Refining the impact of genetic evidence on clinical success.

The cost of drug discovery and development is driven primarily by failure1, with only about 10% of clinical programmes eventually receiving approval2-4. We previously estimated that human genetic evidence doubles the success rate from clinical development to approval5. In this study we leverage the growth in genetic evidence over the past decade to better understand the characteristics that distinguish clinical success and failure. We estimate the probability of success for drug mechanisms with genetic support is 2.6 times greater than those without. This relative success varies among therapy areas and development phases, and improves with increasing confidence in the causal gene, but is largely unaffected by genetic effect size, minor allele frequency or year of discovery. These results indicate we are far from reaching peak genetic insights to aid the discovery of targets for more effective drugs.

Androgen receptor activity in T cells limits checkpoint blockade efficacy.

Immune checkpoint blockade has revolutionized the field of oncology, inducing durable anti-tumour immunity in solid tumours. In patients with advanced prostate cancer, immunotherapy treatments have largely failed1-5. Androgen deprivation therapy is classically administered in these patients to inhibit tumour cell growth, and we postulated that this therapy also affects tumour-associated T cells. Here we demonstrate that androgen receptor (AR) blockade sensitizes tumour-bearing hosts to effective checkpoint blockade by directly enhancing CD8 T cell function. Inhibition of AR activity in CD8 T cells prevented T cell exhaustion and improved responsiveness to PD-1 targeted therapy via increased IFNγ expression. AR bound directly to Ifng and eviction of AR with a small molecule significantly increased cytokine production in CD8 T cells. Together, our findings establish that T cell intrinsic AR activity represses IFNγ expression and represents a novel mechanism of immunotherapy resistance.

Longevity of a Brain-Computer Interface for Amyotrophic Lateral Sclerosis.

The durability of communication with the use of brain-computer interfaces in persons with progressive neurodegenerative disease has not been extensively examined. We report on 7 years of independent at-home use of an implanted brain-computer interface for communication by a person with advanced amyotrophic lateral sclerosis (ALS), the inception of which was reported in 2016. The frequency of at-home use increased over time to compensate for gradual loss of control of an eye-gaze-tracking device, followed by a progressive decrease in use starting 6 years after implantation. At-home use ended when control of the brain-computer interface became unreliable. No signs of technical malfunction were found. Instead, the amplitude of neural signals declined, and computed tomographic imaging revealed progressive atrophy, which suggested that ALS-related neurodegeneration ultimately rendered the brain-computer interface ineffective after years of successful use, although alternative explanations are plausible. (Funded by the National Institute on Deafness and Other Communication Disorders and others; ClinicalTrials.gov number, NCT02224469.).

Phase 3 Trial of Stereotactic Body Radiotherapy in Localized Prostate Cancer.

BACKGROUND: Whether stereotactic body radiotherapy (SBRT) is noninferior to conventionally or moderately hypofractionated regimens with respect to biochemical or clinical failure in patients with localized prostate cancer is unclear. METHODS: We conducted a phase 3, international, open-label, randomized, controlled trial. Men with stage T1 or T2 prostate cancer, a Gleason score of 3+4 or less, and a prostate-specific antigen (PSA) level of no more than 20 ng per milliliter were randomly assigned (in a 1:1 ratio) to receive SBRT (36.25 Gy in 5 fractions over a period of 1 or 2 weeks) or control radiotherapy (78 Gy in 39 fractions over a period of 7.5 weeks or 62 Gy in 20 fractions over a period of 4 weeks). Androgen-deprivation therapy was not permitted. The primary end point was freedom from biochemical or clinical failure, with a critical hazard ratio for noninferiority of 1.45. The analysis was performed in the intention-to-treat population. RESULTS: A total of 874 patients underwent randomization at 38 centers (433 patients in the SBRT group and 441 in the control radiotherapy group) between August 2012 and January 2018. The median age of the patients was 69.8 years, and the median PSA level was 8.0 ng per milliliter; the National Comprehensive Cancer Network risk category was low for 8.4% of the patients and intermediate for 91.6%. At a median follow-up of 74.0 months, the 5-year incidence of freedom from biochemical or clinical failure was 95.8% (95% confidence interval [CI], 93.3 to 97.4) in the SBRT group and 94.6% (95% CI, 91.9 to 96.4) in the control radiotherapy group (unadjusted hazard ratio for biochemical or clinical failure, 0.73; 90% CI, 0.48 to 1.12; P = 0.004 for noninferiority), which indicated the noninferiority of SBRT. At 5 years, the cumulative incidence of late Radiation Therapy Oncology Group (RTOG) grade 2 or higher genitourinary toxic effects was 26.9% (95% CI, 22.8 to 31.5) with SBRT and 18.3% (95% CI, 14.8 to 22.5) with control radiotherapy (P<0.001), and the cumulative incidence of late RTOG grade 2 or higher gastrointestinal toxic effects was 10.7% (95% CI, 8.1 to 14.2) and 10.2% (95% CI, 7.7 to 13.5), respectively (P = 0.94). CONCLUSIONS: Five-fraction SBRT was noninferior to control radiotherapy with respect to biochemical or clinical failure and may be an efficacious treatment option for patients with low-to-intermediate-risk localized prostate cancer as defined in this trial. (Funded by Accuray and others; PACE-B ClinicalTrials.gov number, NCT01584258.).

Converting cancer therapies into cures: lessons from infectious diseases.

During the past decade, cancer drug development has shifted from a focus on cytotoxic chemotherapies to drugs that target specific molecular alterations in tumors. Although these drugs dramatically shrink tumors, the responses are temporary. Research is now focused on overcoming drug resistance, a frequent cause of treatment failure. Here we reflect on analogous challenges faced by researchers in infectious diseases. We compare and contrast the resistance mechanisms arising in cancer and infectious diseases and discuss how approaches for overcoming viral and bacterial infections, such as HIV and tuberculosis, are instructive for developing a more rational approach for cancer therapy. In particular, maximizing the effect of the initial treatment response, which often requires synergistic combination therapy, is foremost among these approaches. A remaining challenge in both fields is identifying drugs that eliminate drug-tolerant "persister" cells (infectious disease) or tumor-initiating/stem cells (cancer) to prevent late relapse and shorten treatment duration.

Chloroquine does not inhibit infection of human lung cells with SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic, which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been associated with more than 780,000 deaths worldwide (as of 20 August 2020). To develop antiviral interventions quickly, drugs used for the treatment of unrelated diseases are currently being repurposed to treat COVID-19. Chloroquine is an anti-malaria drug that is used for the treatment of COVID-19 as it inhibits the spread of SARS-CoV-2 in the African green monkey kidney-derived cell line Vero1-3. Here we show that engineered expression of TMPRSS2, a cellular protease that activates SARS-CoV-2 for entry into lung cells4, renders SARS-CoV-2 infection of Vero cells insensitive to chloroquine. Moreover, we report that chloroquine does not block infection with SARS-CoV-2 in the TMPRSS2-expressing human lung cell line Calu-3. These results indicate that chloroquine targets a pathway for viral activation that is not active in lung cells and is unlikely to protect against the spread of SARS-CoV-2 in and between patients.

Potential circadian effects on translational failure for neuroprotection.

Neuroprotectant strategies that have worked in rodent models of stroke have failed to provide protection in clinical trials. Here we show that the opposite circadian cycles in nocturnal rodents versus diurnal humans1,2 may contribute to this failure in translation. We tested three independent neuroprotective approaches-normobaric hyperoxia, the free radical scavenger α-phenyl-butyl-tert-nitrone (αPBN), and the N-methyl-D-aspartic acid (NMDA) antagonist MK801-in mouse and rat models of focal cerebral ischaemia. All three treatments reduced infarction in day-time (inactive phase) rodent models of stroke, but not in night-time (active phase) rodent models of stroke, which match the phase (active, day-time) during which most strokes occur in clinical trials. Laser-speckle imaging showed that the penumbra of cerebral ischaemia was narrower in the active-phase mouse model than in the inactive-phase model. The smaller penumbra was associated with a lower density of terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL)-positive dying cells and reduced infarct growth from 12 to 72 h. When we induced circadian-like cycles in primary mouse neurons, deprivation of oxygen and glucose triggered a smaller release of glutamate and reactive oxygen species, as well as lower activation of apoptotic and necroptotic mediators, in 'active-phase' than in 'inactive-phase' rodent neurons. αPBN and MK801 reduced neuronal death only in 'inactive-phase' neurons. These findings suggest that the influence of circadian rhythm on neuroprotection must be considered for translational studies in stroke and central nervous system diseases.

Hydroxychloroquine use against SARS-CoV-2 infection in non-human primates.

Coronavirus disease 2019 (COVID-19) has rapidly become a global pandemic and no antiviral drug or vaccine is yet available for the treatment of this disease1-3. Several clinical studies are ongoing to evaluate the efficacy of repurposed drugs that have demonstrated antiviral efficacy in vitro. Among these candidates, hydroxychloroquine (HCQ) has been given to thousands of individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-the virus that causes COVID-19-worldwide but there is no definitive evidence that HCQ is effective for treating COVID-194-7. Here we evaluated the antiviral activity of HCQ both in vitro and in SARS-CoV-2-infected macaques. HCQ showed antiviral activity in African green monkey kidney cells (Vero E6) but not in a model of reconstituted human airway epithelium. In macaques, we tested different treatment strategies in comparison to a placebo treatment, before and after peak viral load, alone or in combination with azithromycin (AZTH). Neither HCQ nor the combination of HCQ and AZTH showed a significant effect on viral load in any of the analysed tissues. When the drug was used as a pre-exposure prophylaxis treatment, HCQ did not confer protection against infection with SARS-CoV-2. Our findings do not support the use of HCQ, either alone or in combination with AZTH, as an antiviral drug for the treatment of COVID-19 in humans.

Genomics of human NAFLD: Lack of data reproducibility and high interpatient variability in drug target expression as major causes of drug failures.

BACKGROUND AND AIMS: NAFLD is a major disease burden and a foremost cause of chronic liver disease. Presently, nearly 300 trials evaluate the therapeutic efficacy of > 20 drugs. Remarkably, the majority of drugs fail. To better comprehend drug failures, we investigated the reproducibility of fatty liver genomic data across 418 liver biopsies and evaluated the interpatient variability of 18 drug targets. APPROACH AND RESULTS: Apart from our own data, we retrieved NAFLD biopsy genomic data sets from public repositories and considered patient demographics. We divided the data into test and validation sets, assessed the reproducibility of differentially expressed genes and performed gene enrichment analysis. Patients were stratified by disease activity score, fibrosis grades and sex, and we investigated the regulation of 18 drug targets across 418 NAFLD biopsies of which 278 are NASH cases. We observed poor reproducibility of differentially expressed genes across 9 independent studies. On average, only 4% of differentially expressed genes are commonly regulated based on identical sex and 2% based on identical NAS disease score and fibrosis grade. Furthermore, we observed sex-specific gene regulations, and for females, we noticed induced expression of genes coding for inflammatory response, Ag presentation, and processing. Conversely, extracellular matrix receptor interactions are upregulated in males, and the data agree with clinical findings. Strikingly, and with the exception of stearoyl-CoA desaturase, most drug targets are not regulated in > 80% of patients. CONCLUSIONS: Lack of data reproducibility, high interpatient variability, and the absence of disease-dependent drug target regulations are likely causes of NASH drug failures in clinical trials.

Rescue Therapy for Failed Mechanical Thrombectomy in Acute Ischemic Stroke: A Pooled Analysis of the Society of Vascular and Interventional Neurology Registry.

OBJECTIVE: We aimed to evaluate the association between rescue therapy (RT) and functional outcomes compared to medical management (MM) in patients presenting after failed mechanical thrombectomy (MT). METHODS: This cross-sectional study utilized prospectively collected and maintained data from the Society of Vascular and Interventional Neurology Registry, spanning from 2011 to 2021. The cohort comprised patients with large vessel occlusions (LVOs) with failed MT. The primary outcome was the shift in the degree of disability, as gauged by the modified Rankin Scale (mRS) at 90 days. Additional outcomes included functional independence (90-day mRS score of 0-2), symptomatic intracranial hemorrhage (sICH), and 90-day mortality. RESULTS: Of a total of 7,018 patients, 958 presented failed MT and were included in the analysis. The RT group comprised 407 (42.4%) patients, and the MM group consisted of 551 (57.5%) patients. After adjusting for confounders, the RT group showed a favorable shift in the overall 90-day mRS distribution (adjusted common odds ratio = 1.79, 95% confidence interval [CI] = 1.32-2.45, p < 0.001) and higher rates of functional independence (RT: 28.8% vs MM: 15.7%, adjusted odds ratio [aOR] = 1.93, 95% CI = 1.21-3.07, p = 0.005) compared to the MM group. RT also showed lower rates of sICH (RT: 3.8% vs MM: 9.1%, aOR = 0.52, 95% CI = 0.28-0.97, p = 0.039) and 90-day mortality (RT: 33.4% vs MM: 45.5%, aOR = 0.61, 95% CI = 0.42-0.89, p = 0.009). INTERPRETATION: Our findings advocate for the utilization of RT as a potential treatment strategy for cases of LVO resistant to first-line MT techniques. Prospective studies are warranted to validate these observations and optimize the endovascular approach for failed MT patients. ANN NEUROL 2024;96:343-355.

Anti-IL-4R versus anti-IL-5/5R after anti-IL-5/5R failure in asthma: An emulated target trial.

BACKGROUND: Switching biologics is now common practice in severe eosinophilic asthma. After insufficient response to anti-IL-5 or 5 receptor (anti-IL-5/5R), the optimal switch between an anti-IL-4R mAb (interclass) or another anti-IL-5/5R drug (intraclass) remains unknown. OBJECTIVE: We sought to compare the effectiveness of these 2 strategies in asthma control in patients with severe eosinophilic asthma and insufficient response to an anti-IL-5/5R mAb. METHODS: We emulated a target randomized trial using observational data from the Recherche sur les AsthMes SEvèreS (RAMSES) cohort. Eligible patients were switched to an anti-IL-4R mAb or another anti-IL-5/5R drug after insufficient response to an anti-IL-5/5R mAb. The primary outcome was the change in Asthma Control Test score at 6 months. RESULTS: Among the 2046 patients in the cohort, 151 were included in the study: 103 switched to an anti-IL-4R mAb and 48 to another anti-IL-5/5R. At 6 months, the difference in Asthma Control Test score improvement was not statistically significant (mean difference groups, 0.82 [-0.47 to 2.10], P = .213). The interclass group exhibited greater cumulative reduction in oral corticosteroid dose (Pinter-intra, -1.05 g [-1.76 to -0.34], P = .041). The interclass group had a better effect, although not significantly, on reducing exacerbations (Δinter-intra, -0.37 [-0.77 to 0.02], P = .124) and increasing lung function (FEV1) (126.8 mL [-12.7 to 266.4], P = .124). CONCLUSIONS: After anti-IL-5/5R mAb insufficient response, switching to dupilumab demonstrated similar improvement in Asthma Control Test scores compared with intraclass switching. However, it appeared more effective in reducing oral corticosteroid use. Larger studies are warranted to confirm these results.

Impact of Low-Frequency Human Immunodeficiency Virus Type 1 Drug Resistance Mutations on Antiretroviral Therapy Outcomes.

BACKGROUND: The association between low-frequency human immunodeficiency virus type 1 (HIV-1) drug resistance mutations (DRMs) and treatment failure (TF) is controversial. We explore this association using next-generation sequencing (NGS) methods that accurately sample low-frequency DRMs. METHODS: We enrolled women with HIV-1 in Malawi who were either antiretroviral therapy (ART) naive (cohort A), had ART failure (cohort B), or had discontinued ART (cohort C). At entry, cohorts A and C began a nonnucleoside reverse transcriptase inhibitor-based regimen and cohort B started a protease inhibitor-based regimen. We used Primer ID MiSeq to identify regimen-relevant DRMs in entry and TF plasma samples, and a Cox proportional hazards model to calculate hazard ratios (HRs) for entry DRMs. Low-frequency DRMs were defined as ≤20%. RESULTS: We sequenced 360 participants. Cohort B and C participants were more likely to have TF than cohort A participants. The presence of K103N at entry significantly increased TF risk among A and C participants at both high and low frequency, with HRs of 3.12 (95% confidence interval [CI], 1.58-6.18) and 2.38 (95% CI, 1.00-5.67), respectively. At TF, 45% of participants showed selection of DRMs while in the remaining participants there was an apparent lack of selective pressure from ART. CONCLUSIONS: Using accurate NGS for DRM detection may benefit an additional 10% of patients by identifying low-frequency K103N mutations.

How We Approach Suppressive Antibiotic Therapy Following Debridement, Antibiotics, and Implant Retention for Prosthetic Joint Infection.

The optimal treatment of prosthetic joint infection (PJI) remains uncertain. Patients undergoing debridement, antibiotics, and implant retention (DAIR) receive extended antimicrobial treatment, and some experts leave patients at perceived highest risk of relapse on suppressive antibiotic therapy (SAT). In this narrative review, we synthesize the literature concerning the role of SAT to prevent treatment failure following DAIR, attempting to answer 3 key questions: (1) What factors identify patients at highest risk for treatment failure after DAIR (ie, patients with the greatest potential to benefit from SAT), (2) Does SAT reduce the rate of treatment failure after DAIR, and (3) What are the rates of treatment failure and adverse events necessitating treatment discontinuation in patients receiving SAT? We conclude by proposing risk-benefit stratification criteria to guide use of SAT after DAIR for PJI, informed by the limited available literature.

Food Insecurity at Tuberculosis Treatment Initiation Is Associated With Clinical Outcomes in Rural Haiti: A Prospective Cohort Study.

BACKGROUND: Tuberculosis is a leading cause of death worldwide, and food insecurity is known to negatively influence health outcomes through multiple pathways. Few studies have interrogated the relationship between food insecurity and tuberculosis outcomes, particularly independent of nutrition. METHODS: We conducted a prospective cohort study of adults initiating first-line treatment for clinically suspected or microbiologically confirmed drug-sensitive tuberculosis at a rural referral center in Haiti. We administered a baseline questionnaire, collected clinical data, and analyzed laboratory samples. We used logistic regression models to estimate the relationship between household food insecurity (Household Hunger Scale) and treatment failure or death. We accounted for exclusion of patients lost to follow-up using inverse probability of censoring weighting and adjusted for measured confounders and nutritional status using inverse probability of treatment weighting. RESULTS: We enrolled 257 participants (37% female) between May 2020 and March 2023 with a median age (interquartile range) of 35 (25-45) years. Of these, 105 (41%) had no hunger in the household, 104 (40%) had moderate hunger in the household, and 48 (19%) had severe hunger in the household. Eleven participants (4%) died, and 6 (3%) had treatment failure. After adjustment, food insecurity was significantly associated with subsequent treatment failure or death (odds ratio 5.78 [95% confidence interval, 1.20-27.8]; P = .03). CONCLUSIONS: Household food insecurity at tuberculosis treatment initiation was significantly associated with death or treatment failure after accounting for loss to follow-up, measured confounders, and nutritional status. In addition to the known importance of undernutrition, our findings indicate that food insecurity independently affects tuberculosis treatment outcomes in Haiti.

Factors Associated With Unfavorable Treatment Outcomes Among Persons With Pulmonary Tuberculosis: A Multicentric Prospective Cohort Study From India.

In this prospective cohort of 2006 individuals with drug-susceptible tuberculosis in India, 18% had unfavorable treatment outcomes (4.7% treatment failure, 2.5% recurrent infection, 4.1% death, 6.8% loss to follow-up) over a median 12-month follow-up period. Age, male sex, low education, nutritional status, and alcohol use were predictors of unfavorable outcomes.

Treatment Failure in a UK Malaria Patient Harboring Genetically Variant Plasmodium falciparum From Uganda With Reduced In Vitro Susceptibility to Artemisinin and Lumefantrine.

BACKGROUND: Recent cases of clinical failure in malaria patients in the United Kingdom (UK) treated with artemether-lumefantrine have implications for malaria chemotherapy worldwide. METHODS: Parasites were isolated from an index case of confirmed Plasmodium falciparum treatment failure after standard treatment, and from comparable travel-acquired UK malaria cases. Drug susceptibility in vitro and genotypes at 6 resistance-associated loci were determined for all parasite isolates and compared with clinical outcomes for each parasite donor. RESULTS: A traveler, who returned to the UK from Uganda in 2022 with Plasmodium falciparum malaria, twice failed treatment with full courses of artemether-lumefantrine. Parasites from the patient exhibited significantly reduced susceptibility to artemisinin (ring-stage survival, 17.3% [95% confidence interval {CI}, 13.6%-21.1%]; P < .0001) and lumefantrine (effective concentration preventing 50% of growth = 259.4 nM [95% CI, 130.6-388.2 nM]; P = .001). Parasite genotyping identified an allele of pfk13 encoding both the A675V variant in the Pfk13 propeller domain and a novel L145V nonpropeller variant. In vitro susceptibility testing of 6 other P. falciparum lines of Ugandan origin identified reduced susceptibility to artemisinin and lumefantrine in 1 additional line, also from a 2022 treatment failure case. These parasites did not harbor a pfk13 propeller domain variant but rather the novel nonpropeller variant T349I. Variant alleles of pfubp1, pfap2mu, and pfcoronin were also identified among the 7 parasite lines. CONCLUSIONS: We confirm, in a documented case of artemether-lumefantrine treatment failure imported from Uganda, the presence of pfk13 mutations encoding L145V and A675V. Parasites with reduced susceptibility to both artemisinin and lumefantrine may be emerging in Uganda.

Virological Failure After Switch to Long-Acting Cabotegravir and Rilpivirine Injectable Therapy: An In-depth Analysis.

BACKGROUND: Long-acting (LA) injectable therapy with cabotegravir (CAB) and rilpivirine (RPV) is currently used as maintenance treatment for human immunodeficiency virus type 1, and has a low risk for virological failure (VF). Although the risk is low, the circumstances and impact of VF in the real-world setting merit further evaluation. METHODS: We performed an in-depth clinical, virological, and pharmacokinetic analysis on the reasons behind and the impact of VF during LA CAB/RPV therapy in 5 cases from the Netherlands. Genotypic resistance testing was performed after the occurrence of VF, and drug plasma (trough) concentrations were measured after VF was established and on any other samples to assess on-treatment drug levels. CAB and RPV drug levels that were below the first quartile of the population cutoff (≤Q1) were considered to be low. RESULTS: Five cases who were eligible for LA CAB/RPV experienced VF despite a low predicted risk at baseline. Genotypic resistance testing revealed extensive selection of nonnucleoside reverse transcriptase inhibitor-associated mutations in all cases, and integrase strand transfer inhibitor mutations in 4 cases. All cases displayed low drug levels of either CAB, RPV, or both during the treatment course, likely contributing to the occurrence of VF. In 3 cases, we were able to identify the potential mechanisms behind these low drug levels. CONCLUSIONS: This is the first in-depth multiple case analysis of VF on LA CAB/RPV therapy in a real-world setting. Our observations stress the need to be aware for (evolving) risk factors and the yield of a comprehensive clinical, virological, and pharmacokinetic approach in case of failure.

Sequential Treatment Failure With Aztreonam-Ceftazidime-Avibactam Followed by Cefiderocol Due to Preexisting and Acquired Mechanisms in a New Delhi Metallo-ß-lactamase-Producing Escherichia coli Causing Fatal Bloodstream Infection.

We report a fatal case of New Delhi metallo-ß-lactamase (NDM)-producing Escherichia coli in a bacteremic patient with sequential failure of aztreonam plus ceftazidime-avibactam followed by cefiderocol. Acquired resistance was documented phenotypically and mediated through preexisting and acquired mutations. This case highlights the need to rethink optimal treatment for NDM-producing organisms.

Onward Virus Transmission after Measles Secondary Vaccination Failure.

Measles in persons with secondary vaccination failure (SVF) may be less infectious than cases in unvaccinated persons. Our systematic review aimed to assess transmission risk for measles after SVF. We searched PubMed, Embase, and Web of Science databases from their inception dates. Inclusion criteria were articles describing persons who were exposed to measles-infected persons who had experienced SVF. Across the included 14 studies, >3,030 persons were exposed to measles virus from SVF cases, of whom 180 were susceptible, indicating secondary attack rates of 0%-6.25%. We identified 109 cases of SVF from the studies; 10.09% (n = 11) of case-patients transmitted the virus, resulting in 23 further cases and yielding an effective reproduction number of 0.063 (95% CI 0.0-0.5). These findings suggest a remarkably low attack rate for SVF measles cases, suggesting that, In outbreak situations, public health management of unvaccinated persons could be prioritized over persons with SVF.

Homozygous pathogenic variants in ACTL9 cause fertilization failure and male infertility in humans and mice.

Total fertilization failure (TFF) can occur during in vitro fertilization (IVF) treatments, even following intracytoplasmic sperm injection (ICSI). Various male or female factors could contribute to TFF. Increasing evidence suggested that genetic variations in PLCZ1, which encodes 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase zeta-1 (PLCζ), is involved in oocyte activation and is a key male factor in TFF. In the present study, we explored the genetic variants in male individuals that led to TFF. A total of 54 couples with TFF or poor fertilization (fertilization rate < 20%) were screened, and 21 couples were determined to have a male infertility factor by the mouse oocyte activation test. Whole-exome sequencing of these 21 male individuals identified three homozygous pathogenic variants in ACTL9 (actin like 9) in three individuals. ACTL9 variations led to abnormal ultrastructure of the perinuclear theca (PT), and PLCζ was absent in the head and present in the neck of the mutant sperm, which contributed to failed normal calcium oscillations in oocytes and subsequent TFF. The key roles of ACTL9 in the PT structure and TFF after ICSI were further confirmed in an Actl9-mutated mouse model. Furthermore, assisted oocyte activation by calcium ionophore exposure successfully overcame TFF and achieved live births in a couple with an ACTL9 variant. These findings identified the role of ACTL9 in the PT structure and the correct localization of PLCζ. The results also provide a genetic marker and a therapeutic option for individuals who have undergone ICSI without successful fertilization.