Efficacy and safety of baricitinib for the treatment of hospitalised adults with COVID-19 (COV-BARRIER): a randomised, double-blind, parallel-group, placebo-controlled phase 3 trial.

BACKGROUND: Baricitinib is an oral selective Janus kinase 1/2 inhibitor with known anti-inflammatory properties. This study evaluates the efficacy and safety of baricitinib in combination with standard of care for the treatment of hospitalised adults with COVID-19. METHODS: In this phase 3, double-blind, randomised, placebo-controlled trial, participants were enrolled from 101 centres across 12 countries in Asia, Europe, North America, and South America. Hospitalised adults with COVID-19 receiving standard of care were randomly assigned (1:1) to receive once-daily baricitinib (4 mg) or matched placebo for up to 14 days. Standard of care included systemic corticosteroids, such as dexamethasone, and antivirals, including remdesivir. The composite primary endpoint was the proportion who progressed to high-flow oxygen, non-invasive ventilation, invasive mechanical ventilation, or death by day 28, assessed in the intention-to-treat population. All-cause mortality by day 28 was a key secondary endpoint, and all-cause mortality by day 60 was an exploratory endpoint; both were assessed in the intention-to-treat population. Safety analyses were done in the safety population defined as all randomly allocated participants who received at least one dose of study drug and who were not lost to follow-up before the first post-baseline visit. This study is registered with ClinicalTrials.gov, NCT04421027. FINDINGS: Between June 11, 2020, and Jan 15, 2021, 1525 participants were randomly assigned to the baricitinib group (n=764) or the placebo group (n=761). 1204 (79·3%) of 1518 participants with available data were receiving systemic corticosteroids at baseline, of whom 1099 (91·3%) were on dexamethasone; 287 (18·9%) participants were receiving remdesivir. Overall, 27·8% of participants receiving baricitinib and 30·5% receiving placebo progressed to meet the primary endpoint (odds ratio 0·85 [95% CI 0·67 to 1·08], p=0·18), with an absolute risk difference of -2·7 percentage points (95% CI -7·3 to 1·9). The 28-day all-cause mortality was 8% (n=62) for baricitinib and 13% (n=100) for placebo (hazard ratio [HR] 0·57 [95% CI 0·41-0·78]; nominal p=0·0018), a 38·2% relative reduction in mortality; one additional death was prevented per 20 baricitinib-treated participants. The 60-day all-cause mortality was 10% (n=79) for baricitinib and 15% (n=116) for placebo (HR 0·62 [95% CI 0·47-0·83]; p=0·0050). The frequencies of serious adverse events (110 [15%] of 750 in the baricitinib group vs 135 [18%] of 752 in the placebo group), serious infections (64 [9%] vs 74 [10%]), and venous thromboembolic events (20 [3%] vs 19 [3%]) were similar between the two groups. INTERPRETATION: Although there was no significant reduction in the frequency of disease progression overall, treatment with baricitinib in addition to standard of care (including dexamethasone) had a similar safety profile to that of standard of care alone, and was associated with reduced mortality in hospitalised adults with COVID-19. FUNDING: Eli Lilly and Company. TRANSLATIONS: For the French, Japanese, Portuguese, Russian and Spanish translations of the abstract see Supplementary Materials section.

Baricitinib versus Placebo or Adalimumab in Rheumatoid Arthritis.

BACKGROUND: Baricitinib is an oral, reversible inhibitor of the Janus kinases JAK1 and JAK2 that may have therapeutic value in patients with rheumatoid arthritis. METHODS: We conducted a 52-week, phase 3, double-blind, placebo- and active-controlled trial in which 1307 patients with active rheumatoid arthritis who were receiving background therapy with methotrexate were randomly assigned to one of three regimens in a 3:3:2 ratio: placebo (switched to baricitinib after 24 weeks), 4 mg of baricitinib once daily, or 40 mg of adalimumab (an anti-tumor necrosis factor α monoclonal antibody) every other week. End-point measures evaluated after adjustment for multiplicity included 20% improvement according to the criteria of the American College of Rheumatology (ACR20 response) (the primary end point), the Disease Activity Score for 28 joints (DAS28), the Health Assessment Questionnaire-Disability Index, and the Simplified Disease Activity Index at week 12, as well as radiographic progression of joint damage as measured by the van der Heijde modification of the total Sharp score (mTSS) (range, 0 to 448, with higher scores indicating greater structural joint damage) at week 24. RESULTS: More patients had an ACR20 response at week 12 with baricitinib than with placebo (primary end point, 70% vs. 40%, P<0.001). All major secondary objectives were met, including inhibition of radiographic progression of joint damage, according to the mTSS at week 24 with baricitinib versus placebo (mean change from baseline, 0.41 vs. 0.90; P<0.001) and an increased ACR20 response rate at week 12 with baricitinib versus adalimumab (70% vs. 61%, P=0.014). Adverse events, including infections, were more frequent through week 24 with baricitinib and adalimumab than with placebo. Cancers were reported in five patients (two who received baricitinib and three who received placebo). Baricitinib was associated with reductions in neutrophil counts and increases in levels of creatinine and low-density lipoprotein cholesterol. CONCLUSIONS: In patients with rheumatoid arthritis who had had an inadequate response to methotrexate, baricitinib was associated with significant clinical improvements as compared with placebo and adalimumab. (Funded by Eli Lilly and Incyte; ClinicalTrials.gov number, NCT01710358 .).

Baricitinib, Methotrexate, or Combination in Patients With Rheumatoid Arthritis and No or Limited Prior Disease-Modifying Antirheumatic Drug Treatment.

OBJECTIVE: We undertook this phase III study to evaluate baricitinib, an orally administered JAK-1/JAK-2 inhibitor, as monotherapy or combined with methotrexate (MTX) compared to MTX monotherapy in patients with active rheumatoid arthritis (RA) who had received no or minimal conventional synthetic disease-modifying antirheumatic drugs (DMARDs) and who were naive to biologic DMARDs. METHODS: A total of 588 patients were randomized 4:3:4 to receive MTX monotherapy (once weekly), baricitinib monotherapy (4 mg once daily), or the combination of baricitinib and MTX for 52 weeks. The primary end point assessment was a noninferiority comparison of baricitinib monotherapy to MTX monotherapy based on the proportion of patients meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) at week 24. RESULTS: The study met its primary objective. Moreover, baricitinib monotherapy was found to be superior to MTX monotherapy at week 24, with a higher ACR20 response rate (77% versus 62%; P ≤ 0.01). Similar results were observed for combination therapy. Compared to MTX monotherapy, significant improvements in disease activity and physical function were observed for both baricitinib groups as early as week 1. Radiographic progression was reduced in both baricitinib groups compared to MTX monotherapy; the difference was statistically significant for baricitinib plus MTX. The rates of serious adverse events (AEs) were similar across treatment groups, while rates of some treatment-emergent AEs, including infections, were increased with baricitinib plus MTX. Three deaths were reported, all occurring in the MTX monotherapy group. Malignancies, including nonmelanoma skin cancer, were reported in 1 patient receiving MTX monotherapy, 1 receiving baricitinib monotherapy, and 4 receiving baricitinib plus MTX. CONCLUSION: Baricitinib alone or in combination with MTX demonstrated superior efficacy with acceptable safety compared to MTX monotherapy as initial therapy for patients with active RA.

Baricitinib in patients with inadequate response or intolerance to conventional synthetic DMARDs: results from the RA-BUILD study.

BACKGROUND: Baricitinib is an oral, reversible, selective Janus kinase 1 and 2 inhibitor. METHODS: In this phase III, double-blind 24-week study, 684 biologic disease-modifying antirheumatic drug (DMARD)-naïve patients with rheumatoid arthritis and inadequate response or intolerance to ≥1 conventional synthetic DMARDs were randomly assigned 1:1:1 to placebo or baricitinib (2 or 4 mg) once daily, stratified by region and the presence of joint erosions. Endpoint measures included American College of Rheumatology 20% response (ACR20, primary endpoint), Disease Activity Score (DAS28) and Simplified Disease Activity Index (SDAI) score ≤3.3. RESULTS: More patients achieved ACR20 response at week 12 with baricitinib 4 mg than with placebo (62% vs 39%, p≤0.001). Compared with placebo, statistically significant improvements in DAS28, SDAI remission, Health Assessment Questionnaire-Disability Index, morning joint stiffness, worst joint pain and worst tiredness were observed. In a supportive analysis, radiographic progression of structural joint damage at week 24 was reduced with baricitinib versus placebo. Rates of adverse events during the treatment period and serious adverse events (SAEs), including serious infections, were similar among groups (SAEs: 5% for baricitinib 4 mg and placebo). One patient had an adverse event of tuberculosis (baricitinib 4 mg); one patient had an adverse event of non-melanoma skin cancer (baricitinib 4 mg). Two deaths and three major adverse cardiovascular events occurred (placebo). Baricitinib was associated with a decrease in neutrophils and increases in low-density and high-density lipoprotein. CONCLUSIONS: In patients with rheumatoid arthritis and an inadequate response or intolerance to conventional synthetic DMARDs, baricitinib was associated with clinical improvement and inhibition of progression of radiographic joint damage. TRIAL REGISTRATION NUMBER: NCT01721057; Results.

Baricitinib in Patients with Refractory Rheumatoid Arthritis.

BACKGROUND: In phase 2 studies, baricitinib, an oral Janus kinase 1 and 2 inhibitor, reduced disease activity in patients with rheumatoid arthritis who had not previously received treatment with biologic disease-modifying antirheumatic drugs (DMARDs). METHODS: In this phase 3 study involving 527 patients with an inadequate response to or unacceptable side effects associated with one or more tumor necrosis factor inhibitors, other biologic DMARDs, or both, we randomly assigned the patients in a 1:1:1 ratio to baricitinib at a dose of 2 or 4 mg daily or placebo for 24 weeks. End points, tested hierarchically at week 12 to control type 1 error, were the American College of Rheumatology 20% (ACR20) response (primary end point), the Health Assessment Questionnaire-Disability Index (HAQ-DI) score, the 28-joint Disease Activity Score based on C-reactive protein level (DAS28-CRP), and a Simplified Disease Activity Index (SDAI) score of 3.3 or less (on a scale of 0.1 to 86.0, with a score of 3.3 or less indicating remission). Comparisons with placebo were made first with the 4-mg dose of baricitinib and then with the 2-mg dose. RESULTS: Significantly more patients receiving baricitinib at the 4-mg dose than those receiving placebo had an ACR20 response at week 12 (55% vs. 27%, P<0.001). Differences between the higher-dose baricitinib group and the placebo group were also significant for the HAQ-DI score and the DAS28-CRP but not for an SDAI score of 3.3 or less. Adverse-event rates through 24 weeks were higher for patients receiving the 2-mg dose of baricitinib and those receiving the 4-mg dose than for patients receiving placebo (71% and 77%, respectively, vs. 64%), including infections (44% and 40%, vs. 31%). The rates of serious adverse events were 4%, 10%, and 7% in the three groups, respectively. Two nonmelanoma skin cancers and two major adverse cardiovascular events, including a fatal stroke, occurred in the higher-dose group. Baricitinib was associated with a small reduction in neutrophil levels and increases in serum creatinine and low-density lipoprotein cholesterol levels. CONCLUSIONS: In patients with rheumatoid arthritis and an inadequate response to biologic DMARDs, baricitinib at a daily dose of 4 mg was associated with clinical improvement at 12 weeks. (Funded by Eli Lilly and Incyte; ClinicalTrials.gov number, NCT01721044.).

Folding and stability of a primitive protein.

We have previously attempted to simulate domain creation in early protein evolution by recombining polypeptide segments from non-homologous proteins, and we have described the structure of one such de novo protein, 1b11, a segment-swapped tetramer with novel architecture. Here, we have analyzed the thermodynamic stability and folding kinetics of the 1b11 tetramer and its monomeric and dimeric intermediates, and of 1b11 mutants with changes at the domain interface. Denatured 1b11 polypeptides fold into transient, folded monomers with marginal stability (DeltaG<1kcalmol(-1)) which convert rapidly ( approximately 6x10(4)M(-1)s(-1)) into dimers (DeltaG=9.8kcal/mol) and then more slowly ( approximately 3M(-1)s(-1)) into tetramers (DeltaG=28kcalmol(-1)). Segment swapping takes place during dimerization, as suggested by mass spectroscopic analysis of covalently linked peptides derived from proteolysis of a disulfide-linked dimer. Our results confirm that segment swapping and associated oligomerization are both powerful ways of stabilizing proteins, and we suggest that this may have been a feature of early protein evolution.

A segment of cold shock protein directs the folding of a combinatorial protein.

It has been suggested that protein domains evolved by the non-homologous recombination of building blocks of subdomain size. In earlier work we attempted to recapitulate domain evolution in vitro. We took a polypeptide segment comprising three beta-strands in the monomeric, five-stranded beta-barrel cold shock protein (CspA) of Escherichia coli as a building block. This segment corresponds to a complete exon in homologous eukaryotic proteins and includes residues that nucleate folding in CspA. We recombined this segment at random with fragments of natural proteins and succeeded in generating a range of folded chimaeric proteins. We now present the crystal structure of one such combinatorial protein, 1b11, a 103-residue polypeptide that includes segments from CspA and the S1 domain of the 30S ribosomal subunit of E. coli. The structure reveals a segment-swapped, six-stranded beta-barrel of unique architecture that assembles to a tetramer. Surprisingly, the CspA segment retains its structural identity in 1b11, recapitulating its original fold and deforming the structure of the S1 segment as necessary to complete a barrel. Our work provides structural evidence that (i) random shuffling of nonhomologous polypeptide segments can lead to folded proteins and unique architectures, (ii) many structural features of the segments are retained, and (iii) some segments can act as templates around which the rest of the protein folds.