Survival outcomes in older men with non-metastatic castration-resistant prostate cancer treated with androgen receptor inhibitors: a US Food and Drug Administration pooled analysis of patient-level data from three randomised trials.

BACKGROUND: Little is known about the benefit-risk profile of second-generation androgen receptor inhibitors in older men with non-metastatic castration-resistant prostate cancer. We aimed to examine the efficacy and safety of second-generation androgen receptor inhibitors in men aged 80 years or older with non-metastatic castration-resistant prostate cancer. METHODS: We searched for all randomised controlled clinical trials evaluating second-generation androgen receptor inhibitors in patients with non-metastatic castration-resistant prostate cancer submitted to the US Food and Drug Administration before Aug 15, 2020, and pooled data from three trials that met the selection criteria. All three trials enrolled patients who were aged 18 years or older with an Eastern Cooperative Oncology Group performance status of 0-1, castration-resistant prostate cancer, prostate-specific antigen (PSA) 2·0 µg/L or greater, PSA doubling time of 10 months or less, and no evidence of distant metastatic disease on conventional imaging per the investigator's assessment at the time of screening. All patients had histologically or cytologically confirmed adenocarcinoma of the prostate without neuroendocrine differentiation or small-cell features. All patients who were randomly assigned to androgen receptor inhibitor or placebo groups in these trials were considered assessable and were included in this pooled analysis. We evaluated the effect of age on metastasis-free survival and overall survival across age groups (<80 years vs ≥80 years) in the intention-to-treat population. Safety analyses were done in patients who received at least one dose of study treatment. FINDINGS: Between Oct 14, 2013, and March 9, 2018, 4117 patients were assigned to androgen receptor inhibitor (apalutamide, enzalutamide, or daralutamide; n=2694) or placebo (n=1423) across three randomised trials. The median follow-up duration for metastasis-free survival was 18 months (IQR 11-26) and for overall survival was 44 months (32-55). In patients aged 80 years or older (n=1023), the estimated median metastasis-free survival was 40 months (95% CI 36-41) in the androgen receptor inhibitor groups and 22 months (18-29) in the placebo groups (adjusted hazard ratio [HR] 0·37 [95% CI 0·28-0·47]), and the median overall survival was 54 months (50-61) versus 49 months (43-58), respectively (adjusted HR 0·79 [0·64-0·98]). In patients younger than 80 years of age (n=3094), the estimated median metastasis-free survival was 41 months (95% CI 36-not estimable [NE]) in the androgen receptor inhibitor groups and 16 months (15-18) in the placebo groups (adjusted HR 0·31 [95% CI 0·27-0·35]), and the median overall survival was 74 months (74-NE) versus 61 months (56-NE), respectively (adjusted HR 0·69 [0·60-0·80]). In patients aged 80 years or older, grade 3 or worse adverse events were reported in 371 (55%) of 672 patients in the androgen receptor inhibitor groups and 140 (41%) of 344 patients in the placebo groups, compared with 878 (44%) of 2015 patients in the androgen receptor inhibitor groups and 321 (30%) of 1073 patients in the placebo groups among patients younger than 80 years. The most common grade 3-4 adverse events were hypertension (168 [8%] of 2015 patients aged <80 years and 51 [8%] of 672 patients aged ≥80 years in the androgen receptor inhibitor groups vs 53 [5%] of 1073 patients aged <80 years and 22 [6%] of 344 patients aged ≥80 years in the placebo groups) and fracture (61 [3%] and 36 [5%] in the androgen receptor inhibitor groups vs 15 [1%] and 11 [3%] in the placebo groups). INTERPRETATION: The findings of this pooled analysis support the use of androgen receptor inhibitors in older men with non-metastatic castration-resistant prostate cancer. Incorporating geriatric assessment tools in the care of older adults with non-metastatic castration-resistant prostate cancer might help clinicians to offer individualised treatment to each patient. FUNDING: None.

Systematic Review of PD-1/PD-L1 Inhibitors in Oncology: From Personalized Medicine to Public Health.

BACKGROUND: To review and summarize all U.S. Food and Drug Administration (FDA) approvals of programmed death (PD)-1 and PD-ligand 1 blocking antibodies (collectively referred to as PD-[L]1 inhibitors) over a 6-year period and corresponding companion/complementary diagnostic assays. MATERIALS AND METHODS: To determine the indications and pivotal trials eligible for inclusion, approval letters and package inserts available on Drugs@FDA were evaluated for approved PD-[L]1 inhibitors to identify all new indications granted from the first approval of a PD-[L]1 inhibitor on September 4, 2014, through September 3, 2020. The corresponding FDA drug and device reviews from the marketing applications for the approved indications were identified through FDA internal records. Two reviewers independently extracted information for the endpoints, efficacy data, basis for approval, type of regulatory approval, and corresponding in vitro diagnostic device test. The results were organized by organ system and tumor type. RESULTS: Of 70 Biologic Licensing Application or supplement approvals that resulted in new indications, 32 (46%) were granted based on response rate (ORR) and durability of response, 26 (37%) on overall survival, 9 (13%) on progression-free survival, 2 (3%) on recurrence-free survival, and 1 (1%) on complete response rate. Most ORR-based approvals were granted under the accelerated approval provisions and were supported with prolonged duration of response. Overall, 21% of approvals were granted with a companion diagnostic. Efficacy results according to tumor type are discussed. CONCLUSION: PD-[L]1 inhibitors are an effective anticancer therapy in a subset of patients. This class of drugs has provided new treatment options for patients with unmet need across a wide variety of cancer types. Yet, the modest response rates in several tumor types signal a lack of understanding of the biology of these diseases. Further preclinical and clinical investigation may be required to identify a more appropriate patient population, particularly as drug development continues and additional treatment alternatives become available. IMPLICATIONS FOR PRACTICE: The number of PD-[L]1 inhibitors in drug development and the associated companion and complementary diagnostics have led to regulatory challenges and questions regarding generalizability of trial results. The interchangeability of PD-L1 immunohistochemical assays between PD-1/PD-L1 drugs is unclear. Furthermore, robust responses in some patients with low levels of PD-L1 expression have limited the use of PD-L1 as a predictive biomarker across all cancers, particularly in the setting of diseases with few alternative treatment options. This review summarizes the biomarker thresholds and assays approved as complementary and companion diagnostics and provides regulatory perspective on the role of biomarkers in oncology drug development.

FDA Approval Summary: Rucaparib for the Treatment of Patients with Deleterious BRCA-Mutated Metastatic Castrate-Resistant Prostate Cancer.

The U.S. Food and Drug Administration (FDA) granted accelerated approval to rucaparib in May 2020 for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer (mCRPC) who have been treated with androgen receptor-directed therapy and a taxane. This approval was based on data from the ongoing multicenter, open-label single-arm trial TRITON2. The primary endpoint, confirmed objective response rate, in the 62 patients who met the above criteria, was 44% (95% confidence interval [CI]: 31%-57%). The median duration of response was not estimable (95% CI: 6.4 to not estimable). Fifty-six percent of patients had a response duration of >6 months and 15% >12 months. The safety profile of rucaparib was generally consistent with that of the class of poly-(ADP-ribose) polymerase enzyme inhibitors and other trials of rucaparib in the treatment of ovarian cancer. Deaths due to adverse events (AEs) occurred in 1.7% of patients, and 8% discontinued rucaparib because of an AE. Grade 3-4 AEs occurred in 59% of patients. No patients with prostate cancer developed myelodysplastic syndrome or acute myeloid leukemia. The trial TRITON3 in patients with mCRPC is ongoing and is planned to verify the clinical benefit of rucaparib in mCRPC. This article summarizes the FDA thought process and data supporting this accelerated approval. IMPLICATIONS FOR PRACTICE: The accelerated approval of rucaparib for the treatment of adult patients with deleterious BRCA mutation (germline and/or somatic)-associated metastatic castrate-resistant prostate cancer who have been treated with androgen receptor-directed therapy and a taxane represents the first approved therapy for this selected patient population. This approval was based on a single-arm trial demonstrating a confirmed objective response rate greater than that of available therapy with a favorable duration of response and an acceptable toxicity profile. The ongoing trial TRITON3 is verifying the clinical benefit of this drug.

Identification of aryl sulfonamides as novel and potent inhibitors of NaV1.5.

We describe the synthesis and biological evaluation of a series of novel aryl sulfonamides that exhibit potent inhibition of NaV1.5. Unlike local anesthetics that are currently used for treatment of Long QT Syndrome 3 (LQT-3), the most potent compound (-)-6 in this series shows high selectivity over hERG and other cardiac ion channels and has a low brain to plasma ratio to minimize CNS side effects. Compound (-)-6 is also effective inshortening prolonged action potential durations (APDs) in a pharmacological model of LQT-3 syndrome in pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). Unlike most aryl sulfonamide NaV inhibitors that bind to the channel voltage sensors, these NaV1.5 inhibitors bind to the local anesthetic binding site in the central pore of the channel.

A gustatory receptor paralogue controls rapid warmth avoidance in Drosophila.

Behavioural responses to temperature are critical for survival, and animals from insects to humans show strong preferences for specific temperatures. Preferred temperature selection promotes avoidance of adverse thermal environments in the short term and maintenance of optimal body temperatures over the long term, but its molecular and cellular basis is largely unknown. Recent studies have generated conflicting views of thermal preference in Drosophila, attributing importance to either internal or peripheral warmth sensors. Here we reconcile these views by showing that thermal preference is not a singular response, but involves multiple systems relevant in different contexts. We found previously that the transient receptor potential channel TRPA1 acts internally to control the slowly developing preference response of flies exposed to a shallow thermal gradient. We now find that the rapid response of flies exposed to a steep warmth gradient does not require TRPA1; rather, the gustatory receptor GR28B(D) drives this behaviour through peripheral thermosensors. Gustatory receptors are a large gene family, widely studied in insect gustation and olfaction, and are implicated in host-seeking by insect disease vectors, but have not previously been implicated in thermosensation. At the molecular level, GR28B(D) misexpression confers thermosensitivity upon diverse cell types, suggesting that it is a warmth sensor. These data reveal a new type of thermosensory molecule and uncover a functional distinction between peripheral and internal warmth sensors in this tiny ectotherm reminiscent of thermoregulatory systems in larger, endothermic animals. The use of multiple, distinct molecules to respond to a given temperature, as observed here, may facilitate independent tuning of an animal's distinct thermosensory responses.

Modulation of TRPA1 thermal sensitivity enables sensory discrimination in Drosophila.

Discriminating among sensory stimuli is critical for animal survival. This discrimination is particularly essential when evaluating whether a stimulus is noxious or innocuous. From insects to humans, transient receptor potential (TRP) channels are key transducers of thermal, chemical and other sensory cues. Many TRPs are multimodal receptors that respond to diverse stimuli, but how animals distinguish sensory inputs activating the same TRP is largely unknown. Here we determine how stimuli activating Drosophila TRPA1 are discriminated. Although Drosophila TRPA1 responds to both noxious chemicals and innocuous warming, we find that TRPA1-expressing chemosensory neurons respond to chemicals but not warmth, a specificity conferred by a chemosensory-specific TRPA1 isoform with reduced thermosensitivity compared to the previously described isoform. At the molecular level, this reduction results from a unique region that robustly reduces the channel's thermosensitivity. Cell-type segregation of TRPA1 activity is critical: when the thermosensory isoform is expressed in chemosensors, flies respond to innocuous warming with regurgitation, a nocifensive response. TRPA1 isoform diversity is conserved in malaria mosquitoes, indicating that similar mechanisms may allow discrimination of host-derived warmth--an attractant--from chemical repellents. These findings indicate that reducing thermosensitivity can be critical for TRP channel functional diversification, facilitating their use in contexts in which thermal sensitivity can be maladaptive.

Analysis of Drosophila TRPA1 reveals an ancient origin for human chemical nociception.

Chemical nociception, the detection of tissue-damaging chemicals, is important for animal survival and causes human pain and inflammation, but its evolutionary origins are largely unknown. Reactive electrophiles are a class of noxious compounds humans find pungent and irritating, such as allyl isothiocyanate (in wasabi) and acrolein (in cigarette smoke). Diverse animals, from insects to humans, find reactive electrophiles aversive, but whether this reflects conservation of an ancient sensory modality has been unclear. Here we identify the molecular basis of reactive electrophile detection in flies. We demonstrate that Drosophila TRPA1 (Transient receptor potential A1), the Drosophila melanogaster orthologue of the human irritant sensor, acts in gustatory chemosensors to inhibit reactive electrophile ingestion. We show that fly and mosquito TRPA1 orthologues are molecular sensors of electrophiles, using a mechanism conserved with vertebrate TRPA1s. Phylogenetic analyses indicate that invertebrate and vertebrate TRPA1s share a common ancestor that possessed critical characteristics required for electrophile detection. These findings support emergence of TRPA1-based electrophile detection in a common bilaterian ancestor, with widespread conservation throughout vertebrate and invertebrate evolution. Such conservation contrasts with the evolutionary divergence of canonical olfactory and gustatory receptors and may relate to electrophile toxicity. We propose that human pain perception relies on an ancient chemical sensor conserved across approximately 500 million years of animal evolution.

Discovery of triazolone derivatives as novel, potent stearoyl-CoA desaturase-1 (SCD1) inhibitors.

Stearoyl-CoA desaturase-1 (SCD1) plays an important role in lipid metabolism. Inhibition of SCD1 activity represents a potential novel approach for the treatment of metabolic diseases such as obesity, type 2 diabetes and dyslipidemia, as well as skin diseases, acne and cancer. Herein, we report the synthesis and structure-activity relationships (SAR) of a series of novel triazolone derivatives, culminating in the identification of pyrazolyltriazolone 17a, a potent SCD1 inhibitor, which reduced plasma C16:1/C16:0 triglycerides desaturation index (DI) in an acute Lewis rat model in a dose dependent manner, with an ED50 of 4.6 mg/kg. In preliminary safety studies, compound 17a did not demonstrate adverse effects related to SCD1 inhibition after repeat dosing at 100mg/kg. Together, these data suggest that sufficient safety margins can be achieved with certain SCD1 inhibitors, thus allowing exploration of clinical utility in metabolic disease settings.

Cytoreductive nephrectomy in the era of immune checkpoint inhibitors: a US Food and Drug Administration pooled analysis.

BACKGROUND: This pooled analysis of patient-level data from trials evaluated the clinical outcomes of patients with metastatic renal cell carcinoma with or without cytoreductive nephrectomy before a combination of immune checkpoint inhibitor and antiangiogenic therapy. METHODS: Data from 5 trials of immune checkpoint inhibitors plus antiangiogenic therapy were pooled. Only patients with stage 4 disease at initial diagnosis were included to ensure that nephrectomy was performed for cytoreductive purposes and not to previously treat an earlier stage of disease. The effect of cytoreductive nephrectomy before immune checkpoint inhibitor therapy on outcomes was evaluated using the Kaplan-Meier method and a Cox proportional hazards regression model, adjusted for age, sex, risk group, performance status, and the presence of sarcomatoid differentiation. RESULTS: A total of 981 patients were included. The estimated median progression-free survival with and without nephrectomy was 15 and 11 months, respectively; the adjusted hazard ratio was 0.71 (95% confidence interval = 0.59 to 0.85). The estimated median overall survival with and without nephrectomy was 46 and 28 months, respectively; the adjusted hazard ratio was 0.63 (95% confidence interval = 0.51 to 0.77). Objective response was 60% of patients with vs 46% of patients without cytoreductive nephrectomy. CONCLUSIONS: Patients with metastatic renal cell carcinoma who undergo cytoreductive nephrectomy before immune checkpoint inhibitor plus antiangiogenic therapy had improved outcomes compared with patients without cytoreductive nephrectomy. Selection factors for cytoreductive nephrectomy may be prognostic and could not be fully controlled for in this retrospective analysis. Prospective determination of and stratification by prior cytoreductive nephrectomy may be considered when designing clinical trials to assess the impact of this factor on prognosis.

FDA Approval Summary: Enfortumab Vedotin plus Pembrolizumab for Cisplatin-Ineligible Locally Advanced or Metastatic Urothelial Carcinoma.

On April 3, 2023, the FDA granted accelerated approval to enfortumab vedotin-ejfv (EV) plus pembrolizumab for treatment of patients with locally advanced or metastatic urothelial carcinoma who are ineligible for cisplatin-containing chemotherapy. Substantial evidence of effectiveness was obtained from EV-103/KEYNOTE-869 (NCT03288545), a multicohort study. Across cohorts, a total of 121 patients received EV 1.25 mg/kg (maximum of 125 mg) intravenously on days 1 and 8 of a 21-day cycle plus pembrolizumab 200 mg intravenously on day 1 of each 21-day cycle until disease progression or unacceptable toxicity. The major efficacy outcome measures were objective response rate (ORR) and duration of response (DoR), determined by blinded independent central review using RECIST v1.1. The confirmed ORR in 121 patients was 68% (95% confidence interval, 59-76), including 12% with complete responses. The median DoR for the 82 responders was 22 months (range: 1+ to 46+). The safety profile of the combination comprised adverse reactions expected to occur with the corresponding monotherapies, but with overall increased frequency of adverse reactions, including skin toxicity, pneumonitis, and peripheral neuropathy. The article summarizes the data and the FDA thought process supporting accelerated approval of EV + pembrolizumab, as well as additional exploratory analyses conducted by the FDA.

Efficacy of Poly(ADP-ribose) Polymerase Inhibitors by Individual Genes in Homologous Recombination Repair Gene-Mutated Metastatic Castration-Resistant Prostate Cancer: A US Food and Drug Administration Pooled Analysis.

PURPOSE: We performed a pooled analysis of multiple trials of poly(ADP-ribose) polymerase inhibitors (PARPi) in metastatic castration-resistant prostate cancer (mCRPC) to investigate the efficacy of PARPi in each individual homologous recombination repair (HRR) mutated (m) gene. PATIENTS AND METHODS: We pooled patient-level data from trials of PARPi in mCRPC that reported mutation status in individual HRR genes. Any HRR gene with available data across all the randomized trials of PARPi in first-line mCRPC was selected. The hazard ratios (HRs; 95% CI) for radiographic progression-free survival (rPFS; by blinded independent review) and overall survival (OS) of a PARPi plus an androgen receptor pathway inhibitor (ARPI) relative to placebo plus an ARPI in the pool of three randomized trials in first-line mCRPC were calculated using Kaplan-Meier estimates and a Cox proportional hazards model. RESULTS: In ATMm (N = 268), rPFS HR was 1.05 (0.74 to 1.49) and OS HR was 1.18 (0.82 to 1.71). In BRCA1m (N = 64), rPFS HR was 0.51 (0.23 to 1.1) and OS HR was 0.74 (0.34 to 1.61). In BRCA2m (N = 422), rPFS HR was 0.31 (0.23 to 0.42) and OS HR was 0.66 (0.49 to 0.89). In CDK12m (N = 164), rPFS HR was 0.50 (0.32 to 0.80) and OS HR was 0.63 (0.39 to 0.99). In CHEK2m (N = 172), rPFS HR was 1.06 (0.67 to 1.66) and OS HR was 1.53 (0.95 to 2.46). In PALB2m (N = 41) rPFS HR was 0.52 (0.23 to 1.17) and OS HR was 0.78 (0.34 to 1.8). CONCLUSION: In this pooled analysis, benefit from PARPi appeared greatest for patients with BRCA1m, BRCA2m, CDK12m, and PALB2m. Given limitations of this exploratory analysis, the apparent lack of benefit from PARPi in patients with CHEK2m or ATMm should be further explored in future clinical trials.

A Pooled Analysis of Treatment-Free Survival in Advanced Renal Cell Carcinoma.

PURPOSE: A clinically meaningful attribute of some immune-oncology (IO) regimens is potential durable clinical benefit during a treatment-free interval. We characterize treatment-free survival (TFS) with and without ongoing toxicity in trials of frontline IO-VEGF tyrosine kinase inhibitor (TKI) combinations in patients with advanced renal cell carcinoma (aRCC). PATIENTS AND METHODS: Individual patient data were pooled by treatment arm from randomized trials submitted to the FDA evaluating IO-TKI combination in treatment-naïve aRCC with at least 30 months of median follow-up. OS, TFS, TFS with and without toxicity, and time to all protocol therapy cessation were assessed. TFS was estimated by 30-month restricted mean times defined as area between Kaplan-Meier curves for two time-to-event endpoints originating at randomization: time to all protocol therapy cessation and time to subsequent systemic therapy initiation or death. RESULTS: Three trials met criteria for analysis; 1183 pts received IO-TKI versus 1184 on control arms received TKI alone (sunitinib [SUN]). IO-TKI and SUN groups spent 9% (2.7 months [95% confidence interval (CI): 1.8, 3.5]) and 10% (2.9 months [95% CI: 2.1, 3.8]) of the 30-mo period alive and treatment-free, respectively. Mean TFS without grade ≥3 toxicity was 1.7 and 2.3 months in IO-TKI and SUN groups, respectively. CONCLUSIONS AND RELEVANCE: In this post hoc partitioned survival analysis, TFS and TFS without toxicity appeared similar in the IO-TKI group compared to the SUN group. These findings may reflect continuation of TKI until progression per protocol design in all trials and discontinuation of IO after 2 years in 2 trials.

US Food and Drug Administration Approval Summary: Talazoparib in Combination With Enzalutamide for Treatment of Patients With Homologous Recombination Repair Gene-Mutated Metastatic Castration-Resistant Prostate Cancer.

PURPOSE: The US Food and Drug Administration (FDA) approved talazoparib with enzalutamide for first-line treatment of patients with homologous recombination repair (HRR) gene-mutated metastatic castration-resistant prostate cancer (mCRPC). PATIENTS AND METHODS: The approval was based on the HRR gene-mutated (HRRm) population of TALAPRO-2, a randomized, double-blind trial that randomly assigned 1,035 patients with mCRPC to receive enzalutamide with either talazoparib or placebo. Two cohorts enrolled sequentially: an all-comer population (Cohort 1), followed by an HRRm-only population (Cohort 2). The independent primary end points were radiographic progression-free survival (rPFS) per blinded independent central review (BICR) in Cohort 1 (all-comers) and in the combined HRRm population (all HRRm patients from Cohorts 1 and 2). Overall survival (OS) was a key secondary end point. RESULTS: A statistically significant improvement in rPFS by BICR was demonstrated in both the all-comers cohort and the combined HRRm population, with hazard ratio (HR) of 0.63 (95% CI, 0.51 to 0.78; P < .0001) and 0.45 (95% CI, 0.33 to 0.61; P < .0001), respectively. In an exploratory analysis of the 155 patients with BRCA-mutated (BRCAm) mCRPC, rPFS HR was 0.20 (95% CI, 0.11 to 0.36). In the non-HRRm/unknown stratum of Cohort 1 (n = 636), the rPFS HR was 0.70 (95% CI, 0.54 to 0.89). OS was immature. CONCLUSION: Despite a statistically significant rPFS improvement in the all-comer cohort, FDA did not consider the magnitude of rPFS clinically meaningful in the context of the broad indication, combination treatment, and safety profile. Approval was therefore limited to patients with HRRm mCRPC, for whom there was a statistically significant and clinically meaningful improvement in rPFS and favorable OS results. This represents the first approval for the first-line treatment of patients with HRRm mCRPC.

The contribution of NaV1.6 to the efficacy of voltage-gated sodium channel inhibitors in wild type and NaV1.6 gain-of-function (GOF) mouse seizure control.

BACKGROUND AND PURPOSE: Inhibitors of voltage-gated sodium channels (NaVs) are important anti-epileptic drugs, but the contribution of specific channel isoforms is unknown since available inhibitors are non-selective. We aimed to create novel, isoform selective inhibitors of Nav channels as a means of informing the development of improved antiseizure drugs. EXPERIMENTAL APPROACH: We created a series of compounds with diverse selectivity profiles enabling block of NaV1.6 alone or together with NaV1.2. These novel NaV inhibitors were evaluated for their ability to inhibit electrically evoked seizures in mice with a heterozygous gain-of-function mutation (N1768D/+) in Scn8a (encoding NaV1.6) and in wild-type mice. KEY RESULTS: Pharmacologic inhibition of NaV1.6 in Scn8aN1768D/+ mice prevented seizures evoked by a 6-Hz shock. Inhibitors were also effective in a direct current maximal electroshock seizure assay in wild-type mice. NaV1.6 inhibition correlated with efficacy in both models, even without inhibition of other CNS NaV isoforms. CONCLUSIONS AND IMPLICATIONS: Our data suggest NaV1.6 inhibition is a driver of efficacy for NaV inhibitor anti-seizure medicines. Sparing the NaV1.1 channels of inhibitory interneurons did not compromise efficacy. Selective NaV1.6 inhibitors may provide targeted therapies for human Scn8a developmental and epileptic encephalopathies and improved treatments for idiopathic epilepsies.

Utilization of counseling services at one medical school.

OBJECTIVES: The purpose of this study was to assess the usage of mental health counseling services by medical students. Medical students experience high rates of burnout, depression, and suicidal ideation. Our medical school (Baylor) provides free professional counseling services. METHODS: The authors administered a survey that included a burnout scale; a depression screen; and questions about demographics, usage of counseling services, and helpful coping mechanisms for 526 first-through third-year students (336 respondents) at one school. RESULTS: Approximately 24% of students with high rates of burnout and 24% of students with depressive symptoms took advantage of counseling services at least once. Of the students who had not used counseling services, approximately 49% were found to have high rates of burnout in the domain of emotional exhaustion. Similarly, of the students who had not accessed counseling services, 56% had depressive symptoms. CONCLUSIONS: A large percentage of medical students across three classes did not use mental health counseling services provided by the school. Students should be clearly informed about the availability of counseling services and their potential utility. In addition, specific barriers to attendance should be identified and reduced.

DMKPs provide a generalizable strategy for studying genes required for reproduction or viability in nontraditional model organisms.

The advent of CRISPR/Cas9-mediated genome editing has expanded the range of animals amenable to targeted genetic analysis. This has accelerated research in animals not traditionally studied using molecular genetics. However, studying genes essential for reproduction or survival in such animals remains challenging, as they lack the tools that aid genetic analysis in traditional genetic model organisms. We recently introduced the use of distinguishably marked knock-in pairs (DMKPs) as a strategy for rapid and reliable genotyping in such species. Here we show that DMKPs also facilitate the maintenance and study of mutations that cannot be maintained in a homozygous state, a group which includes recessive lethal and sterile mutations. Using DMKPs, we disrupt the zero population growth locus in Drosophila melanogaster and in the dengue vector mosquito Aedes aegypti. In both species, DMKPs enable the maintenance of zero population growth mutant strains and the reliable recovery of zero population growth mutant animals. Male and female gonad development is disrupted in fly and mosquito zero population growth mutants, rendering both sexes sterile. In Ae. aegypti, zero population growth mutant males remain capable of inducing a mating refractory period in wild-type females and of competing with wild-type males for mates, properties compatible with zero population growth serving as a target in mosquito population suppression strategies. DMKP is readily generalizable to other species amenable to CRISPR/Cas9-mediated gene targeting, and should facilitate the study of sterile and lethal mutations in multiple organisms not traditionally studied using molecular genetics.

Humidity sensors that alert mosquitoes to nearby hosts and egg-laying sites.

To reproduce and to transmit disease, female mosquitoes must obtain blood meals and locate appropriate sites for egg laying (oviposition). While distinct sensory cues drive each behavior, humidity contributes to both. Here, we identify the mosquito's humidity sensors (hygrosensors). Using generalizable approaches designed to simplify genetic analysis in non-traditional model organisms, we demonstrate that the ionotropic receptor Ir93a mediates mosquito hygrosensation as well as thermosensation. We further show that Ir93a-dependent sensors drive human host proximity detection and blood-feeding behavior, consistent with the overlapping short-range heat and humidity gradients these targets generate. After blood feeding, gravid females require Ir93a to seek high humidity associated with preferred egg-laying sites. Reliance on Ir93a-dependent sensors to promote blood feeding and locate potential oviposition sites is shared between the malaria vector Anopheles gambiae and arbovirus vector Aedes aegypti. These Ir93a-dependent systems represent potential targets for efforts to control these human disease vectors.

Survey of the prevalence of burnout, stress, depression, and the use of supports by medical students at one school.

OBJECTIVE: The authors determined the prevalence of stress, depression, and burnout in medical students and the resources used by students in one school to alleviate psychological distress. METHODS: A survey was administered to 526 students in the first 3 years of medical school (336 responders; response rate: 70%) at one institution, using a modified Maslach Burnout Inventory Human Services Survey (MBI-HSS), the two-question PRIME-MD depression screening survey, the Perceived Medical School Stress Scale, along with questions on demographics and helpful programs to cope with stress. RESULTS: The percentage of respondents scoring in the High Burnout range was approximately 55% for all three subscales. Depressive symptoms were reported by 60% of respondents. The most helpful coping mechanisms reported were social support from peers and faculty, counseling services, and extracurricular activities. CONCLUSIONS: The prevalences of burnout, depression, and stress were higher in this sample of first- through third-year medical students when compared with other medical student groups previously studied. Important limitations of this research included the fact that it was cross-sectional in design and that the PRIME-MD tool is simply a screening tool and does not diagnose major depression. Medical educators, deans, and administrators should appreciate the possibility of higher levels of psychological distress among their own students than those previously reported.

Can statins lessen the burden of virus mediated cancers?

BACKGROUND: Oncogenic viruses, including hepatitis B virus (HBV), hepatitis C virus (HCV), human papillomavirus (HPV), Epstein Barr virus (EBV), and Kaposi Sarcoma Herpes virus (KSHV) contribute to a significant proportion of the world's cancers. Given the sizeable burden of virus mediated cancers, development of strategies to prevent and/or treat these cancers is critical. While large population studies suggest that treatment with hydroxymethylglutaryl-CoA reductase inhibitors, commonly known as statins, may reduce the risk of many cancer types including HBV/HCV related hepatocellular carcinoma, few studies have specifically evaluated the impact of statin use in populations at risk for other types of virus mediated cancers. MAIN BODY: Studies of populations with HBV and HCV suggest a protective, dose-dependent effect of statins on hepatocellular carcinoma risk and support the theory that statins may offer clinical benefit if used as chemoprophylactic agents to reduce liver cancer incidence. However, no population level data exists describing the impact of statins on populations with other oncogenic viral infections, such as HPV, EBV, and KSHV. CONCLUSION: Further study of statin use in diverse, global populations with or at high risk for oncogenic viral infections is essential to determine the impact of statin therapy on virus mediated cancer risk.

FDA Approval Summary: Tivozanib for Relapsed or Refractory Renal Cell Carcinoma.

On March 10, 2021, the FDA granted regular approval to tivozanib for treatment of patients with relapsed or refractory (R/R) advanced renal cell carcinoma (RCC) following two or more prior systemic therapies. Approval was based on the TIVO-3 study, a randomized trial of tivozanib versus sorafenib in patients with R/R advanced RCC. In TIVO-3, patients were randomized to receive either tivozanib 1.34 mg orally once daily for 21 consecutive days of every 28-day cycle or sorafenib 400 mg orally twice daily continuously. The primary endpoint was progression-free survival (PFS) per RECIST v1.1. Tivozanib demonstrated efficacy compared with sorafenib with an improvement in PFS [HR, 0.73; 95% confidence interval (CI), 0.56-0.95; P = 0.016]. The estimated median PFS was 5.6 months and 3.9 months in the tivozanib and sorafenib arms, respectively. There was no evidence of a detrimental effect on overall survival: HR, 0.97 (95% CI, 0.75-1.24). The most common grade 3 to 4 adverse reaction on the tivozanib arm was hypertension (24%). Compared with sorafenib, tivozanib was associated with lower rates of grade 3 to 4 diarrhea, rash, and palmar-plantar erythrodysesthesia. Patients receiving tivozanib in TIVO-3 had lower rates of dose reduction, interruption, or permanent discontinuation than those receiving sorafenib.