Durable responses to ATR inhibition with ceralasertib in tumors with genomic defects and high inflammation

BACKGROUNDPhase 1 study of ATRinhibition alone or with radiation therapy (PATRIOT) was a first-in-human phase I study of the oral ATR (ataxia telangiectasia and Rad3-related) inhibitor ceralasertib (AZD6738) in advanced solid tumors.METHODSThe primary objective was safety. Secondary objectives included assessment of antitumor responses and pharmacokinetic (PK) and pharmacodynamic (PD) studies. Sixty-seven patients received 20-240 mg ceralasertib BD continuously or intermittently (14 of a 28-day cycle).RESULTSIntermittent dosing was better tolerated than continuous, which was associated with dose-limiting hematological toxicity. The recommended phase 2 dose of ceralasertib was 160 mg twice daily for 2 weeks in a 4-weekly cycle. Modulation of target and increased DNA damage were identified in tumor and surrogate PD. There were 5 (8%) confirmed partial responses (PRs) (40-240 mg BD), 34 (52%) stable disease (SD), including 1 unconfirmed PR, and 27 (41%) progressive disease. Durable responses were seen in tumors with loss of AT-rich interactive domain-containing protein 1A (ARID1A) and DNA damage-response defects. Treatment-modulated tumor and systemic immune markers and responding tumors were more immune inflamed than nonresponding.CONCLUSIONCeralasertib monotherapy was tolerated at 160 mg BD intermittently and associated with antitumor activity.TRIAL REGISTRATIONClinicaltrials.gov: NCT02223923, EudraCT: 2013-003994-84.FUNDINGCancer Research UK, AstraZeneca, UK Department of Health (National Institute for Health Research), Rosetrees Trust, Experimental Cancer Medicine Centre.

Epitope Lability of Phosphorylated Biomarkers of the DNA Damage Response Pathway Results in Increased Vulnerability to Effects of Delayed or Incomplete Formalin Fixation

Phosphorylated biomarkers are crucial for our understanding of drug mechanism of action and dose selection during clinical trials, particularly for drugs that target protein kinases, such as DNA-damage-response (DDR) inhibitors. However, tissue fixation conditions needed to preserve DDR-specific phospho-biomarkers have not been previously investigated. Using xenograft tissues and tightly controlled formalin fixation conditions, we assessed how preanalytical factors affect phosphorylated DDR biomarkers pRAD50(Ser635), ɣH2AX(Ser139), pKAP1(Ser824), and non-phosphorylated biomarkers cMYC and ATM. Cold ischemia times ranged from 15 min to 6 hr, and the fixation duration ranged from 24 hr to 4 weeks. Epitopes pRAD50 and pKAP1 appeared the most labile assessed with staining loss after just 15 min of cold ischemia time, while ATM was more robust showing consistent expression up to 1 hr of cold ischemia. Notably, ɣH2AX expression was lost with formalin fixation over 48 hr. The use of core needle biopsies where possible and novel fixation methods such as the 2-step temperature-controlled formalin approach may improve phosphorylated biomarker preservation; however, practical challenges may affect wider clinical application. The most essential tissue-processing step when downstream analysis includes DDR phosphorylated biomarkers is immediate tissue submersion in formalin, without delay, upon excision from the patient, followed by room temperature fixation for 24 hr.

Specific targeting of the KRAS mutational landscape in myeloma as a tool to unveil the elicited antitumor activity

Alterations in KRAS have been identified as the most recurring somatic variants in the multiple myeloma (MM) mutational landscape. Combining DNA and RNA sequencing, we studied 756 patients and observed KRAS as the most frequently mutated gene in patients at diagnosis; in addition, we demonstrated the persistence or de novo occurrence of the KRAS aberration at disease relapse. Small-molecule inhibitors targeting KRAS have been developed; however, they are selective for tumors carrying the KRASG12C mutation. Therefore, there is still a need to develop novel therapeutic approaches to target the KRAS mutational events found in other tumor types, including MM. We used AZD4785, a potent and selective antisense oligonucleotide that selectively targets and downregulates all KRAS isoforms, as a tool to dissect the functional sequelae secondary to KRAS silencing in MM within the context of the bone marrow niche and demonstrated its ability to significantly silence KRAS, leading to inhibition of MM tumor growth, both in vitro and in vivo, and confirming KRAS as a driver and therapeutic target in MM.

Retrospective analysis of Schlafen11 (SLFN11) to predict the outcomes to therapies affecting the DNA damage response

Background

The absence of the putative DNA/RNA helicase Schlafen11 (SLFN11) is thought to cause resistance to DNA-damaging agents (DDAs) and PARP inhibitors.

Methods

We developed and validated a clinically applicable SLFN11 immunohistochemistry assay and retrospectively correlated SLFN11 tumour levels to patient outcome to the standard of care therapies and olaparib maintenance.

Results

High SLFN11 associated with improved prognosis to the first-line treatment with DDAs platinum-plus-etoposide in SCLC patients, but was not strongly linked to paclitaxel–platinum response in ovarian cancer patients. Multivariate analysis of patients with relapsed platinum-sensitive ovarian cancer from the randomised, placebo-controlled Phase II olaparib maintenance Study19 showed SLFN11 tumour levels associated with sensitivity to olaparib. Study19 patients with high SLFN11 had a lower progression-free survival (PFS) hazard ratio compared to patients with low SLFN11, although both groups had the benefit of olaparib over placebo. Whilst caveated by small sample size, this trend was maintained for PFS, but not overall survival, when adjusting for BRCA status across the olaparib and placebo treatment groups, a key driver of PARP inhibitor sensitivity.

Conclusion

We provide clinical evidence supporting the role of SLFN11 as a DDA therapy selection biomarker in SCLC and highlight the need for further clinical investigation into SLFN11 as a PARP inhibitor predictive biomarker.

AZD0364 Is a Potent and Selective ERK1/2 Inhibitor That Enhances Antitumor Activity in KRAS-Mutant Tumor Models when Combined with the MEK Inhibitor, Selumetinib

The RAS-regulated RAF-MEK1/2-ERK1/2 (RAS/MAPK) signaling pathway is a major driver in oncogenesis and is frequently dysregulated in human cancers, primarily by mutations in BRAF or RAS genes. The clinical benefit of inhibitors of this pathway as single agents has only been realized in BRAF-mutant melanoma, with limited effect of single-agent pathway inhibitors in KRAS-mutant tumors. Combined inhibition of multiple nodes within this pathway, such as MEK1/2 and ERK1/2, may be necessary to effectively suppress pathway signaling in KRAS-mutant tumors and achieve meaningful clinical benefit. Here, we report the discovery and characterization of AZD0364, a novel, reversible, ATP-competitive ERK1/2 inhibitor with high potency and kinase selectivity. In vitro, AZD0364 treatment resulted in inhibition of proximal and distal biomarkers and reduced proliferation in sensitive BRAF-mutant and KRAS-mutant cell lines. In multiple in vivo xenograft models, AZD0364 showed dose- and time-dependent modulation of ERK1/2-dependent signaling biomarkers resulting in tumor regression in sensitive BRAF- and KRAS-mutant xenografts. We demonstrate that AZD0364 in combination with the MEK1/2 inhibitor, selumetinib (AZD6244 and ARRY142886), enhances efficacy in KRAS-mutant preclinical models that are moderately sensitive or resistant to MEK1/2 inhibition. This combination results in deeper and more durable suppression of the RAS/MAPK signaling pathway that is not achievable with single-agent treatment. The AZD0364 and selumetinib combination also results in significant tumor regressions in multiple KRAS-mutant xenograft models. The combination of ERK1/2 and MEK1/2 inhibition thereby represents a viable clinical approach to target KRAS-mutant tumors.

ERRATUM: "YOUNG STELLAR OBJECTS IN THE MASSIVE STAR FORMING REGION W49"

[This corrects the article PMC7489494.].

YOUNG STELLAR OBJECTS IN THE MASSIVE STAR-FORMING REGION W49

We present the initial results of our investigation of the star-forming complex W49, one of the youngest and most luminous massive star-forming regions in our Galaxy. We used Spitzer/Infrared Array Camera (IRAC) data to investigate massive star formation with the primary objective of locating a representative set of protostars and the clusters of young stars that are forming around them. We present our source catalog with the mosaics from the IRAC data. In this study we used a combination of IRAC, MIPS, Two Micron All Sky Survey, and UKIRT Deep Infrared Sky Survey (UKIDSS) data to identify and classify the young stellar objects (YSOs). We identified 232 Class 0/I YSOs, 907 Class II YSOs, and 74 transition disk candidate objects using color-color and color-magnitude diagrams. In addition, to understand the evolution of star formation in W49, we analyzed the distribution of YSOs in the region to identify clusters using a minimal spanning tree method. The fraction of YSOs that belong to clusters with ⩾7 members is found to be 52% for a cutoff distance of 96″, and the ratio of Class II/I objects is 2.1. We compared the W49 region to the G305 and G333 star-forming regions and concluded that W49 has the richest population, with seven subclusters of YSOs.

Interim evaluation of the Rural Health Scholars Program

BACKGROUND

The imperative to address physician maldistribution has been directed in part at medical schools.

DESCRIPTION

The Rural Health Scholars Program (RHSP) is an enrichment initiative that has been implemented at 2 medical schools to increase the number of students likely to practice primary care in rural, underserved areas. It is a longitudinal program that includes a skill-building workshop; a 5-week summer preceptorship with community-based preceptors in rural, underserved areas; and opportunities to return to preceptorship sites during 3rd- and 4th-year rotations. Students also attend community-based and teleconference seminars and workshops, as well as informal social gatherings.

EVALUATION

A static-group comparison design was used to compare program participants with nonparticipants regarding residency program types and locations.

CONCLUSIONS

The RHSP is meeting some interim objectives conducive to its long-term goal of developing physicians who will practice primary care medicine in rural, underserved areas of North Carolina.

Can a 3-day preceptorship change first-year medical students' opinions about living and working in small towns?

BACKGROUND

Research of medical school initiatives that attempt to orient medical students toward rural medicine may facilitate development of initiatives to alleviate physician maldistribution. This study investigated the effect of a 3-day family medicine preceptorship in a small town on first-year medical students' opinions about a) living and working in small towns and b) plans to live in and practice medicine in small towns. Student feedback about the preceptorship was also examined.

METHODS

Questionnaires were administered to 137 first-year medical students using a separate sample pretest-posttest design.

RESULTS

Student feedback indicated that the preceptorship was a valuable learning experience, but the preceptorship did not appear to influence students' opinions about or interest in living in and working in small towns or rural areas.

CONCLUSION

Brief exposure to rural medicine early in the curriculum appears to have little effect on variables that might precede practice location decisions.

Using a standardized family to teach clinical skills to medical students

BACKGROUND

The use of standardized patients has been an accepted instructional methodology in medical education for many years. A logical evolution of this methodology is the creation of a standardized patient family.

DESCRIPTION

This article describes one such standardized family, the Jones family, and how the family is used to teach interpersonal skills, interviewing, communication, counseling, and history-taking skills to medical students.

EVALUATION

After several years of using the Jones family, we have found that more comprehensive scripts need to be developed, that recruitment and retention of standardized patients for a year long program does not seem to be a problem, and that the value added by a standardized family greatly enhances the educational experience for students. A standardized family seems a logical educational vehicle for teaching continuity of care, confidentiality, contextual placement of medical information within family dynamics, cultural beliefs, community orientation, and generalism.

CONCLUSION

A standardized family is a viable instructional methodology that deserves greater use in medical education.

Are medical students ready to provide HIV-prevention counseling?

PURPOSE

To determine whether medical students were prepared to assess risk and counsel patients about prevention of HIV infection, and whether HIV-related experience produced better knowledge and counseling skills.

METHOD

In 1995, students at four North Carolina medical schools interviewed a standardized patient portraying a young woman concerned about HIV infection. The standardized patient recorded whether students asked risk-behavior questions and provided risk-reduction advice. A 21-item questionnaire assessed the students' knowledge of HIV testing and prevention. Students indicated whether they had had experience in educational settings related to HIV or STDs.

RESULTS

415 students completed both the patient interview and the questionnaire. Many failed to ask the patient about several HIV-risk behaviors. Although nearly all (98%) inquired about condom use, fewer than two thirds asked about the patient's history of STDs, number of sexual partners, or specific sexual practices. Most students advised the patient to use condoms. The average score on the knowledge test was 79%; 70% of students confused anonymous with confidential testing, more than half overestimated the risk of HIV transmission from a needle stick, and nearly one in ten did not know how to use a condom. Educational exposures did not produce significantly better risk assessment, counseling information, or knowledge scores.

CONCLUSION

A majority of experienced medical students did not assess several important risk factors of a patient concerned about HIV infection, and many would have provided incorrect information related to HIV testing and prevention of infection. Patient contact in traditional clinical settings did not influence prevention knowledge or behavior. More innovative methods are needed to train students in HIV-infection prevention and counseling.

Development of a measure of medical faculty attitudes toward clinical evaluation of students

PURPOSE

This research involved the development, and in particular the evaluation of the reliability, of scales to measure medical faculty attitudes toward clinical evaluation (ACE) of medical students. The intent was to create measures that yield reliable data and have practical utility in medical education research and faculty development.

METHOD

A systematic, eight-step scale development protocol was used to create the instrument. In early 1993 factor analysis was used on data from 217 clinical faculty at four medical schools to refine the measures. Internal consistency and test-retest reliability analyses were performed. Analyses were also done to determine whether the attitude scores were influenced by such faculty demographic attributes as employing medical school, gender, age, tenure track status, academic rank, or academic department.

RESULTS

An initial pool of 52 items was reduced to 30 items based on iterative reliability studies. Factor analysis on the 30 items yielded two scales: (1) Quality of Evaluation Procedures, 12 items, alpha = .81; and (2) Content of Departmental Evaluations, eight items, alpha = .85. Test-retest reliabilities (12 weeks) for the scales were .67 and .74, respectively. Faculty demographics did not influence attitudes about the quality of evaluation procedures. However, family physicians showed a slightly more positive attitude toward the content of departmental evaluations than did physicians in five other medical specialties.

CONCLUSION

The goal of developing reliable measures of faculty attitudes toward clinical evaluation of medical students has been achieved. With baseline reliabilities established, future research should assess the validity and utility of the scales, especially in the context of clinical practice examinations.

Partial gastrointestinal obstruction for one month due to a linear foreign body in a cat

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Drug abuse and psychiatric findings in HIV-seropositive pregnant patients

In a sample of 55 human immunodeficiency virus (HIV)-seropositive pregnant patients, a history of drug abuse was significantly associated with increased psychopathology, particularly depression and personality disorders. Psychiatric disorders preceded the HIV diagnosis in most of the patients studied. Intravenous drug abuse was also associated with increased prostitution, incarceration, and previous suicide attempts. Psychiatric findings were influenced much less by the HIV diagnosis and much more by the presence or absence of a history of drug abuse.

Measurement of the magnesium concentration in perennial ryegrass (Lolium perenne) using near infrared reflectance spectroscopy

Near infrared reflectance spectroscopy (NIR) was used to develop calibration equations to measure the magnesium concentration in perennial ryegrass herbage (Lolium perenne). A subset of 72 samples was selected on the basis of spectral variation from 400 samples grown in 1988-1989. Three alternative equations were chosen using stepwise multiple linear regression, with standard errors ranging from 0.4 to 0.3 g/kg DM with corresponding squared multiple correlation coefficients ( R2) of 0.68 to 0.82. The equations had 2, 4 and 4 wavelength terms respectively. When these equations were tested on an independent population of perennial ryegrass samples, a significant bias existed when using the 4 term equations but there was no bias when the 2 term equation was used. We conclude that NIR can be used to screen large numbers of perennial ryegrass plants for magnesium concentration. However, for the calibration equations to be used for the analysis of other populations equation performance must be monitored by comparing reference and NIR analyses on a small number of samples.

N-acetylcysteine in the treatment of human arsenic poisoning

A 32-year-old man was brought to the emergency department 5 1/2 hours after ingesting a potentially lethal dose (900 mg) of sodium arsenate ant poison in a suicide attempt. The patient deteriorated progressively for 27 hours. After intramuscular dimercaprol and supportive measures failed to improve his condition, he was given N-acetylcysteine intravenously. The patient showed remarkable clinical improvement during the following 24 hours and was discharged from the hospital several days later.

Throat culture or rapid strep test?

Clearly, rapid tests for streptococci identification are here to stay, and development of the technology is likely to continue. The most rational use of these tests is to identify streptococcal pharyngitis when patients have severe symptoms or when special situations warrant early detection. Throat culture alone is sufficient for most other patients, and all negative rapid tests should be confirmed by throat culture. Specific antistreptococcal therapy should be initiated if either the rapid test or culture is positive. If the physician decides on the basis of clinical criteria to treat pharyngitis with an antibiotic that covers group A beta-hemolytic streptococci, a rapid test is not necessary. If confirmation of the infection is warranted in these cases, throat culture alone should suffice. No rapid strep test kit clearly outperforms others. With any test, good results depend on the quality of the specimen.

Chancroid

Although chancroid is still one of the minor sexually transmitted diseases in the United States, the incidence has increased, with over 3000 cases in 1986. Cases have been reported in 21 states, primarily among black and Hispanic heterosexual men. Patients may be asymptomatic, but frequently both primary and secondary sexual contacts have ulcers. Because confirmation of the diagnosis requires special laboratory conditions, diagnosis usually is based on characteristics of the lesions. Chancroid can be confused with other more common diseases, particularly genital herpes. Differential characteristics are incubation period, location and appearance of lesions, and the presence or absence of associated lymphadenopathy. A simple regimen of antibiotic therapy is highly effective, but control of outbreaks requires prompt identification, treatment of a patient's sexual contacts, and patient education about prevention.

Whole blood platelet aggregation in dogs with liver disease

Whole blood platelet aggregation was determined in response to collagen, arachidonic acid, and adenosine diphosphate in 20 dogs with liver disease and in 20 control dogs. Platelet aggregation in response to collagen and arachidonic acid was reduced in dogs with liver disease, compared with control dogs (P less than 0.05), whereas there was no significant difference in platelet response to adenosine diphosphate between the 2 groups of dogs. Adenosine diphosphate was found not to be a reliable aggregation agent for determination of whole blood platelet aggregation in dogs. Dogs whose platelets did not aggregate in response to collagen and/or arachidonic acid manifested bleeding tendencies that could be attributed to platelet dysfunction.

Reversible cardiomyopathy due to selenium deficiency

Selenium is an essential trace element and a component of glutathione peroxidase, an enzyme that may help to prevent oxidative damage to cells. Selenium deficiency has been linked to the development of Keshan disease, a dilated congestive cardiomyopathy occurring primarily in children living in rural China. Sporadic cases have been reported in the United States in individuals with poor nutritional intake, mostly in individuals on long-term home parenteral nutrition. This report describes a young black woman with Crohn's disease in whom a congestive cardiomyopathy developed and was subsequently reversed following administration of selenium.

Evaluating oral mucosa bleeding times in healthy dogs using a spring-loaded device

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