Treatment of tuberculosis infection (TBI) is a key pillar of the World Health Organization End TB Strategy. Two short-course rifamycin-based regimens—3 months of weekly isoniazid plus rifapentine (3HP) and 4 months of daily rifampicin (4RIF)—are widely recommended; however, they have not previously been directly compared in a randomized controlled trial. We compared treatment completion between 3HP and 4RIF among individuals with TBI.MethodsWe conducted a multicenter, open-label, parallel-group randomized controlled trial across 7 tuberculosis clinics in Sydney, Australia, between July 2019 and June 2024. Participants of any age with TBI were randomized 1:1, stratified by site, to receive either weekly 3HP or daily 4RIF. All doses were self-administered. Participants in the 3HP group received weekly Short Message Service (SMS) adherence reminders; both groups received standard clinic follow-up. The primary outcome was treatment completion, defined as ingestion of ≥90% of prescribed doses. Analyses were conducted on an intention-to-treat basis.ResultsA total of 210 participants were enrolled (106 assigned to 3HP and 104 to 4RIF). Treatment completion was significantly higher in the 3HP group (84.9%) than in the 4RIF group (65.4%; relative risk, 1.30 [95% confidence interval, 1.22–1.38]; P < .001). Adverse events of any grade occurred in 24.5% of participants receiving 3HP and 20.2% receiving 4RIF. No treatment-related deaths were reported.ConclusionsWeekly 3HP supported by SMS reminders achieved significantly higher treatment completion than daily 4RIF, with similar safety. These findings support broader implementation of 3HP to optimize adherence and outcomes in TBI treatment programs.Clinical Trials RegistrationAustralian New Zealand Clinical Trials Registry (ACTRN12618001672246).

Safe and effective therapies are needed for hospitalized patients with complicated Staphylococcus aureus infections, including approaches capable of eradicating intracellular bacterial reservoirs that contribute to treatment failure. This study evaluated the safety, tolerability, and pharmacokinetics of DSTA4637S, an antibody–antibiotic conjugate combining an anti-S. aureus antibody with a rifamycin-class antibiotic, in patients with complicated S. aureus bacteremia.MethodsIn this phase 1b, randomized, double-blind, placebo-controlled study, 25 patients with methicillin-sensitive (MSSA, 68%) or -resistant (MRSA, 32%) complicated S. aureus bacteremia received weekly intravenous doses of DSTA4637S at 15, 45, or 100 mg/kg in combination with at least 4 weeks of standard-of-care antistaphylococcal antibiotics.ResultsMost patients (92%) experienced ≥1 treatment-emergent adverse event (TEAE), of which 44% were considered treatment-related. Grade ≥3 TEAEs and serious adverse events occurred in 72% and 56% of patients, respectively. The most common grade ≥3 TEAEs were infusion-related reactions (IRRs), pneumonia, anemia, and respiratory failure. Four patients (21%) receiving DSTA4637S discontinued study treatment due to treatment-related IRRs. Systemic exposure of DSTA4637S in patients increased approximately dose-proportionally from 15 to 100 mg/kg but was 30%–60% lower than previously observed in healthy volunteers.ConclusionsThe safety profile of DSTA4637S, characterized by unpredictable IRRs, and its pharmacokinetic behavior in patients differed substantially from those observed in healthy volunteers, highlighting the critical importance of conducting early phase studies in the target patient population.

The Rifamycin Sodium Injection Market is expected to grow from 400 USD Million in 2025 to 800 USD Million by 2035. The Rifamycin Sodium Injection Market CAGR (growth rate) is expected to be around 6.3...

People receiving immunosuppressive medications are at increased risk of tuberculosis. Tuberculosis preventive treatment (TPT) can reduce risk, however its safety among these populations is uncertain. We conducted a meta-analysis to evaluate adverse events (AE) associated with TPT among people receiving or about to initiate immunosuppressive medications.MethodsWe searched MEDLINE, Cochrane, Health Star, and EMBASE (1952–May 1, 2025), for studies reporting AE during TPT among people receiving or about to initiate immunosuppressives. We used random-effects generalized linear mixed models with Hartung-Knapp 95% confidence intervals to estimate our primary outcome: pooled proportion of AE-related discontinuation, stratified by TPT regimen.ResultsWe included 27 studies (3184 participants). Populations included biologics/steroids recipients and solid organ/hematopoietic transplant candidates/recipients. For the primary outcome (25 studies, 2802 participants), TPT regimens included 6–12-month mono-isoniazid regimens (1511 participants), 4-months mono-rifamycin regimens (228 participants), 3-month isoniazid-rifamycin combination regimens (990 participants), and 6–9-month fluoroquinolone–based regimens (73 participants). Only mono-isoniazid regimens were provided while receiving immunosuppressives. Pooled AE-related discontinuation was 5.3% (95% CI: 3.1–8.9%; I2=65.4%) for mono-isoniazid regimens, 4.4% (95% CI: 0.1–75.4%; I2=86.3%) for mono-rifamycin regimens, 2.0% (1.0–4.1%; I2=0.0%) for isoniazid-rifamycin combination regimens, and 6.9% (95% CI: 0–92.3%; I2=65.4%) for fluoroquinolone-based regimens. Proportions were similar when stratified by biologics/steroids and transplant populations.ConclusionOverall, AE-related TPT discontinuation was like the broader TPT literature. AE-related discontinuation of TPT was lowest with rifamycin-containing regimens, but these were only provided prior to initiating immunosuppressives. Data on the safety of non-isoniazid regimens among people receiving immunosuppressives are needed.

We conducted a systematic review and meta-analysis to compare effectiveness and safety of 9 months of isoniazid (9H) versus shorter rifamycin-containing regimens for treating latent tuberculosis infection (TBI) in children.MethodsWe systematically searched MEDLINE, Embase, and Cochrane Central Register of Controlled Trials to June 2025 for randomized, controlled trials (RCTs) and cohort studies that compared regimens that were shorter than 9 months of isoniazid in children aged 1–18 years. Outcomes were development of TB disease, treatment completion, and adverse events. Risk of bias was assessed using RoB 2.0 and the Risk Of Bias In Non-Randomized Studies - of Interventions (ROBINS-I) tool; certainty of evidence was graded using Grading of Recommendations Assessment, Development, and Evaluation (GRADE).ResultsFive RCTs and 7 nonrandomized studies that enrolled approximately 2950 children in trials and >25 000 in observational cohorts were included. In pooled analysis of 3 RCTs, shorter rifamycin-containing regimens resulted in little to no difference in development of TB disease compared with 9H (odds ratio [OR], 0.19; 95% confidence interval [CI], .03–1.12; moderate-certainty evidence). Treatment completion was probably higher with shorter regimens (OR, 0.51; 95% CI, .42–0.62; moderate-certainty evidence). Adverse events were similar between groups, but evidence is uncertain (low-certainty evidence). Observational data were consistent with these findings, showing higher completion rates and lower hepatotoxicity with shorter treatments.ConclusionsShorter rifamycin-containing regimens for pediatric TBI probably increase treatment completion and have similar safety outcomes, with no important difference in development of TB disease compared with the standard regimen. These findings support current guideline recommendations that favor shorter regimens in children.

AbstractBackground. Treatment of tuberculosis infection (TBI) is a key pillar of the World Health Organization End TB Strategy. Two short-course rifamycin-

Mycobacterium abscessus is a rapidly growing non-tuberculous Mycobacterium causing severe pulmonary infections, especially in immunocompromised individuals and those with underlying lung conditions li...

Five new rifamycin derivatives, named salinirifamycins A–E (1–5), were isolated from a Brazilian marine Salinispora arenicola (BRA-213) strain extract. The structures of the new rifamycins were elucid...

Dublin, Ireland--(Newsfile Corp. - May 18, 2026) - Cosmo N.V. (SIX: COPN) (XETRA: C43) (“Cosmo” or “the Company”) today announced the completion of patient enrolment in its Phase II clinical trial (EUCT number: 2023-506917-23-00) evaluating its novel investigational therapy, Rifamycin enema, for the treatment of distal ulcerative colitis (UC) and ulcerative proctitis. A total of 77 patients were enrolled at 24 clinical sites in Europe, reflecting strong investigator engagement...

Rifaquizinone is a dual-pharmacophore antibiotic combining rifamycin and a fluoroquinolone-like compound, showing strong bactericidal activity against resistant Staphylococcus aureus strains and biofi...