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Targeting BTK has profoundly changed the face of CLL treatment over the past decade. Iterative advances in the cat and mouse game of resistance and redesign have moved BTK inhibitors from covalent to non-covalent and now targeted protein degraders. However, contrary to the presumption that protein degraders may be impervious to mutations in BTK, we now present clinical evidence that a mutation in the kinase domain of BTK, namely A428D, can confer disease resistance to a BTK degrader currently in clinical trials, that is BGB-16673. Modeling of a BTK A428D mutation places a negatively charged aspartic acid in place of the hydrophobic side chain of alanine within the binding pocket of another BTK-degrader in clinical development, namely NX-2127, suggesting that CLL cells with BTK A428D also may be resistant to NX-2127, as they already are known to be with either non-covalent or covalent inhibitors of BTK. Consequently, the two BTK degraders furthest advanced in clinical trials potentially may select for CLL cells with BTK A428D that are resistant to all approved BTKis.

The efficacy of ritlecitinib, an oral JAK3/TEC family kinase inhibitor, on active and stable lesions was evaluated in patients with active non-segmental vitiligo in a phase 2b trial (NCT03715829). Patients were randomized to placebo or daily ritlecitinib 50 mg (with or without 4-week 100-mg or 200-mg loading dose), 30 mg, or 10 mg for 24 weeks. Active lesions showed greater baseline expression of inflammatory/immune markers IFNG and CCL5, levels of CD103, and T-cell infiltrates than stable lesions. Patients with more active than stable vitiligo lesions showed higher baseline serum levels of CXCL9 and PD-L1, while patients with more stable than active lesions showed higher baseline serum levels of HO-1. At Week 24, ritlecitinib 50 mg significantly stabilized mean percent change from baseline in depigmentation extent in both active lesions and stable lesions vs. placebo-response, with stable lesions showing greater repigmentation. After 24 weeks of treatment, ritlecitinib 50 mg increased expression of melanocyte markers in stable lesions, while Th1/Th2-related and co-stimulatory molecules decreased significantly in both stable and active lesions. Serum from patients with more active than stable lesions showed decreased levels of ICOS and NK cell activation markers. These data, confirmed at transcription/protein levels, indicate that stable lesion repigmentation occurs early with ritlecitinib, while active lesions require stabilization of inflammation first. ClinicalTrials.gov: NCT03715829.

Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6is) have revolutionized breast cancer therapy. However,

UNLABELLED: The comprehensive genomic analysis of the head and neck squamous cell carcinoma (HNSCC) oncogenome revealed the frequent loss of p16INK4A (CDKN2A) and amplification of cyclin D1 genes in most human papillomavirus-negative HNSCC lesions. However, cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors have shown modest effects in the clinic. The aberrant activation of the PI3K/mTOR pathway is highly prevalent in HNSCC, and recent clinical trials have shown promising clinical efficacy of mTOR inhibitors (mTORi) in the neoadjuvant and adjuvant settings but not in patients with advanced HNSCC. By implementing a kinome-wide CRISPR/Cas9 screen, we identified cell-cycle inhibition as a synthetic lethal target for mTORis. A combination of mTORi and palbociclib, a CDK4/6-specific inhibitor, showed strong synergism in HNSCC-derived cells in vitro and in vivo. Remarkably, we found that an adaptive increase in cyclin E1 (CCNE1) expression upon palbociclib treatment underlies the rapid acquired resistance to this CDK4/6 inhibitor. Mechanistically, mTORi inhibits the formation of eIF4G-CCNE1 mRNA complexes, with the consequent reduction in mRNA translation and CCNE1 protein expression. Our findings suggest that mTORi reverts the adaptive resistance to palbociclib. This provides a multimodal therapeutic option for HNSCC by cotargeting mTOR and CDK4/6, which in turn may halt the emergence of palbociclib resistance. SIGNIFICANCE: A kinome-wide CRISPR/Cas9 screen identified cell-cycle inhibition as a synthetic lethal target of mTORis. A combination of mTORi and palbociclib, a CDK4/6-specific inhibitor, showed strong synergistic effects in HNSCC. Mechanistically, mTORis inhibited palbociclib-induced increase in CCNE1.

BACKGROUND: Neurotrophic tyrosine receptor kinase (NTRK) gene fusions are rare oncogenic drivers prevalent in 0.3% of solid tumors. They are most common in salivary gland cancer (2.6%), thyroid cancer (1.6%), and soft-tissue sarcoma (1.5%). Currently, there are 2 US Food and Drug Administration-approved targeted therapies for NTRK gene fusions: larotrectinib, approved in 2018, and entrectinib, approved in 2019. To date, the real-world uptake of tyrosine receptor kinase inhibitor (TRKi) use for NTRK-positive solid tumors in academic cancer centers remains largely unknown. OBJECTIVE: To describe the demographics, clinical and genomic characteristics, and testing and treatment patterns of patients with NTRK-positive solid tumors treated at US academic cancer centers. METHODS: This was a retrospective chart review study conducted in academic cancer centers in the United States. All patients diagnosed with an NTRK fusion-positive (NTRK1, NTRK2, NTRK3) solid tumor (any stage) and who received cancer treatment at participating sites between January 1, 2012, and July 1, 2023, were included in this study. Patient demographics, clinical characteristics, genomic characteristics, NTRK testing data, and treatment patterns were collected from electronic medical records and analyzed using descriptive statistics as appropriate. RESULTS: In total, 6 centers contributed data for 55 patients with NTRK-positive tumors. The mean age was 49.3 (SD = 20.5) years, 51% patients were female, and the majority were White (78%). The median duration of time from cancer diagnosis to NTRK testing was 85 days (IQR = 44-978). At the time of NTRK testing, 64% of patients had stage IV disease, compared with 33% at cancer diagnosis. Prevalent cancer types in the overall cohort included head and neck (15%), thyroid (15%), brain (13%), lung (13%), and colorectal (11%). NTRK1 fusions were most common (45%), followed by NTRK3 (40%) and NTRK2 (15%). Across all lines of therapy, 51% of patients (n = 28) received a TRKi. Among TRKi-treated patients, 71% had stage IV disease at TRKi initiation. The median time from positive NTRK test to initiation of TRKi was 48 days (IQR = 9-207). TRKis were commonly given as first-line (30%) or second-line (48%) therapies. Median duration of therapy was 610 (IQR = 182-764) days for TRKi use and 207.5 (IQR = 42-539) days for all other first-line therapies. CONCLUSIONS: This study reports on contemporary real-world NTRK testing patterns and use of TRKis in solid tumors, including time between NTRK testing and initiation of TRKi therapy and duration of TRKi therapy.

First-generation Bruton tyrosine kinase (BTK) inhibitor, ibrutinib, has been associated with an increased risk of cardiovascular toxicities. Zanubrutinib is a more selective, next-generation BTK inhibitor. In this analysis, incidence rates of atrial fibrillation, symptomatic (grade ≥2) ventricular arrhythmia, and hypertension were evaluated in a pooled analysis of 10 clinical studies with zanubrutinib monotherapy in patients (N = 1550) with B-cell malignancies and a pooled analysis of head-to-head studies comparing zanubrutinib with ibrutinib (ASPEN cohort 1; ALPINE). Among the 10 studies, most patients (median age, 67 years) were male (66.3%) and had CLL/SLL (60.5%). Overall incidence and exposure-adjusted incidence rates (EAIR) for atrial fibrillation, symptomatic ventricular arrhythmia, and hypertension were lower with zanubrutinib than ibrutinib. Despite a similar prevalence of preexisting cardiovascular events in ASPEN and ALPINE, atrial fibrillation/flutter incidence rates (6.1% vs 15.6%) and EAIR (0.2 vs 0.64 persons per 100 person-months; P < .0001) were lower with zanubrutinib than with ibrutinib. Symptomatic ventricular arrhythmia incidence was low for both zanubrutinib (0.7%) and ibrutinib (1.7%) with numerically lower EAIR (0.02 vs 0.06 persons per 100 person-months, respectively) for zanubrutinib. The hypertension EAIR was lower with zanubrutinib than ibrutinib in ASPEN but similar between treatment arms in ALPINE. The higher hypertension EAIR in ALPINE was inconsistent with other zanubrutinib studies. However, fewer discontinuations (1 vs 14) and deaths (0 vs 6) due to cardiac disorders occurred with zanubrutinib versus ibrutinib in ALPINE. These data support zanubrutinib as a treatment option with improved cardiovascular tolerability compared with ibrutinib for patients with B-cell malignancies in need of BTK inhibitors. These trials were registered at www.ClinicalTrials.gov as # NCT03053440, NCT03336333, NCT03734016, NCT04170283, NCT03206918, NCT03206970, NCT03332173, NCT03846427, NCT02343120, and NCT03189524.

FLT3 tyrosine kinase inhibitors (TKIs) have clinical efficacy for patients with FLT3-mutated AML (acute myeloid leukemia), but their impact is limited by resistance in the setting of monotherapy and by tolerability problems when used in combination therapies. FF-10101 is a novel compound that covalently binds to a cysteine residue near the active site of FLT3, irreversibly inhibiting receptor signaling. It is effective against most FLT3 activating mutations, and, unlike other inhibitors, is minimally vulnerable to resistance induced by FLT3 ligand. We conducted a phase 1 dose escalation study of oral FF-10101 in patients with relapsed and/or refractory AML, the majority of whom harbored FLT3-activating mutations and/or had prior exposure to FLT3 inhibitors. Fifty-four participants enrolled in cohorts receiving doses ranging from 10 to 225 mg per day and 50 to 100 mg twice daily (BID). The dose limiting toxicities were diarrhea and QT prolongation. Among 40 response-evaluable participants, the composite complete response rate was 10%, and the overall response rate (including partial responses) was 12.5%, including patients who had progressed on gilteritinib. Overall, 56% of participants had prior exposure to FLT3 inhibitors. The recommended phase 2 dose was 75 mg BID. FF-10101 potentially represents a next-generation advance in the management of FLT3-mutated AML. This trial was registered at www.ClinicalTrials.gov as #NCT03194685.

Mediator kinases CDK19 and CDK8, pleiotropic regulators of transcriptional reprogramming, are differentially regulated by androgen signaling, but both kinases are upregulated in castration-resistant prostate cancer (CRPC). Genetic or pharmacological inhibition of CDK8 and CDK19 reverses the castration-resistant phenotype and restores the sensitivity of CRPC xenografts to androgen deprivation in vivo. Prolonged CDK8/19 inhibitor treatment combined with castration not only suppressed the growth of CRPC xenografts but also induced tumor regression and cures. Transcriptomic analysis revealed that Mediator kinase inhibition amplified and modulated the effects of castration on gene expression, disrupting CRPC adaptation to androgen deprivation. Mediator kinase inactivation in tumor cells also affected stromal gene expression, indicating that Mediator kinase activity in CRPC molded the tumor microenvironment. The combination of castration and Mediator kinase inhibition downregulated the MYC pathway, and Mediator kinase inhibition suppressed a MYC-driven CRPC tumor model even without castration. CDK8/19 inhibitors showed efficacy in patient-derived xenograft models of CRPC, and a gene signature of Mediator kinase activity correlated with tumor progression and overall survival in clinical samples of metastatic CRPC. These results indicate that Mediator kinases mediated androgen-independent in vivo growth of CRPC, supporting the development of CDK8/19 inhibitors for the treatment of this presently incurable disease.

Therapeutic applications of nuclease-based genome editing would benefit from improved methods for transgene integration via homology-directed repair (HDR). To improve HDR efficiency, we screened six small-molecule inhibitors of DNA-dependent protein kinase catalytic subunit (DNA-PKcs), a key protein in the alternative repair pathway of non-homologous end joining (NHEJ), which generates genomic insertions/deletions (INDELs). From this screen, we identified AZD7648 as the most potent compound. The use of AZD7648 significantly increased HDR (up to 50-fold) and concomitantly decreased INDELs across different genomic loci in various therapeutically relevant primary human cell types. In all cases, the ratio of HDR to INDELs markedly increased, and, in certain situations, INDEL-free high-frequency (>50%) targeted integration was achieved. This approach has the potential to improve the therapeutic efficacy of cell-based therapies and broaden the use of targeted integration as a research tool.

Chronic myeloid leukemia (CML) is initiated and maintained by BCR::ABL which is clinically targeted using tyrosine kinase inhibitors (TKIs). TKIs can induce long-term remission but are also not curative. Thus, CML is an ideal system to test our hypothesis that transcriptome-based state-transition models accurately predict cancer evolution and treatment response. We collected time-sequential blood samples from tetracycline-off (Tet-Off) BCR::ABL-inducible transgenic mice and wild-type controls. From the transcriptome, we constructed a CML state-space and a three-well leukemogenic potential landscape. The potential's stable critical points defined observable disease states. Early states were characterized by anti-CML genes opposing leukemia; late states were characterized by pro-CML genes. Genes with expression patterns shaped similarly to the potential landscape were identified as drivers of disease transition. Re-introduction of tetracycline to silence the BCR::ABL gene returned diseased mice transcriptomes to a near healthy state, without reaching it, suggesting parts of the transition are irreversible. TKI only reverted the transcriptome to an intermediate disease state, without approaching a state of health; disease relapse occurred soon after treatment. Using only the earliest time-point as initial conditions, our state-transition models accurately predicted both disease progression and treatment response, supporting this as a potentially valuable approach to time clinical intervention, before phenotypic changes become detectable.

Ponatinib, the only approved all known-BCR::ABL1 inhibitor, is a third-generation tyrosine-kinase inhibitor (TKI) designed to inhibit BCR::ABL1 with or without any single resistance mutation, including T315I, and induced robust and durable responses at 45 mg/day in patients with CP-CML resistant to second-generation TKIs in the PACE trial. However, cardiovascular toxicities, including arterial occlusive events (AOEs), have emerged as treatment-related AEs within this class of TKIs. The OPTIC trial evaluated the efficacy and safety of ponatinib using a novel, response-based, dose-reduction strategy in patients with CP-CML whose disease is resistant to ≥2 TKIs or who harbor T315I. To assess the dose-response relationship and the effect on the safety of ponatinib, we examined the outcomes of patients with CP-CML enrolled in PACE and OPTIC who received 45 mg/day of ponatinib. A propensity score analysis was used to evaluate AOEs across both trials. Survival rates and median time to achieve ≤1% BCR::ABL1IS in OPTIC were similar or better than in PACE. The outcomes of patients with T315I mutations were robust in both trials. Patients in OPTIC had a lower exposure-adjusted incidence of AOEs compared with those in PACE. This analysis demonstrates that response-based dosing for ponatinib improves treatment tolerance and mitigates cardiovascular risk.

Glioblastoma, a grade 4 glioma as per the World Health Organization, poses a challenge in adult primary brain tumor management despite advanced surgical techniques and multimodal therapies. This review delves into the potential of targeting epidermal growth factor receptor (EGFR) with small-molecule inhibitors and antibodies as a treatment strategy. EGFR, a mutationally active receptor tyrosine kinase in over 50% of glioblastoma cases, features variants like EGFRvIII, EGFRvII and missense mutations, necessitating a deep understanding of their structures and signaling pathways. Although EGFR inhibitors have demonstrated efficacy in other cancers, their application in glioblastoma is hindered by blood-brain barrier penetration and intrinsic resistance. The evolving realm of nanodrugs and convection-enhanced delivery offers promise in ensuring precise drug delivery to the brain. Critical to success is the identification of glioblastoma patient populations that benefit from EGFR inhibitors. Tools like radiolabeled anti-EGFR antibody 806i facilitate the visualization of EGFR conformations, aiding in tailored treatment selection. Recognizing the synergistic potential of combination therapies with downstream targets like mTOR, PI3k, and HDACs is pivotal for enhancing EGFR inhibitor efficacy. In conclusion, the era of precision oncology holds promise for targeting EGFR in glioblastoma, contingent on tailored treatments, effective blood-brain barrier navigation, and the exploration of synergistic therapies.

Polypharmacology drugs-compounds that inhibit multiple proteins-have many applications but are difficult to design. To address this challenge we have developed POLYGON, an approach to polypharmacology based on generative reinforcement learning. POLYGON embeds chemical space and iteratively samples it to generate new molecular structures; these are rewarded by the predicted ability to inhibit each of two protein targets and by drug-likeness and ease-of-synthesis. In binding data for >100,000 compounds, POLYGON correctly recognizes polypharmacology interactions with 82.5% accuracy. We subsequently generate de-novo compounds targeting ten pairs of proteins with documented co-dependency. Docking analysis indicates that top structures bind their two targets with low free energies and similar 3D orientations to canonical single-protein inhibitors. We synthesize 32 compounds targeting MEK1 and mTOR, with most yielding >50% reduction in each protein activity and in cell viability when dosed at 1-10 μM. These results support the potential of generative modeling for polypharmacology.

The cancer stem cell (CSC) hypothesis postulates that heterogeneous human cancers harbor a population of stem-like cells which are resistant to cytotoxic therapies, thus providing a reservoir of relapse following conventional therapies like chemotherapy and radiation (RT). CSCs have been observed in multiple human cancers, and their presence has been correlated with worse clinical outcomes. Here, we sought to evaluate the impact of drug dosing of the multi-tyrosine kinase inhibitor, sorafenib, on CSC and non-CSCs in soft tissue sarcoma (STS) models, hypothesizing differential effects of sorafenib based on dose and target cell population. In vitro, human cancer cell lines and primary STS from surgical specimens were exposed to escalating doses of sorafenib to determine cell viability and expression of CSC marker aldehyde dehydrogenase (ALDH). In vivo, ALDHbright CSCs were isolated, exposed to sorafenib, and xenograft growth and survival analyses were performed. We observed that sarcoma CSCs appear to paradoxically respond to the tyrosine kinase inhibitor sorafenib at low doses with increased proliferation and stem-like function of CSCs, whereas anti-viability effects dominated at higher doses. Importantly, STS patients receiving neoadjuvant sorafenib and RT on a clinical trial (NCT00864032) showed increased CSCs post therapy, and higher ALDH scores post therapy were associated with worse metastasis-free survival. These data suggest that low-dose sorafenib may promote the CSC phenotype in STS with clinically significant effects, including increased tumor growth and higher rates of metastasis formation in sarcoma patients.

Targeted therapy has the potential to be used in the neoadjuvant setting for odontogenic tumors, reducing the morbidities associated with major surgery. In this regard, the aim of this study was to summarize the current evidence on the different forms of targeted therapy, effectiveness, and drawbacks of this course of treatment. Four databases were searched electronically without regard to publication date or language. Grey literature searches and manual searches were also undertaken. Publications with sufficient clinical data on targeted therapy for odontogenic tumors were required to meet the criteria for eligibility. The analysis of the data was descriptive. A total of 15 papers comprising 17 cases (15 ameloblastomas and 2 ameloblastic carcinomas) were included. Numerous mutations were found, with BRAF V600E being most common. Dabrafenib was the most utilized drug in targeted therapy. Except for one case, the treatment reduced the size of the lesion (16/17 cases), showing promise. Most of the adverse events recorded were mild, such as skin issues, voice changes, abnormal hair texture, dry eyes, and systemic symptoms (e.g., fatigue, joint pain, and nausea). It is possible to reach the conclusion that targeted therapy for ameloblastoma and ameloblastic carcinoma may be a useful treatment strategy, based on the findings of the included studies. [ABSTRACT FROM AUTHOR]

Despite clinical advances with protein kinase inhibitors (PKIs), oral administration of many PKIs is associated with highly variable plasma exposure and a narrow therapeutic window. We developed a novel hybrid nanoparticle‐amorphous solid dispersion (ASD) technology platform consisting of an amorphous PKI embedded in a polymer matrix. The technology was used to manufacture immediate‐release formulations of 2 tyrosine kinase inhibitors (TKIs), dasatinib and sorafenib. Our primary objective was to improve the absorption properties and reduce the pharmacokinetic (PK) variability of each TKI. The PKs of XS004 (dasatinib‐ASD, 100 mg tablet) and XS005 (sorafenib‐ASD, 2 × 50 mg capsules) were compared with their crystalline formulated reference drugs (140 mg of dasatinib‐reference and 200 mg of sorafenib‐reference). The in vitro biopharmaceutics of dasatinib‐ASD and XS005‐granulate showed sustained increased solubility in the pH range 1.2‐8.0 compared to their crystalline references. In vivo, XS004 was bioequivalent at a 30% lower dose and showed increased absorption and bioavailability, with 2.1‐4.8 times lower intra‐ and intersubject variability compared to the reference. XS005 had an increased absorption and bioavailability of 45% and 2.2‐2.8 times lower variability, respectively, but it was not bioequivalent at the investigated dose level. Taken together, the formulation platform is suited to generate improved PKI formulations with consistent bioavailability and a reduced pH‐dependent absorption process. [ABSTRACT FROM AUTHOR]

Introduction: Incorporation of AKT inhibitors into adjuvant therapy for advanced or metastatic breast cancer has improved clinical outcomes. However, the safety of AKT inhibitors should be better evaluated, given the possibility of prolonging survival and impacting patient quality of life. Our aim was to assess how the addition of AKT inhibitors to adjuvant therapy affects treatment-related adverse events. Methods: We evaluated binary outcomes with risk ratios (RRs), with 95% confidence intervals (CIs). We used DerSimonian and Laird random-effect models for all endpoints. Heterogeneity was assessed using I2 statistics. R, version 4.2.3, was used for statistical analyses. Results: A total of seven RCTs comprising 1619 patients with BC. The adverse effects that show significance statistical favoring the occurrence of adverse effects in AKT inhibitor were diarrhea (RR 3.05; 95% CI 2.48–3.75; p < 0.00001; I2 = 49%), hyperglycemia (RR 3.4; 95% CI 1.69–6.83; p = 0.00058; I2 = 75%), nausea (RR 1.69; 95% CI 1.34–2.13; p = 0.000008; I2 = 42%), rash (RR 2.79; 95% CI 1.49–5.23; p = 0.0013; I2 = 82%), stomatitis (RR 2.24; 95% CI 1.69–2.97; p < 0.00001; I2 = 16%) and vomiting (RR 2.99; 95% CI 1.85–4.86; p = 0.00009; I2 = 42%). There was no significant difference between the groups for alopecia (p = 0.80), fatigue (p = 0.087), and neuropathy (p = 0.363380). Conclusion: The addition of AKT inhibitors to adjuvant therapy was associated with an increase in treatment-related adverse events. These results provide safety information for further clinical trials evaluating AKT inhibitor therapy for patients with metastatic BC. Clinicians should closely monitor patients for treatment-related adverse events to avoid discontinuation of therapy and morbidity caused by these early-stage therapies. [ABSTRACT FROM AUTHOR]

WhatIs Known and Objective. Anti‐EGFR (epidermal growth factor receptor) drugs are indicated for non‐small‐cell lung cancer (NSCLC). This review summarises the information available to date on the first anti‐EGFRs granted market authorisation: erlotinib TARCEVA®, gefitinib IRESSA®, afatinib GIOTRIF®, dacomitinib VIZIMPRO®, and osimertinib TAGRISSO®. Methods. A literature search was conducted in the PubMed database including studies published in English using the terms gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib. Furthermore, bibliographies of selected references were also studied for relevant articles. Clinical trial (CT) data were extracted from clinicaltrials.gov (ongoing trials and adverse events (AEs)). Assessment of AEs for these drugs was conducted using global pharmacovigilance data from VigiBase®. Results and Discussion. Erlotinib and gefitinib are first‐generation anti‐EGFR drugs, able to bind competitively and reversibly to the ATP‐ (adenosine triphosphate‐) binding site of the EGFR exon 19 and exon 21 mutations. Afatinib and dacomitinib are second‐generation anti‐EGFRs able to bind covalently and irreversibly to the ATP site and inhibit EGFR and HER (human epidermal growth factor receptor) such as HER2 and HER4 enzyme activity. Osimertinib is a third‐generation PKI and overcomes the EGFR T790M gatekeeper mutation through covalent binding at the ATP site. Medical interactions with these drugs are reported, notably with cytochrome P450 inducers or inhibitors. The most reported AEs in CTs are cutaneous reactions and gastrointestinal disorders. The occurrence of cutaneous reactions is less reported with third generation than with first‐ and second‐generation anti‐EGFR drugs. These results are consistent with the results from the VigiBase® global pharmacovigilance database. What Is New and Conclusion. This review summarises current knowledge regarding five anti‐EGFRs in the literature. The third‐generation anti‐EGFR appears to be more effective than the first and second generations and is indicated as first‐line therapy. This trial is registered with NCT01523587, NCT01466660, NCT01774721, NCT01360554, and NCT02296125. [ABSTRACT FROM AUTHOR]

In recent years, significant improvement has been made in the management of non‐small cell lung cancer (NSCLC), primarily driven by advances in targeted therapy and immunotherapy. Research on neoadjuvant targeted therapy has also experienced considerable development, primarily directed towards NSCLC harboring epidermal growth factor receptor or anaplastic lymphoma kinase mutations. Nevertheless, there remains a dearth of studies investigating neoadjuvant targeted therapy in the context of BRAF (V‐Raf murine sarcoma viral oncogene homolog B) V600E mutant NSCLC. Herein, we describe the clinical trajectory of a stage IIIA NSCLC patient who underwent a two‐month course of neoadjuvant targeted therapy comprising BRAF and MEK (mitogen‐activated extracellular signal‐regulated kinase) inhibitors prior to surgical intervention, and subsequent postoperative evaluation unveiled a pathological complete response. The case reported here indicates the efficacy and safety of combining BRAF and MEK inhibitors as neoadjuvant targeted therapy in BRAF V600E‐mutant NSCLC and suggests the potential viability of such a therapeutic modality in improving treatment outcomes in this subset of NSCLC. [ABSTRACT FROM AUTHOR]

Tunlametinib (科露平®) is an oral, selective, mitogen-activated protein kinase kinase 1 and 2 (MEK 1/2) inhibitor being developed by Shanghai KeChow Pharma, Inc. for the treatment of solid tumours with RAS and RAF mutations, including melanoma, non-small cell cancer (NSCLC), colorectal cancer (CRC) and neurofibromatosis type 1 (NF1) plexiform neurofibromas. In March 2024, tunlametinib was granted conditional approval in China (based on surrogate endpoints) for use in patients with NRAS-mutated advanced melanoma who have failed anti-PD-1/PD-L1 treatment. This article summarizes the milestones in the development of tunlametinib leading to this first approval for the treatment of solid tumours with RAS and RAF mutations. [ABSTRACT FROM AUTHOR]

Tovorafenib (OJEMDA™) is a once-weekly oral, selective, brain-penetrant, type II RAF kinase inhibitor being developed by Day One Biopharmaceuticals, Inc., under a license from Takeda Oncology, for the treatment of paediatric low-grade glioma (pLGG) and solid tumours. Most pLGGs harbour alterations in the MAPK pathway, such as a BRAF mutation or BRAF fusion, which result in aberrant intracellular signalling. Tovorafenib is an inhibitor of mutant BRAF V600E, wild-type BRAF and wild-type CRAF kinases and BRAF fusions. In April 2024, tovorafenib received its first approval in the USA for the treatment of patients aged ≥ 6 months with relapsed or refractory pLGGs harbouring a BRAF fusion or rearrangement, or BRAF V600 mutation. It received accelerated approval for this indication based on the response rate and duration of response achieved in this population in the ongoing, pivotal, phase 2 FIREFLY-1 study. Clinical development of tovorafenib is underway in numerous countries worldwide. This article summarizes the milestones in the development of tovorafenib leading to this first approval for relapsed or refractory pLGG with an activating BRAF alteration. [ABSTRACT FROM AUTHOR]

Simple Summary: Combining drugs is crucial for enhancing anti-cancer responses. However, the potential of pre-clinical data in identifying suitable combinations and dosage is often underutilized. In this study, we leverage pre-clinical in vitro cell line drug response data and computational modeling of signal transduction and of pharmacokinetics to elucidate distinct dose requirements for the combination of pan-RAF and MEK inhibitors in melanoma. Our findings reveal a more synergistic but narrower dosing landscape in NRAS vs. BRAF mutant melanoma, which we link to a mechanism of adaptive resistance through negative feedback. Further, our analysis suggests the importance of drug dosing strategies to optimize synergy based on mutational context yet highlights the real-world challenges of maintaining a narrow dose range. This approach establishes a framework for translational investigation of drug responses in the refinement of combination therapy, balancing the potential for synergy and practical feasibility in cancer treatment planning. Purpose: This study explores the potential of pre-clinical in vitro cell line response data and computational modeling in identifying the optimal dosage requirements of pan-RAF (Belvarafenib) and MEK (Cobimetinib) inhibitors in melanoma treatment. Our research is motivated by the critical role of drug combinations in enhancing anti-cancer responses and the need to close the knowledge gap around selecting effective dosing strategies to maximize their potential. Results: In a drug combination screen of 43 melanoma cell lines, we identified specific dosage landscapes of panRAF and MEK inhibitors for NRAS vs. BRAF mutant melanomas. Both experienced benefits, but with a notably more synergistic and narrow dosage range for NRAS mutant melanoma (mean Bliss score of 0.27 in NRAS vs. 0.1 in BRAF mutants). Computational modeling and follow-up molecular experiments attributed the difference to a mechanism of adaptive resistance by negative feedback. We validated the in vivo translatability of in vitro dose–response maps by predicting tumor growth in xenografts with high accuracy in capturing cytostatic and cytotoxic responses. We analyzed the pharmacokinetic and tumor growth data from Phase 1 clinical trials of Belvarafenib with Cobimetinib to show that the synergy requirement imposes stricter precision dose constraints in NRAS mutant melanoma patients. Conclusion: Leveraging pre-clinical data and computational modeling, our approach proposes dosage strategies that can optimize synergy in drug combinations, while also bringing forth the real-world challenges of staying within a precise dose range. Overall, this work presents a framework to aid dose selection in drug combinations. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigated one of the treatment options for advanced breast cancer patients after they completed standard therapy that combines hormone therapy and specific targeted agents called cyclin-dependent kinase 4/6 inhibitors. We wanted to understand why in real-world patients start chemotherapy after finishing standard initial treatment, how they respond to it, and what factors might affect their outcomes. We found that chemotherapy was often used when patients faced dissemination to internal organs with the risk of further progression, but it provided limited benefits. We suggest that modern drugs recommended by guidelines before chemotherapy should be better reimbursed in Poland. This research could help doctors make better treatment decisions and improve future clinical trials. The standard therapy for hormone-receptor-positive, human epidermal growth factor receptor 2-negative advanced breast cancer includes the use of cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) with endocrine therapy. The optimal post-CDK4/6i treatment sequence is unclear. This cohort study evaluated the initiation, characteristics, and outcomes of chemotherapy following CDK4/6i-based treatment. Among the 227 patients who began CDK4/6i therapy, 114 completed it. Seventy-nine female patients received further treatment, including 55 receiving chemotherapy. The average age was 60.1 years. Post-CDK4/6i chemotherapy was typically (69.1%) first-line due to an impending visceral crisis. The median progression-free survival (mPFS) was 3.0 months (range 0.5–18.9), and the median overall survival (mOS) was 8.3 months (0.5–26.1). The median OS from the end of CDK4/6i treatment was 12.4 months (1.5–26.8). In univariate analysis, neither mPFS nor mOS was associated with age, tumor grade, receptor status, Ki67 status, time from diagnosis to CDK4/6i cessation, therapy line, or CDK4/6i type. Dose reduction occurred in 12 patients (21.8%), and chemotherapy was ceased due to adverse events in 8 patients (14.6%). Chemotherapy showed limited benefit regardless of the regimen. The role of chemotherapy may evolve with broader CDK4/6i use in adjuvant treatment. [ABSTRACT FROM AUTHOR]

Simple Summary: Regorafenib offers longer survival for patients with refractory metastatic colorectal cancer (mCRC). We aimed to identify biomarkers for regorafenib through preclinical and translational studies. In silico analysis identified matrix metalloproteinase (MMP)-14 and MMP-9 as key biomarkers. Validation in patients receiving regorafenib or FTD/TPI showed that high MMP-14 levels were correlated with a better response to regorafenib. Additionally, lower MMP-9 levels before the second cycle were linked to improved disease control and survival. These findings suggest that MMP-14 and MMP-9 could serve as prognostic markers for regorafenib efficacy. In identifying biomarkers for anticancer drugs, the lack of objectivity in selecting candidate factors makes interpretation difficult. We performed preclinical analysis and a translational validation study to identify candidate biomarkers for regorafenib efficacy in metastatic colorectal cancer (mCRC). Using in silico COMPARE analysis with a human cancer cell line panel, JFCR39, we selected candidate biomarkers whose expression correlates with regorafenib sensitivity. We validated predictive values in mCRC patients receiving regorafenib (discovery, n = 53) and FTD/TPI (control, n = 16). Blood samples were obtained at baseline (BL), before the second cycle (2nd), and at progressive disease (PD), and biomarker levels were measured using ELISA. Our analysis showed that high matrix metalloproteinase (MMP)-14 expression was associated with a high sensitivity to regorafenib. In the discovery cohort, high MMP-14 levels at BL and PD were correlated with tumor shrinkage and longer progression-free survival (PFS). A subsequent analysis of other related factors further indicated that the patients with decreased MMP-9 levels at the 2nd had higher disease control rates, tumor shrinkage, longer PFS, and overall survival than those with increased changes. These findings were not observed in the control cohort. Our study suggests MMP-14 and MMP-9 may serve as prognostic markers for regorafenib and provide insights into novel combination therapies with anti-MMP-9 agents or FTD/TPI. [ABSTRACT FROM AUTHOR]

Simple Summary: The Aerococcus viridans bacterial lactate oxidase (LOX) is an enzyme absent in mammalian cells. LOX catalyzes lactate to pyruvate and hydrogen peroxide (H2O2), a function that was recently used for tumor microenvironment (TME) lactate removal and H2O2 production to induce cancer cell death. However, the functions of TME lactate other than being a metabolic intermediate or an energy source and the mechanism of LOX disruption of lactate-mediated cancer cell survival remain unknown. Our study aims at addressing these important cancer-related biological questions. We identified a novel onco-signaling nexus initiated by TME lactate activation of its cellular receptor hydroxycarboxylic acid receptor 1 (HCAR1) and amplified by HCAR-associated proteins that mediate the RAS and the PI3K pathways. This signaling model could explain many key survival strategies exerted by RAS, PI3K, and their effectors for cancer cell adaptation to TME changes, especially in the cells' use of lactate beyond an energy source. LOX was recently shown to inhibit cancer cell proliferation and tumor growth. The mechanism of this inhibition, however, has been exclusively attributed to LOX depletion of TME lactate, a cancer cell energy source, and production of H2O2, an oxidative stressor. We report that TME lactate triggers the assembly of the lactate receptor hydroxycarboxylic acid receptor 1 (HCAR1)-associated protein complex, which includes GRB2, SOS1, KRAS, GAB1, and PI3K, for the activation of both the RAS and the PI3K oncogenic signaling pathways in breast cancer (BCa) cells. LOX treatment decreased the levels of the proteins in the protein complex via induction of their proteasomal degradation. In addition, LOX inhibited lactate-stimulated expression of the lactate transporters MCT1 and MCT4. Our data suggest that HCAR1 activation by lactate is crucial for the assembly and function of the RAS and PI3K signaling nexus. Shutting down lactate signaling by disrupting this nexus could be detrimental to cancer cells. HCAR1 is therefore a promising target for the control of the RAS and the PI3K signaling required for BCa progression. Thus, our study provides insights into lactate signaling regulation of cancer progression and extends our understanding of LOX's functional mechanisms that are fundamental for exploring its therapeutic potential. [ABSTRACT FROM AUTHOR]

We present the case of a 34‐year‐old Japanese man with anaplastic lymphoma kinase (ALK)‐positive non‐small cell lung cancer and brain metastases. After central nervous system (CNS) disease progression with alecintib and brigatinib, treatment with lorlatinib resulted in a good intracranial response. In this case, we investigated brain penetration ratio of brigatinib using cerebrospinal fluid and paired serum samples, and the ratio was 0.012. Further, we investigated resistance mechanisms via next‐generation sequencing (NGS) using lung biopsy at lung cancer diagnosis and brain biopsy sample at progressive disease of brigatinib. No apparent resistance mechanism of known ALK resistance, such as ALK mutations, amplifications, epithelial‐mesenchymal transition (EMT) and bypass pathway activation were detected. Taken together, we speculate that the low CNS penetration rate of brigatinib confers CNS progression. Further studies are warranted to reveal the resistance mechanism and propose a treatment strategy for CNS progression in ALK‐positive patients. [ABSTRACT FROM AUTHOR]

This study aimed to assess the feasibility of applying two recent phase I meta‐analyses methods to protein kinase inhibitors (PKIs) developed in oncology and to identify situations where these methods could be both feasible and useful. This ancillary study used data from a systematic review conducted to identify dose‐finding studies for PKIs. PKIs selected for meta‐analyses were required to have at least five completed dose‐finding studies involving cancer patients, with available results, and dose escalation guided by toxicity assessment. To account for heterogeneity caused by various administration schedules, some studies were divided into study parts, considered as separate entities in the meta‐analyses. For each PKI, two Bayesian random‐effects meta‐analysis methods were applied to model the toxicity probability distribution of the recommended dose and to estimate the maximum tolerated dose (MTD). Meta‐analyses were performed for 20 PKIs including 96 studies corresponding to 115 study parts. The median posterior probability of toxicity probability was below the toxicity thresholds of 0.20 for 70% of the PKIs, even if the resulting credible intervals were very wide. All approved doses were below the MTD estimated for the minimum toxicity threshold, except for one, for which the approved dose was above the MTD estimated for the maximal threshold. The application of phase I meta‐analysis methods has been feasible for the majority of PKI; nevertheless, their implementation requires multiple conditions. However, meta‐analyses resulted in estimates with large uncertainty, probably due to limited patient numbers and/or between‐study variability. This calls into question the reliability of the recommended doses. [ABSTRACT FROM AUTHOR]

BI 187004, a selective small‐molecule inhibitor of 11β‐hydroxysteroid dehydrogenase‐1 (11β‐HSD1), displayed complex nonlinear pharmacokinetics (PK) in humans. Following nine single oral doses, BI 187004 exhibited nonlinear PK at low doses and linear PK at higher doses. Notably, substantial hepatic 11β‐HSD1 inhibition (50%) was detected in a very low‐dose group, achieving a consistent 70% hepatic enzyme inhibition in subsequent ascending doses without any dose‐dependent effects. The unusual PK and PD profiles of BI 187004 suggest the presence of pharmacological target‐mediated drug disposition (TMDD), arising from the saturable binding of BI 187004 compound to its high‐affinity and low‐capacity target 11β‐HSD1. The non‐intuitive dose, exposure, and response relationship for BI 187004 pose a significant challenge in rational dose selection. This study aimed to construct a TMDD model to explain the complex nonlinear PK behavior and underscore the importance of recognizing TMDD in this small‐molecule compound. Among the various models explored, the best model was a two‐compartment TMDD model with three transit absorption components. The final model provides insights into 11β‐HSD1 binding‐related parameters for BI 187004, including the total amount of 11β‐HSD1 in the liver (estimated to be 8000 nmol), the second order association rate constant (estimated to be 0.102 nM−1h−1), and the first‐order dissociation rate constant (estimated to be 0.11 h−1). Our final population PK model successfully characterized the intricate nonlinear PK of BI 187004 across a wide dose range. This modeling work serves as a valuable reference for the rational selection of the dose regimens for BI 187004's future clinical trials. [ABSTRACT FROM AUTHOR]

Oral mucositis (OM) is one of the common adverse events associated with cancer treatment that decreases the quality of life and affects treatment outcomes. However, the medications used to manage OM are generally only palliative, and our knowledge of the syndrome is limited. The etiology of the syndrome is thought to be complex and multifactorial. We investigated the trends and characteristics of OM and estimated molecular initiating events (MIEs) associated with the development of the syndrome using the FDA Adverse Event Reporting System. The study of trends and characteristics suggested that OM is significantly more likely to occur in females and nonelderly patients and is likely to be induced by protein kinase inhibitors such as afatinib and everolimus. Next, we used Toxicity Predictor, an in-house quantitative structure–activity relationship system, to estimate OM-associated MIEs. The results revealed that the agonist activity of the human pregnane X receptor, thyroid-stimulating hormone-releasing hormone receptor, and androgen receptor may be associated with OM development. Our study findings are expected to help avoid the risk of OM induction during the drug discovery process and clinical use of antineoplastic agents. [ABSTRACT FROM AUTHOR]

Simple Summary: This study aimed to assess the 3-year time to relapse (TTR) and overall survival (OS) of melanoma, including acral and mucosal subtypes, treated with anti-PD-1 antibody (Ab) or the combination of dabrafenib and trametinib. The 3-year TTR of the acral and mucosal types was 28.1% and 38.5%, respectively. The acral subtype and TT were detected as important prognostic factors. In the 3-year OS, only tumor ulceration was associated with the OS in both univariate and multiple analyses. There was no significant difference in baseline or treatment-related factors of the mucosal type (p > 0.05). This study suggests that both acral and mucosal types in the adjuvant setting are less effective than non-acral cutaneous melanoma at the 3-year TTR. Background: Adjuvant therapy has improved the clinical prognosis for postoperative melanoma patients. However, the long-term efficacy of this therapy on the melanoma acral and mucosal subtypes has not been fully evaluated in previous trials. This study assessed the 3-year recurrence-free survival and overall survival of patients with melanoma, including the acral and mucosal subtypes, treated with anti-PD-1 antibody (Ab) or with the combination of the BRAF and MEK inhibitors dabrafenib and trametinib. Methods: We retrospectively analyzed both the 3-year time to relapse (TTR) and overall survival (OS) of 120 patients treated with anti-PD-1 antibody (Ab), or with the combination of dabrafenib and trametinib. Results: The overall median TTR was 18.4 months, with a range of 0.69 to 36 months. The 3-year TTR of the acral and mucosal types was 28.1% and 38.5%, respectively. Baseline tumor thickness (TT) and acral type were associated with the TTR in subgroup analysis. Moreover, we classified 104 acral and non-acral cutaneous patients into the anti-PD-1 Abs or dabrafenib plus trametinib combined therapies cohort in multiple analyses. The acral subtype and TT were detected as important prognostic factors. In the 3-year OS, only tumor ulceration was associated with the OS in both univariate and multiple analyses. There was no significant difference in baseline or treatment-related factors of the mucosal type (p > 0.05). Conclusion: This study suggests that adjuvant therapy is more effective with non-acral cutaneous melanoma than either the acral or mucosal types at the 3-year TTR endpoint. [ABSTRACT FROM AUTHOR]

The low knock-in efficiency, especially in primary human cells, limits the use of the genome editing technology for therapeutic purposes, rendering it important to develop approaches for increasing the knock-in levels. In this work, the efficiencies of several approaches were studied using a model of knock-in of a construct coding for the peptide HIV fusion inhibitor MT-C34 into the human CXCR4 locus in the CEM/R5 T cell line. First, donor DNA modification was evaluated as a means to improve the efficiency of plasmid transport into the nucleus. The donor plasmid was modified to include the simian virus 40 (SV40) DNA nuclear targeting sequence (DTS) or binding sites for the transcription factor NF-κB, whose effects on the knock-in levels have not been described. The modification was ineffective in the model of MT-C34 knock-in into the CXCR4 locus. A second approach consisted in modification of Cas9 nuclease by introducing two additional nuclear localization signals (NLSs) and increased the knock-in level by 30%. Finally, blocking DNA repair via the nonhomologous end joining (NHEJ) pathway with DNA-dependent protein kinase inhibitors caused a 1.8-fold increase in knock-in. A combination of the last two approaches caused an additive effect. Thus, increasing the number of NLSs in the Cas9 protein and inhibiting DNA repair via the NHEJ pathway significantly increased the level of knock-in of the HIV-1 fusion inhibitory peptide into the clinically relevant locus CXCR4. The finding can be used to develop effective gene therapy approaches for treating HIV infection. [ABSTRACT FROM AUTHOR]

The mitogen‐activated protein kinase kinase 4 (MKK4), a member of the MAP kinase kinase family, directly phosphorylates and activates the c‐Jun NH2‐terminal kinases (JNK), in response to proinflammatory cytokines and cellular stresses. Regulation of the MKK4 activity is considered to be a novel approach for the prevention and treatment of inflammation. The aim of this study was to identify whether fisetin, a potential anti‐inflammatory compound, targets MKK4‐JNK cascade to inhibit lipopolysaccharide (LPS)‐stimulated inflammatory response. RAW264 macrophage pretreated with fisetin following LPS stimulation was used as a cell model to investigate the transactivation and expression of related‐inflammatory genes by transient transfection assay, electrophoretic mobility shift assay (EMSA), or enzyme‐linked immunosorbent assay (ELISA), and cellular signaling as well as binding of related‐signal proteins by Western blot, pull‐down assay and kinase assay, and molecular modeling. The transactivation and expression of cyclooxygenase‐2 (COX‐2) gene as well as prostaglandin E2 (PGE2) secretion induced by LPS were inhibited by fisetin in a dose‐dependent manner. Signaling transduction analysis demonstrated that fisetin selectively inhibited MKK4‐JNK1/2 signaling to suppress the phosphorylation of transcription factor AP‐1 without affecting the NF‐κB and Jak2‐Stat3 signaling as well as the phosphorylation of Src, Syk, and TAK1. Furthermore, in vitro and ex vivo pull‐down assay using cell lysate or purified protein demonstrated that fisetin could bind directly to MKK4. Molecular modeling using the Molecular Operating Environment™ software indicated that fisetin docked into the ATP‐binding pocket of MKK4 with a binding energy of −71.75 kcal/mol and formed a 1.70 Å hydrogen bound with Asp247 residue of MKK4. The IC50 of fisetin against MKK4 was estimated as 2.899 μM in the kinase assay, and the ATP‐competitive effect was confirmed by ATP titration. Taken together, our data revealed that fisetin is a potent selective ATP‐competitive MKK4 inhibitor to suppress MKK4‐JNK1/2‐AP‐1 cascade for inhibiting LPS‐induced inflammation. [ABSTRACT FROM AUTHOR]

Background This study aimed to compare the survival outcomes of patients with initially unresectable hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT) who underwent or did not undergo salvage surgery followed by a triple combination conversion treatment consisted of locoregional treatment (LRT), tyrosine kinase inhibitors (TKIs), and anti-PD-1 antibodies. Methods The data from 93 consecutive patients with initially unresectable HCC and PVTT across 4 medical centers were retrospectively reviewed. They were converted successfully by the triple combination treatment and underwent or did not undergo salvage resection. The baseline characteristics, conversion schemes, conversion treatment-related adverse events (CTRAEs), overall survival (OS), and progression-free survival (PFS) of the salvage surgery and non-surgery groups were compared. Multivariate Cox regression analysis was performed to identify independent risk factors for OS and PFS. Additionally, subgroup survival analysis was conducted by stratification of degree of tumor response and type of PVTT. Results Of the 93 patients, 44 underwent salvage surgery, and 49 did not undergo salvage surgery. The OS and PFS of the salvage surgery and non-surgery groups were not significantly different (P  = .370 and.334, respectively). The incidence and severity of CTRAEs of the 2 groups were also comparable. Subgroup analyses revealed that for patients with complete response (CR) or types III-IV PVTT, there was a trend toward better survival in patients who did not undergo salvage surgery. Multivariate analysis showed that baseline α-fetoprotein and best tumor response per mRECIST criteria were independent prognostic factors for OS and PFS. Conclusions For patients with initially unresectable HCC and PVTT who were successfully converted by the triple combination therapy, salvage liver resection may not be necessary, especially for the patients with CR or types III-IV PVTT. [ABSTRACT FROM AUTHOR]

MYC is a transcription factor crucial for maintaining cellular homeostasis, and its dysregulation is associated with highly aggressive cancers. Despite being considered "undruggable" due to its unstable protein structure, MYC gains stability through its interaction with its partner protein, MAX. The MYC-MAX heterodimer orchestrates the expression of numerous genes that contribute to an oncogenic phenotype. Previous efforts to develop small molecules, disrupting the MYC-MAX interaction, have shown promise in vitro but none have gained clinical approval. Our current computer-aided study utilizes an approach to explore drug repurposing as a strategy for inhibiting the c-MYC-MAX interaction. We have focused on compounds from DrugBank library, including Food and Drug Administration-approved drugs or those under investigation for other medical conditions. First, we identified a potential druggable site on flat interface of the c-MYC protein, which served as the target for virtual screening. Using both activity-based and structure-based screening, we comprehensively assessed the entire DrugBank library. Structure-based virtual screening was performed on AutoDock Vina and Glide docking tools, while activity-based screening was performed on two independent quantitative structure-activity relationship models. We focused on the top 2% of hit molecules from all screening methods. Ultimately, we selected consensus molecules from these screenings—those that exhibited both a stable interaction with c-MYC and superior inhibitory activity against c-MYC-MAX interaction. Among the evaluated molecules, we identified a protein kinase inhibitor (tyrosine kinase inhibitor [TKI]) known as nilotinib as a promising candidate targeting c-MYC-MAX dimer. Molecular dynamic simulations demonstrated a stable interaction between MYC and nilotinib. The interaction with nilotinib led to the stabilization of a region of the MYC protein that is distorted in apo-MYC and is important for MAX binding. Further analysis of differentially expressed gene revealed that nilotinib, uniquely among the tested TKIs, induced a gene expression program in which half of the genes were known to be responsive to c-MYC. Our findings provide the foundation for subsequent in vitro and in vivo investigations aimed at evaluating the efficacy of nilotinib in managing MYC oncogenic activity. [ABSTRACT FROM AUTHOR]

Objective This study aimed to investigate the neuroprotective effect of microglia polarization mediated by Raf kinase inhibitor protein (RKIP) intracerebral hemorrhage (ICH) model. Methods Forty-eight adult male Sprague-Dawley (SD) rats were randomly divided into three groups: the Sham + Vector group, the ICH + Vector group, and the ICH + RKIP group, with 16 rats in each group. The collagenase ICH model was established in ICH+Vector group and ICH + RKIP group. Before operation and 1, 3, 5, and 7 days after operation, 8 animals in each group were tested for behavior. Apoptosis of neurons was detected by flow cytometry. Seven days after ICH, the expressions of RKIP, p-p65, and TRAF6 around hematoma were analyzed by protein blot. Results Compared with ICH + Vector group, rats in ICH + RKIP group need less time to find the platform, spend longer time in the target quadrant, and significantly reduce the times of crossing the platform (P < 0.05) . The number of Nissl corpuscles in ICH + RKIP group was significantly higher than that in ICH + Vector group (P < 0.05) . In addition, the number of neuronal apoptosis in ICH + RKIP group was significantly lower than that in ICH + Vector group (P < 0.05) . Compared with Sham group, rats receiving ICH showed a gradual decrease in RKIP expression, and reached the lowest value on the 7th day (P < 0.05) . Seven days after ICH, the expression of RKIP protein in hematoma of rats in ICH + RKIP group was significantly higher than that in ICH + Vector group (P < 0.05), and the expression of p-p65 and TRAF6 protein was significantly lower than that in ICH + Vector group (P < 0.05) . Compared with ICH + Vector group, the number of iNOS + Ibal1+ cells in ICH + RKIP group decreased significantly (P < 0.05), while the number of Arg-1 + Ibal1+ cells increased significantly (P < 0.05) . Conclusion Up-regulation of RKIP promotes functional recovery after ICH, and its mechanism involves inhibiting TRAF6/NF-kB signaling pathway. [ABSTRACT FROM AUTHOR]

Simple Summary: Estrogen Receptor α (ERα) is a key target for hormonal treatment of breast cancer. However, treatment with antihormonal therapies such as tamoxifen will eventually fail, presumably through hormone-independent signaling through estrogen receptors. It has been shown that a component of this resistance to hormonal therapy may be through expression of an alternative form of estrogen receptor, ERα36. Here, we show that targeting the enzyme CK2, either with the clinical stage CK2 inhibitor CX-4945, or by disrupting expression of its regulatory β subunit, can result in decreased expression of both the canonical form of ERα protein as well as the ERα36 isoform in tamoxifen-sensitive and tamoxifen-resistant breast cancer cells. Our studies provide a rationale for the clinical investigation of CX-4945 in the treatment of ERα-expressing breast cancers. Aberrant estrogen receptor (ERα) signaling mediates detrimental effects of tamoxifen including drug resistance and endometrial hyperplasia. ERα36, an alternative isoform of ERα, contributes to these effects. We have demonstrated that CK2 modulates ERα expression and function in breast cancer (BCa). Here, we assess if CX-4945 (CX), a clinical stage CK2 inhibitor, can disrupt ERα66 and ERα36 signaling in BCa. Using live cell imaging, we assessed the antiproliferative effects of CX in tamoxifen-sensitive and tamoxifen-resistant BCa cells in monolayer and/or spheroid cultures. CX-induced alterations in ERα66 and ERα36 mRNA and protein expression were assessed by RT-PCR and immunoblot. Co-immunoprecipitation was performed to determine the differential interaction of ERα isoforms with HSP90 and CK2 upon CX exposure. CX caused concentration-dependent decreases in proliferation in tamoxifen-sensitive MCF-7 and tamoxifen-resistant MCF-7 Tam1 cells and significantly repressed spheroid growth in 3D models. Additionally, CX caused dramatic decreases in endogenous or exogenously expressed ERα66 and ERα36 protein. Silencing of CK2β, the regulatory subunit of CK2, resulted in destabilization and decreased proliferation, similar to CX. Co-immunoprecipitation demonstrated that ERα66/36 show CK2 dependance for interaction with molecular chaperone HSP90. Our findings show that CK2 functions regulate the protein stability of ERα66 and ERα36 through a mechanism that is dependent on CK2β subunit and HSP90 chaperone function. CX may be a component of a novel therapeutic strategy that targets both tamoxifen-sensitive and tamoxifen-resistant BCa, providing an additional tool to treat ERα-positive BCa. [ABSTRACT FROM AUTHOR]

Background: In tumor treatment, protein tyrosine kinase inhibitors (TKIs) have been extensively utilized. However, the efficacy of TKI is significantly compromised by drug resistance. Consequently, finding an effective solution to overcome TKI resistance becomes crucial. Reactive oxygen species (ROS) are a group of highly active molecules that play important roles in targeted cancer therapy including TKI targeted therapy. In this review, we concentrate on the ROS-associated mechanisms of TKI lethality in tumors and strategies for regulating ROS to reverse TKI resistance in cancer. Main body: Elevated ROS levels often manifest during TKI therapy in cancers, potentially causing organelle damage and cell death, which are critical to the success of TKIs in eradicating cancer cells. However, it is noteworthy that cancer cells might initiate resistance pathways to shield themselves from ROS-induced damage, leading to TKI resistance. Addressing this challenge involves blocking these resistance pathways, for instance, the NRF2-KEAP1 axis and protective autophagy, to promote ROS accumulation in cells, thereby resensitizing drug-resistant cancer cells to TKIs. Additional effective approaches inducing ROS generation within drug-resistant cells and providing exogenous ROS stimulation. Conclusion: ROS play pivotal roles in the eradication of tumor cells by TKI. Harnessing the accumulation of ROS to overcome TKI resistance is an effective and widely applicable approach. [ABSTRACT FROM AUTHOR]

Background: Intestinal ischemia–reperfusion (I/R) injury is a severe vascular emergency. Previous research indicated the protective effects of Emodin on I/R injury. Our study aims to explore the effect of Emodin on intestinal I/R (II/R) injury and elucidate the underlying mechanisms. Methods: C57BL/6 mice and Caco-2 cells were used for in vivo and in vitro studies. We established an animal model of II/R injury by temporarily occluding superior mesenteric artery. We constructed an oxygen–glucose deprivation/reoxygenation (OGD/R) cell model using a hypoxia-reoxygenation incubator. Different doses of Emodin were explored to determine the optimal therapeutic dose. Additionally, inhibitors targeting the protein kinase B (Akt) or Heme oxygenase-1 (HO-1) were administered to investigate their potential protective mechanisms. Results: Our results demonstrated that in animal experiments, Emodin mitigated barrier disruption, minimized inflammation, reduced oxidative stress, and inhibited apoptosis. When Akt or HO-1 was inhibited, the protective effect of Emodin was eliminated. Inhibiting Akt also reduced the level of HO-1. In cell experiments, Emodin reduced inflammation and apoptosis in the OGD/R cell model. Additionally, when Akt or HO-1 was inhibited, the protective effect of Emodin was weakened. Conclusions: Our findings suggest that Emodin may protect the intestine against II/R injury through the Akt/HO-1 signaling pathway. [ABSTRACT FROM AUTHOR]

Insect neuronal nicotinic acetylcholine receptors (nAChRs) are transmembrane receptors that play a key role in the development and synaptic plasticity of both vertebrates and invertebrates and are considered to be major targets of neonicotinoid insecticides. We used dorsal unpaired median (DUM) neurons, which are insect neurosecretory cells, in order to explore the intracellular mechanisms leading to the regulation of insect neuronal nAChRs in more detail. Using whole‐cell patch‐clamp and fura‐2AM calcium imaging techniques, we found that a novel CaMKK/AMPK pathway could be involved in the intracellular regulation of DUM neuron nAChRs. The CaMKK selective inhibitor, STO, reduced nicotinic current amplitudes, and strongly when co‐applied with α‐Bgt. Interestingly, intracellular application of the AMPK activator, A‐76, prevented the reduction in nicotine‐induced currents observed in the presence of the AMPK inhibitor, dorsomorphin. STO prevented the increase in intracellular calcium induced by nicotine, which was not dependent on α‐Bgt. Currents induced by 1 mM LMA, a selective activator of nAChR2, were reduced under bath application of STO, and mecamylamine, which blocked nAChR2 subtype, inhibited the increase in intracellular calcium induced by LMA. These findings provide insight into potential complex mechanisms linked to the modulation of the DUM neuron nAChRs and CaMKK pathway. [ABSTRACT FROM AUTHOR]

The phase 2, multicohort, open-label LEAP-005 study evaluated lenvatinib plus pembrolizumab in patients with previously treated advanced solid tumors. We report outcomes from the ovarian cancer cohort. Eligible patients had metastatic/unresectable ovarian cancer and had received 3 previous lines of therapy. Patients received lenvatinib 20 mg/day plus pembrolizumab 200 mg every 3 weeks. Treatment continued until progression, unacceptable toxicity, or (for pembrolizumab) completion of 35 cycles. Primary endpoints were objective response rate (ORR) per RECIST version 1.1 and safety. Secondary endpoints included duration of response (DOR), progression-free survival (PFS), and overall survival (OS). Thirty-one patients were enrolled. 39% had high grade serous ovarian cancer, 23% were platinum-sensitive, 55% were platinum-resistant, 23% were platinum-refractory, and 84% had tumors that had a PD-L1 combined positive (CPS) score ≥1. ORR (95% CI) was 26% (12%–45%) by investigator assessment and 35% (19%–55%) by blinded independent central review (BICR). Per BICR, median DOR was 9.2 (1.5+ to 37.8+) months. ORRs (95% CI) by BICR were 35% (9/26 patients; 17%–56%) for PD-L1 CPS ≥ 1 disease and 50% (2/4 patients; 7%–93%) for PD-L1 CPS < 1 disease. Median (95% CI) PFS by BICR and OS were 6.2 (4.0–8.5) months and 21.3 (11.7–32.3) months, respectively. Treatment-related AEs occurred in 94% of patients (grade 3–4, 77%). One patient died from treatment-related hypovolemic shock. Lenvatinib plus pembrolizumab demonstrated antitumor activity as fourth line therapy in patients with advanced ovarian cancer, and no unanticipated safety signals were identified. Responses were observed regardless of PD-L1 status. • We evaluated lenvatinib plus pembrolizumab as fourth-line therapy in 31 patients with advanced ovarian cancer. • Lenvatinib plus pembrolizumab had an objective response rate of 35% by blinded independent central review in this population. • Median duration of response by blinded independent central review was 9.2 (1.5+ to 37.8+) months. • Median progression-free survival was 6.2 months and median overall survival was 21.3 months. • Treatment-related adverse events occurred in 94% of patients (grade 3–4, 77%; grade 5, 3%). [ABSTRACT FROM AUTHOR]

Simple Summary: Cancer cells often become resistant to treatment, making it harder to fight the disease effectively. This resistance can happen due to genetic changes, proteins that pump out drugs, or the environment around the tumor. Crizotinib is a drug that helps overcome this resistance in certain lung cancers and lymphomas by targeting specific proteins. It can also break down a harmful protein found in some cancers. Researchers have found that combining crizotinib with other drugs can improve its effectiveness, especially for cancers with specific genetic mutations. Chemoresistance is a major obstacle in cancer treatment, often leading to disease progression and poor outcomes. It arises through various mechanisms such as genetic mutations, drug efflux pumps, enhanced DNA repair, and changes in the tumor microenvironment. These processes allow cancer cells to survive despite chemotherapy, underscoring the need for new strategies to overcome resistance and improve treatment efficacy. Crizotinib, a first-generation multi-target kinase inhibitor, is approved by the FDA for the treatment of ALK-positive or ROS1-positive non-small cell lung cancer (NSCLC), refractory inflammatory (ALK)-positive myofibroblastic tumors (IMTs) and relapsed/refractory ALK-positive anaplastic large cell lymphoma (ALCL). Crizotinib exists in two enantiomeric forms: (R)-crizotinib and its mirror image, (S)-crizotinib. It is assumed that the R-isomer is responsible for the carrying out various processes reviewed here The S-isomer, on the other hand, shows a strong inhibition of MTH1, an enzyme important for DNA repair mechanisms. Studies have shown that crizotinib is an effective multi-kinase inhibitor targeting various kinases such as c-Met, native/T315I Bcr/Abl, and JAK2. Its mechanism of action involves the competitive inhibition of ATP binding and allosteric inhibition, particularly at Bcr/Abl. Crizotinib showed synergistic effects when combined with the poly ADP ribose polymerase inhibitor (PARP), especially in ovarian cancer harboring BRCA gene mutations. In addition, crizotinib targets a critical vulnerability in many p53-mutated cancers. Unlike its wild-type counterpart, the p53 mutant promotes cancer cell survival. Crizotinib can cause the degradation of the p53 mutant, sensitizing these cancer cells to DNA-damaging substances and triggering apoptosis. Interestingly, other reports demonstrated that crizotinib exhibits anti-bacterial activity, targeting Gram-positive bacteria. Also, it is active against drug-resistant strains. In summary, crizotinib exerts anti-tumor effects through several mechanisms, including the inhibition of kinases and the restoration of drug sensitivity. The potential of crizotinib in combination therapies is emphasized, particularly in cancers with a high prevalence of the p53 mutant, such as triple-negative breast cancer (TNBC) and high-grade serous ovarian cancer (HGSOC). [ABSTRACT FROM AUTHOR]

Simple Summary: Prostate cancer (PCa) is the most common cancer in males in the UK, resulting in more than 12,000 deaths per year in the UK. A large proportion of patients stop responding to currently available treatments; consequently, identifying alternative treatment options is key to prolonging the life of these men and improving survival rates. Protein kinases regulate signalling pathways, which are often dysregulated in cancer, leading to tumour growth. Additionally, kinase driven phosphorylation regulates androgen receptor activity, which is a key driver of PCa. Understanding how these signalling pathways contribute towards PCa is critical in the development of novel treatment options. The kinase, casein kinase 1 alpha (CK1α), has potential as a PCa therapeutic. Here we describe the current literature supporting this hypothesis and identify where further research is needed to fully understand the functional role and therapeutic potential of CK1α in PCa. The androgen receptor (AR) is a key driver of prostate cancer (PCa) and, as such, current mainstay treatments target this molecule. However, resistance commonly arises to these therapies and, therefore, additional targets must be evaluated to improve patient outcomes. Consequently, alternative approaches for indirectly targeting the AR are sought. AR crosstalk with other signalling pathways, including several protein kinase signalling cascades, has been identified as a potential route to combat therapy resistance. The casein kinase 1 (CK1) family of protein kinases phosphorylate a multitude of substrates, allowing them to regulate a diverse range of pathways from the cell cycle to DNA damage repair. As well as its role in several signalling pathways that are de-regulated in PCa, mutational data suggest its potential to promote prostate carcinogenesis. CK1α is one isoform predicted to regulate AR activity via phosphorylation and has been implicated in the progression of several other cancer types. In this review, we explore how the normal biological function of CK1 is de-regulated in cancer, the impact on signalling pathways and how this contributes towards prostate tumourigenesis, with a particular focus on the CK1α isoform as a novel therapeutic target for PCa. [ABSTRACT FROM AUTHOR]

Simple Summary: The treatment of BRAF-mutant melanoma with BRAF inhibitors is severely limited in clinical practice, in part due to the emergence of drug tolerance via non-genetic adaptation to therapies. Improving our understanding of the molecular mechanisms that underlie drug tolerance may lead to improved treatment strategies. Here, we describe a novel calcium-dependent signaling mechanism induced by BRAF inhibitor (BRAFi) treatment that provides compensatory mitogenic signaling to drug-tolerant persister cells in the form of MAPK reactivation. This calcium signaling mechanism has not previously been recognized in BRAFi-tolerant melanoma, may initiate a novel line of scientific inquiry, and presents a host of novel targets for therapeutic development in this field. Drug tolerance is a major cause of relapse after cancer treatment. Despite intensive efforts, its molecular basis remains poorly understood, hampering actionable intervention. We report a previously unrecognized signaling mechanism supporting drug tolerance in BRAF-mutant melanoma treated with BRAF inhibitors that could be of general relevance to other cancers. Its key features are cell-intrinsic intracellular Ca2+ signaling initiated by P2X7 receptors (purinergic ligand-gated cation channels) and an enhanced ability for these Ca2+ signals to reactivate ERK1/2 in the drug-tolerant state. Extracellular ATP, virtually ubiquitous in living systems, is the ligand that can initiate Ca2+ spikes via P2X7 channels. ATP is abundant in the tumor microenvironment and is released by dying cells, ironically implicating treatment-initiated cancer cell death as a source of trophic stimuli that leads to ERK reactivation and drug tolerance. Such a mechanism immediately offers an explanation of the inevitable relapse after BRAFi treatment in BRAF-mutant melanoma and points to actionable strategies to overcome it. [ABSTRACT FROM AUTHOR]

Simple Summary: Evidence on cardiotoxicity prevention and treatment strategies in patients receiving anthracyclines or HER2 receptor inhibitors, vital treatments for breast cancer and hematologic malignancies, is quite a significant field of cardio-oncology. The present systematic review and meta-analysis investigated cardioprotective strategies in these patients and found that dexrazoxane, angiotensin-converting enzyme inhibitors, and β-blockers could decrease more than half the cardiotoxicity symptoms, cardiac abnormalities risk, and cardiovascular risk, indicating, thus, that cardioprotective medication is necessary for patients under chemotherapy. Background: This meta-analysis and systematic review aim to consolidate evidence on cardiotoxicity prevention and treatment strategies in patients receiving anthracyclines or HER2 receptor inhibitors, vital treatments for breast cancer and hematologic malignancies. By synthesizing existing research, the goal is to provide impactful insights that enhance patient care and outcomes. Methods: Comprehensive research across PubMed, Scopus, EMBASE, and the Cochrane Central Register for Controlled Trials was conducted, selecting clinical trials focusing on cardioprotection in anthracyclines or HER2 inhibitor-treated individuals. Effect sizes were computed using OpenMeta (Analyst), with leave-out meta-analysis to assess potential small study effects. Meta-regression explored treatment duration and sample size effects. Evidence quality for primary outcomes was evaluated using ROB, Robins 2, and Newcastle-Ottawa tools. Results: Twenty -three studies involving a total of 14,652 patients (13,221 adults and 1431 kids) were included in the current systematic review and meta-analysis. The risk of bias and methodological quality of the included studies suggested good and moderate quality. Patients prescribed β-blockers demonstrated a 74% lower likelihood of exhibiting cardiotoxicity symptoms (OR 1.736). Similarly, the use of dexrazoxane was linked to a threefold decrease in cardiac abnormalities risk (OR 2.989), and ACE inhibitor administration showed half the risk compared with the control group (OR 1.956). Conclusions: Through this systematic review and meta-analysis, it was shown that there is a reduction in cardiotoxicity from either anthracyclines or HER2 inhibitors in patients receiving pharmacoprophylaxis. [ABSTRACT FROM AUTHOR]

Simple Summary: Drug resistance is still an imminent issue for melanoma patients even after the use of BRAFi/MEKi combination therapy in clinic. Tumor heterogeneity and heterogeneity in treatment responses make it difficult to find consensus genes and pathways in resistance to therapy. This study used an objective method to analyze published gene expression data from pre-treated tumors and drug-resistant tumors, and identified possible targets and markers for resistant tumors, which centered on the PLXNC1 gene, which promotes a pro-inflammatory tumor microenvironment. Melanoma tumors exhibit a wide range of heterogeneity in genomics even with shared mutations in the MAPK pathway, including BRAF mutations. Consistently, adaptive drug resistance to BRAF inhibitors and/or BRAF plus MEK inhibitors also exhibits a wide range of heterogeneous responses, which poses an obstacle for discovering common genes and pathways that can be used in clinic for overcoming drug resistance. This study objectively analyzed two sets of previously published tumor genomics data comparing pre-treated melanoma tumors and BRAFi- and/or MEKi-resistant tumors. Heterogeneity in response to BRAFi and BRAFi/MEKi was evident because the pre-treated tumors and resistant tumors did not exhibit a tendency of clustering together. Differentially expressed gene (DEG) analysis revealed eight genes and two related enriched signature gene sets (matrisome and matrisome-associated signature gene sets) shared by both sets of data. The matrisome was closely related to the tumor microenvironment and immune response, and five out of the eight shared genes were also related to immune response. The PLXNC1 gene links the shared gene set and the enriched signature gene sets as it presented in all analysis results. As the PLXNC1 gene was up-regulated in the resistant tumors, we validated the up-regulation of this gene in a laboratory using vemurafenib-resistant cell lines. Given its role in promoting inflammation, this study suggests that resistant tumors exhibit an inflammatory tumor microenvironment. The involvement of the matrisome and the specific set of immune genes identified in this study may provide new opportunities for developing future therapeutic methods. [ABSTRACT FROM AUTHOR]

Simple Summary: Medullary thyroid carcinoma (MTC) is driven by a small number of pathogenic genetic variants and tumours usually exhibit a correspondingly low tumour mutational burden. This reduces tumour visibility to the immune system and impacts the immune cell profile of the tumour microenvironment. In the last decade targeted pathway inhibitors have revolutionized the therapeutic landscape for patients with advanced disease, with increasing options for systemic therapy tailored to the molecular signature of the tumour. Therefore, understanding the molecular basis of disease, pathogenesis of immune evasion and mechanisms of escape of pathway inhibition is of paramount importance. Here, we summarize genetic and molecular drivers of MTC and their relevance to tumour immunogenicity, the cellular milieu of the tumour microenvironment, and response to targeted therapy. In this review, we explore the underlying molecular biology of medullary thyroid carcinoma (MTC) and its interplay with the host immune system. MTC is consistently driven by a small number of specific pathogenic variants, beyond which few additional genetic events are required for tumorigenesis. This explains the exceedingly low tumour mutational burden seen in most MTC, in contrast to other cancers. However, because of the low tumour mutational burden (TMB), there is a correspondingly low level of tumour-associated neoantigens that are presented to the host immune system. This reduces tumour visibility and vigour of the anti-tumour immune response and suggests the efficacy of immunotherapy in MTC is likely to be poor, acknowledging this inference is largely based on the extrapolation of data from other tumour types. The dominance of specific RET (REarranged during Transfection) pathogenic variants in MTC tumorigenesis rationalizes the observed efficacy of the targeted RET-specific tyrosine kinase inhibitors (TKIs) in comparison to multi-kinase inhibitors (MKIs). Therapeutic durability of pathway inhibitors is an ongoing research focus. It may be limited by the selection pressure TKI treatment creates, promoting survival of resistant tumour cell clones that can escape pathway inhibition through binding-site mutations, activation of alternate pathways, and modulation of the cellular and cytokine milieu of the tumour microenvironment (TME). [ABSTRACT FROM AUTHOR]

Background: Endoxifen, a protein kinase C inhibitor and selective estrogen receptor modulator, primarily used in breast cancer treatment, has recently emerged as a potential therapeutic option for managing manic episodes associated with bipolar disorder (BD). This review aims to assess the existing evidence base for endoxifen in BD treatment and evaluate the strengths and limitations of current research findings. Methods: A systematic search was conducted on Medline, Embase, and Web of Science databases. We included studies published in English that used endoxifen in BD, alongside any relevant studies identified through manual searching and conference papers with full‐text availability. Information pertaining to dose, duration, clinical effects, and safety profiles was extracted from the included studies. The Cochrane Risk of Bias 2 tool was used to assess the risk of bias in clinical trials. Results: The final review included seven case reports (including two conference presentations), two clinical trials, and one prospective study. Most studies administered endoxifen 8 mg and reported an improvement in manic symptoms. Several case reports included patients with comorbid substance use, and most patients received mood stabilizers concurrently. Few reports lacked any structured outcome measures. The clinical trials used divalproex 1000 mg as an active comparator, which was deemed sub‐therapeutic. Despite being multicentric, the first trial lacked data on center‐wise recruitment, and certain methodological concerns were observed across the included trials. There were no serious adverse effects noted, except for a significant elevation in lipid profile within a 3‐week period. Limited data were available regarding endoxifen efficacy and safety in mixed episodes, depressive episodes, and maintenance treatment. Conclusion: There is a paucity of research on the efficacy and safety of endoxifen in BD. While existing evidence suggests short‐term efficacy in manic episodes, significant limitations were identified in most of the included studies. Further research is imperative to establish the efficacy and safety of endoxifen in BD before considering its recommendation as a viable treatment option. [ABSTRACT FROM AUTHOR]

Population‐based studies have demonstrated a high risk of second cancers, especially of the skin, among patients with chronic lymphocytic leukaemia (CLL). We describe age‐standardised incidence ratios (SIRs) of second primary malignancies (SPM) in Australian patients with relapsed/refractory CLL treated with at least two lines of therapy, including ibrutinib. From December 2014 to November 2017, 156 patients were identified from 13 sites enrolled in the Australasian Lymphoma and Related Diseases Registry, and 111 had follow‐up data on rates of SPM. At 38.4 months from ibrutinib therapy commencement, 25% experienced any SPM. SIR for melanoma and all cancers (excluding nonmelanomatous skin cancers) were 15.8 (95% confidence interval (CI): 7.0–35.3) and 4.6 (95% CI: 3.1–6.9) respectively. These data highlight the importance of primary preventive interventions and surveillance, particularly as survival from CLL continues to improve. [ABSTRACT FROM AUTHOR]