensitive to the GEM-E therapy based on the predictive biomarkers, which suggest that the predictive biomarkers provide ideas for personalized medicine in pancreatic cancer.

Chemotherapy and radiotherapy for advanced pancreatic cancer

BACKGROUND

Pancreatic cancer (PC) is a lethal disease with few effective treatment options. Many anti-cancer therapies have been tested in the locally advanced and metastatic setting, with mixed results. This review synthesises all the randomised data available to help better inform patient and clinician decision-making. It updates the previous version of the review, published in 2018.

OBJECTIVES

To assess the effects of chemotherapy, radiotherapy, or both on overall survival, severe or life-threatening adverse events, and quality of life in people undergoing first-line treatment of advanced pancreatic cancer.

SEARCH METHODS

We searched for published and unpublished studies in CENTRAL, MEDLINE, Embase, and CANCERLIT, and handsearched various sources for additional studies. The latest search dates were in March and July 2023.

SELECTION CRITERIA

We included randomised controlled trials comparing chemotherapy, radiotherapy, or both with another intervention or best supportive care. Participants were required to have locally advanced, unresectable pancreatic cancer or metastatic pancreatic cancer not amenable to curative intent treatment. Histological confirmation was required. Trials were required to report overall survival.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 75 studies in the review and 51 in the meta-analysis (11,333 participants). We divided the studies into seven categories: any anti-cancer treatment versus best supportive care; various chemotherapy types versus gemcitabine; gemcitabine-based combinations versus gemcitabine alone; various chemotherapy combinations versus gemcitabine plus nab-paclitaxel; fluoropyrimidine-based studies; miscellaneous studies; and radiotherapy studies. In general, the included studies were at low risk for random sequence generation, detection bias, attrition bias, and reporting bias, at unclear risk for allocation concealment, and high risk for performance bias. Compared to best supportive care, chemotherapy likely results in little to no difference in overall survival (OS) (hazard ratio (HR) 1.08, 95% confidence interval (CI) 0.88 to 1.33; absolute risk of death at 12 months of 971 per 1000 versus 962 per 1000; 4 studies, 298 participants; moderate-certainty evidence). The adverse effects of chemotherapy and impacts on quality of life (QoL) were uncertain. Many of the chemotherapy regimens were outdated. Eight studies compared non-gemcitabine-based chemotherapy regimens to gemcitabine. These showed that 5-fluorouracil (5FU) likely reduces OS (HR 1.69, 95% CI 1.26 to 2.27; risk of death at 12 months of 914 per 1000 versus 767 per 1000; 1 study, 126 participants; moderate certainty), and grade 3/4 adverse events (QoL not reported). Fixed dose rate gemcitabine likely improves OS (HR 0.79, 95% CI 0.66 to 0.94; risk of death at 12 months of 683 per 1000 versus 767 per 1000; 2 studies, 644 participants; moderate certainty), and likely increase grade 3/4 adverse events (QoL not reported). FOLFIRINOX improves OS (HR 0.51, 95% CI 0.43 to 0.60; risk of death at 12 months of 524 per 1000 versus 767 per 1000; P < 0.001; 2 studies, 652 participants; high certainty), and delays deterioration in QoL, but increases grade 3/4 adverse events. Twenty-eight studies compared gemcitabine-based combinations to gemcitabine. Gemcitabine plus platinum may result in little to no difference in OS (HR 0.94, 95% CI 0.81 to 1.08; risk of death at 12 months of 745 per 1000 versus 767 per 1000; 6 studies, 1140 participants; low certainty), may increase grade 3/4 adverse events, and likely worsens QoL. Gemcitabine plus fluoropyrimidine improves OS (HR 0.88, 95% CI 0.81 to 0.95; risk of death at 12 months of 722 per 1000 versus 767 per 1000; 10 studies, 2718 participants; high certainty), likely increases grade 3/4 adverse events, and likely improves QoL. Gemcitabine plus topoisomerase inhibitors result in little to no difference in OS (HR 1.01, 95% CI 0.87 to 1.16; risk of death at 12 months of 770 per 1000 versus 767 per 1000; 3 studies, 839 participants; high certainty), likely increases grade 3/4 adverse events, and likely does not alter QoL. Gemcitabine plus taxane result in a large improvement in OS (HR 0.71, 95% CI 0.62 to 0.81; risk of death at 12 months of 644 per 1000 versus 767 per 1000; 2 studies, 986 participants; high certainty), and likely increases grade 3/4 adverse events and improves QoL. Nine studies compared chemotherapy combinations to gemcitabine plus nab-paclitaxel. Fluoropyrimidine-based combination regimens improve OS (HR 0.79, 95% CI 0.70 to 0.89; risk of death at 12 months of 542 per 1000 versus 628 per 1000; 6 studies, 1285 participants; high certainty). The treatment arms had distinct toxicity profiles, and there was little to no difference in QoL. Alternative schedules of gemcitabine plus nab-paclitaxel likely result in little to no difference in OS (HR 1.10, 95% CI 0.82 to 1.47; risk of death at 12 months of 663 per 1000 versus 628 per 1000; 2 studies, 367 participants; moderate certainty) or QoL, but may increase grade 3/4 adverse events. Four studies compared fluoropyrimidine-based combinations to fluoropyrimidines alone, with poor quality evidence. Fluoropyrimidine-based combinations are likely to result in little to no impact on OS (HR 0.84, 95% CI 0.61 to 1.15; risk of death at 12 months of 765 per 1000 versus 704 per 1000; P = 0.27; 4 studies, 491 participants; moderate certainty) versus fluoropyrimidines alone. The evidence suggests that there was little to no difference in grade 3/4 adverse events or QoL between the two groups. We included only one radiotherapy (iodine-125 brachytherapy) study with 165 participants. The evidence is very uncertain about the effect of radiotherapy on outcomes.

AUTHORS' CONCLUSIONS

Combination chemotherapy remains standard of care for metastatic pancreatic cancer. Both FOLFIRINOX and gemcitabine plus a taxane improve OS compared to gemcitabine alone. Furthermore, the evidence suggests that fluoropyrimidine-based combination chemotherapy regimens improve OS compared to gemcitabine plus nab-paclitaxel. The effects of radiotherapy were uncertain as only one low-quality trial was included. Selection of the most appropriate chemotherapy for individuals still remains unpersonalised, with clinicopathological stratification remaining elusive. Biomarker development is essential to assist in rationalising treatment selection for patients.

Variability of quality-of-life measurements and reporting in randomised controlled trials of pancreatic cancer: a systematic review

OBJECTIVES

This systematic review aims to evaluate the methodology used in pancreatic cancer (PC) randomised controlled trials (RCTs) measuring quality of life (QOL) and focuses on the type, frequency, survey compliance and duration of these assessments.

DESIGN

Systematic review of PC RCTs measuring QOL.

DATA SOURCES

A search of PubMed.gov and ClinicalTrials.gov was conducted for PC RCTs measuring QOL from inception to 21 March 2023. Only phase III RCTs were included. Studies were excluded if QOL was not measured, the study was phase I/II, in the second-line setting or unavailable in English. Data were independently extracted by two reviewers in a standardised fashion.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcomes included the type of QOL instrument used, the timing and frequency of assessments, methods of analysis and survey completion rates (SCRs) over time. Secondary outcomes included patient demographics, significant QOL improvements and the frequency of trials measuring QOL.

RESULTS

Out of 269 studies screened, 54 RCTs were identified, and 24 measured QOL (involving 11 229 patients). Instruments used included the EORTC QLQ-C30 (n=15), FACT-HEP (n=3), Spitzer-QOL-Index (n=2), EQ-5D (n=2), LASA (n=1) and FACT-PA (n=1). Most trials assessed QOL until disease progression or death (10/24), with 4-week intervals being the most common (7/24). SCRs were reported in 15/24 trials, with disease stage influencing SCRs over time. In trials with metastatic, locally advanced/metastatic, and resectable disease, the median times to reach a 50% response rate-defined as the point where the number of surveys completed was half of the enrolled participants-were 12.41 weeks (n=2), 14.14 weeks (n=10), and 54.2 weeks (n=3), respectively." Only 2/24 trials reported significant QOL improvements between treatment arms. Patient age was reported in all trials, while race/ethnicity was only reported in 4/24 trials.

CONCLUSIONS

Significant variability exists in the timing, methods and reporting of QOL assessments in PC trials. There is a need for further research to assess the implications of missing data and consider the temporality of QOL assessment in patients with advanced cancers and poor prognosis.

Unveiling the Promise: Navigating Clinical Trials 1978-2024 for PDAC

Despite many decades of research, pancreatic ductal adenocarcinoma (PDAC) remains one of the most difficult cancers to diagnose and treat effectively. Although there have been improvements in the 5-year overall survival rate, it is still very low at 12.5%. The limited efficacy of current therapies, even when PDAC is detected early, underscores the aggressive nature of the disease and the urgent need for more effective treatments. Clinical management of PDAC still relies heavily on a limited repertoire of therapeutic interventions, highlighting a significant gap between research efforts and available treatments. Over 4300 clinical trials have been or are currently investigating different treatment modalities and diagnostic strategies for PDAC, including targeted therapies, immunotherapies, and precision medicine approaches. These trials aim to develop more effective treatments and improve early detection methods through advanced imaging techniques and blood-based biomarkers. This review seeks to categorize and analyze PDAC-related clinical trials across various dimensions to understand why so few chemotherapeutic options are available to patients despite the numerous trials being conducted. This review aims to provide a comprehensive and nuanced understanding of the landscape of PDAC-related clinical trials, with the overarching goal of identifying opportunities to accelerate progress in drug development and improve patient outcomes in the fight against this devastating disease.

Consensus, debate, and prospective on pancreatic cancer treatments

Pancreatic cancer remains one of the most aggressive solid tumors. As a systemic disease, despite the improvement of multi-modality treatment strategies, the prognosis of pancreatic cancer was not improved dramatically. For resectable or borderline resectable patients, the surgical strategy centered on improving R0 resection rate is consensus; however, the role of neoadjuvant therapy in resectable patients and the optimal neoadjuvant therapy of chemotherapy with or without radiotherapy in borderline resectable patients were debated. Postoperative adjuvant chemotherapy of gemcitabine/capecitabine or mFOLFIRINOX is recommended regardless of the margin status. Chemotherapy as the first-line treatment strategy for advanced or metastatic patients included FOLFIRINOX, gemcitabine/nab-paclitaxel, or NALIRIFOX regimens whereas 5-FU plus liposomal irinotecan was the only standard of care second-line therapy. Immunotherapy is an innovative therapy although anti-PD-1 antibody is currently the only agent approved by for MSI-H, dMMR, or TMB-high solid tumors, which represent a very small subset of pancreatic cancers. Combination strategies to increase the immunogenicity and to overcome the immunosuppressive tumor microenvironment may sensitize pancreatic cancer to immunotherapy. Targeted therapies represented by PARP and KRAS inhibitors are also under investigation, showing benefits in improving progression-free survival and objective response rate. This review discusses the current treatment modalities and highlights innovative therapies for pancreatic cancer.

Modeling Overall Survival in Patients With Pancreatic Cancer From a Pooled Analysis of Phase II Trials

BACKGROUND

We evaluated the validity of surrogacy of progression-free survival (PFS) or time-to-progression (TTP) and overall response rate (ORR) in phase II trials of pancreatic ductal adenocarcinoma (PDAC). In addition, we explored the impact of predictive variables on overall survival (OS) and developed an optimal OS model.

METHODS

We analyzed 1867 clinical endpoint from 619 phase II PDAC trials with a systematic search from PubMed. Endpoint correlations were determined by Spearman's rank correlation. The assessed predictive factors included PFS/TTP, treatment size, therapy type, stage, and previous treatment. The relationship between predictors and OS was explored by a gamma generalized linear model (GLM) with a log-link function and compared with linear models.

RESULTS

The Spearman rank correlation coefficient between PFS/TTP and OS was 0.88 (95% confidence interval [CI] 0.85-0.89; p < 0.0001; n = 610) and between ORR and OS was 0.58 (0.52-0.64; p < 0.0001; n = 514). Model comparison favored the GLM model over the linear model, offering more accurate predictions for higher OS values. Consequently, PFS/TTP was the strongest predictor (pseudo-R2 = 0.75), with 1 added median PFS/TTP month associated with 13% (95% CI 13%-14%) increase in median OS. Subgroup analysis revealed that chemotherapy conferred significantly longer OS compared to targeted therapy in 1-Agent and 2-Agent trials, exhibiting a "very large" and "medium" effect size, respectively (rank biserial, rrb = 0.40 [95% CI 0.22-0.56] and rrb = 0.29 [0.16-0.41], both p < 0.0001), although inconsistent efficacy in 3-Agent trials (rrb = 0.12 [-0.07-0.30], p = 0.21).

CONCLUSIONS

PFS/TTP is a more reliable surrogate than ORR and a strong predictor of OS in phase II trials of pancreatic cancer. Moreover, gamma GLM (log-link function) is a robust tool for modeling positively skewed survival data with non-constant variance, thus can be applied to other cancers' OS data of such nature.

KRAS-Driven Tumorigenesis and KRAS-Driven Therapy in Pancreatic Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is associated with significant morbidity and mortality and is projected to be the second leading cause of cancer-related deaths by 2030. Mutations in KRAS are found in the vast majority of PDAC cases and plays an important role in the development of the disease. KRAS drives tumor cell proliferation and survival through activating the MAPK pathway to drive cell cycle progression and to lead to MYC-driven cellular programs. Moreover, activated KRAS promotes a protumorigenic microenvironment through forming a desmoplastic stroma and by impairing antitumor immunity. Secretion of granulocyte-macrophage colony-stimulating factor and recruitment of myeloid-derived suppressor cells and protumorigenic macrophages results in an immunosuppressive environment while secretion of secrete sonic hedgehog and TGFβ drive fibroblastic features characteristic of PDAC. Recent development of several small molecules to directly target KRAS marks an important milestone in precision medicine. Many molecules show promise in preclinical models of PDAC and in early phase clinical trials. In this review, we discuss the underlying cell intrinsic and extrinsic roles of KRAS in PDAC tumorigenesis, the pharmacologic development of KRAS inhibition, and therapeutic strategies to target KRAS in PDAC.

Clinical Perspectives on the Histomolecular Features of the Pancreatic Precursor Lesions: A Narrative Review

Pancreatic cancer (PC) is a lethal cancer with poor prognoses. Identifying and characterizing pancreatic cystic lesions (PCLs) in the early detection and follow-up plans is thought to help detect pancreatic malignancy. Besides, the molecular features of PCLs are thought to unravel potentials for targeted therapies. We present a narrative review of the existing literature on the role of PCLs in the early detection, risk stratification, and medical management of PC. High-grade intraductal papillary mucinous neoplasms (IPMN) and pancreatic intraepithelial neoplasia (PanIN) stage III are high-risk lesions for developing PC. These lesions often require thorough histomolecular characterization using endoscopic ultrasound (EUS), before a surgical decision is made. EUS is also useful in the risk assessment of PCLs with tentative plans-for instance, in branch-duct IPMNs (BD-IPMN)- where the final decision might change. Besides the operative decisions, recent improvements in the application of targeted therapies are expected to improve survival measures. Knowledge of molecular features has helped develop targeted therapies. In summary, the histomolecular characterization of PCLs is helpful in optimizing management plans in PC. Further improvements are still needed for the broad application of this knowledge in the clinical setting.

Evaluation of KRAS inhibitor-directed therapies for pancreatic cancer treatment

Despite significant advancements in the treatment of other cancers, pancreatic ductal adenocarcinoma (PDAC) remains one of the world's deadliest cancers. More than 90% of PDAC patients harbor a Kirsten rat sarcoma (KRAS) gene mutation. Although the clinical potential of anti-KRAS therapies has long been realized, all initial efforts to target KRAS were unsuccessful. However, with the recent development of a new generation of KRAS-targeting drugs, multiple KRAS-targeted treatment options for patients with PDAC have entered clinical trials. In this review, we provide an overview of current standard of care treatment, describe RAS signaling and the relevance of KRAS mutations, and discuss RAS isoform- and mutation-specific differences. We also evaluate the clinical efficacy and safety of mutation-selective and multi-selective inhibitors, in the context of PDAC. We then provide a comparison of clinically relevant KRAS inhibitors to second-line PDAC treatment options. Finally, we discuss putative resistance mechanisms that may limit the clinical effectiveness of KRAS-targeted therapies and provide a brief overview of promising therapeutic approaches in development that are focused on mitigating these resistance mechanisms.

Anlotinib plus tislelizumab for recurrent metastatic pancreas ductal adenocarcinoma with germline BRCA2 mutation: A case report

While combined immunotherapy and anti-angiogenic therapy have demonstrated efficacy in renal cell carcinoma, non-small cell lung cancer and hepatocellular carcinoma, the efficacy of first-line treatment for pancreatic ductal adenocarcinoma (PDAC) with germline BRCA2 mutation remains unproven. We described a BRCA2-mutated patient with PDAC who presented with posterior cardiac metastasis 8 months after surgery. After receiving four cycles of anlotinib combined with tislelizumab, abdominal CT scans indicated a complete response. The patient sustained this response for over 14 months on the combination regimen, with no reported adverse events. In conclusion, the combination of tislelizumab and anlotinib may offer a viable therapeutic option for recurrent metastatic BRCA2-mutated PDAC.

Efficacy and safety of first-line chemotherapies for patients with advanced pancreatic ductal adenocarcinoma: A systematic review and network meta-analysis

Background

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease, often diagnosed at an advanced stage. Systemic chemotherapy is the primary treatment, but direct comparisons of different regimens are limited. This study conducted a systematic review and network meta-analysis (NMA) to compare the efficacy and safety of various chemotherapy regimens, with the unique advantage of only including Phase III randomized controlled trials (RCTs).

Methods

NMA was conducted regarding the searched phase III RCTs by comparing overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse events (AEs) of different chemotherapy protocols.

Results

The analysis included 24 studies with 11470 patients across 25 treatment modalities. Among the chemotherapy regimens evaluated, FOLFIRINOX (fluorouracil, leucovorin, irinotecan, and oxaliplatin) demonstrated the highest OS and PFS, with a risk ratio (logHR) of 4.5 (95 % confidence interval 4.32-4.68) compared to gemcitabine monotherapy. The PEFG regimen (cisplatin, epirubicin, 5-fluorouracil, and gemcitabine) exhibited the highest ORR, with an odds ratio (OR) of 6.67 (2.08-20) compared to gemcitabine monotherapy. Notably, gemcitabine plus sorafenib was associated with the lowest hematological toxicity, with an odds ratio (OR) of 0.1 (0.02-0.48).

Conclusion

Combination therapies may offer greater benefits but also cause more toxic effects. However, combinations with targeted agents seem to have fewer adverse reactions.

Protein lipidation in health and disease: molecular basis, physiological function and pathological implication

Posttranslational modifications increase the complexity and functional diversity of proteins in response to complex external stimuli and internal changes. Among these, protein lipidations which refer to lipid attachment to proteins are prominent, which primarily encompassing five types including S-palmitoylation, N-myristoylation, S-prenylation, glycosylphosphatidylinositol (GPI) anchor and cholesterylation. Lipid attachment to proteins plays an essential role in the regulation of protein trafficking, localisation, stability, conformation, interactions and signal transduction by enhancing hydrophobicity. Accumulating evidence from genetic, structural, and biomedical studies has consistently shown that protein lipidation is pivotal in the regulation of broad physiological functions and is inextricably linked to a variety of diseases. Decades of dedicated research have driven the development of a wide range of drugs targeting protein lipidation, and several agents have been developed and tested in preclinical and clinical studies, some of which, such as asciminib and lonafarnib are FDA-approved for therapeutic use, indicating that targeting protein lipidations represents a promising therapeutic strategy. Here, we comprehensively review the known regulatory enzymes and catalytic mechanisms of various protein lipidation types, outline the impact of protein lipidations on physiology and disease, and highlight potential therapeutic targets and clinical research progress, aiming to provide a comprehensive reference for future protein lipidation research.

Advances in the management of pancreatic cancer

Pancreatic cancer remains among the malignancies with the worst outcomes. Survival has been improving, but at a slower rate than other cancers. Multimodal treatment, including chemotherapy, surgical resection, and radiotherapy, has been under investigation for many years. Because of the anatomical characteristics of the pancreas, more emphasis on treatment selection has been placed on local extension into major vessels. Recently, the development of more effective treatment regimens has opened up new treatment strategies, but urgent research questions have also become apparent. This review outlines the current management of pancreatic cancer, and the recent advances in its treatment. The review discusses future treatment pathways aimed at integrating novel findings of translational and clinical research.

Oncogenic KRAS triggers metabolic reprogramming in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with an extremely high lethality rate. Oncogenic KRAS activation has been proven to be a key driver of PDAC initiation and progression. There is increasing evidence that PDAC cells undergo extensive metabolic reprogramming to adapt to their extreme energy and biomass demands. Cell-intrinsic factors, such as KRAS mutations, are able to trigger metabolic rewriting. Here, we update recent advances in KRAS-driven metabolic reprogramming and the associated metabolic therapeutic potential in PDAC.

Signalling in pancreatic cancer: from pathways to therapy

Pancreatic cancer (PC) is a common malignant tumour in the digestive system. Due to the lack of sensitive diagnostic markers, strong metastasis ability, and resistance to anti-cancer drugs, the prognosis of PC is inferior. In the past decades, increasing evidence has indicated that the development of PC is closely related to various signalling pathways. With the exploration of RAS-driven, epidermal growth factor receptor, Hedgehog, NF-κB, TGF-β, and NOTCH signalling pathways, breakthroughs have been made to explore the mechanism of pancreatic carcinogenesis, as well as the novel therapies. In this review, we discussed the signalling pathways involved in PC and summarised current targeted agents in the treatment of PC. Furthermore, opportunities and challenges in the exploration of potential therapies targeting signalling pathways were also highlighted.

Targeting KRAS for the potential treatment of pancreatic ductal adenocarcinoma: Recent advancements provide hope (Review)

Kirsten rat sarcoma viral oncogene homolog (KRAS) is one of the most frequently mutated oncogenes in solid tumors. More than 90% of pancreatic ductal adenocarcinoma (PDAC) are driven by mutations in the KRAS gene, suggesting the importance of targeting this oncogene in PDAC. Initial efforts to target KRAS have been unsuccessful due to its small size, high affinity for guanosine triphosphate/guanosine diphosphate, and lack of distinct drug‑binding pockets. Therefore, much of the focus has been directed at inhibiting the activation of major signaling pathways downstream of KRAS, most notably the PI3K/AKT and RAF/MAPK pathways, using tyrosine kinase inhibitors and monoclonal antibodies. While preclinical studies showed promising results, clinical data using the inhibitors alone and in combination with other standard therapies have shown limited practicality, largely due to the lack of efficacy and dose‑limiting toxicities. Recent therapeutic approaches for KRAS‑driven tumors focus on mutation‑specific drugs such as selective KRASG12C inhibitors and son of sevenless 1 pan‑KRAS inhibitors. While KRASG12C inhibitors showed great promise against patients with non‑small cell lung cancer (NSCLC) harboring KRASG12C mutations, they were not efficacious in PDAC largely because the major KRAS mutant isoforms in PDAC are G12D, G12V, and G12R. As a result, KRASG12D and pan‑KRAS inhibitors are currently under investigation as potential therapeutic options for PDAC. The present review summarized the importance of KRAS oncogenic signaling, challenges in its targeting, and preclinical and clinical targeted agents including recent direct KRAS inhibitors for blocking KRAS signaling in PDAC.

Targeting KRAS in Pancreatic Ductal Adenocarcinoma: The Long Road to Cure

Pancreatic ductal adenocarcinoma (PDAC) remains an important cause of cancer-related mortality, and it is expected to play an even bigger part in cancer burden in the years to come. Despite concerted efforts from scientists and physicians, patients have experienced little improvement in survival over the past decades, possibly because of the non-specific nature of the tested treatment modalities. Recently, the discovery of potentially targetable molecular alterations has paved the way for the personalized treatment of PDAC. Indeed, the central piece in the molecular framework of PDAC is starting to be unveiled. KRAS mutations are seen in 90% of PDACs, and multiple studies have demonstrated their pivotal role in pancreatic carcinogenesis. Recent investigations have shed light on the differences in prognosis as well as therapeutic implications of the different KRAS mutations and disentangled the relationship between KRAS and effectors of downstream and parallel signaling pathways. Additionally, the recognition of other mechanisms involving KRAS-mediated pathogenesis, such as KRAS dosing and allelic imbalance, has contributed to broadening the current knowledge regarding this molecular alteration. Finally, KRAS G12C inhibitors have been recently tested in patients with pancreatic cancer with relative success, and inhibitors of KRAS harboring other mutations are under clinical development. These drugs currently represent a true hope for a meaningful leap forward in this dreadful disease.

Post-translational modifications and their implications in cancer

Post-translational modifications (PTMs) are crucial regulatory mechanisms that alter the properties of a protein by covalently attaching a modified chemical group to some of its amino acid residues. PTMs modulate essential physiological processes such as signal transduction, metabolism, protein localization, and turnover and have clinical relevance in cancer and age-related pathologies. Majority of proteins undergo post-translational modifications, irrespective of their occurrence in or after protein biosynthesis. Post-translational modifications link to amino acid termini or side chains, causing the protein backbone to get cleaved, spliced, or cyclized, to name a few. These chemical modifications expand the diversity of the proteome and regulate protein activity, structure, locations, functions, and protein-protein interactions (PPIs). This ability to modify the physical and chemical properties and functions of proteins render PTMs vital. To date, over 200 different protein modifications have been reported, owing to advanced detection technologies. Some of these modifications include phosphorylation, glycosylation, methylation, acetylation, and ubiquitination. Here, we discuss about the existing as well as some novel post-translational protein modifications, with their implications in aberrant states, which will help us better understand the modified sites in different proteins and the effect of PTMs on protein functions in core biological processes and progression in cancer.

Virtual screening and biological evaluation to identify pharmaceuticals potentially causing hypertension and hypokalemia by inhibiting steroid 11β-hydroxylase

Several drugs were found after their market approval to unexpectedly inhibit adrenal 11β-hydroxylase (CYP11B1)-dependent cortisol synthesis. Known side-effects of CYP11B1 inhibition include hypertension and hypokalemia, due to a feedback activation of adrenal steroidogenesis, leading to supraphysiological concentrations of 11-deoxycortisol and 11-deoxycorticosterone that can activate the mineralocorticoid receptor. This results in potassium excretion and sodium and water retention, ultimately causing hypertension. With the risk known but usually not addressed in preclinical evaluation, this study aimed to identify drugs and drug candidates inhibiting CYP11B1. Two conceptually different virtual screening methods were combined, a pharmacophore based and an induced fit docking approach. Cell-free and cell-based CYP11B1 activity measurements revealed several inhibitors with IC50 values in the nanomolar range. Inhibitors include retinoic acid metabolism blocking agents (RAMBAs), azole antifungals, α2-adrenoceptor ligands, and a farnesyltransferase inhibitor. The active compounds share a nitrogen atom embedded in an aromatic ring system. Structure activity analysis identified the free electron pair of the nitrogen atom as a prerequisite for the drug-enzyme interaction, with its pKa value as an indicator of inhibitory potency. Another important parameter is drug lipophilicity, exemplified by etomidate. Changing its ethyl ester moiety to a more hydrophilic carboxylic acid group dramatically decreased the inhibitory potential, most likely due to less efficient cellular uptake. The presented work successfully combined different in silico and in vitro methods to identify several previously unknown CYP11B1 inhibitors. This workflow facilitates the identification of compounds that inhibit CYP11B1 and therefore pose a risk for inducing hypertension and hypokalemia.

Genomic landscape of clinically advanced KRAS wild-type pancreatic ductal adenocarcinoma

Introduction

KRAS mutation is a common occurrence in Pancreatic Ductal Adenocarcinoma (PDA) and is a driver mutation for disease development and progression. KRAS wild-type PDA may constitute a distinct molecular and clinical subtype. We used the Foundation one data to analyze the difference in Genomic Alterations (GAs) that occur in KRAS mutated and wild-type PDA.

Methods

Comprehensive genomic profiling (CGP) data, tumor mutational burden (TMB), microsatellite instability (MSI) and PD-L1 by Immunohistochemistry (IHC) were analyzed.

Results and discussion

Our cohort had 9444 cases of advanced PDA. 8723 (92.37%) patients had KRAS mutation. 721 (7.63%) patients were KRAS wild-type. Among potentially targetable mutations, GAs more common in KRAS wild-type included ERBB2 (mutated vs wild-type: 1.7% vs 6.8%, p <0.0001), BRAF (mutated vs wild-type: 0.5% vs 17.9%, p <0.0001), PIK3CA (mutated vs wild-type: 2.3% vs 6.5%, p <0.001), FGFR2 (mutated vs wild-type: 0.1% vs 4.4%, p <0.0001), ATM (mutated vs wild-type: 3.6% vs 6.8%, p <0.0001). On analyzing untargetable GAs, the KRAS mutated group had a significantly higher percentage of TP53 (mutated vs wild-type: 80.2% vs 47.6%, p <0.0001), CDKN2A (mutated vs wild-type: 56.2% vs 34.4%, p <0.0001), CDKN2B (mutated vs wild-type: 28.9% vs 23%, p =0.007), SMAD4 (mutated vs wild-type: 26.8% vs 15.7%, p <0.0001) and MTAP (mutated vs wild-type: 21.7% vs 18%, p =0.02). ARID1A (mutated vs wild-type: 7.7% vs 13.6%, p <0.0001 and RB1(mutated vs wild-type: 2% vs 4%, p =0.01) were more prevalent in the wild-type subgroup. Mean TMB was higher in the KRAS wild-type subgroup (mutated vs wild-type: 2.3 vs 3.6, p <0.0001). High TMB, defined as TMB > 10 mut/mB (mutated vs wild-type: 1% vs 6.3%, p <0.0001) and very-high TMB, defined as TMB >20 mut/mB (mutated vs wild-type: 0.5% vs 2.4%, p <0.0001) favored the wild-type. PD-L1 high expression was similar between the 2 groups (mutated vs wild-type: 5.7% vs 6%,). GA associated with immune checkpoint inhibitors (ICPIs) response including PBRM1 (mutated vs wild-type: 0.7% vs 3.2%, p <0.0001) and MDM2 (mutated vs wild-type: 1.3% vs 4.4%, p <0.0001) were more likely to be seen in KRAS wild-type PDA.

Targeting Harvey rat sarcoma viral oncogene homolog in head and neck cancer: how to move forward?

PURPOSE OF REVIEW

Despite recent advances, treatment personalization remains an issue for recurrent metastatic head and neck squamous cell carcinoma (RM HNSCC) patients. After human papilloma virus (HPV) and programmed death ligand 1 (PDL1) expression, Harvey rat sarcoma viral oncogene homolog (HRAS) appears as an emerging target in this field. In this review, we summarize the features of HRAS -mutated HNSCC and its targeting by farnesyl transferase inhibitors.

RECENT FINDINGS

HRAS mutations define a small subgroup of RM HNSCC patients with a poor prognosis and often refractory to the standard treatments. Posttranslational processing of HRAS being dependent on farnesylation, farnesyl transferase inhibitors have been evaluated in HRAS -mutated tumors. Tipifarnib, a first in class farnesyl transferase inhibitor, has shown efficacy in phase 2 trials with HRAS -mutated tumors. Despite reported high response rates in selected population, the efficacy of Tipifarnib is inconsistent and always transient, probably because of limiting hematological toxicities leading to dose reduction and occurrence of secondary resistance mutations.

SUMMARY

Tipifarnib is the first in the class of farnesyl transferase inhibitors to show efficacy in HRAS -mutated RM HNSCC. The understanding of mechanisms of resistance will pave the way for the design of second-generation farnesyl transferases inhibitors.

Targeting KRASG12C in colorectal cancer: the beginning of a new era

RAS mutation is considered one of the most relevant oncogenic drivers in human cancers. Unfortunately, for more than three decades, RAS has been considered an undruggable target. Recently, the discovery of selective and potent KRAS^G12C inhibitors represented a light at the end of the tunnel. Indeed, sotorasib and adagrasib proved clinical activity in patients with refractory metastatic colorectal cancer harboring KRAS^G12C mutation; however, responses are lower than expected, suggesting the presence of intrinsic resistance. Consequently, novel combinatory strategies to disrupt the RAS signaling pathways are under clinical investigation. This review aims to discuss the current knowledge and novel routes of KRAS^G12C inhibition in metastatic colorectal cancer.

Personalized matched targeted therapy in advanced pancreatic cancer: a pilot cohort analysis

Despite progress, 2-year pancreatic cancer survival remains dismal. We evaluated a biomarker-driven, combination/N-of-one strategy in 18 patients (advanced/metastatic pancreatic cancer) (from Molecular Tumor Board). Targeted agents administered/patient = 2.5 (median) (range, 1-4); first-line therapy (N = 5); second line, (N = 13). Comparing patients (high versus low degrees of matching) (matching score ≥50% versus <50%; reflecting number of alterations matched to targeted agents divided by number of pathogenic alterations), survival was significantly longer (hazard ratio [HR] 0.24 (95% confidence interval [CI], 0.078-0.76, P = 0.016); clinical benefit rates (CBR) (stable disease ≥6 months/partial/complete response) trended higher (45.5 vs 0.0%, P = 0.10); progression-free survival, HR, 95% CI, 0.36 (0.12-1.10) (p = 0.075). First versus ≥2nd-line therapy had higher CBRs (80.0 vs 7.7%, P = 0.008). No grade 3-4 toxicities occurred. The longest responder achieved partial remission (17.5 months) by co-targeting MEK and CDK4/6 alterations (chemotherapy-free). Therefore, genomically matched targeted agent combinations were active in these advanced pancreatic cancers. Larger prospective trials are warranted.

Targeting RAS mutants in malignancies: successes, failures, and reasons for hope

RAS genes are the most frequently mutated oncogenes and play critical roles in the development and progression of malignancies. The mutation, isoform (KRAS, HRAS, and NRAS), position, and type of substitution vary depending on the tissue types. Despite decades of developing RAS-targeted therapies, only small subsets of these inhibitors are clinically effective, such as the allele-specific inhibitors against KRASG12C . Targeting the remaining RAS mutants would require further experimental elucidation of RAS signal transduction, RAS-altered metabolism, and the associated immune microenvironment. This study reviews the mechanisms and efficacy of novel targeted therapies for different RAS mutants, including KRAS allele-specific inhibitors, combination therapies, immunotherapies, and metabolism-associated therapies.

Targeting Mast Cells in Allergic Disease: Current Therapies and Drug Repurposing

The incidence of allergic disease has grown tremendously in the past three generations. While current treatments are effective for some, there is considerable unmet need. Mast cells are critical effectors of allergic inflammation. Their secreted mediators and the receptors for these mediators have long been the target of allergy therapy. Recent drugs have moved a step earlier in mast cell activation, blocking IgE, IL-4, and IL-13 interactions with their receptors. In this review, we summarize the latest therapies targeting mast cells as well as new drugs in clinical trials. In addition, we offer support for repurposing FDA-approved drugs to target mast cells in new ways. With a multitude of highly selective drugs available for cancer, autoimmunity, and metabolic disorders, drug repurposing offers optimism for the future of allergy therapy.

Onco-immunomodulatory properties of pharmacological interference with RAS-RAF-MEK-ERK pathway hyperactivation

Hyperactivation of the RAS-RAF-MEK-ERK cascade - a mitogen-activated protein kinase pathway – has a well-known association with oncogenesis of leading tumor entities, including non-small cell lung cancer, colorectal carcinoma, pancreatic ductal adenocarcinoma, and malignant melanoma. Increasing evidence shows that genetic alterations leading to RAS-RAF-MEK-ERK pathway hyperactivation mediate contact- and soluble-dependent crosstalk between tumor, tumor microenvironment (TME) and the immune system resulting in immune escape mechanisms and establishment of a tumor-sustaining environment. Consequently, pharmacological interruption of this pathway not only leads to tumor-cell intrinsic disruptive effects but also modification of the TME and anti-tumor immunomodulation. At the same time, the importance of ERK signaling in immune cell physiology and potentiation of anti-tumor immune responses through ERK signaling inhibition within immune cell subsets has received growing appreciation. Specifically, a strong case was made for targeted MEK inhibition due to promising associated immune cell intrinsic modulatory effects. However, the successful transition of therapeutic agents interrupting RAS-RAF-MEK-ERK hyperactivation is still being hampered by significant limitations regarding durable efficacy, therapy resistance and toxicity. We here collate and summarize the multifaceted role of RAS-RAF-MEK-ERK signaling in physiology and oncoimmunology and outline the rationale and concepts for exploitation of immunomodulatory properties of RAS-RAF-MEK-ERK inhibition while accentuating the role of MEK inhibition in combinatorial and intermittent anticancer therapy. Furthermore, we point out the extensive scientific efforts dedicated to overcoming the challenges encountered during the clinical transition of various therapeutic agents in the search for the most effective and safe patient- and tumor-tailored treatment approach.

Targeting farnesylation as a novel therapeutic approach in HRAS-mutant rhabdomyosarcoma

Activating RAS mutations are found in a subset of fusion-negative rhabdomyosarcoma (RMS), and therapeutic strategies to directly target RAS in these tumors have been investigated, without clinical success to date. A potential strategy to inhibit oncogenic RAS activity is the disruption of RAS prenylation, an obligate step for RAS membrane localization and effector pathway signaling, through inhibition of farnesyltransferase (FTase). Of the major RAS family members, HRAS is uniquely dependent on FTase for prenylation, whereas NRAS and KRAS can utilize geranylgeranyl transferase as a bypass prenylation mechanism. Tumors driven by oncogenic HRAS may therefore be uniquely sensitive to FTase inhibition. To investigate the mutation-specific effects of FTase inhibition in RMS we utilized tipifarnib, a potent and selective FTase inhibitor, in in vitro and in vivo models of RMS genomically characterized for RAS mutation status. Tipifarnib reduced HRAS processing, and plasma membrane localization leading to decreased GTP-bound HRAS and decreased signaling through RAS effector pathways. In HRAS-mutant cell lines, tipifarnib reduced two-dimensional and three-dimensional cell growth, and in vivo treatment with tipifarnib resulted in tumor growth inhibition exclusively in HRAS-mutant RMS xenografts. Our data suggest that small molecule inhibition of FTase is active in HRAS-driven RMS and may represent an effective therapeutic strategy for a genomically-defined subset of patients with RMS.

KRAS: A Druggable Target in Colon Cancer Patients

Mutations in KRAS are among the most frequent aberrations in cancer, including colon cancer. KRAS direct targeting is daunting due to KRAS protein resistance to small molecule inhibition. Moreover, its elevated affinity to cellular guanosine triphosphate (GTP) has made the design of specific drugs challenging. Indeed, KRAS was considered 'undruggable'. KRASG12C is the most commonly mutated variant of KRAS in non-small cell lung cancer. Currently, the achievements obtained with covalent inhibitors of this variant have given the possibility to assess the best therapeutic approach to KRAS-driven tumors. Mutation-related biochemical assets and the tissue of origin are expected to influence responses to treatment. Further attempts to obtain mutant-specific KRAS (KRASG12C) switch-II covalent inhibitors are ongoing and the results are promising. Drugs targeted to block KRAS effector pathways could be combined with direct KRAS inhibitors, immunotherapy or T cell-targeting approaches in KRAS-mutant tumors. The development of valuable combination regimens will be essential against potential mechanisms of resistance that may arise during treatment.

Liquid Biopsy as a Prognostic and Theranostic Tool for the Management of Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinomas (PDAC) represent one of the deadliest cancers worldwide. Survival is still low due to diagnosis at an advanced stage and resistance to treatment. Herein, we review the main types of liquid biopsy able to help in both prognosis and adaptation of treatments.

Comparative Outcomes of First-Line Chemotherapy for Metastatic Pancreatic Cancer Among the Regimens Used in Japan: A Systematic Review and Network Meta-analysis

IMPORTANCE

Various first-line chemotherapy treatment regimens for patients with metastatic pancreatic cancer have been approved in Japan, including gemcitabine (GEM); fluorouracil, leucovorin, irinotecan, and oxaliplatin combination (FOLFIRINOX); GEM plus albumin-bound paclitaxel (GEM+NPTX), and S-1 (tegafur + gimeracil + oteracil). However, direct comparisons of these chemotherapy regimens are limited.

OBJECTIVE

To assess the short-term and long-term outcomes associated with first-line chemotherapy regimens for metastatic pancreatic cancer compared with chemotherapy regimens recommended in Japanese guidelines.

DATA SOURCES

In this systematic review and network meta-analysis, the bibliographic databases PubMed, Cochrane Library, and Web of Science, as well as medical journals published between January 1, 2002, and December 31, 2018, were searched for clinical trials comparing chemotherapy regimens.

STUDY SELECTION

Randomized 2-arm clinical trials evaluating first-line chemotherapy for advanced or metastatic pancreatic cancer were included.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Extension Statement for Reporting of Systematic Reviews Incorporating Network Meta-analyses of Health Care Interventions was followed for data abstractions. Data were pooled using a random-effects model. The SIGN 50 Quality Assessment Instrument was used to assess the risk of bias and overall study quality of the selected trials.

MAIN OUTCOMES AND MEASURES

The primary end point was overall survival (OS), and the secondary end point was progression-free survival (PFS) compared with GEM for first-line chemotherapy for metastatic pancreatic cancer. The Kaplan-Meier curve of GEM from the literature and the estimated hazard ratios (HRs) were used to model the long-term associations to calculate the area under the curve (AUC) (person-months) for OS and PFS of each chemotherapy. Sensitivity analyses with multiple functional models were conducted to confirm the long-term estimations.

RESULTS

A total of 22 regimens (25 studies) for OS and a total of 18 regimens (21 studies) for PFS were identified from literature. The total number of participants was 10 186, with 5856 male (57.5%) and 4330 female (42.5%). The FOLFIRINOX and GEM+NPTX regimens were associated with reduction in the risk of death, with an HR of 0.57 (95% CI, 0.41-0.79) and 0.72 (95% CI, 0.55-0.95) compared with GEM, respectively. The curve estimation also showed that FOLFIRINOX had the largest AUC for survival at 15.49 person-months (range, 13.84-15.51 person-months), followed by GEM+NPTX with 12.36 person-months (range, 10.98-12.59 person-months), GEM+ERLO with 10.84 person-months (range, 9.66-11.23 person-months), S-1 with 8.44 person-months (range, 8.26-9.74 person-months), and GEM with 8.10 person-months (range, 7.93-9.38 person-months).

CONCLUSIONS AND RELEVANCE

The results of this network meta-analysis support the relative short-term and long-term outcomes associated with first-line chemotherapy for metastatic pancreatic cancer used clinically in Japan.

Moving Towards Dawn: KRas Signaling and Treatment in Pancreatic Ductal Adenocarcinoma

"Pancreatic ductal adenocarcinoma (PDAC)" is robust, nearly clueless, and all-around deadly among all tumors. Below 10 %, the general 5-year endurance period has remained adamantly unaltered in the last 30 years, regardless of enormous clinical and therapeutic endeavors. The yearly number of deaths is more than the number of recently analyzed cases. Not a classic one, but "Carbohydrate Antigen CA19- 9" remains the prevailing tool for diagnosis. MicroRNAs and non-invasive techniques are now incorporated for the effective prognosis of PDAC than just CA19-9. Mutated "Rat sarcoma virus Ras" conformation "V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog KRas" is 95 % accountable for PDAC, and its active (GTP-bound) formation activates signaling cascade comprising "Rapidly accelerated fibrosarcoma Raf"/"Mitogen-activated protein kinase MEK"/ "Extracellular signal-regulated kinase ERK" with "Phosphoinositide 3-kinase PI3K"/ "protein kinase B Akt"/ "mammalian target of rapamycin mTOR" pathways. KRas has acquired the label of 'undruggable' since the crosstalk in the nexus of pathways compensates for Raf and PI3K signaling cascade blocking. It is arduous to totally regulate KRascoordinated PDAC with traditional medicaments like "gemcitabine GEM" plus nabpaclitaxel/ FOLFIRINOX. For long-haul accomplishments aiming at KRas, future endeavors should be directed to combinatorial methodologies to adequately block KRas pathways at different standpoints. Currently they are contributing to healing PDAC. In this review article, we outline the function of KRas in carcinogenesis in PDAC, its signaling cascade, former techniques utilized in hindering Kras, current and future possibilities for targeting Kras.

Context Matters-Why We Need to Change From a One Size Fits all Approach to Made-to-Measure Therapies for Individual Patients With Pancreatic Cancer

Pancreatic cancer is one of the deadliest cancers and remains a major unsolved health problem. While pancreatic ductal adenocarcinoma (PDAC) is associated with driver mutations in only four major genes (KRAS, TP53, SMAD4, and CDKN2A), every tumor differs in its molecular landscape, histology, and prognosis. It is crucial to understand and consider these differences to be able to tailor treatment regimens specific to the vulnerabilities of the individual tumor to enhance patient outcome. This review focuses on the heterogeneity of pancreatic tumor cells and how in addition to genetic alterations, the subsequent dysregulation of multiple signaling cascades at various levels, epigenetic and metabolic factors contribute to the oncogenesis of PDAC and compensate for each other in driving cancer progression if one is tackled by a therapeutic approach. This implicates that besides the need for new combinatorial therapies for PDAC, a personalized approach for treating this highly complex cancer is required. A strategy that combines both a target-based and phenotypic approach to identify an effective treatment, like Reverse Clinical Engineering® using patient-derived organoids, is discussed as a promising way forward in the field of personalized medicine to tackle this deadly disease.

Mutations in key driver genes of pancreatic cancer: molecularly targeted therapies and other clinical implications

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers, with a minimal difference between its incidence rate and mortality rate. Advances in oncology over the past several decades have dramatically improved the overall survival of patients with multiple cancers due to the implementation of new techniques in early diagnosis, therapeutic drugs, and personalized therapy. However, pancreatic cancers remain recalcitrant, with a 5-year relative survival rate of <9%. The lack of measures for early diagnosis, strong resistance to chemotherapy, ineffective adjuvant chemotherapy and the unavailability of molecularly targeted therapy are responsible for the high mortality rate of this notorious disease. Genetically, PDAC progresses as a complex result of the activation of oncogenes and inactivation of tumor suppressors. Although next-generation sequencing has identified numerous new genetic alterations, their clinical implications remain unknown. Classically, oncogenic mutations in genes such as KRAS and loss-of-function mutations in tumor suppressors, such as TP53, CDNK2A, DPC4/SMAD4, and BRCA2, are frequently observed in PDAC. Currently, research on these key driver genes is still the main focus. Therefore, studies assessing the functions of these genes and their potential clinical implications are of paramount importance. In this review, we summarize the biological function of key driver genes and pharmaceutical targets in PDAC. In addition, we conclude the results of molecularly targeted therapies in clinical trials and discuss how to utilize these genetic alterations in further clinical practice.

Potential of Farnesyl Transferase Inhibitors in Combination Regimens in Squamous Cell Carcinomas

Current therapies for recurrent and metastatic SCC are associated with poor outcomes, and options for later lines of treatment are limited. Insights into potential therapeutic targets, as well as mechanisms of resistance to available therapies, have begun to be elucidated, creating the basis for exploration of combination approaches to drive better patient outcomes. Tipifarnib, a farnesyl transferase inhibitor (FTI), is a small molecule drug that has demonstrated encouraging clinical activity in a genetically-defined subset of head and neck squamous cell carcinoma (HNSCC)-specifically, tumors that express a mutation in the HRAS protooncogene. More recently, bioinformatic analyses and results from patient-derived xenograft modeling indicate that HRAS pathway dependency may extend to a broader subpopulation of SCCs beyond HRAS mutants in the context of combination with agents such as cisplatin, cetuximab, or alpelisib. In addition, tipifarnib can also inactivate additional farnesylated proteins implicated in resistance to approved therapies, including immunotherapies, through a variety of distinct mechanisms, suggesting that tipifarnib could serve as an anchor for combination regimens in SCCs and other tumor types.

Oncogenic KRAS blockade therapy: renewed enthusiasm and persistent challenges

Across a broad range of human cancers, gain-of-function mutations in RAS genes (HRAS, NRAS, and KRAS) lead to constitutive activity of oncoproteins responsible for tumorigenesis and cancer progression. The targeting of RAS with drugs is challenging because RAS lacks classic and tractable drug binding sites. Over the past 30 years, this perception has led to the pursuit of indirect routes for targeting RAS expression, processing, upstream regulators, or downstream effectors. After the discovery that the KRAS-G12C variant contains a druggable pocket below the switch-II loop region, it has become possible to design irreversible covalent inhibitors for the variant with improved potency, selectivity and bioavailability. Two such inhibitors, sotorasib (AMG 510) and adagrasib (MRTX849), were recently evaluated in phase I-III trials for the treatment of non-small cell lung cancer with KRAS-G12C mutations, heralding a new era of precision oncology. In this review, we outline the mutations and functions of KRAS in human tumors and then analyze indirect and direct approaches to shut down the oncogenic KRAS network. Specifically, we discuss the mechanistic principles, clinical features, and strategies for overcoming primary or secondary resistance to KRAS-G12C blockade.

Targeting KRAS in pancreatic cancer: new drugs on the horizon

Kirsten Rat Sarcoma (KRAS) is a master oncogene involved in cellular proliferation and survival and is the most commonly mutated oncogene in all cancers. Activating KRAS mutations are present in over 90% of pancreatic ductal adenocarcinoma (PDAC) cases and are implicated in tumor initiation and progression. Although KRAS is a critical oncogene, and therefore an important therapeutic target, its therapeutic inhibition has been very challenging, and only recently specific mutant KRAS inhibitors have been discovered. In this review, we discuss the activation of KRAS signaling and the role of mutant KRAS in PDAC development. KRAS has long been considered undruggable, and many drug discovery efforts which focused on indirect targeting have been unsuccessful. We discuss the various efforts for therapeutic targeting of KRAS. Further, we explore the reasons behind these obstacles, novel successful approaches to target mutant KRAS including G12C mutation as well as the mechanisms of resistance.

Emerging strategies to target RAS signaling in human cancer therapy

RAS mutations (HRAS, NRAS, and KRAS) are among the most common oncogenes, and around 19% of patients with cancer harbor RAS mutations. Cells harboring RAS mutations tend to undergo malignant transformation and exhibit malignant phenotypes. The mutational status of RAS correlates with the clinicopathological features of patients, such as mucinous type and poor differentiation, as well as response to anti-EGFR therapies in certain types of human cancers. Although RAS protein had been considered as a potential target for tumors with RAS mutations, it was once referred to as a undruggable target due to the consecutive failure in the discovery of RAS protein inhibitors. However, recent studies on the structure, signaling, and function of RAS have shed light on the development of RAS-targeting drugs, especially with the approval of Lumakras (sotorasib, AMG510) in treatment of KRASG12C-mutant NSCLC patients. Therefore, here we fully review RAS mutations in human cancer and especially focus on emerging strategies that have been recently developed for RAS-targeting therapy.

Hacking Pancreatic Cancer: Present and Future of Personalized Medicine

Pancreatic cancer (PC) is a recalcitrant disease characterized by high incidence and poor prognosis. The extremely complex genomic landscape of PC has a deep influence on cultivating a tumor microenvironment, resulting in the promotion of tumor growth, drug resistance, and immune escape mechanisms. Despite outstanding progress in personalized medicine achieved for many types of cancer, chemotherapy still represents the mainstay of treatment for PC. Olaparib was the first agent to demonstrate a significant benefit in a biomarker-selected population, opening the doors for a personalized approach. Despite the failure of a large number of studies testing targeted agents or immunotherapy to demonstrate benefits over standard chemotherapy regimens, some interesting agents, alone or in combination with other drugs, have achieved promising results. A wide spectrum of therapeutic strategies, including immune-checkpoint inhibitors tyrosine kinase inhibitors and agents targeting metabolic pathways or the tumor microenvironment, is currently under investigation. In this review, we aim to provide a comprehensive overview of the current landscape and future directions of personalized medicine for patients affected by PC.

Antibiotic use influences outcomes in advanced pancreatic adenocarcinoma patients

Recent studies defined a potentially important role of the microbiome in modulating pancreatic ductal adenocarcinoma (PDAC) and responses to therapies. We hypothesized that antibiotic usage may predict outcomes in patients with PDAC.

We retrospectively analyzed clinical data of patients with resectable or metastatic PDAC seen at MD Anderson Cancer from 2003 to 2017. Demographic, chemotherapy regimen and antibiotic use, duration, type, and reason for indication were recorded.

A total of 580 patients with PDAC were studied, 342 resected and 238 metastatic patients, selected retrospectively from our database. Antibiotic use, for longer than 48 hrs, was detected in 209 resected patients (61%) and 195 metastatic ones (62%). On resectable patients, we did not find differences in overall survival (OS) or progression‐free survival (PFS), based on antibiotic intake. However, in the metastatic cohort, antibiotic consumption was associated with a significantly longer OS (13.3 months vs. 9.0 months, HR 0.48, 95% CI 0.34–0.7, p = 0.0001) and PFS (4.4 months vs. 2 months, HR 0.48, 95% CI 0.34–0.68, p = <0.0001). In multivariate analysis, the impact of ATB remained significant for PFS (HR 0.59, p = 0.005) and borderline statistically significant for OS (HR 0.69, p = 0.06). When we analyzed by chemotherapy regimen, we found that patients who received gemcitabine‐based chemotherapy as first‐line therapy (n = 118) had significantly prolonged OS (HR 0.4, p 0.0013) and PFS (HR 0.55, p 0.02) if they received antibiotics, while those receiving 5FU‐based chemotherapy (n = 98) had only prolonged PFS (HR 0.54, p = 0.03).

Antibiotics‐associated modulation of the microbiome is associated with better outcomes in patients with metastatic PDAC.

We have analyzed the effect of antibiotics’ intake on two cohorts of patients with pancreatic adenocarcinoma, resectable, and metastatic. We have found that on the metastatic cohort, antibiotics use was significantly associated with better outcomes, particularly, on patients that received gemcitabine based‐chemotherapy as the first line.

Translating complexity and heterogeneity of pancreatic tumor: 3D in vitro to in vivo models

Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive type of cancer with an overall survival rate of less than 7-8%, emphasizing the need for novel effective therapeutics against PDAC. However only a fraction of therapeutics which seemed promising in the laboratory environment will eventually reach the clinic. One of the main reasons behind this low success rate is the complex tumor microenvironment (TME) of PDAC, a highly fibrotic and dense stroma surrounding tumor cells, which supports tumor progression as well as increases the resistance against the treatment. In particular, the growing understanding of the PDAC TME points out a different challenge in the development of efficient therapeutics - a lack of biologically relevant in vitro and in vivo models that resemble the complexity and heterogeneity of PDAC observed in patients. The purpose and scope of this review is to provide an overview of the recent developments in different in vitro and in vivo models, which aim to recapitulate the complexity of PDAC in a laboratory environment, as well to describe how 3D in vitro models can be integrated into drug development pipelines that are already including sophisticated in vivo models. Hereby a special focus will be given on the complexity of in vivo models and the challenges in vitro models face to reach the same levels of complexity in a controllable manner. First, a brief introduction of novel developments in two dimensional (2D) models and ex vivo models is provided. Next, recent developments in three dimensional (3D) in vitro models are described ranging from spheroids, organoids, scaffold models, bioprinted models to organ-on-chip models including a discussion on advantages and limitations for each model. Furthermore, we will provide a detailed overview on the current PDAC in vivo models including chemically-induced models, syngeneic and xenogeneic models, highlighting hetero- and orthotopic, patient-derived tissues (PDX) models, and genetically engineered mouse models. Finally, we will provide a discussion on overall limitations of both, in vitro and in vivo models, and discuss necessary steps to overcome these limitations to reach an efficient drug development pipeline, as well as discuss possibilities to include novel in silico models in the process.

Performance status as prognostic factor in phase III trials of first-line chemotherapy of unresectable or metastatic pancreatic cancer: A trial-level meta-analysis

For patients with unresectable or metastatic pancreatic adenocarcinoma (mPDAC), there are no standardized prognostic and predictive factors beyond performance status (PS). A poor PS, as defined by Eastern Cooperative Oncology Group (ECOG) score of 2 or more, has been related with a detrimental effect of chemotherapy. Therefore, even more trials enrolled patients with good PS. The current analysis aims to evaluate the results of PS as a prognostic factor in phase III trials of patients with mPDAC receiving first-line chemotherapy. A literature search on two databases, from 2000 to 2019, and a further selection of clinical trials were performed by predefined criteria. Twelve phase III studies have been included in the analysis: the trials, enrolling 5619 patients, confirmed the worse prognosis of patients with higher ECOG PS scores (hazard ratio [HR] = 1.45; 95% confidence interval [CI], 1.21-1.74; p-value < 0.001), and a similar trend was evident for patients with an ECOG PS 1 versus 0 (HR = 1.61; 95% CI, 1.43-1.80; p-value < 0.001) in six studies, enrolling 2799 patients. Heterogeneity of trials was high, with I²  = 91%. Some possible moderators have been suggested, such as the number of drugs in the chemotherapy regimen and the male gender. In conclusion, a low ECOG PS score appears to be related with a longer survival even in trials that excluded patients with an ECOG PS 2 score, but the meta-analyses reported high heterogeneity and publication bias.

Blocking K-Ras Interaction With the Plasma Membrane Is a Tractable Therapeutic Approach to Inhibit Oncogenic K-Ras Activity

Ras proteins are membrane-bound small GTPases that promote cell proliferation, differentiation, and apoptosis. Consistent with this key regulatory role, activating mutations of Ras are present in ∼19% of new cancer cases in the United States per year. K-Ras is one of the three ubiquitously expressed isoforms in mammalian cells, and oncogenic mutations in this isoform account for ∼75% of Ras-driven cancers. Therefore, pharmacological agents that block oncogenic K-Ras activity would have great clinical utility. Most efforts to block oncogenic Ras activity have focused on Ras downstream effectors, but these inhibitors only show limited clinical benefits in Ras-driven cancers due to the highly divergent signals arising from Ras activation. Currently, four major approaches are being extensively studied to target K-Ras–driven cancers. One strategy is to block K-Ras binding to the plasma membrane (PM) since K-Ras requires the PM binding for its signal transduction. Here, we summarize recently identified molecular mechanisms that regulate K-Ras–PM interaction. Perturbing these mechanisms using pharmacological agents blocks K-Ras–PM binding and inhibits K-Ras signaling and growth of K-Ras–driven cancer cells. Together, these studies propose that blocking K-Ras–PM binding is a tractable strategy for developing anti–K-Ras therapies.

Pandey M, Plano D, Amin S, Lu J, Sharma AK. Novel Seleno-Aspirinyl Compound AS-10 Induces Apoptosis, G1 Arrest of Pancreatic Ductal Adenocarcinoma Cells, Inhibits Their NF-κB Signaling, and Synergizes with Gemcitabine Cytotoxicity

Current available therapies for pancreatic ductal adenocarcinoma (PDAC) provide minimal overall survival benefits and cause severe adverse effects. We have identified a novel molecule AS-10, a selenazolidine-bis-aspirinyl derivative, that was two to three orders of magnitude more potent than aspirin and at least one to two orders of magnitude more potent than gemcitabine in inhibiting PDAC cancer cell growth/viability against three PDAC cell lines while sparing mouse embryonic fibroblasts in the same exposure range. In Panc-1 cells, AS-10 induced apoptosis without necrosis, principally through caspase-3/7 cascade and reactive oxygen species, in addition to an induction of G1 cell cycle block. Transcriptomic profiling with RNA-seq indicated the top responses to AS-10 exposure as CDKN1A (P21Cip1), CCND1, and nuclear transcription factor-kappa B (NF-κB) complex and the top functions as cell cycle, cell death, and survival without inducing the DNA damage gene signature. AS-10 pretreatment (6 h) decreased cytokine tumor necrosis factor-alpha (TNF-α)-stimulated NF-κB nuclear translocation, DNA binding activity, and degradation of cytosolic inhibitor of κB (IκB) protein. As NF-κB activation in PDAC cells confers resistance to gemcitabine, the AS-10 combination with gemcitabine increased the in vitro cytotoxicity more than the additivity of both compounds. Overall, our results suggest AS-10 may be a promising drug lead for PDAC, both as a single agent and in combination therapy.

The Role of Wild-Type RAS in Oncogenic RAS Transformation

The RAS family of oncogenes (HRAS, NRAS, and KRAS) are among the most frequently mutated protein families in cancers. RAS-mutated tumors were originally thought to proliferate independently of upstream signaling inputs, but we now know that non-mutated wild-type (WT) RAS proteins play an important role in modulating downstream effector signaling and driving therapeutic resistance in RAS-mutated cancers. This modulation is complex as different WT RAS family members have opposing functions. The protein product of the WT RAS allele of the same isoform as mutated RAS is often tumor-suppressive and lost during tumor progression. In contrast, RTK-dependent activation of the WT RAS proteins from the two non-mutated WT RAS family members is tumor-promoting. Further, rebound activation of RTK–WT RAS signaling underlies therapeutic resistance to targeted therapeutics in RAS-mutated cancers. The contributions of WT RAS to proliferation and transformation in RAS-mutated cancer cells places renewed interest in upstream signaling molecules, including the phosphatase/adaptor SHP2 and the RasGEFs SOS1 and SOS2, as potential therapeutic targets in RAS-mutated cancers.

A review of response in neoadjuvant therapy for exocrine pancreatic cancer

Despite overall advances in cancer therapy, patients with pancreatic ductal adenocarcinoma continue to have a poor prognosis. While adjuvant therapy is still considered standard, there is mounting evidence that neoadjuvant therapy confers similar benefits in patients with locally advanced disease. The primary measures of response are radiographic, biochemical, margin status, and pathologic. Given overall low response rates and the need for new treatment strategies, standard metrics remain important to the investigation of new systemic agents.

The importance of Ras in drug resistance in cancer

In this review, we analyse the impact of oncogenic Ras mutations in mediating cancer drug resistance and the progress made in the abrogation of this resistance, through pharmacological targeting. At a physiological level, Ras is implicated in many cellular proliferation and survival pathways. However, mutations within this small GTPase can be responsible for the initiation of cancer, therapeutic resistance and failure, and ultimately disease relapse. Often termed "undruggable," Ras is notoriously difficult to target directly, due to its structure and intrinsic activity. Thus, Ras-mediated drug resistance remains a considerable pharmacological problem. However, with advances in both analytical techniques and novel drug classes, the therapeutic landscape against Ras is changing. Allele-specific, direct Ras-targeting agents have reached clinical trials for the first time, indicating there may, at last, be hope of targeting such an elusive but significant protein for better more effective cancer therapy.

A Clinically Applicable 24-Protein Model for Classifying Risk Subgroups in Pancreatic Ductal Adenocarcinomas using Multiple Reaction Monitoring-Mass Spectrometry

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) subtypes have been identified using various methodologies. However, it is a challenge to develop classification system applicable to routine clinical evaluation. We aimed to identify risk subgroups based on molecular features and develop a classification model that was more suited for clinical applications.

EXPERIMENTAL DESIGN

We collected whole dissected specimens from 225 patients who underwent surgery at Seoul National University Hospital [Seoul, Republic of Korea (South)], between October 2009 and February 2018. Target proteins with potential relevance to tumor progression or prognosis were quantified with robust quality controls. We used hierarchical clustering analysis to identify risk subgroups. A random forest classification model was developed to predict the identified risk subgroups, and the model was validated using transcriptomic datasets from external cohorts (N = 700), with survival analysis.

RESULTS

We identified 24 protein features that could classify the four risk subgroups associated with patient outcomes: stable, exocrine-like; activated, and extracellular matrix (ECM) remodeling. The "stable" risk subgroup was characterized by proteins that were associated with differentiation and tumor suppressors. "Exocrine-like" tumors highly expressed pancreatic enzymes. Two high-risk subgroups, "activated" and "ECM remodeling," were enriched in terms such as cell cycle, angiogenesis, immunocompetence, tumor invasion metastasis, and metabolic reprogramming. The classification model that included these features made prognoses with relative accuracy and precision in multiple cohorts.

CONCLUSIONS

We proposed PDAC risk subgroups and developed a classification model that may potentially be useful for routine clinical implementations, at the individual level. This clinical system may improve the accuracy of risk prediction and treatment guidelines.See related commentary by Thakur and Singh, p. 3272.