Daily Respiratory Research Analysis

BACKGROUND: We evaluated whether a daily nasal spray of interferon-alpha (IFN-α) would reduce the incidence of COVID-19 or community-acquired respiratory viral infections in adult cancer patients. METHODS: In this multicenter, randomized, double-blinded, placebo-controlled trial, participants were randomized 1:1 to receive daily 40 000 IU IFN-α nasal spray or normal saline placebo. Participants who developed influenza-like symptoms self-collected nasal swabs for PCR testing of SARS-CoV-2, influenza A/B, respiratory syncytial virus, parainfluenza, adenovirus, seasonal coronavirus, picornavirus, human metapneumovirus, and/or SARS-CoV-2 rapid antigen testing. Co-primary endpoints were incidence of COVID-19 and/or other respiratory viruses ≤90 days of randomization. RESULTS: Four hundred and thirty-three participants were randomized to IFN-α (n = 217) or placebo (n = 216). The incidence of COVID-19 was lower in the IFN-α group versus placebo (8.3% vs 14.4%), indicating a 40% reduced risk of infection (relative risk [RR]: .60; 95% credible interval [CrI]: .33-.97). Other respiratory viral infection incidence was 5.1% and 5.1% in both groups (RR: 1.12; .43-2.34). In the per-protocol cohort (n = 389), the incidence of COVID-19 in IFN-α and placebo groups was 7.7% and 16.0% (RR: .50; .26-.84) with other respiratory virus incidence of 4.6% and 5.7%, respectively. Subgroup analysis demonstrated lower COVID-19 in the IFN-α group for ages <65 years (RR: .48; .20-.92), female sex (RR: .44; .19-.85), and COVID-19 vaccinated (RR: .50; .26-.82), but no difference by underlying malignancy. No differences were observed in secondary endpoints of severity, hospitalization, and mortality. IFN-α was well tolerated and safe. CONCLUSIONS: IFN-α nasal spray prophylaxis reduced the incidence of COVID-19 among adult cancer patients. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov identifier: NCT04534725 (ANZCTR: ACTRN12620000843954).

Idiopathic pulmonary fibrosis (IPF) is a disease of progressive lung remodeling and collagen deposition that leads to respiratory failure. Myeloid cells are abundant in IPF lung and in murine lung fibrosis, but their functional effects are incompletely understood. Using mouse and human lung models, we show that ornithine produced by myeloid cells expressing arginase 1 (ARG1) serves as a substrate for proline and collagen synthesis by lung fibroblasts. The predominant ARG1-expressing myeloid cells in mouse lung were macrophages, but in IPF lung, high-dimensional imaging revealed ARG1 was expressed mainly in neutrophils. Small-molecule ARG1 inhibition suppressed both ornithine levels and collagen expression in cultured, precision-cut IPF lung slices and in murine lung fibrosis. These results were confirmed in macrophage-specific Arg1-KO mice. Furthermore, we found that this pathway is regulated by cell-to-cell crosstalk, starting with purinergic signaling: extracellular ATP receptor P2RX4 was necessary for fibroblast IL-6 expression, which, in turn, was necessary for ARG1 expression by myeloid cells. Taken together, our findings define an immune-mesenchymal circuit that governs profibrotic metabolism in lung fibrosis.

The efficacy of VIR-7831, a class 3 anti-SARS-CoV-2 monoclonal antibody (mAb), was demonstrated repeatedly in clinical trials; yet, reduced neutralization against Omicron variants in cell-line-based neutralization assays led to its withdrawal from clinical use. We developed organoid-based neutralization assays to measure mAb potency. We found that most class 3 mAbs, especially those not blocking receptor-binding domain-ACE2 binding, including VIR-7831, were substantially underestimated in cell-line-based assays. Nasal organoids adequately recapitulated the real-world effectiveness of VIR-7831 because of biologically relevant low ACE2 expression, and exclusively reproduced the in vivo protection of S2 mAbs due to the high TMPRSS2 expression, reminiscent of native human respiratory epithelial cells. Collectively, the robust organoid culture system and biologically relevant expression profiles of ACE2 and TMPRSS2 make nasal organoids present a correlate of in vivo protection of neutralizing mAbs exclusively. The organoid-based neutralization assays, superior to conventional cell-line-based assays, can recapitulate and predict the real-world efficacy of mAbs.