Short-course, high-dose primaquine regimens for the treatment of liver-stage vivax malaria in children

OBJECTIVES

To assess the pharmacokinetics, safety, and tolerability of two high-dose, short-course primaquine (PQ) regimens compared with standard care in children with Plasmodium vivax infections.

METHODS

We performed an open-label pediatric dose-escalation study in Madang, Papua New Guinea (Clinicaltrials.gov NCT02364583). Children aged 5-10 years with confirmed blood-stage vivax malaria and normal glucose-6-phosphate dehydrogenase activity were allocated to one of three PQ treatment regimens in a stepwise design (group A: 0.5 mg/kg once daily for 14 days, group B: 1 mg/kg once daily for 7 days, and group C: 1 mg/kg twice daily for 3.5-days). The study assessments were completed at each treatment time point and fortnightly for 2 months after PQ administration.

RESULTS

Between August 2013 and May 2018, 707 children were screened and 73 met the eligibility criteria (15, 40, and 16 allocated to groups A, B, and C, respectively). All children completed the study procedures. The three regimens were safe and generally well tolerated. The pharmacokinetic analysis indicated that an additional weight adjustment of the conventionally recommended milligram per kilogram PQ doses is not necessary to ensure the therapeutic plasma concentrations in pediatric patients.

CONCLUSIONS

A novel, ultra-short 3.5-day PQ regimen has potential benefits for improving the treatment outcomes in children with vivax malaria that warrants further investigation in a large-scale clinical trial.

Optimizing (O) rifapentine-based (RI) regimen and shortening (EN) the treatment of drug-susceptible tuberculosis (T) (ORIENT) using an adaptive seamless design: study protocol of a multicenter randomized controlled trial

BACKGROUND

Standard treatment for drug-susceptible tuberculosis (DS-TB) includes a multidrug regimen requiring at least 6 months of treatment, and this lengthy treatment easily leads to poor adherence. There is an urgent need to simplify and shorten treatment regimens to reduce interruption and adverse event rates, improve compliance, and reduce costs.

METHODS

ORIENT is a multicenter, randomized controlled, open-label, phase II/III, non-inferiority trial involving DS-TB patients to evaluate the safety and efficacy of short-term regimens compared with the standardized six-month treatment regimen. In stage 1, corresponding to a phase II trial, a total of 400 patients are randomly divided into four arms, stratified by site and the presence of lung cavitation. Investigational arms include 3 short-term regimens with rifapentine 10 mg/kg, 15 mg/kg, and 20 mg/kg, while the control arm uses the standardized six-month treatment regimen. A combination of rifapentine, isoniazid, pyrazinamide, and moxifloxacin is administered for 17 or 26 weeks in rifapentine arms, while a 26-week regimen containing rifampicin, isoniazid, pyrazinamide, and ethambutol is applied in the control arm. After the safety and preliminary effectiveness analysis of patients in stage 1, the control arm and the investigational arm meeting the conditions will enter into stage 2, which is equivalent to a phase III trial and will be expanded to recruit DS-TB patients. If all investigational arms do not meet the safety conditions, stage 2 will be canceled. In stage 1, the primary safety endpoint is permanent regimen discontinuation at 8 weeks after the first dose. The primary efficacy endpoint is the proportion of favorable outcomes at 78 weeks after the first dose for both two stages.

DISCUSSION

This trial will contribute to the optimal dose of rifapentine in the Chinese population and suggest the feasibility of the short-course treatment regimen containing high-dose rifapentine and moxifloxacin for DS-TB.

TRIAL REGISTRATION

The trial has been registered on ClinicalTrials.gov on 28 May 2022 with the identifier NCT05401071.

Person-centred care in practice: perspectives from a short course regimen for multi-drug resistant tuberculosis in Karakalpakstan, Uzbekistan

Introduction

Person-centred care, an internationally recognised priority, describes the involvement of people in their care and treatment decisions, and the consideration of their needs and priorities within service delivery. Clarity is required regarding how it may be implemented in practice within different contexts. The standard multi-drug resistant tuberculosis (MDR-TB) treatment regimen is lengthy, toxic and insufficiently effective. 2019 World Health Organisation guidelines include a shorter (9–11-month) regimen and recommend that people with MDR-TB be involved in the choice of treatment option. We examine the perspectives and experiences of people with MDR-TB and health-care workers (HCW) regarding person-centred care in an MDR-TB programme in Karakalpakstan, Uzbekistan, run by Médecins Sans Frontières and the Ministry of Health.

Methods

A qualitative study comprising 48 interviews with 24 people with MDR-TB and 20 HCW was conducted in June–July 2019. Participants were recruited purposively to include a range of treatment-taking experiences and professional positions. Interview data were analysed thematically using coding to identify emerging patterns, concepts, and categories relating to person-centred care, with Nvivo12.

Results

People with MDR-TB were unfamiliar with shared decision-making and felt uncomfortable taking responsibility for their treatment choice. HCW were viewed as having greater knowledge and expertise, and patients trusted HCW to act in their best interests, deferring the choice of appropriate treatment course to them. HCW had concerns about involving people in treatment choices, preferring that doctors made decisions. People with MDR-TB wanted to be involved in discussions about their treatment, and have their preference sought, and were comfortable choosing whether treatment was ambulatory or hospital-based. Participants felt it important that people with MDR-TB had knowledge and understanding about their treatment and disease, to foster their sense of preparedness and ownership for treatment. Involving people in their care was said to motivate sustained treatment-taking, and it appeared important to have evidence of treatment need and effect.

Conclusions

There is a preference for doctors choosing the treatment regimen, linked to shared decision-making unfamiliarity and practitioner-patient knowledge imbalance. Involving people in their care, through discussions, information, and preference-seeking could foster ownership and self-responsibility, supporting sustained engagement with treatment.

Implementation of multidrug-resistant tuberculosis (MDR-TB) treatment in Gabon: lessons learnt from the field

PURPOSE

Since May 2016, WHO recommended a 9-12 month short-treatment regimen for multidrug-resistant tuberculosis (MDR-TB) treatment known as the 'Bangladesh Regimen'. However, limited data exist on the appropriateness thereof, and its implementation in low- and middle-income countries (LMIC). We report here on the pilot phase of the evaluation of the Bangladesh regimen in Gabon, prior to its endorsement by the WHO.

METHODS

This ongoing observational study started in September 2015. Intensive training of hospital health workers as well as community information and education were conducted. GeneXpert-confirmed MDR-TB patients received the second-line anti-tuberculosis drugs (4KmMfxPtoHCfzEZ/5MfxCfzEZ). Sputum smears and cultures were done monthly. Adverse events were monitored daily.

RESULTS

Eleven patients have been treated for MDR-TB piloting the short regimen. All were HIV-negative and presented in poor health with extensive pulmonary lesions. The overall sputum culture conversion rate was 64% after 4 months of treatment. Three patients developed marked hearing loss; one a transient cutaneous rash. Of 11 patients in our continuous care, 7 (63.6%) significantly improved clinically and bacteriologically. One (9.1%) patient experienced a treatment failure, two (18.2%) died, and one (9.1%) was lost to follow up.

CONCLUSIONS

Our pioneering data on systematic MDR-TB treatment in Gabon, with currently almost total absence of resistance against the second-line drugs, demonstrate that a 9-month regimen has the capacity to facilitate early culture negativity and sustained clinical improvement. Close adverse events monitoring and continuous care are vital to success.