The impact of a small-group mammography video discussion on promoting screening uptake among nonadherent Chinese American immigrant women: A randomized controlled trial.

BACKGROUND: The objective of this study was to evaluate the efficacy of an in-person, small-group mammography video discussion (SMVD) intervention on mammography uptake among nonadherent Chinese American immigrant women. METHODS: Women (N = 956) were randomized into either an SMVD group, where Chinese-speaking community health workers (CHWs) used an effective, culturally appropriate video to discuss mammography, or a video-only group, which viewed the cultural video sent by mail. Outcomes were mammography uptake at 6 months and 21 months postintervention. RESULTS: Women in both groups increased mammography uptake, and an outcome analysis revealed no group differences (adjusted odds ratio [AOR], 1.18; 95% confidence interval [CI], .68-2.06). Overall, 61.2% of the SMVD group and 55.3% of the video-only group had at least one mammogram during the 21-month follow-up period. When considering attendance to the SMVD, SMVD attendees had higher mammography uptake than the video-only group (AOR, 1.51; 95% CI, 1.19-1.92), and SMVD nonattendees had lower mammography uptake than the video-only group (AOR, .33; 95% CI, .22-.50). CONCLUSIONS: Both intervention strategies were associated with increased mammography uptake. The authors observed that the increase in use was greater among women who participated in the SMVD session compared with those who viewed the cultural video only. Future research may explore a virtual SMVD intervention for higher session attendance and increased mammography uptake (ClinicalTrials.gov identifier NCT01292200).

Results From First-in-Human Phase I Dose-Escalation Study of a Novel Bicycle Toxin Conjugate Targeting EphA2 (BT5528) in Patients With Advanced Solid Tumors.

PURPOSE: BT5528 is a Bicycle Toxin Conjugate, a novel class of chemically synthesized molecules, comprising a bicyclic peptide targeting EphA2 tumor antigen, linked to a cytotoxin (monomethyl auristatin E [MMAE]). EphA2 is overexpressed in many solid tumors and contributes to oncogenesis, tumor-associated angiogenesis, and metastasis. MATERIALS AND METHODS: The primary objectives were to investigate the safety and tolerability of BT5528 and to define the maximum-tolerated dose, if observed, and recommended phase II dose (RP2D)/expansion dose. Dose escalation exploring once every week or once every 2 weeks administration of BT5528 employed a 3 + 3 dose-escalation design for the first two dose levels, followed by a Bayesian logistic regression model. Secondary and exploratory end points included preliminary efficacy and the pharmacokinetics of BT5528 and MMAE. RESULTS: Forty-five patients were enrolled and received BT5528 doses between 2.2 mg/m2 once every week to 10.0 mg/m2 once every 2 weeks within the dose-escalation stage of the study. The most frequent BT5528-related adverse events (AEs) were nausea (44.4%), diarrhea (35.6%), and fatigue (33.3%), and the most common grade ≥3 BT5528-related AE was neutropenia/neutrophil count decrease (22.2%). Dose level 6.5 mg/m2 once every 2 weeks was selected as a RP2D. At 6.5 mg/m2 once every 2 weeks, the overall response rate was 6.7%, and the disease control rate was 20.0%. BT5528 and MMAE pharmacokinetics are generally dose proportional. BT5528 has a short half-life (0.4-0.7 hours), and the half-life of MMAE is longer (35-47 hours). CONCLUSION: BT5528 was well tolerated and demonstrated favorable and preliminary antitumor activity. We believe these data provide preliminary validation of a Bicycle Toxin Conjugate approach to EphA2 tumor antigen. The study is ongoing and is evaluating BT5528 as monotherapy at a RP2D of 6.5 mg/m2 once every 2 weeks.

A multimodal generative AI copilot for human pathology.

Computational pathology1,2 has witnessed considerable progress in the development of both task-specific predictive models and task-agnostic self-supervised vision encoders3,4. However, despite the explosive growth of generative artificial intelligence (AI), there have been few studies on building general-purpose multimodal AI assistants and copilots5 tailored to pathology. Here we present PathChat, a vision-language generalist AI assistant for human pathology. We built PathChat by adapting a foundational vision encoder for pathology, combining it with a pretrained large language model and fine-tuning the whole system on over 456,000 diverse visual-language instructions consisting of 999,202 question and answer turns. We compare PathChat with several multimodal vision-language AI assistants and GPT-4V, which powers the commercially available multimodal general-purpose AI assistant ChatGPT-4 (ref. 6). PathChat achieved state-of-the-art performance on multiple-choice diagnostic questions from cases with diverse tissue origins and disease models. Furthermore, using open-ended questions and human expert evaluation, we found that overall PathChat produced more accurate and pathologist-preferable responses to diverse queries related to pathology. As an interactive vision-language AI copilot that can flexibly handle both visual and natural language inputs, PathChat may potentially find impactful applications in pathology education, research and human-in-the-loop clinical decision-making.

Towards a general-purpose foundation model for computational pathology.

Quantitative evaluation of tissue images is crucial for computational pathology (CPath) tasks, requiring the objective characterization of histopathological entities from whole-slide images (WSIs). The high resolution of WSIs and the variability of morphological features present significant challenges, complicating the large-scale annotation of data for high-performance applications. To address this challenge, current efforts have proposed the use of pretrained image encoders through transfer learning from natural image datasets or self-supervised learning on publicly available histopathology datasets, but have not been extensively developed and evaluated across diverse tissue types at scale. We introduce UNI, a general-purpose self-supervised model for pathology, pretrained using more than 100 million images from over 100,000 diagnostic H&E-stained WSIs (>77 TB of data) across 20 major tissue types. The model was evaluated on 34 representative CPath tasks of varying diagnostic difficulty. In addition to outperforming previous state-of-the-art models, we demonstrate new modeling capabilities in CPath such as resolution-agnostic tissue classification, slide classification using few-shot class prototypes, and disease subtyping generalization in classifying up to 108 cancer types in the OncoTree classification system. UNI advances unsupervised representation learning at scale in CPath in terms of both pretraining data and downstream evaluation, enabling data-efficient artificial intelligence models that can generalize and transfer to a wide range of diagnostically challenging tasks and clinical workflows in anatomic pathology.

Efficacy of Community Health Worker-Delivered Family Health History-Based Breast Cancer Education and Services Among Chinese Americans.

Family health history (FHH) is an evidence-based genomics tool used in cancer prevention and education. Chinese Americans, the largest Asian American group, face unique barriers in FHH collection and communication. This study aimed to evaluate the efficacy of culturally and linguistically appropriate community health worker (CHW)-delivered FHH-based breast cancer (BC) education and services to Chinese Americans. A total of 1129 Chinese Americans received FHH-based BC education and service delivered by our trained Chinese American CHWs. Participants responded to evaluation surveys before, immediately after, and 3 months after the education and service. Participating Chinese Americans showed significant increases in rates of collecting FHH of BC, discussing FHH of BC with family members, informing their primary care physicians of their FHH of BC, and discussing their FHH of BC with their primary care physicians at 3 months post-education and service compared to the baseline data (all Ps < 0.01). Attitudes, intention, and self-efficacy related to FHH of BC communication and collection and FHH of BC knowledge were improved both immediately after and 3 months after the delivery of the education and services (all Ps < 0.01). Within 3 months, ~ 14.3% of participants who had a high risk of BC based on FHH reported visiting geneticists for genetic evaluation. Our Chinese American CHW-delivered FHH-based BC education and services showed initial success in increasing knowledge, collection and communication of BC-related FHH, and genetic service utilization among Chinese American participants. This study can serve as a starting point for conducting more robust studies, such as randomized controlled trials, in the future.

CXCR2 antagonist navarixin in combination with pembrolizumab in select advanced solid tumors: a phase 2 randomized trial.

C-X-C motif chemokine receptor 2 (CXCR2) has a role in tumor progression, lineage plasticity, and reduction of immune checkpoint inhibitor efficacy. Preclinical evidence suggests potential benefit of CXCR2 inhibition in multiple solid tumors. In this phase 2 study (NCT03473925), adults with previously treated advanced or metastatic castration-resistant prostate cancer (CRPC), microsatellite-stable colorectal cancer (MSS CRC), or non-small-cell lung cancer (NSCLC) were randomized 1:1 to the CXCR2 antagonist navarixin 30 or 100 mg orally once daily plus pembrolizumab 200 mg intravenously every 3 weeks up to 35 cycles. Primary endpoints were investigator-assessed objective response rate (RECIST v1.1) and safety. Of 105 patients (CRPC, n=40; MSS CRC, n=40; NSCLC, n=25), 3 had a partial response (2 CRPC, 1 MSS CRC) for ORRs of 5%, 2.5%, and 0%, respectively. Median progression-free survival was 1.8-2.4 months without evidence of a dose-response relationship, and the study was closed at a prespecified interim analysis for lack of efficacy. Dose-limiting toxicities occurred in 2/48 patients (4%) receiving navarixin 30 mg and 3/48 (6%) receiving navarixin 100 mg; events included grade 4 neutropenia and grade 3 transaminase elevation, hepatitis, and pneumonitis. Treatment-related adverse events occurred in 70/105 patients (67%) and led to treatment discontinuation in 7/105 (7%). Maximal reductions from baseline in absolute neutrophil count were 44.5%-48.2% (cycle 1) and 37.5%-44.2% (cycle 2) and occurred within 6-12 hours postdose in both groups. Navarixin plus pembrolizumab did not demonstrate sufficient efficacy in this study. Safety and tolerability of the combination were manageable. (Trial registration: ClinicalTrials.gov , NCT03473925).

Human Rights in Hospitals: an End to Routine Shackling.

Medical students (NSB, NM, JDW) spearheaded revision of the policy and clinical practice for shackling incarcerated patients at Boston Medical Center (BMC), the largest safety net hospital in New England. In American hospitals, routine shackling of incarcerated patients with metal restraints is widespread-except for perinatal patients-regardless of consciousness, mobility, illness severity, or age. The modified policy includes individualized assessments and allows incarcerated patients to be unshackled if they meet defined criteria. The students also formed the Stop Shackling Patients Coalition (SSP Coalition) of clinicians, public health practitioners, human rights advocates, and community members determined to humanize the inpatient treatment of incarcerated patients. Changes pioneered at BMC led the Mass General Brigham health system to follow suit. The Massachusetts Medical Society adopted a resolution authored by the SSP Coalition, which condemned universal shackling and advocated for use of the least restrictive alternative. This will be presented to the American Medical Association in June 2024. The Coalition led a similar effort to coauthor a policy statement on the issue, which was formally adopted by the American Public Health Association in November 2023. Most importantly, in an unprecedented human rights victory, a BMC patient who was incarcerated, sedated, and intubated was unshackled by correctional officers for the purpose of preserving human dignity.

X-chromosome and kidney function: evidence from a multi-trait genetic analysis of 908,697 individuals reveals sex-specific and sex-differential findings in genes regulated by androgen response elements.

X-chromosomal genetic variants are understudied but can yield valuable insights into sexually dimorphic human traits and diseases. We performed a sex-stratified cross-ancestry X-chromosome-wide association meta-analysis of seven kidney-related traits (n = 908,697), identifying 23 loci genome-wide significantly associated with two of the traits: 7 for uric acid and 16 for estimated glomerular filtration rate (eGFR), including four novel eGFR loci containing the functionally plausible prioritized genes ACSL4, CLDN2, TSPAN6 and the female-specific DRP2. Further, we identified five novel sex-interactions, comprising male-specific effects at FAM9B and AR/EDA2R, and three sex-differential findings with larger genetic effect sizes in males at DCAF12L1 and MST4 and larger effect sizes in females at HPRT1. All prioritized genes in loci showing significant sex-interactions were located next to androgen response elements (ARE). Five ARE genes showed sex-differential expressions. This study contributes new insights into sex-dimorphisms of kidney traits along with new prioritized gene targets for further molecular research.

Mediational roles of stress-coping factors in the relationship between patient-perceived communication quality and physical functioning: racial difference between Chinese and Non-Hispanic White American breast cancer survivors.

PURPOSE: The assumption that patient-provider communication may mediate patients' sense of control over cancer to affect health outcomes has limited evidence. This study examines whether patient-perceived cancer care communication quality (PPCQ) mediates stress appraisal and coping behavior, affecting physical functioning across different racial groups. METHODS: Two hundred and twenty Chinese American and 216 non-Hispanic White (NHW) women (ages 28-80) with stage 0-III breast cancer, 1-5 years post-diagnosis, and without recurrence, enrolled and completed a cross-sectional telephone survey. Physical functioning was measured by the NIH-PROMIS short form. Validated measures of PPCQ, patients' evaluation of their socioeconomic well-being, stress appraisal (perceived severity and control), use of coping strategies, treatment-related symptoms, and comorbidities were also assessed. Path analyses were used to examine the mediation for each racial group. RESULTS: Regardless of race, treatment-related symptoms, comorbidities, and socioeconomic well-being were all directly related to physical functioning (p < 0.05). The impact of PPCQ on physical functioning was mediated by perceived control in the Chinese American group (p < 0.05), but not in the NHW group. Perceived severity and coping were not mediators of physical functioning in either group. CONCLUSIONS: The mediational pathway from PPCQ to perceived control to physical functioning in Chinese American survivors may be partially explained by their lower socioeconomic well-being and culturally valued conformity to physicians as a medical authority. These sociocultural dynamics reinforce the importance of cancer care communication. For NHW survivors, the impact of treatment-related symptoms and socioeconomic well-being on physical functioning outweighed their PPCQ and perceived control.

Association of Race, Ethnicity, Language, and Insurance with Time to Treatment Initiation Among Women with Breast Cancer at an Urban, Academic, Safety-Net Hospital.

INTRODUCTION: Initial treatment for nonmetastatic breast cancer is resection or neoadjuvant systemic therapy, depending on tumor biology and patient factors. Delays in treatment have been shown to impact survival and quality of life. Little has been published on the performance of safety-net hospitals in delivering timely care for all patients. METHODS: We conducted a retrospective study of patients with invasive ductal or lobular breast cancer, diagnosed and treated between 2009 and 2019 at an academic, safety-net hospital. Time to treatment initiation was calculated for all patients. Consistent with a recently published Committee on Cancer timeliness metric, a treatment delay was defined as time from tissue diagnosis to treatment of greater than 60 days. RESULTS: A total of 799 eligible women with stage 1-3 breast cancer met study criteria. Median age was 60 years, 55.7% were non-white, 35.5% were non-English-speaking, 18.9% were Hispanic, and 49.4% were Medicaid/uninsured. Median time to treatment was 41 days (IQR 27-56 days), while 81.1% of patients initiated treatment within 60 days. The frequency of treatment delays did not vary by race, ethnicity, insurance, or language. Diagnosis year was inversely associated with the occurrence of a treatment delay (OR: 0.944, 95% CI 0.893-0.997, p value: 0.039). CONCLUSION: At our institution, race, ethnicity, insurance, and language were not associated with treatment delay. Additional research is needed to determine how our safety-net hospital delivered timely care to all patients with breast cancer, as reducing delays in care may be one mechanism by which health systems can mitigate disparities in the treatment of breast cancer.

Microsatellites used in forensics are in regions enriched for trait-associated variants.

The 20 short tandem repeat (STR) loci of the combined DNA index system (CODIS) are the basis of the vast majority of forensic genetics in the United States. One argument for permissive rules about the collection of CODIS genotypes is that the CODIS loci are thought to contain little information about ancestry or traits. However, in the past 20 years, a growing field has identified hundreds of thousands of genotype-trait associations. Here, we conduct a survey of the landscape of such associations surrounding the CODIS loci as compared with non-CODIS STRs. Although this study cannot establish or quantify associations between CODIS genotypes and phenotypes, we find that the regions around the CODIS loci are enriched for both known pathogenic variants (> 90th percentile) and for trait-associated SNPs identified in genome-wide association studies (GWAS) (≥ 95th percentile in 10kb and 100kb flanking regions), compared with other random sets of autosomal tetranucleotide-repeat STRs.

Effects of Educational Interventions in Facilitating Mammography Screening Among Asian American Women: A Meta-Analysis.

PROBLEM IDENTIFICATION: This meta-analysis evaluated the effects of various types of educational interventions on increasing breast cancer screening uptake among Asian American women. LITERATURE SEARCH: Web of Science, MEDLINE®, PubMed®, and Cochrane Library were searched for randomized controlled trials published from 2010 to 2020 of interventions developed to promote mammography uptake among Asian American women. DATA EVALUATION: A random-effects model was used to estimate pooled effect sizes using relative risk measures. A funnel plot was used to assess publication bias. SYNTHESIS: Seven studies were included in this review. Educational interventions identified were primarily culturally sensitive approaches combined with access-enhancing, individually tailored, or group-based approaches. The interventions were effective at increasing the receipt of mammography. IMPLICATIONS FOR NURSING: This review provides insight into the importance of combining other approaches with educational interventions to increase their effectiveness for Asian American women. Future interventions can incorporate various approaches to enhance the ability of Asian American women to overcome barriers to breast cancer screening.

A General-Purpose Self-Supervised Model for Computational Pathology.

Tissue phenotyping is a fundamental computational pathology (CPath) task in learning objective characterizations of histopathologic biomarkers in anatomic pathology. However, whole-slide imaging (WSI) poses a complex computer vision problem in which the large-scale image resolutions of WSIs and the enormous diversity of morphological phenotypes preclude large-scale data annotation. Current efforts have proposed using pretrained image encoders with either transfer learning from natural image datasets or self-supervised pretraining on publicly-available histopathology datasets, but have not been extensively developed and evaluated across diverse tissue types at scale. We introduce UNI, a general-purpose self-supervised model for pathology, pretrained using over 100 million tissue patches from over 100,000 diagnostic haematoxylin and eosin-stained WSIs across 20 major tissue types, and evaluated on 33 representative CPath clinical tasks in CPath of varying diagnostic difficulties. In addition to outperforming previous state-of-the-art models, we demonstrate new modeling capabilities in CPath such as resolution-agnostic tissue classification, slide classification using few-shot class prototypes, and disease subtyping generalization in classifying up to 108 cancer types in the OncoTree code classification system. UNI advances unsupervised representation learning at scale in CPath in terms of both pretraining data and downstream evaluation, enabling data-efficient AI models that can generalize and transfer to a gamut of diagnostically-challenging tasks and clinical workflows in anatomic pathology.

First-in-human Study of AZD5153, A Small-molecule Inhibitor of Bromodomain Protein 4, in Patients with Relapsed/Refractory Malignant Solid Tumors and Lymphoma.

AZD5153, a reversible, bivalent inhibitor of the bromodomain and extraterminal family protein BRD4, has preclinical activity in multiple tumors. This first-in-human, phase I study investigated AZD5153 alone or with olaparib in patients with relapsed/refractory solid tumors or lymphoma. Adults with relapsed tumors intolerant of, or refractory to, prior therapies received escalating doses of oral AZD5153 once daily or twice daily continuously (21-day cycles), or AZD5153 once daily/twice daily continuously or intermittently plus olaparib 300 mg twice daily, until disease progression or unacceptable toxicity. Between June 30, 2017 and April 19, 2021, 34 patients received monotherapy and 15 received combination therapy. Dose-limiting toxicities were thrombocytopenia/platelet count decreased (n = 4/n = 2) and diarrhea (n = 1). The recommended phase II doses (RP2D) were AZD5153 30 mg once daily or 15 mg twice daily (monotherapy) and 10 mg once daily (intermittent schedule) with olaparib. With AZD5153 monotherapy, common treatment-emergent adverse events (TEAE) included fatigue (38.2%), thrombocytopenia, and diarrhea (each 32.4%); common grade ≥ 3 TEAEs were thrombocytopenia (14.7%) and anemia (8.8%). With the combination, common TEAEs included nausea (66.7%) and fatigue (53.3%); the most common grade ≥ 3 TEAE was thrombocytopenia (26.7%). AZD5153 had dose-dependent pharmacokinetics, with minimal accumulation, and demonstrated dose-dependent modulation of peripheral biomarkers, including upregulation of HEXIM1. One patient with metastatic pancreatic cancer receiving combination treatment had a partial response lasting 4.2 months. These results show AZD5153 was tolerable as monotherapy and in combination at the RP2Ds; common toxicities were fatigue, hematologic AEs, and gastrointestinal AEs. Strong evidence of peripheral target engagement was observed.

Phase 1 Study of JNJ-64619178, a Protein Arginine Methyltransferase 5 Inhibitor, in Advanced Solid Tumors.

PURPOSE: In this first-in-human, Phase 1, open-label, multicenter study, we evaluated JNJ-64619178, a selective and potent PRMT5 inhibitor, in patients with advanced malignant solid tumors or non-Hodgkin lymphomas (NHL). The primary objective was to evaluate the safety and to identify a recommended Phase 2 dose (RP2D) of JNJ-64619178. PATIENTS AND METHODS: Adult patients with treatment-refractory advanced solid tumors or NHL and measurable disease received escalating doses of JNJ-64619178 following two schedules (Schedule A: 14 days on/7 days off; Schedule B: every day on a 21-day cycle). Safety, pharmacokinetics (PK), pharmacodynamics (PD), and clinical activity were evaluated. RESULTS: Ninety patients received JNJ-64619178. Thrombocytopenia was identified as the only dose-limiting toxicity. JNJ-64619178 showed dose-proportional PK and robust target engagement, as measured by plasma symmetric dimethylarginine, across all dose levels. The objective response rate was 5.6% (5 of 90). Patients with adenoid cystic carcinoma (ACC) had an ORR of 11.5% (3 of 26) and a median progression-free survival of 19.1 months. CONCLUSIONS: JNJ-64619178 demonstrated manageable dose-dependent toxicity and preliminary evidence of antitumor activity in ACC and other tumor types. Plasma exposure was dose dependent, and target inhibition was maintained with intermittent and continuous dosing. On the basis of safety, clinical activity, PK, and PD findings, two provisional RP2Ds were selected: 1.5 mg intermittently and 1.0 mg once daily. Aside from ACC, clinical benefit was limited, and biomarkers to enrich for responsiveness to PRMT5 inhibition will be needed for further development.

The Role of Gender-Concordant Mentorship in Women Premedical Students' Perception and Pursuit of Surgical Careers.

OBJECTIVE: Evaluate the impact of a 6-month structured mentorship program between women premedical student mentees paired with women medical students and surgical residents on mentees' interests and perceptions of surgical careers. DESIGN: Prospective qualitative and quantitative study. SETTING: This study took place at the Boston University School of Medicine, a single institution tertiary care hospital. PARTICIPANTS: Self-identified women premedical students at Boston University were eligible for inclusion in this program (n=90). Participants were recruited and grouped with self-identified women medical student (n=52) and resident (n=19) mentors. Participants were provided with a monthly curriculum to guide discussions. Mentees completed pre- and postprogram surveys with 5-point Likert scale questions regarding interest and exposure to surgery, role models and mentorship, and effect of COVID-19 on their career interests. Pre- and postprogram responses were compared using a Wilcoxon rank sum test. RESULTS: Of the 90 mentees, 63 (70%) completed preprogram surveys, and 53 (59%) completed postprogram surveys. Survey respondents indicated statistically significant increased exposure to positive role models (preprogram mean 3.15, postprogram mean 4.06, p=0.0003), increased exposure to women role models (preprogram 2.30, postprogram 3.79, p<0.0001), increased access to dedicated mentors (preprogram 2.11, postprogram 3.75, p<0.0001), and increased availability of support persons to answer their questions and concerns about careers in surgery (preprogram 3.03, postprogram 3.85, p=0.001). There was also a statistically significant increase in the reported effect that exposure to gender-concordant role models in surgery had on participants' decisions to consider a surgical career (preprogram 3.58, postprogram 4.23, p=0.001). CONCLUSION: This 6-month structured mentorship program for undergraduate premedical students increased mentees' exposure to positive women role models and mentors, and increased mentee's interest in pursuing a surgical career. This emphasizes the need for structured gender-concordant mentorship programs early in women's careers to encourage pursuit of surgical careers in an otherwise men-dominated field.

Algorithmic fairness in artificial intelligence for medicine and healthcare.

In healthcare, the development and deployment of insufficiently fair systems of artificial intelligence (AI) can undermine the delivery of equitable care. Assessments of AI models stratified across subpopulations have revealed inequalities in how patients are diagnosed, treated and billed. In this Perspective, we outline fairness in machine learning through the lens of healthcare, and discuss how algorithmic biases (in data acquisition, genetic variation and intra-observer labelling variability, in particular) arise in clinical workflows and the resulting healthcare disparities. We also review emerging technology for mitigating biases via disentanglement, federated learning and model explainability, and their role in the development of AI-based software as a medical device.

Results of an open-label phase 1b study of the ERK inhibitor MK-8353 plus the MEK inhibitor selumetinib in patients with advanced or metastatic solid tumors.

AIM: We evaluated MK-8353 (small molecule inhibitor of extracellular signal-regulated kinase 1/2) plus selumetinib (mitogen-activated extracellular signal-regulated kinase 1/2 inhibitor) in patients with advanced solid tumors. METHODS: This phase 1b, open-label, dose-escalation study (NCT03745989) enrolled adults with histologically/cytologically documented, locally advanced/metastatic solid tumors. MK-8353/selumetinib dose combinations were intended to be investigated in sequence: 50/25, 100/50, 150/75, 200/75, 200/100, and 250/100. Each agent was administered orally BID 4 days on/3 days off in repeating cycles every 21 days. Primary objectives were safety and tolerability and to establish preliminary recommended phase 2 doses for combination therapy. RESULTS: Thirty patients were enrolled. Median (range) age was 61.5 (26-78) years and 93% had received previous cancer therapy. Among 28 patients in the dose-limiting toxicities [DLT]-evaluable population, 8 experienced DLTs: 1/11 (9%) in the MK-8353/selumetinib 100/50-mg dose level experienced a grade 3 DLT (urticaria), and 7/14 (50%) in the 150/75-mg dose level experienced grade 2/3 DLTs (n = 2 each of blurred vision, retinal detachment, vomiting; n = 1 each of diarrhea, macular edema, nausea, retinopathy). The DLT rate in the latter dose level exceeded the prespecified target DLT rate (~30%). Twenty-six patients (87%) experienced treatment-related adverse events (grade 3, 30%; no grade 4/5), most commonly diarrhea (67%), nausea (37%), and acneiform dermatitis (33%). Three patients (10%) experienced treatment-related adverse events leading to treatment discontinuation. Best response was stable disease in 14 patients (n = 10 with MK-8353/selumetinib 150/75 mg). CONCLUSION: MK-8353/selumetinib 50/25 mg and 100/50 mg had acceptable safety and tolerability, whereas 150/75 mg was not tolerable. No responses were observed.