Wang, Z

Background Lumbar facet arthropathy (LFA) is a degenerative, arthritic joint disorder and a common specific cause of axial low back pain and functional impairment. Currently, no disease-modifying therapies are available for symptomatic LFA. Mesenchymal stem/stromal cell (MSC)-based therapy represents an emerging regenerative treatment modality with the promise to target the underlying pathophysiology of LFA. Despite encouraging clinical evidence supporting the safety and efficacy of MSC therapy in other osteoarthritis, its therapeutic utility in LFA remains largely unexplored. We recently completed a prospective, single-arm, open-label phase I clinical trial that demonstrated a favourable safety profile and preliminary clinical benefit following intra-articular administration of bone marrow-derived MSCs (BMSCs) in patients with symptomatic LFA. Building on these findings, we present the protocol for CellKine II , a prospective, randomised, double-blind, placebo-controlled, cross-over phase II clinical trial to evaluate the safety and preliminary efficacy of intra-articular delivery of allogeneic, culture-expanded BMSCs in patients with painful LFA. Methods and analysis This study is a single-centre, randomised, double-blind, placebo-controlled, cross-over phase II trial with a target accrual of 40 patients. Eligible patients will be randomly assigned in a 1:1 ratio to receive a single intra-articular injection of either Arm A: BMSC or Arm B: Placebo (dimethyl sulfoxide). At the 6-month follow-up, all patients will be unblinded. Patients initially randomised to Arm A will continue follow-up for up to 12 months. Patients initially randomised to Arm B may cross over to receive the BMSC treatment, followed by an additional 12 months of post-BMSC treatment follow-up, or they may continue observation for another 6 months without BMSC treatment. Overall, each patient will be followed up to 12 months after BMSC treatment. The primary endpoints are back pain, functional outcomes and adverse events at 6 months post-randomisation. Ethics and dissemination This study will be conducted in compliance with U.S. federal regulations and Mayo Clinic institutional research policies and procedures. The protocol has been approved by the Mayo Clinic Institutional Review Board (IRB) and the Data Safety Monitoring Board (IRB No. 21-013278). The results of this trial will be disseminated through publication in peer-reviewed journals and on ClinicalTrials.gov. Trial registration number NCT06001853 .

Abstract Rationale Community-acquired pneumonia (CAP) remains a leading cause of morbidity and mortality worldwide; current guidelines recommend either the use of β-lactam therapy with a macrolide (azithromycin; AZM) or monotherapy with a fluoroquinolone for treatment. Limited evidence exists on their comparative effectiveness. To address this gap, we examined the differences in outcomes among CAP patients treated with β-lactam therapy plus AZM or fluoroquinolone monotherapymethods: We emulated a randomized clinical trial that hypothetically assigned patients to β-lactam therapy plus AZM or fluoroquinolone. Eligible patients were all adults hospitalized for nonsevere community-acquired pneumonia (CAP) based on ATS/IDSA criteria; at Mayo Clinic hospitals (3 academic and 16 community) between May 2018 and September 2022 and received one of the two treatments within 12 hours of admission. Ensemble machine learning with augmented inverse probability weighting (AIPW) was used to evaluate “intention to treat” effects on hospital-free days (HFDs), 180-day mortality, use of advanced respiratory support, in-hospital mortality, and the composite of advanced respiratory support and/or in-hospital mortality. We used the E-value and post-discharge systolic blood pressure (SBP) (negative outcome) to evaluate effects of potential unmeasured confounding and alternative “doubly robust” inverse probably weighting with regression adjustment (IPWRA) to evaluate robustness of the findings. Results 2,451 patients (2,142 β-lactam therapy plus AZM and 309 fluoroquinolone) were eligible and included in the analyses: 53.9% were female, 86.8% were White, and mean age was 58.4 years (SD: 17.02). Compared with β-lactam therapy plus AZM, the fluoroquinolone group experienced significantly higher HFD (1.50 days; 95% CI: 1.08, 1.91), lower use of advanced respiratory support (RR: 0.32; 95% CI: 0.09, 0.54), lower in-hospital mortality (RR: 0.14; 95% CI: 0.00, 0.40), and composite of advanced respiratory support and/or in-hospital mortality (RR: 0.29; 95% CI: 0.08, 0.49). Moderate to large e-values (ranging from 3.50 to 4.74) and use of negative outcomes (post-discharge SBP) suggested that unmeasured confounding is unlikely to change the findings. Sensitivity analysis using IPWRA showed very similar results. Conclusion Among hospitalized patients with non-severe CAP, treatment with fluoroquinolone monotherapy was associated with more hospital-free days, lower in-hospital mortality, and reduced need for advanced respiratory support compared with AZM and β-lactam combination. The findings highlight the role of fluoroquinolone as a beneficial alternative CAP patients. However, further studies are needed to explore the underlying mechanisms driving these differences and assess whether specific patient subgroups may benefit most from quinolone-based therapy. This abstract is funded by: none