A new thought piece led by the Harvard Pilgrim Health Care Institute with collaborators from Duke University and Kaiser Permanente Washington Health Research Institute highlights the challenges facing healthcare researchers and decision makers in the quest to improve population health in a constantly evolving healthcare landscape. The authors offer strategies to enhance the effectiveness of pragmatic clinical trials and increase their impact on real-world healthcare settings.
Pragmatic clinical trials, designed to inform health care decision-makers about the comparative benefits, burdens, and risks of health interventions, have seen a significant increase in interest over the past decade. Since 2012, the NIH Pragmatic Trials Collaboratory has supported 32 such trials, addressing critical issues like suicide prevention, opioid prescribing, and infection control.
Pragmatic clinical trials are designed to bridge the gap between research and care, and we believe this bridge can be built even more efficiently. – Richard Platt, MD, MSc
Pragmatic clinical trials compare treatments in everyday clinical settings, rather than under ideal conditions. However, the authors note that the adoption of trial findings by healthcare systems has been inconsistent.
“Our goal is to ensure that the findings from these trials are not only scientifically sound but also readily implementable in diverse healthcare settings,” says lead author Richard Platt, Harvard Medical School distinguished professor of population medicine at the Harvard Pilgrim Health Care Institute. “Pragmatic clinical trials are designed to bridge the gap between research and care, and we believe this bridge can be built even more efficiently.”
The authors identify key challenges and propose solutions to align trial goals with healthcare system needs, including:
Identifying relevant outcomes: Collaborate with healthcare leaders to determine the clinical or cost-saving outcomes that would motivate adoption.
Shortening trial duration: Designing trials to span 2-3 years to match the decision-making timelines of healthcare systems.
Conducting interim assessments: Utilizing interim analyses to provide timely information and potentially stop or modify trials early.
Considering costs: Understanding and planning for associated costs to ensuring interventions are sustainable post-trial.
“By accommodating the priorities of healthcare leaders and introducing adaptive trial designs, we can generate actionable evidence that truly improves patient care,” adds Dr Platt.
The method can be used to explore treatment effects in people underrepresented in clinical trials
Researchers used real-world clinical data to attempt to emulate a randomised controlled trial testing the effectiveness of two blood thinners, apixaban and warfarin, to prevent stroke in patients with non-valvular atrial fibrillation. The study, led by Emma Maud Powell at the London School of Hygiene and Tropical Medicine, UK, and publishing August 29th in the open-access journal PLOS Medicine, provides a method to explore the effects of treatments in patients who are underrepresented or excluded from clinical trials.
Patients experiencing atrial fibrillation – a potentially dangerous medical condition in which the upper chambers of the heart beat irregularly – will often be prescribed blood thinners such as apixaban or warfarin to prevent a stroke. However, these treatment recommendations are based on results from randomized controlled trials, and it is unknown if they are applicable to populations of patients who were not included in the trial or present only in very low numbers.
In the new study, researchers used routinely collected health data from patients in the United Kingdom to attempt to emulate a previous randomized controlled trial that compared the effectiveness of apixaban and warfarin. They attempted to emulate the patient eligibility, selection and analysis approaches as the previous trial. They found that patients prescribed apixaban had similar outcomes to patients prescribed warfarin, but unlike the previous trial, they did not find that apixaban was superior. The researchers observed the differences in results may have been linked to higher quality of warfarin control, sub-optimal dosing of apixaban, and differences in the ethnicity of patients and use of concomitant medications compared with the clinical trial population.
Overall, the study established that using an existing randomised controlled trial (the reference trial) as a guide for the design of observational analysis of real patient data is an effective and valid way to estimate the treatment effects and risks of blood thinners given to patients with atrial fibrillation. The methods developed in this study can be used to investigate the effects of these medications in patient groups that are excluded from or underrepresented in these clinical trials, such as the elderly, those with multiple conditions and people with a higher risk of bleeding. This method can also help medical researchers to understand whether results from randomized controlled trials are transferable to “real-world” practices, and provides a framework that can be adapted to investigate treatment effects for other conditions.
The authors add, “Our study aimed to emulate a reference trial in oral anticoagulants in patients with atrial fibrillation using routinely collected UK healthcare data. Reference-trial informed design provides a framework for the study of treatment effects in patient groups excluded from or under-represented in trials.”
Cancer patients who participate in clinical trials hoping for better outcomes fare no better than those who do not, when setting aside the new treatment’s effect, according to the results of a study published in the Journal of the American Medical Association. The analysis found that while overall, trials had a positive benefit, this effect diminished after accounting for various factors common to trial participants such as being younger. Evidence of publication bias was also uncovered.
Participation in a clinical trial may confer a survival benefit to cancer patients is known as a trial effect, and results from access to effective new therapies (the treatment effect), but it is also thought that a trial’s closer monitoring provides a distinct benefit as well (the participation effect). The treatment effect only applies if the treatment proves to be effective, while the participation effect should apply regardless of treatment effect. But the evidence for the participation effect has been conflicting. A pair of reviews, one conducted in 2001 and the other in 2004, found no evidence of a participation effect.
The researchers therefore sought to account for biases and confounding in differences between routine care patients and trial patients. A search was performed for studies comparing survival outcomes for the two groups between January 1 2000 and August 31 2022, which turned up 12 791 records. After screening for eligibility and duplicates, this yielded 39 studies (85 comparisons) for analysis. These comparisons involved haematologic (21%), breast (16%), lung (14%), central nervous system (7%), prostate (7%), and pancreatic cancers (5%), as well as melanoma (6%). The remaining 24% consisted of bladder, cervical, colorectal, oesophageal, gastric, head and neck, kidney, ovarian, and solid mix tumours. One-third of the comparisons involved advanced or metastatic cancer.
Initially, the meta-analysis revealed a statistically significant overall survival benefit for trial participants (HR [hazard ratio], 0.76) when all studies were pooled without regard to their design or quality. But in study subsets matching trial participants and routine care patients for eligibility criteria, the survival benefits diminished (HR, 0.85). Finally, the survival benefit disappeared when only high-quality studies were pooled (HR, 0.91). They also disappeared when estimates were adjusted for potential publication bias (HR, 0.94).
Further analysis (using funnel plots and Egger’s regression test) indicated there was a publication bias against studies which lacked a participation effect.
In an accompanying editorial, Wilson et al. note that the participation effect explains that, “Patients in trials are generally younger, fitter, have fewer comorbidities, and come from higher socioeconomic groups; this enrollment bias largely explains the participation effect. The implications of this finding are important for understanding how trials are often viewed in clinical practice. The participation effect is often used to promote the view that “a clinical trial is the best treatment option, ‘but this may be a false narrative.”
Corresponding author Jonathan Kimmelman, PhD concluded: “Our findings provide reassurance that inability to enroll in a cancer trial doesn’t disadvantage a patient, at least in terms of survival. Our findings can help patients (and physicians) focus their consent discussions on the most relevant and evidence-based benefits of trial participation: the prospects of advancing the care of future patients.”
Randomized controlled trials, or RCTs, are believed to be the best way to study the safety and efficacy of new treatments in clinical research. However, a recent study from Michigan State University found that people of colour and white women are significantly underrepresented in RCTs due to systematic biases.
The study, published in the Journal of Ethnicity in Substance Abuse, reviewed 18 RCTs conducted over the last 15 years that tested treatments for post-traumatic stress and alcohol use disorder. The researchers found that despite women having double the rates of post-traumatic stress and alcohol use disorder than men, and people of colour having worse chronicity than white people, most participants were white (59.5%) and male (about 78%).
“Because RCTs are the gold standard for treatment studies and drug trials, we rarely ask the important questions about their limitations and failings,” said Nicole Buchanan, co-author of the study and professor in MSU’s Department of Psychology. “For RCTs to meet their full potential, investigators need to fix barriers to inclusion. Increasing representation in RCTs is not simply an issue for equity, but it is also essential to enhancing the quality of our science and meeting the needs of the public that funds these studies through their hard-earned tax dollars.”
The researchers found that the design and implementation of the randomised controlled trials contributed to the lack of representation of people of colour and women. This happened because trials were conducted in areas where white men were the majority demographic group and study samples almost always reflected the demographic makeup where studies occurred. Additionally, those designing the studies seldom acknowledged race or gender differences, meaning they did not intentionally recruit diverse samples.
Furthermore, the journals publishing these studies did not have regulations requiring sample diversity, equity or inclusion as appropriate to the conditions under investigation.
“Marginalized groups have unique experiences from privileged groups, and when marginalised groups are poorly included in research, we remain in the dark about their experiences, insights, needs and strengths,” said Mallet Reid, co-author of the study and doctoral candidate in MSU’s Department of Psychology. “This means that clinicians and researchers may unknowinglyremain ignorant to how to attend to the trauma and addiction challenges facing marginalised groups and may unwittingly perpetuate microaggressions against marginalised groups in clinical settings or fail to meet their needs.”
A massive and long-awaited study of an experimental tuberculosis vaccine has kicked off in South Africa. Marcus Low reports.
Photo by National Cancer Institute
By Marcus Low for Spotlight
The first jabs in a much-anticipated clinical trial of an experimental tuberculosis (TB) vaccine have been administered at a clinical trial site at the University of the Witwatersrand in Johannesburg. Up to 20 000 people are anticipated to take part in the study, according to study sponsor, the Bill and Melinda Gates Medical Research Institute (Gates MRI).
The study will be conducted at 60 different sites in South Africa, Zambia, Malawi, Mozambique, Kenya, Indonesia, and Vietnam. The researchers estimate that between 50% and 60% of the study participants will be in South Africa.
The experimental vaccine called M72/AS01E (M72 for short) made waves in 2018 and 2019 when it was found to be around 50% effective at preventing people with latent TB infection from falling ill with TB over a three-year period in a phase 2b clinical trial. In June 2023, it was announced that, after some delays, $550 million in funding had been secured for a phase 3 study of the vaccine. Medicines or vaccines are typically only registered and brought to market after being shown to be safe and effective in large, phase 3 clinical trials.
While most cases of TB can be cured using a combination of four antibiotics for four or six months, TB rates are declining relatively slowly and it is widely thought that an effective vaccine would help bring TB rates down much more quickly. The World Health Organization estimates that at the level of protection seen in the phase 2b trial, the vaccine could potentially save 8.5 million lives and prevent 76 million people from falling ill with TB over a 25-year period. The one TB vaccine we already have, called bacille Calmette-Guerin (BCG), is over a century old and only provides limited protection against severe illness for children and no protection for adolescents or adults.
“Reaching Phase 3 with an urgently needed TB vaccine candidate is an important moment for South Africans because it demonstrates that there is a strong local and global commitment to fight a disease that remains distressingly common in our communities,” said Dr Lee Fairlie, national principal investigator for the trial in South Africa, in a media statement released by Gates MRI.
“South Africa also has considerable experience with TB- and vaccine-related clinical trials and a strong track record for protecting patient safety and generating high quality data essential for regulatory approvals.”
Fairlie is also the Director of Maternal and Child Health at the Wits Reproductive Health and HIV Institute at Wits University.
The initial response from TB activists was positive.
“TB Proof (a South African TB advocacy group) is delighted that the M72 phase 3 trial has been launched,” the organisation’s Ruvandhi Nathavitharana and Ingrid Schoeman told Spotlight. “Having an effective TB vaccine is critical for TB elimination efforts.”
While he said it is good to finally see the phase 3 trial of M72 get underway, Mike Frick, TB co-director at Treatment Action Group, a New York-based TB advocacy organisation, went on to say:
“The fact that we had to wait so long between phase II and phase III says everything one needs to know about the headwinds – financial, political, commercial – that TB research is up against.”
How the study will work
Half of the up to 20 000 study participants will receive the M72 jab and the other half a placebo. The vaccine is administered as two intramuscular injections given a month apart. After being jabbed, study participants, all aged 15 to 44, will be followed for four years from the date of the first study participant being enrolled to see if they fall ill with TB.
“The plan is to complete enrolment in 2 years,” Fairlie and Alemnew Dagnew, clinical lead for the trial, told Spotlight in response to written questions. They explained that the actual duration of the trial will depend on how long it takes for 110 people in the study to fall ill with TB. According to the Gates MRI statement, the study is expected to take around five years to complete.
According to Fairlie and Dagnew, the majority of study participants (around 18 000 people) will be people who are HIV negative and who have latent TB infection – that is to say people who have TB bacteria in their lungs, but who are not ill with TB. Latent TB infection is thought to be very common in South Africa and only around 10% of people with latent infection ever fall ill with TB. In the study, latent infection will be tested for using a type of test called an IGRA (Interferon-Gamma Release Assay).
Around 1000 HIV negative people with no TB infection will also be recruited to the study. This is being done to make sure the vaccine is safe and effective in this group of people – while latent infection will be tested for in the study, in the real world such testing may not always be feasible prior to vaccination.
It is anticipated that 1000 of the 20 000 study participants will be people living with HIV. Establishing how well the vaccine works in people living with HIV is important since around 13% of people in South Africa are living with HIV and HIV substantially increases the risk of falling ill with TB. The main phase 2b study of M72 did not include people living with HIV although another phase 2 study looked specifically at the safety and immunogenicity of M72 in people living with HIV – according to Fairlie and Dagnew, “that trial “was completed and supported the inclusion of such participants in a phase 3 trial”.
Smaller than previously thought
When funding for the phase 3 trial was announced last year, it was estimated that 26 000 people would participate in the study. That number has now been revised down to 20 000.
“As a result of ongoing discussions between the institute and our funders, the decision was taken to review the study protocol with the intent of simplifying the study given its size and complexity. This will not affect the safety of the trial. It is common to continue to refine a protocol. We found a way to expedite the study that would potentially allow us to offer the public health impact of this vaccine to those in need sooner. All partners, including the trial funders, are fully aligned to the protocol refinements,” Fairlie and Dagnew explained to Spotlight.
“Some assumptions used to inform the design of the first protocol were deemed overly conservative, so the clinical team used slightly less conservative assumptions on vaccine efficacy and TB incidence rate, thus allowing for a reduction in the number of participants in the trial, while still retaining the primary goal of confirming the safety and efficacy of the M72/AS01-E-4 vaccine for prevention of TB, guided by the final results of the phase 2b study completed several years ago.”
Planning for access
The development of M72 has taken a somewhat unusual path – with the pharmaceutical company GSK leading development up to the end of phase 2b and then largely passing the baton to Gates MRI with the conclusion of a licensing deal in 2020. GSK has come in for some criticism for not moving more quickly after the initial publication of the phase 2b results in 2018. A ProPublica article published last year suggested that the development of M72 slowed because GSK were focussing on more profitable vaccines.
According to the Gates MRI statement, GSK continues to provide technical assistance to the Gates MRI, supplies the adjuvant component of the vaccine for the phase 3 trial, and will provide the adjuvant post licensure should the trial be successful. An adjuvant is an agent included in the vaccine that improves the immune response elicited by the vaccine – in the case of M72/AS01E the AS01E refers to the adjuvant made by GSK.
This ongoing dependence on a single company for the adjuvant has some activists worried. “We are concerned about reports that scaling this vaccine may be difficult due to limited availability of the vaccine adjuvant. Access for everyone who needs it should be part of the early phases of the research process – not an afterthought,” said Nathavitharana and Schoeman.
“The press release announcing the study’s start in several places refers to the ‘complexity’ of ‘developing and ensuring access’ to a new vaccine. Part of the unspoken complexity here is the opaque licensing deal GSK and Gates MRI signed in 2020 in which GSK gave rights to develop and commercialise M72 to Gates MRI while retaining control over the AS01E adjuvant,” Frick told Spotlight. “There are legitimate concerns that the fine print of this arrangement could work against equitable access, but terms of the licence remain unknown to the public.”
When asked about supply concerns, Gates MRI told Spotlight: “Gates MRI collaboration with GSK includes provisions to ensure there is sufficient supply of adjuvant for the clinical development and first adoption in low-income countries with high TB burden, at an affordable price, should the vaccine candidate be successful in phase 3 trials and approved for use. For broader implementation, GSK has committed to working with its partners to ensure there is sufficient supply.”
Disclosure: The Gates MRI is a non-profit subsidiary of the Bill and Melinda Gates Foundation. Spotlight receives funding from the Bill and Melinda Gates Foundation. Spotlight is editorially independent and a member of the South African Press Council.
Personalised treatment for the most common form of adult leukaemia helps patients survive for longer and stay in remission, a phase III trial has found. The trial, by the University of Leeds, has been identified as groundbreaking research by the New England Journal of Medicine and the 65th American Society of Hematology (ASH) Annual Meeting and Exposition in San Diego, where the results were presented.
The data shows that the duration of therapy can be individualised for each patient by using regular blood tests to monitor their response. In the trial, this approach resulted in significant improvements in both progression-free and overall survival in patients with previously untreated chronic lymphocytic leukaemia (CLL). The effect was stronger among patients with poorer outcomes to standard treatments, such as those with some genetic mutations.
Adult patients were given a combination of cancer growth blocking drugs over varied durations depending on how rapidly their disease responded.
The trial found that this approach significantly improved progression-free and overall survival compared to the standard treatment for CLL, with more than 19 in 20 patients in remission three years after starting treatment.
The study, named FLAIR, is a phase III randomised controlled trial for untreated CLL, taking place in more than 100 hospitals across the UK.
Lead author Peter Hillmen, Professor of Experimental Haematology in the University of Leeds’ School of Medicine, and Honorary Consultant Haematologist at Leeds Teaching Hospitals NHS Trust, said: “Our findings show that, for this group of patients, the treatment is very effective at tackling their disease and is well tolerated by them. This means that patients on our trial had better outcomes while also enjoying a better quality of life during their treatment. Most patients treated with the new combination have no detectable leukaemia in their blood or bone marrow by the end of treatment which is better than with previous treatments and is very encouraging.”
Dr Iain Foulkes, Executive Director of Research and Innovation at Cancer Research UK, said: “We are delighted to see these results from the FLAIR trial which show the importance and effectiveness of tailoring cancer treatment to the individual patient. Not only this, but the trial has found a way to do so without requiring frequent bone marrow tests which are more invasive and can be painful.
“The collaborative effort that went into this trial – involving researchers, healthcare professionals, funders and dedicated patients and their families – point to a new standard of care which could see real progress made against leukaemia.”
Chronic lymphocytic leukaemia is a type of cancer that affects the blood and bone marrow. It cannot usually be cured but can be managed with treatment. More than nine in 10 people are aged 55 and over when they are diagnosed.
Current treatments include chemotherapy, immunotherapy, or cancer growth blockers.
The FLAIR trial tested cancer growth blockers called Ibrutinib and Venetoclax (I+V), which are usually administered either continuously or for the same fixed duration rather than tailored to each patient’s response. This means that many patients may stop treatment too early, missing the full potential benefit from their therapy or continue therapy for longer than necessary. This could lead to a greater chance of relapse of their leukaemia and/or of treatment side effects.
FLAIR researchers aimed to discover whether it was possible to personalise I+V treatment duration for patients based on regular blood sampling and / or bone marrows, and whether this was as effective or better than standard treatment (FCR).
This regular blood and bone marrow monitoring gave researchers a more up-to-date picture of how patients were responding to I+V, and meant that the duration of I+V treatment could be tailored accordingly to each patient. In addition, it was found that basing the duration of treatment on less invasive, quicker blood samples was just as effective as using bone marrows, which can be painful and sometimes require sedation.
FLAIR was launched in 2014, recruiting 1509 patients with CLL. They were randomised to four treatment groups, each receiving a different treatment.
This part of the FLAIR trial compared two of the groups, placing 260 patients on I+V and 263 on the standard treatment, known as FCR. Almost three quarters were male, which was to be expected as CLL occurs more frequently in males. The average age was 62, and just over a third had advanced disease.
At the end of this stage of the trial, 87 patients had seen their disease progress, 75 of which were on FCR, and 12 on I+V.
To date, 34 of these patients have died during the trial. Of these, 25 were treated with FCR and only nine with I+V.
The patients on I+V underwent blood tests and bone marrows to monitor their response to treatment. The technique used is known as measurable residual disease (MRD) which allows clinicians to see the number of remaining cancer cells. The number of cells may be so small that the patient is asymptomatic. An MRD positive test result means that there are remaining cancer cells.
The research team now hope that this more personalised therapy approach, guided by blood test monitoring will be adopted as a new standard of care for patients needing first line CLL treatment.
Professor Hillmen said: “The results of the FLAIR Trial, led by the Leeds Cancer Research UK Clinical Trials Unit at the University of Leeds, are exceptional and herald a change in the way chronic lymphocytic leukaemia will be treated. FLAIR has been a huge collaborative effort over the last decade by the UK’s leading CLL specialists and by the haematology teams in over 100 hospitals throughout the UK. The participation of patient groups, individual patients and their families were critical to delivering such progress particularly through the challenges of the pandemic.”
The trial was co-ordinated by the Leeds Cancer Research UK Clinical Trials Unit at the University of Leeds. Deputy Director Professor David Cairns said: “The vision of the Leeds Cancer Research UK CTU is to improve the length and quality of survival for cancer patients on a worldwide scale. Our strategy to do this is to ensure that we build evidence to identify the correct treatment, for the correct duration, for the correct patient. FLAIR is a trial well aligned to our strategy, and reflects team science including clinicians, laboratory scientists, methodologists and operational experts working together to deliver important trial results. None of this would be achieved without the selfless commitment of trial participants who contribute their time and data.”
The FLAIR trial was funded by Cancer Research UK, Janssen Research & Development, LLC, and AbbVie Pharmaceutical Research and Development.
Of more than four hundred phase 2 and 3 randomised trials of cancer drugs registered in China between 2016 and 2017, about sixty had suboptimal control arms
More than one-eighth of the randomised trials of cancer drugs seeking regulatory approval in China in recent years used inappropriate controls to test the effectiveness and safety of the drugs, according to a new study published December 12th in the open access journal PLOS Medicineby Professor Xiaodong Guan of Peking University, China, and colleagues.
In randomised trials, patients are assigned to either a control arm, in which they receive the current optimal treatment, or an experimental arm, in which they receive the new drug being tested. However, studies have previously found that control arms in cancer clinical trials (including in the United States) are not supported by relevant guidelines, instead using treatments other than the standard-of-care. Adopting a suboptimal control group may bias a study’s results in favour of the experimental arm, potentially exposing patients to substandard therapy and producing unreliable results of clinical efficacy.
In the new study, researchers analysed the control arms of 453 Phase II/III and Phase III randomised oncology trials authorised by Chinese institutional review boards between 2016 and 2021, supporting investigational new drug applications of these drugs in China.
Overall, 60 trials (13.2%) used suboptimal control arms. Of those suboptimal trials, 35 (58.3%) used comparators that were not recommended by a prior guideline. In total, 18 610 people enrolled in clinical trials (15.1% of the total number in all samples trials) were exposed to suboptimal treatments due to the control arms. Trials using suboptimal controls were more likely to report a positive result for the experimental arm. In addition, the researchers found an overall upward trend in the number of trials using inappropriate control arms.
“Trial sponsors, ethical review boards, and oncologists should make collaborative efforts to protect patients from unnecessary harm and drugs with uncertain clinical benefits over the existing standard of care,” the authors say. “Regulatory agencies should be cautious when reviewing investigational new drug applications whose supporting trial used a suboptimal control.”
The authors add, “This research highlights the necessity to refine the design of randomised trials to generate optimal clinical evidence for new cancer therapies. In November 2021, China issued the Guidance on Clinical Value-Oriented Oncology Drug Research and Development, aiming to promote a better generation of clinically relevant novel oncology drugs in China. We hope our research findings can provide empirical evidence to the stakeholders and draw regulators’ attention to this matter so that the guideline can be delivered in the manner that it set out to be.”
For decades, the standard way to prevent people who were exposed to tuberculosis (TB) from falling ill with the disease was to offer them a medicine called isoniazid, taken daily for six or more months. That changed in the last decade with the development of new preventive therapy regimens that are taken for four, three, or even just one month.
One complexity, however, is that both isoniazid and the new regimens are much better at preventing normal drug-sensitive TB than they are at preventing drug-resistant forms of TB. This is not surprising. As explained by Paediatric Infectious Disease doctor and Professor of Global Child Health at Imperial College London, Dr James Seddon, the two drugs that have mainly been used to prevent drug-susceptible TB are isoniazid and rifampicin (rifampicin’s sister drug rifapentine is also used). Now, by definition, he explains multidrug-resistant (MDR) TB is resistant to both these drugs so it’s unlikely to have any impact.
The situation is particularly tricky when it comes to children. In a 2020 statement the World Health Organization (WHO) says that it estimated that worldwide between 25 000 and 32 000 children develop MDR-TB each year, and mainly acquire it through transmission from close contact with an adult or adolescent who has MDR-TB. According to Seddon, while there is some emerging observational evidence on the use of drugs other than isoniazid and rifampicin to prevent MDR-TB, there has been no clinically tested regimen to give to children following MDR-TB exposure.
Now, much anticipated results from a phase three trial has shown that a single antibiotic pill, given daily for six months, is safe and effective to use in children who have been exposed to MDR-TB.
Results from TB CHAMP
The trial, called TB-CHAMP, looked at the efficacy and safety of using the antibiotic levofloxacin to prevent TB in children exposed to MDR-TB. Top-line findings from the study was presented last week at the Union World Lung Conference held in Paris, France.
“The paediatric population is probably the most neglected of all the populations affected by MDR-TB,” Dr Anneke Hesseling, Director of the Paediatric TB Research Programme at Stellenbosch University, told the conference. “Fewer than 20% who develop MDR-TB disease are actually diagnosed and treated, and so to find more cases and prevent more cases is really, really critical…So prevention is really key, and the TB-CHAMP trial is really a phase three efficacy trial looking at levofloxacin to prevent new cases of TB in children and also looking at the safety of levofloxacin.”
Hesseling, who is the Principal Investigator of the study, says that TB-CHAMP is the first trial to provide clinical data on what drug might be used to prevent TB in children who have been exposed to MDR-TB. It was conducted at five sites across South Africa, all with high MDR-TB burdens. The study was led by Stellenbosch University and the Desmund Tutu TB Centre. The findings have not yet been published in a peer-reviewed journal.
922 children were randomised to receive either levofloxacin or a placebo for six months. 453 children got levofloxacin and 469 got the placebo. The primary efficacy data featured data from 916 of those children, with 451 in the levofloxacin arm and 465 in the placebo arm.
Hesseling says that only children who were exposed to an adult in their household with confirmed MDR-TB were included in the study. At first children below the age of five were recruited, regardless of their TB infection status. Later children between the ages of five and 17 were included, but they had to either have a TB infection or be living with HIV. The majority of the children, 90%, were younger than five years. TB infection was confirmed with a blood test.
By 48 weeks, Hesseling says five children in the levofloxacin arm versus 12 in the placebo arm developed TB, which amounts to an incidence rate of 1.1% in the levofloxacin arm, and 2.6% in the placebo arm.
Implication of results
“While TB preventive therapy (TPT) has long been recommended and available for young child contacts of people with drug-susceptible TB, there has not been sufficient evidence to make strong recommendations for treatment that could prevent DR-TB. Therefore, the TB-CHAMP findings are critically important for a number of reasons,” says Professor Guy Marks, President and Interim Executive Director, International Union Against Tuberculosis and Lung Disease (The Union).
“The study provides the first high-quality evidence that DR-TB can be prevented in children by using six months of daily levofloxacin, and that this is a safe medication. Furthermore, this will encourage more community-based contact screening, which will also lead to early detection of children and contacts of all ages who already have disease, and initiate treatment,” he adds.
“The impact [of the TB-CHAMP results] is potentially tremendous as it would prevent DR TB among child contacts. DR TB is more complex to treat and cure and often children are marginalised, so this study puts the spotlight on an effective way to protect children. This is not just about the life and health of the child but the social, economic and mental health implications for the caregiver and the entire family,” says Dr Priashni Subrayen, Technical Director for TB at The Aurum Institute.
Seddon, who is also one of the Co-PIs for the study, tells Spotlight that it was important to establish the safety of levofloxacin since it belongs to a class of drugs called the fluoroquinolones, which were thought to have terrible side effects when used in children.
Results from TB-CHAMP show that this is not the case.
The side effects were mild, and the regimen was well tolerated, according to Hesseling, with only eight children having a grade one or higher adverse event in the levofloxacin arm compared to four in the placebo arm. Two deaths were reported, one in each study arm, but were unrelated to the study. Overall, six children in the levofloxacin arm discontinued treatment or left the study early.
Researchers from TB-CHAMP collaborated with researchers from the V-QUIN trial – a phase three study that looked at levofloxacin as TB prevention in adults in Vietnam – in order to combine their data which allowed them to show data for levofloxacin across different age groups. Seddon explains: “They’ve applied a novel analytic approach, which uses a Bayesian, or probabilistic, framework, where we take the results of TB-CHAMP and we say well, if we actually use some of the information from V-QUIN to inform the TB-CHAMP results, we can make that a slightly more confident estimate,” he says.
The combined results, according to Hesseling were able to also show that levofloxacin reduced the risk of TB by about 60% across the age spectrum but with a tighter confidence interval, indicating a more precise estimate of the effect.
Seddon tells Spotlight that the combined data showed that there were no serious adverse events, but the adult population experienced more grade one and grade two side effects than the children, but these went away either over time or when the drug was stopped. The side effects included inflammation in the joints and tendons, which is a known side effect of this class of drug.
Not a silver bullet
While the findings could be a game-changer and potentially inform MDR-TB prevention guidelines, particularly in children, the regimen is by no means a silver bullet. Seddon says that while the regimen was safe, when participants were asked whether they liked the medicine, more people said they didn’t like it in the levofloxacin group versus the placebo. Another downside is that the pill was an adult formulation and thus needed to be cut and/or crushed for the kids to swallow.
Seddon explains that the WHO, who have been provided with the data from both studies and expected to meet in early December, would need to consider a variety of factors before deciding what to recommend about the use of levofloxacin for prevention. That includes the fact that you need to treat a lot of children for six months who might not have TB despite being exposed in order to prevent a few cases.
“You have to weigh up the benefits versus the risks and the risks are low, but it is still giving a drug for six months to children and most of them don’t need it. But the consequences of getting MDR-TB are so bad that we really want to prevent that,” he says.
There is also the question around what effect using a broad antibiotic as preventive treatment will have on the microbiome of children and how this might drive resistance to the fluoroquinolones. Seddon says stool samples were collected from the study participants to determine how the drug affected a child’s microbiome and the potential for driving resistance. These data will also be provided to the WHO.
“I think that the evidence base is now very strong on the basis of these two trials. I think you can really say the issue of whether levofloxacin prevents MDR-TB, we’ve put that to bed,” he says. “Are there going to be other studies? Yes. I think that this is not over, levofloxacin is not the perfect drug for preventive therapy.”
Marks adds to this saying: “An important next step for TPT in DR-TB contacts will be studies that evaluate regimens that are shorter than six months – a long time to take medication every day, which can often be challenging. Effective and safe shorter regimens are now being used for child contacts of drug-susceptible TB and we hope the same progress can be made for contacts of DR-TB.”
As Marks has already stated, currently there are no strong recommendations for MDR-TB prevention by the WHO. In the 2020 TB prevention guidelines, it recommends that the preventative treatment for MDR-TB should be either a fluroquinolone or other second-line agent. It does however caution that these recommendations are based on low-quality evidence. Because of this, it recommends that the preventative treatment for MDR-TB should be individualised, and it be based on the drug resistance profile of the presumed contact. The drugs levofloxacin and moxifloxacin- both fluoroquinolones – may be used unless resistance is suspected. For levofloxacin a dosing schedule for both adults and children are proposed in the document.
Subrayen says that in South Africa the 2019 guidelines for the management of Rifampicin Resistant-TB (RR-TB) does indicate the use of levofloxacin as prevention treatment. The guidelines state that for prevention treatment a fluoroquinolone-based, multidrug regimen is preferred (either levofloxacin and high-dose isoniazid or levofloxacin, high-dose isoniazid and ethambutol). And if exposed to fluoroquinolone-resistant RR-TB, then high-dose isoniazid could be given. Delamanid could be considered as a potential option in very select cases. A training manual published this year by the Department of Health suggests that levofloxacin can be given on its own – but also stresses that the evidence base is weak, something that TB-CHAMP has presumably now changed.
Future of TPT
Seddon says that in a perfect world the ideal TB preventive regimen would be a so-called Pan regimen that could be given for a short period of time, to someone who has been exposed to TB and it works regardless of whether they had been exposed to drug-susceptible or drug-resistant TB.
“There are studies planned to use other drugs for prevention. There’s a study planned to use bedaquiline for a month or two and potentially using injectables that you just have to give once every couple of weeks. So, I think although this [levofloxacin] is a good option now, and it’s probably the best option we have now, this is not perfect,” Seddon says.
The study Seddon is referring to is the BREACH-TB study, a phase three trial that will look at whether a one-month treatment regimen of oral bedaquiline could prevent all forms of tuberculosis. It would be given to people exposed to both drug-resistant and drug-susceptible TB, and in people with HIV infection, including pregnant women and children.
Responding to questions from Spotlight earlier this year when this study was announced in the press, Sonya Krishnan, Assistant Professor of Medicine at Johns Hopkins University and Eric Nuermberger, Professor of Medicine at Johns Hopkins University, said that they anticipate recruiting between 1600 and 2 00 people to take part in the study – they expect around 400 to 500 of these will be people living with HIV. They also said that the control arm will receive the current standard of care in the country rather than placebo.
When asked whether any South African study sites will be included in the clinical trial, they said, “We very much plan to partner with study sites in South Africa. South Africa has a long-standing history of research excellence in TB.”
“A shorter regimen that fights both drug-resistant and drug-susceptible TB would be a game-changer for those living with TB and get us closer to our shared goal of ending the epidemic by 2030,” said Dr. Atul Gawande, USAID assistant administrator for Global Health, in a statement on the study. “This clinical trial will lay the foundation for a remarkable innovation in our fight against TB: a single-dose, long-acting injectable medicine.”
Indeed, if the science and development pans out as Gawande suggests it might, the future of TB preventive therapy might well be an entire course of therapy delivered through a single injection rather than a month or more of pills. As indicated in an article in the journal Clinical Infectious Diseases, work is already underway on the development of bedaquline, isoniazid, and rifapentine long-acting injections – though the research is for now still only in mice.
‘Communities need to be involved’
Hesseling raises the point that when treating or preventing TB, more than just the latest research advancement is needed to improve TB outcomes.
“For me treatment follows diagnosis, actually strengthening healthcare services, making communities more aware and creating demand for kids accessing diagnosis, preventive treatment and appropriate treatment, is actually where it starts,” she says. “So tools are amazing, but we actually need to have strong, effective healthcare services and knowledgeable, empowered communities.”
Seddon adds to this saying that results like those from TB-CHAMP are “a bit irrelevant if it is all kind of top down, paternalistic coming from the researchers, coming from the health system”.
“We really need to generate a community demand for this, where individuals living in communities where this is a problem are calling for this and getting angry about this and demanding it in a way that I think we’ve achieved very well with the HIV community,” he says. “It’s all well and good doing the science and then even better to get it [levofloxacin] into a guideline, but until there’s real demand for from the end user, I think it’s only going to have a certain amount of reach.”
Note: The terms DR-TB and MDR-TB are used somewhat interchangeably – Spotlight uses DR-TB to refer to drug-resistant forms of TB in general and MDR-TB to refer specifically to TB that is resistant to isoniazid and rifampicin.
Newly announced results of a pivotal phase 3 trial have demonstrated the effectiveness of a new one-dose treatment for gonorrhoea. The medicine, called zoliflodacin, is the first new drug developed to treat gonorrhoea in over 30 years. More than half of the 930 patients included in the trial were from South Africa, including women, adolescents, and people living with HIV.
Zoliflodacin, which was shown to be non-inferior to (as good as) the currently used treatment in treating uncomplicated gonorrhoea, provides an important new tool to combat rising rates of drug resistant gonorrhoea. It was found to be generally well tolerated and there were no serious adverse events or deaths recorded in the trial. So far, only top line results have been shared in a media release and the findings have not yet been published in a medical journal. (You can see some technical details of the study design on ClinicalTrials.gov)
The World Health Organization raised the alarm about increasing rates of drug resistant gonorrhoea in 2017, noting the emergence of cases of untreatable gonorrhoea resistant to all available antibiotics. According to the United States Centers for Disease Control and Prevention “medication to treat gonorrhoea has been around for decades, but the bacteria has grown resistant to nearly every drug ever used to treat it”. They say: “only one class of antibiotics known as cephalosporins remains to treat the infection”.
As a drug from a new class of antibiotics, zoliflodacin, offers a new potential treatment for patients whose gonorrhoea was previously untreatable, as well as a new tool for safeguarding the ongoing effectiveness of currently available antibiotics.
How zoliflodacin may change gonorrhoea treatment
Professor Sinead Delany-Moretlwe, Director of Research for Wits RHI and the National Principal Investigator for the trial in South Africa, told Spotlight that while zoliflodacin may be used to treat drug resistant gonorrhoea, it also provides an attractive new treatment option for first-line treatment of gonorrhoea in some countries (in other words, gonorrhoea that is not resistant to other treatments).
Zoliflodacin, which is taken as a single oral dose, is simpler to administer than the current standard of care, which involves a combination of injectable ceftriaxone and oral azithromycin. Removing the need for an injection could simplify the administration of gonorrhoea treatment and improve its uptake.
Using zoliflodacin as first-line gonorrhoea treatment can also help safeguard the ongoing effectiveness of cephalosporins (including ceftriaxone), according to Delany-Moretlwe, which she adds are needed not just for treatment of gonorrhoea, but also other infections.
According to Delany-Moretlwe, because zoliflodacin is the first of a new class of antibiotics with novel mechanisms of action and without existing cross resistance, the hope is that widespread use of zoliflodacin as first-line gonorrhoea treatment will slow the emergence of resistance compared with the medicines currently being used.
The Global Antibiotic Research and Development Partnership (GARDP), a non-profit that sponsored the trial, points out that: “Antimicrobial resistance [AMR] has been around for millions of years, long before the first man-made antibiotics. So, drug-resistant bacteria are inevitable and will eventually affect all antibiotics”. They state: “to beat AMR we need a steady supply of new antibiotics to be developed that are effective against drug-resistant bacteria, particularly for priority pathogens that have the greatest public health impact.”
Gonorrhoea in South Africa
South Africa has incredibly high rates of gonorrhoea, with an estimated 2 million new cases annually. While data on rates of drug resistance in the country is limited, the data that is available indicates that ceftriaxone resistance in the country is low, but azithromycin resistance is concerningly high in some parts of the country.
As there is no routine screening for gonorrhoea in South Africa, linkage to treatment remains a challenge. Currently, diagnosis is largely done through symptomatic reporting by patients. But this approach misses many cases as some patients do not self-report symptoms and some cases of gonorrhoea are asymptomatic.
In 2022, the Southern African HIV Clinicians Society released new guidelines for the management of sexually transmitted infections which called for provider-initiated symptomatic screening and provider-initiated diagnostic screening in high-risk populations.
The country’s new National Strategic Plan on HIV, TB and STIs has set a target to increase the number of pregnant women tested for gonorrhoea from 10% in 2023 to 80% by 2028 and has committed to implementing diagnostic testing in other priority populations, including adolescent girls and young women.
How will new gonorrhoea treatments be commercialised?
Zoliflodacin was developed by GARDP in collaboration with the company Innoviva Specialty Therapeutics. According to GARDP, it holds the rights to register and commercialise zoliflodacin in more than three-quarters of the world’s countries, including all low-income countries, most middle-income countries, and several high-income countries. While, Entasis Therapeutics Limited, an affiliate of Innoviva Specialty Therapeutics, “retains the commercial rights for zoliflodacin in the major markets in North America, Europe, Asia-Pacific, and Latin America”.
South Africa is one of the countries in which GARDP holds the rights to register and commercialise zoliflodacin. It is anticipated that this will be done through selection and licensing of companies to manufacture and supply zoliflodacin in South Africa and other countries where GARDP holds commercialisation rights.
GARDP recently launched a request for proposals from partners that are interested in commercialising zoliflodacin. GARDP has also signed a memorandum of understanding with two generic producers to explore opportunities to commercialise the medicine in low-and-middle-income countries.
While the price that will be offered by commercial partners for the product remains to be seen, it is anticipated that products will be made available at affordable prices in line with GARDP’s goal to ensure that “all GARDP products are available, affordable, and appropriately used across populations that need them”.
“This is the first study to address a World Health Organization priority pathogen that has been sponsored and led by a non-profit organization,” says GARDP.
“This demonstrates that GARDP’s model can play a crucial role in helping to fix the public health failure at the heart of the global AMR crisis,” says Professor Glenda Gray, GARDP board member and President of the South African Medical Research Council.
SA involvement
According to GARDP, South Africa had the highest number of participants in the global trial, across six sites in four provinces: Wits RHI in Hillbrow, Johannesburg; the Desmond Tutu HIV Foundation in Masiphumelele, Cape Town; Setshaba Research Centre in Soshanguve, Gauteng; the SAMRC’s clinical research sites in Botha’s Hill and Tongaat in KwaZulu-Natal; and Ndlovu Research Centre in Groblersdal, Limpopo.
“We have also been able to leverage our HIV experience to build capacity for trials of novel STI technologies, a previously neglected area. Undertaking this vital work on a new treatment for gonorrhoea has also given us the opportunity to focus sharply on the local situation in South Africa,” says Delany-Moretlwe.
Professor Shabir Madhi has been appointed as an honorary Commander of the Most Excellent Order of the British Empire (CBE) by King Charles III.
Wits Professor of Vaccinology Shabir Madhi led the Oxford University sponsored Oxford/AstraZeneca Covid-19 vaccine clinical trials in South Africa
Wits University and the University of Oxford contributed scientifically to informing the public health response to the Covid-19 pandemic in South Africa and globally.
Madhi receives the Order in recognition of his services to science and public health in a global pandemic.
Madhi led South Africa and the continent’s first Covid-19 vaccine trials in 2020/2021 as founder and Director of the South African Medical Research Council (SAMRC) Wits Vaccines and Infectious Diseases Analytics (Wits VIDA) Research Unit.
An internationally recognised leader in his field, the National Research Foundation A-rated scientist was involved in multiple clinical and serology epidemiology studies on Covid-19, in addition to his research on vaccines against other life-threatening diseases.
The first of (subsequently two) Wits University-led South African Covid-19 vaccine trials, Madhi led the Oxford/AstraZeneca Covid-19 vaccine clinical trials in South Africa, in association with the University of Oxford.
Professor Sir Andrew Pollard, Director of the Oxford Vaccine Group, University of Oxford, and Madhi’s UK counterpart in these Covid-19 vaccine trials, says of Madhi’s CBE appointment: “I am delighted that Professor Shabir Madhi CBE has been honoured by King Charles for his remarkable contributions to global public health and particularly for his extraordinary leadership in the midst of a global pandemic. It has been a huge privilege for me to work alongside him and his team on the development of the globally impactful Oxford-AstraZeneca vaccine.”
Over the course of the pandemic (2020-2022), Madhi had been an outspoken, articulate, and ardent advocate of Covid-19 vaccination as well as for increased access to these and other vaccines in Africa.
On his appointment as CBE, Madhi says: “The privilege of being conferred this honour is credit to the tremendous effort of the incredible Wits VIDA research team that I have the privilege of leading at Wits University – before, during and beyond the Covid-19 pandemic. As a collective, and together with colleagues at the University of Oxford and in South Africa, we are proud to have contributed scientifically to informing the public health response to the Covid-19 pandemic in South Africa and globally.”
