Clinical trials

This is a longitudinal, multicentre observational study conducted across three established microbiology units integrated within hospital and community health systems in Thailand, Lao PDR, and Cambodia. The hospital cohort will enroll approximately1,000 patients with positive melioidosis. Participants will be followed at six time points from admission through one year (post-discharge) to capture acute and recovery-phase outcomes, with clinical data collected on demographics, comorbidities, exposures, treatment, adherence, and outcomes. For each confirmed case, a healthy control will be recruited within two weeks and matched by age, sex, and village of residence. Controls with no symptoms or history of melioidosis will provide a single blood sample at enrolment and will be followed by telephone at 6 and 12 months. In addition to hospital-based surveillance, a high-risk community in northern Ubon Ratchathani-referred to as the Sandbox Village-will be intensively monitored to capture subclinical infections and to assess environmental factors influencing disease acquisition. This study is funded by the Wellcome Trust. The grant reference number is 323077/Z/24/Z

This study aims to assess the efficacy, safety and acceptability of ascending doses of arpraziquantel in children infected with Opisthorchis viverrini. The primary objective is to determine the dose-response relationship in terms of cure rate. This study will involve children aged 6-7 years, since O. viverrini infections often occur in pre-school and school-aged children, and this group is largely left untreated in current public health programs.

Tobacco use remains the leading modifiable risk factor for preventing cancer globally, particularly among people with HIV (PWH). In Laos, 61-80% of male PWH and 3-10% of female PWH smoke cigarettes. PWH who smoke in Laos have no reliable smoking cessation support. Thus, implementing sustainable and evidence-based smoking cessation interventions for PWH in Laos is needed. The investigators developed a scalable and affordable mHealth-based automated treatment program (MAP) to support Lao and Cambodian smokers to quit smoking. MAP involves interactive, tailored, personalized content (text messages, photos, and videos) delivered via a smartphone app. Along with effective cessation treatments, it is imperative to implement procedures to identify patients who smoke and to connect them to treatment. Our team pioneered the Ask-Advise-Connect (AAC, asking patients about smoking at every visit, briefly advising those who smoke to quit, and connecting them to treatment) approach, which showed great impact in our previous US studies. The purpose of this study is to compare 2 smoking cessation implementation strategies in 8 antiretroviral therapy (ART) clinics in the 6 most populous regions in Laos, using a hybrid type-2 pragmatic effectiveness-implementation study and a parallel cluster randomized trial design. Specifically, the investigators will compare an AAC approach paired with our previously developed MAP (AA-MAP) to an AAC approach paired with less resource-intensive printed self-help material (AA-SH). The investigators will use the Practical, Robust Implementation and Sustainability Model (PRISM), which expands the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework to include more contextual factors relevant to program implementation. Aim 1 is to evaluate the reach and effectiveness of AA-MAP versus AA-SH. Reach is the proportion of PWH who smoke and are willing to make a quit attempt that enroll in treatment. Effectiveness is the proportion of enrolled participants who achieve biochemically confirmed point prevalence abstinence 6 months after enrollment. The investigators will also estimate the real-world impact (impact = reach × effectiveness) of each intervention. Aim 2 is to determine other implementation outcomes of AA-MAP and AA-SH. Aim 3 is to assess the resource use and costs of implementing AA-MAP and AA-SH. The project has the potential to transform HIV care and to reduce tobacco-related cancers and other morbidities.

Tafenoquine was recently approved by regulatory authorities in the USA and Australia. Tafenoquine is an alternative radical curative treatment to primaquine acting against the dormant liver stage of Plasmodium vivax (the hypnozoite). Tafenoquine (an 8-aminoquinoline) has the substantial advantage of single dosing as compared to a 14-day course of primaquine to achieve radical cure. The recommended tafenoquine dose is 300 mg, which was shown to be significantly worse in radical curative efficacy to a total primaquine dose of 3.5 mg/kg in Southeast Asia. The cure rate of tafenoquine 300 mg in Southeast Asian study sites was only 74%. The comparator 3.5 mg/kg total primaquine dose is the standard and most commonly used dose globally, but in Southeast Asia and the Western Pacific, higher doses of primaquine are needed for radical cure. This study aims to determine the optimal dose of tafenoquine in Southeast Asia. Addendum for Indonesia: The INSPECTOR trial results showed that tafenoquine 300mg was not efficacious for radical cure (79% probability for recurrence after treatment). The comparator arm, low-dose primaquine 3.5mg/kg divided equally over 14 days, showed a 48% probability of recurrence after treatment). The standard of care for radical cure in Indonesia is high-dose primaquine 7mg/kg divided in 7 daily doses).

This trial will use a previously validated platform, to quantitatively assess antiviral effects in low-risk patients with high viral burdens and uncomplicated influenza, to determine in-vivo antiviral activity. In this randomised, open-label, controlled, group sequential, adaptive, platform trial, we will compare the performance of available influenza antivirals, and those with potential activity, relative to the control (no treatment) and each other. AD ASTRA study is supported by the Wellcome Trust Grant ref: 223195/Z/21/Z through the COVID-19 Therapeutics Accelerator

The trial will develop and validate a platform for quantitative assessment of antiviral effects in low-risk patients with high viral burdens and uncomplicated COVID-19 to determine in-vivo antiviral activity. In this randomized open label, controlled, group sequential adaptive platform trial, we will assess the performance of three distinct types of intervention relative to control (no treatment): A: Small molecule drugs; B: Monoclonal antibodies; C: Dose finding for the constituent parts of nirmatrelvir/ritonavir PLATCOV study is supported by the Wellcome Trust Grant ref: 223195/Z/21/Z through the COVID-19 Therapeutics Accelerator.

This is a mixed-methods program evaluation from a health systems and policy perspective, involving (i) stakeholder analysis, (ii) policy-implementation gap analysis, and (iii) comparative country case studies. This study aims to understand how national oxygen strategies achieve impact at national, and subnational level, across country contexts, at what cost. The the investigators seek to: 1. Involve policymakers, implementers (including private sector), and medical oxygen users in identifying challenges and understanding potential solutions to medical oxygen access; 2. Generate new data on how medical oxygen systems work and can be improved from multiple perspectives; 3. Draw lessons on medical oxygen that can directly inform national and global practice and policy. This study will be conducted in 6 of the 9 countries participating in the Clinton Health Access Initiative (CHAI) led Medical Oxygen Implementation (MOXY) program (Uganda, Nigeria, Rwanda, Liberia, Lao PDR, Cambodia). Key informants will be selected representing government, non-governmental agencies, professional associations, private sector, and civil society. This study will be completed over 4 years, with timelines varying between country study sites.

This prospective multi-site observational study aims to describe causes and clinical outcomes of acute febrile illness as well as host biomarkers in patients aged \>28 days residing in rural areas in Laos, Myanmar, Thailand, the Thai-Myanmar border region, and Bangladesh and presenting with acute febrile illnesses (≤ 14 days duration) to participating health facilities. This study is funded by the UK Wellcome Trust. The grant reference number is 215604/Z/19/Z

In Lao People's Democratic Republic (Lao PDR), 51% of adult men and 7% of adult women smoke tobacco. The development and evaluation of sustainable tobacco cessation interventions suitable for widespread adoption in nations such as Lao PDR are pressing public health needs. To address this need, the investigators propose a project that adapts a theoretically and empirically based mobile health (mHealth) technology to help people quit smoking cigarettes in Lao PDR. This mHealth approach includes a fully automated, interactive, personalized, smartphone-delivered intervention for behavioral treatment, delivered through our Insight™ platform. This proposed project for Lao PDR includes 2 main phases. In the R21 Phase, the investigators will use formative research methods to adapt our intervention content to the sociocultural context, language, and communication styles of Laotians. In the subsequent R33 Phase, the investigators will conduct a randomized controlled trial (RCT) to evaluate the efficacy of our mHealth intervention and technology. Adult smokers of both sexes will be recruited through 2 large hospitals: Setthathirath Hospital in Vientiane and Champasak Hospital in Champasak Province. Participants (n=500) will be randomized to 1 of 2 treatment groups: Standard Care (SC; n=250) or Automated Treatment (AT; n=250). SC consists of brief advice to quit smoking delivered by research staff, self-help written materials, and a 2-week supply of NRT (transdermal patches). AT consists of all SC components plus a fully automated smartphone-based treatment program that involves interactive and personalized proactive messages, images, or videos. The primary health outcome of the trial is biochemically confirmed self-reported 7-day point prevalence abstinence 12 months post study enrollment. The project also aims to advance mHealth research capacity in Lao PDR and sustain the US-Lao PDR research network. The project has the potential to transform healthcare services for tobacco cessation treatment throughout the country and, ultimately, to reduce tobacco-induced morbidity and mortality significantly.

This trial will use a previously validated platform, to quantitatively assess antiviral effects in low-risk patients with high viral burdens and uncomplicated Respiratory Syncytial Virus (RSV), to determine in-vivo antiviral activity. In this randomised, open-label, controlled, group sequential adaptive platform trial, we will assess and compare the performance of currently licensed interventions (including repurposed drugs) with activity against RSV, and those with potential activity demonstrated in pre-clinical and early clinical studies relative to each-other, and the control (no antiviral treatment). ARSYNAL-FC study is funded by Wellcome Trust Grant ref: 226933/Z/23/Z through the COVID-19 Therapeutics Accelerator

The goal of this study is to find out if adding HPV vaccination to adolescent health services works to increase HPV vaccine uptake in 10-13-year-old girls in Laos. The study will also look at the effects of adding HPV vaccination on the use of other health services in 10-13-year-old boys and girls. The main questions the study aims to answer are: 1. Does adding HPV vaccination to adolescent health services increase HPV vaccine uptake in girls aged 10-13 years compared to girls who only receive standard HPV vaccination services? 2. Does adding HPV vaccination to adolescent health services increase the use of other health services in 10-13-year-old adolescent boys and girls compared to adolescents who only receive standard HPV vaccination services? 3. What are the barriers and facilitators to using the combined intervention in Laos? 4. What are the opinions of adolescents, caregivers, healthcare providers, and other stakeholders on the combined intervention? 5. How much does it cost and how well it works to combine HPV vaccination with adolescent health services, as opposed to providing HPV vaccination alone? Researchers will compare a combined intervention to standard HPV vaccination services to see if the combined intervention works to increase HPV vaccination uptake and the use of other health services. The combined intervention includes HPV vaccination given at schools, health facilities, and through community outreach. It also includes education on sexual and reproductive health, counseling, and other health services. Participants in the combined intervention group will: 1. Receive the HPV vaccine at school or at a health facility. 2. Take part in group discussions about sexual and reproductive health. 3. Take part in individual counseling sessions. 4. Use other health services as needed. Participants in the comparison group will receive standard HPV vaccination services, including: • HPV vaccination given at schools, health facilities, and through community outreach.

Murine typhus is a disease caused by Rickettisa typhi, an obligate intracellular bacterium transmitted by rodent fleas. The disease has a worldwide distribution; however the true burden is unknown, related to its non-specific presentation and lack of access to diagnosis in many regions. A systematic review of untreated murine typhus based on observational studies of a total of 239 patients has estimated the mortality associated with the disease at between 0.4% and 3.6%. Scrub typhus is caused by Orientia tsutsugamushi and transmitted by the larval stage of chigger mites (Trombiculidae family). It has been estimated to affect at least one million people each year. A systematic review found varying reports of the mortality associated with untreated scrub typhus ranging from 0-70% (median 6%). Polymerase chain reaction (PCR) based diagnosis of rickettsial infections is only available in one centre (Mahosot Hospital) in Vientiane. A number of hospitals use a variety of point-of-care antibody tests to diagnose rickettsial infections however many of these have not been validated and they are of uncertain sensitivity and specificity. In 2006 results of a two year prospective study of 427 patients presenting to Mahosot Hospital with a febrile illness and negative blood cultures showed that 115 (27%) patients had an acute rickettsial infection, confirmed by serological testing. Among these patients, 41 were diagnosed with murine typhus and 63 with scrub typhus. Antibacterial agents with activity against rickettsial pathogens include doxycycline, azithromycin, chloramphenicol and rifampicin. Azithromycin is often reserved for pregnant women or children below the age of 8 years due to lasting concerns after the tetracycline-associated staining of growing bones and teeth in the past. Evidence is accumulating that doxycycline is superior to azithromycin for the treatment of rickettsial disease. Clinical treatment failures have occurred following azithromycin treatment of murine typhus. The relationship between rickettsial bacteria load and both disease severity and response to treatment has not been characterised. Rickettsial concentrations in blood are generally low, of the order of 210 DNA copies/mL blood for R. typhi and 284 DNA copies/mL blood for O. tsutsugamushi. At present, there is no standard antibiotic susceptibility testing (AST) method for R. typhi and O. tsutsugamushi. The gold standard method for AST for Rickettsia pathogens is the plaque assay which determines minimal inhibitory concentration (MICs) from the smallest antimicrobial concentration inhibiting rickettsial plaque forming unit formation. This method is laborious and time consuming, taking approximately 14-16 days based on species to yield a result. Molecular detection methods are useful for diagnosing patients infected with rickettsial pathogens and has been applied for antibiotic susceptibility testing. Antibiotic susceptibility testing based on DNA synthesis inhibition detecting by quantitative PCR (qPCR) for O. tsutsugamushi clinical isolates has been reported. However, the relationship between antibiotic susceptibility profiles and treatment response has not been studied. There is a need to develop a reliable ex vivo method to characterize the treatment response and compare susceptibility of R. typhi and O. tsutsugamushi to different agents.

The study aims to assess the effectiveness of male-female VHV/Ws working in pairs on women's uptake of second PNC visits in rural Sepone, Lao PDR. Methods A quasi-experimental cluster study will be conducted between July 2024 and October 2026 in 37 selected sites from two districts in southern Lao PDR. In 19 selected intervention villages in the Sepone district, female-male VHV/Ws pairs will promote postpartum services, whereas, in 18 similar control villages in the Vilabuly district, VHV/Ws will work as individuals.