OP18 Efficacy and safety of filgotinib for the treatment of perianal fistulizing Crohn’s Disease: Results from the phase 2 DIVERGENCE 2 study

Background

Treatment of perianal fistulizing Crohn’s disease (PFCD) is a major unmet need. Filgotinib (FIL) is a once-daily, oral, preferential Janus kinase 1 inhibitor in development for the treatment of inflammatory bowel diseases. The efficacy and safety of FIL for the treatment of PFCD was evaluated in the phase 2, double-blind, randomized, placebo (PBO)-controlled DIVERGENCE 2 study (NCT03077412).

Methods

Patients (18–75 years old) with PFCD (documented diagnosis of CD for at least 3 months and 1–3 external openings [EOs] with drainage [spontaneous or on compression] for ≥ 4 weeks before screening) previously treated with antibiotics, immunomodulators and/or tumour necrosis factor inhibitors (TNFi) were randomized (2:2:1) to receive FIL 200 mg, FIL 100 mg or PBO once daily for up to 24 weeks. Active luminal CD was permitted providing that the Crohn’s Disease Activity Index score was ≤ 300 at screening. The primary endpoint was combined fistula response (reduction of ≥ 1 from baseline in the number of draining EOs determined by investigator assessment and no fluid collections > 1 cm on centrally read pelvic magnetic resonance imaging [MRI]) at Week 24. Combined fistula remission (closure of all draining EOs present at baseline and no fluid collections > 1 cm) at Week 24 was a key secondary endpoint. The study was not powered for statistical comparisons and was prematurely terminated owing to low recruitment rates during the COVID-19 pandemic.

Results

Baseline characteristics were broadly similar across the treatment groups (Table 1). Overall, 91.2% of patients had complex perianal fistulae and TNFi treatment had previously failed in 64.9% of patients. A lower proportion of patients randomized to receive FIL 200 mg discontinued the study compared with those who received PBO (Table 2). The proportion of patients who achieved a combined fistula response at Week 24 was numerically higher in the FIL 200 mg group (47.1%; 90% confidence interval [CI]: 26.0–68.9) than in the PBO group (25.0%; 90% CI: 7.2–52.7) (Figure 1), with similar results observed for combined fistula remission (FIL 200 mg [47.1%; CI: 26.0–68.9] versus PBO [16.7%; CI: 3.0–43.8]) (Figure 2). Treatment-emergent severe adverse events were highest in the FIL 200 mg group (Table 2). Adverse event rates were otherwise similar across treatment groups.

Conclusion

In this phase 2 study, numerically higher fistula response and remission rates were observed after 24 weeks of treatment with FIL 200 mg versus PBO in patients with active PFCD and a history of multiple medical treatment failures. FIL was well tolerated overall. Further studies of FIL for the treatment of PFCD are warranted.

Adjunct antibody administration with standard treatment reduces relapse rates in a murine tuberculosis model of necrotic granulomas

Matrix metalloproteinase (MMP)-9 is a zinc-dependent protease associated with early immune responses to Mycobacterium tuberculosis infection, macrophage recruitment and granuloma formation. We evaluated whether adjunctive inhibition of MMP-9 could improve the response to standard TB treatment in a mouse model that develops necrotic lesions. Six weeks after an aerosol infection with M. tuberculosis, C3HeB/FeJ mice received standard TB treatment (12 weeks) comprising rifampin, isoniazid and pyrazinamide alone or in combination with either anti-MMP-9 antibody, etanercept (positive control) or isotype antibody (negative control) for 6 weeks. Anti-MMP-9 and the isotype control had comparable high serum exposures and expected terminal half-life. The relapse rate in mice receiving standard TB treatment was 46.6%. Compared to the standard TB treatment, relapse rates in animals that received adjunctive treatments with anti-MMP-9 antibody or etanercept were significantly decreased to 25.9% (P = 0.006) and 29.8% (P = 0.019) respectively, but were not different from the arm that received the isotype control antibody (25.9%). Immunostaining demonstrated localization of MMP-9 primarily in macrophages in both murine and human lung tissues infected with M. tuberculosis, suggesting the importance of MMP-9 in TB pathogenesis. These data suggest that the relapse rates in M. tuberculosis-infected mice may be non-specifically improved by administration of antibodies in conjunction with standard TB treatments. Future studies are needed to evaluate the mechanism(s) leading to improved outcomes with adjunctive antibody treatments.

A preliminary quality of life questionnaire-bronchiectasis: a patient-reported outcome measure for bronchiectasis

BACKGROUND

The Quality of Life Questionnaire-Bronchiectasis (QOL-B) is the first disease-specific, patient-reported outcome measure for patients with bronchiectasis. Content validity, cognitive testing, responsivity to open-label treatment, and psychometric analyses are presented.

METHODS

Reviews of literature, existing measures, and physician input were used to generate the initial QOL-B. Modifications following preliminary cognitive testing (N = 35 patients with bronchiectasis) generated version (V) 1.0. An open-ended patient interview study (N = 28) provided additional information and was content analyzed to derive saturation matrices, which summarized all disease-related topics mentioned by each participant. This resulted in QOL-B V2.0. Psychometric analyses were carried out using results from an open-label phase 2 trial, in which 89 patients were enrolled and treated with aztreonam for inhalation solution. Responsivity to open-label treatment was observed. Additional analyses generated QOL-B V3.0, with 37 items on eight scales: respiratory symptoms; physical, role, emotional, and social functioning; vitality; health perceptions; and treatment burden. For each scale, scores are standardized on a 0-to-100-point scale; higher scores indicate better health-related quality of life. No total score is calculated. A final cognitive testing study (N = 40) resulted in a minor change to one social functioning scale item (QOL-B V3.1).

RESULTS

Content validity, cognitive testing, responsivity to open-label treatment, and initial psychometric analyses supported QOL-B items and structure.

CONCLUSIONS

This interim QOL-B is a promising tool for evaluating the efficacy of new therapies for patients with bronchiectasis and for measuring symptoms, functioning, and quality of life in these patients on a routine basis. A final psychometric validation study is needed and is forthcoming.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00805025; URL: www.clinicaltrials.gov.

Fosfomycin/tobramycin for inhalation in patients with cystic fibrosis with pseudomonas airway infection

RATIONALE

Fosfomycin/tobramycin for inhalation (FTI), a unique, broad-spectrum antibiotic combination, may have therapeutic potential for patients with cystic fibrosis (CF).

OBJECTIVES

To evaluate safety and efficacy of FTI (160/40 mg or 80/20 mg), administered twice daily for 28 days versus placebo, in patients greater than or equal to 18 years of age, with CF, chronic Pseudomonas aeruginosa (PA) airway infection, and FEV(1) greater than or equal to 25% and less than or equal to 75% predicted.

METHODS

This double-blind, placebo-controlled, multicenter study assessed whether FTI/placebo maintained FEV(1) % predicted improvements achieved following a 28-day, open-label, run-in course of aztreonam for inhalation solution (AZLI).

MEASUREMENTS AND MAIN RESULTS

A total of 119 patients were randomized to FTI (160/40 mg: n = 41; 80/20 mg: n = 38) or placebo (n = 40). Mean age was 32 years and mean FEV(1) was 49% predicted at screening. Relative improvements in FEV(1) % predicted achieved by the AZLI run-in were maintained in FTI groups compared with placebo (160/40 mg vs. placebo: 6.2% treatment difference favoring FTI, P = 0.002 [primary endpoint]; 80/20 mg vs. placebo: 7.5% treatment difference favoring FTI, P < 0.001). The treatment effect on mean PA sputum density was statistically significant for the FTI 80/20 mg group versus placebo (-1.04 log(10) PA colony-forming units/g sputum difference, favoring FTI; P = 0.01). Adverse events, primarily cough, were consistent with CF disease. Respiratory events, including dyspnea and wheezing, were less common with FTI 80/20 mg than FTI 160/40 mg. No clinically significant differences between groups were reported for laboratory values.

CONCLUSIONS

FTI maintained the substantial improvements in FEV(1) % predicted achieved during the AZLI run-in and was well tolerated. FTI is a promising antipseudomonal therapy for patients with CF.

Reactivity of antibodies from syphilis patients to a protein array representing the Treponema pallidum proteome

To identify antigens important in the human immune response to syphilis, the serum antibody reactivity of syphilitic patients was examined with 908 of the 1,039 proteins in the proteome of Treponema pallidum subsp. pallidum using a protein array enzyme-linked immunosorbent assay. Thirty-four proteins exhibited significant reactivity when assayed with human sera from patients in the early latent stage of syphilis. A subset of antigens identified were further scrutinized for antibody reactivity at primary, secondary, and latent disease stages, and the results demonstrate that the humoral immune response to individual T. pallidum proteins develops at different rates during the time course of infection.

Genome scale identification of Treponema pallidum antigens

Antibody responses for 882 of the 1,039 proteins in the proteome of Treponema pallidum were examined. Sera collected from infected rabbits were used to systematically identify 106 antigenic proteins, including 22 previously identified antigens and 84 novel antigens. Additionally, sera collected from rabbits throughout the course of infection demonstrated a progression in the breadth and intensity of humoral immunoreactivity against a representative panel of T. pallidum antigens.

Transcriptome of Treponema pallidum: gene expression profile during experimental rabbit infection

RNA transcript levels in the syphilis spirochete Treponema pallidum subsp. pallidum (Nichols) isolated from experimentally infected rabbits were determined by the use of DNA microarray technology. This characterization of the T. pallidum transcriptome during experimental infection provides further insight into the importance of gene expression levels for the survival and pathogenesis of this bacterium.

Systematic cloning of Treponema pallidum open reading frames for protein expression and antigen discovery

A topoisomerase-based method was used to clone PCR products encoding 991 of the 1041 open reading frames identified in the genome sequence of the bacterium that causes syphilis, Treponema pallidum subsp. pallidum. Cloning the open reading frames into the univector plasmid system permitted the rapid conversion of the original clone set to other functional vectors containing a variety of promoters or tag sequences. A computational prediction of signal sequences identified 248 T. pallidum proteins that are potentially secreted from the cell. These clones were systematically converted into vectors designed to express the encoded proteins as glutathione-S-transferase fusion proteins. To test the potential of the clone set for novel antigen discovery, 85 of these fusion proteins were expressed from Escherichia coli, partially purified, and tested for antigenicity by using sera from rabbits infected with T. pallidum. Twelve of the 85 proteins bound significant levels of antibody. Of these 12 proteins, seven had previously been identified as T. pallidum antigens, and the remaining five represent novel antigens. These results demonstrate the potential of the T. pallidum clone set for antigen discovery and, more generally, for advancing the biology of this enigmatic spirochete.

BAC library of T. pallidum DNA in E. coli

Treponema pallidum subspecies pallidum (Nichols) chromosomal DNA was used to construct a large insert bacterial artificial chromosome (BAC) library in Escherichia coli DH10B using the pBeloBAC11 cloning vector; 678 individual insert termini of 339 BAC clones (13.9 x coverage) were sequenced and the cloned chromosomal region in each clone was determined by comparison to the genomic sequence. A single 15.6-kb region of the T. pallidum chromosome was missing in the BAC library, between bp 248727 and 264323. In addition to the 12 open reading frames (ORFs) coded by this region, one additional ORF (TP0596) was not cloned as an intact gene. Altogether, 13 predicted T. pallidum ORFs (1.25% of the total) were incomplete or missing in the library. Three of 338 clones mapped by restriction enzyme digestion had detectable deletions and one clone had a detectable insertion within the insert. Of mapped clones, 19 were selected to represent the minimal set of E. coli BAC clones covering 1026 of the total 1040 (98.7%) predicted T. pallidum ORFs. Using this minimal set of clones, at least 12 T. pallidum proteins were shown to react with pooled sera from rabbits immunized with T. pallidum, indicating that at least some T. pallidum genes are transcribed and expressed in E. coli.

Use of the arabinose p(bad) promoter for tightly regulated display of proteins on bacteriophage

Phage display is a widely used method to optimize the binding characteristics of protein-ligand interactions. In addition, it has been used to clone genes from genomic and cDNA libraries based on their ligand-binding characteristics. One difficulty often encountered when expressing heterologous proteins by phage display is the toxicity of the protein on the Escherichia coli host. Previous studies have shown that heterologous protein expression can be tightly controlled using plasmids with the P(BAD) promoter of the arabinose operon of E. coli, and the araC gene, which is both a positive and negative regulator of the promoter. We constructed a set of phage display vectors that utilize the P(BAD) promoter to control the expression of proteins on the surface of the M13 bacteriophage. These vectors exhibit tightly controlled expression of proteins on the surface of the phage. In addition, the amount of protein displayed on the phage is modulated by the amount of arabinose present in the growth medium during phage propagation. This may be useful for altering the stringency of binding enrichment during phage display.

Natural history of recurrent urinary tract infections in women

To evaluate the natural history of uncomplicated urinary tract infections in women, we observed 51 infection-prone women in a standardized fashion for a median of 9 years. During intervals when patients were not receiving antimicrobial prophylaxis, infections occurred at an average rate of 2.6 per patient-year, but the rate varied widely from patient to patient (range 0.3-7.6 episodes per year). Seventy-three percent of the observed episodes were symptomatic, with an 18:1 ratio of cystitis to pyelonephritis episodes. Infectious episodes were strikingly clustered, and rates of infection decreased in the winter months. Antimicrobial prophylaxis was highly effective in preventing acute cystitis, asymptomatic bacteriuria, and acute pyelonephritis, even when used for as long as 5 years. The proportions of infecting strains resistant in vitro to ampicillin (19%-32%) and nitrofurantoin (5%-18%) were unchanged over the 15-year observation period, while resistance to trimethoprim-sulfamethoxazole increased in the last 5 years of the study.

Acute renal infection in women: treatment with trimethoprim-sulfamethoxazole or ampicillin for two or six weeks. A randomized trial

We compared the efficacy of orally administered ampicillin, 2 g/d, with that of trimethoprim-sulfamethoxazole, 320 mg/d-1600 mg/d, given for 2 or 6 weeks for outpatient management of acute uncomplicated renal infection in women. Of 98 women participating in the trial, 60 had renal infections with susceptible strains, complied with drug therapy, and completed 6 weeks of follow-up. Before treatment, 39 women had symptoms and signs of acute pyelonephritis; 21 had symptoms of cystitis but positive tests for antibody-coated bacteria. All 60 women had alleviation of symptoms and resolution of bacteriuria after 7 days of therapy. Subsequent recurrences occurred in 12 of 27 women given ampicillin, compared with 4 of 33 given trimethoprim-sulfamethoxazole (p = 0.008). Serotyping showed that most recurrences were reinfections with ampicillin-resistant strains. With each drug, a 2-week regimen of therapy proved as efficacious as a 6-week regimen, but the longer regimen was less well tolerated. We conclude that a 2-week treatment regimen is sufficient to manage acute pyelonephritis in outpatients and that trimethoprim-sulfamethoxazole is preferable to ampicillin therapy.

Management of recurrent urinary tract infections with patient-administered single-dose therapy

In a randomized crossover trial, 38 women with recurrent urinary tract infections were assigned to use either continuous prophylaxis with trimethoprim-sulfamethoxazole or intermittent self-administered therapy (single-dose trimethoprim-sulfamethoxazole taken for acute urinary symptoms). The infection rate for patients on prophylaxis was 0.2 episodes/patient-year compared with 2.2 infections/patient-year for patients on self-administered therapy (p less than 0.001). Thirty-five of thirty-eight symptomatic episodes diagnosed by patients as infection were confirmed microbiologically, and 30 of the 35 infections responded clinically and microbiologically to patient-administered therapy with single-dose trimethoprim-sulfamethoxazole. No complications were seen in the 5 patients in whom therapy failed. The annual costs of prophylaxis and self-therapy were similar ($256 and $239, respectively) and both were less expensive than conventional therapy in women having 2 or more infections per year. In selected women, self-therapy is efficacious and economical compared with conventional therapy or prophylaxis.

Treatment of cystitis in women with a single dose of trimethoprim-sulfamethoxazole

The efficacy of a single dose (four tablets) and of 10-day courses of trimethoprim-sulfamethoxazole (TMP-SMZ) was studied in 77 women with symptomatic cystitis and negative tests for antibody-coated bacteria. Cure rates after six weeks were 76% for single-dose therapy and 87% for 10 days of treatment. For Escherichia coli infections, cure rates after six weeks were 80% and 86%, respectively. However, 10-day treatment eliminated enteric bacilli from urethral and vaginal sites more often than did single-dose therapy. Two weeks after completion of treatment, perineal colonization was observed more often in the women who developed recurrent infections than in those who did not (P = 0.01). During these two weeks, recurrent infections were found somewhat more often in the women who had received single-dose therapy than in those who had undergone 10-day treatment (5 of 38 vs. 2 of 39; P = 0.07). With conventional courses of antibiotics, retreatment of all recurrent infections was less successful in women previously given single-dose therapy. Recurrent infections were also more frequent in women infected with bacteria other than E. coli. Both drug regimens were well tolerated. However, serious adverse reactions were fewer in patients treated with a single dose (8.5%) than in patients treated for 10 days (15%). Single-dose therapy with TMP-SMZ appears as effective as 10-day therapy in acute uncomplicated cystitis caused by E. coli.

Urinary prophylaxis with trimethoprim and trimethoprim-sulfamethoxazole: efficacy, influence on the natural history of recurrent bacteriuria, and cost control

Low-dose trimethoprim (TMP), trimethoprim-sulfamethoxazole (TMP-SMZ), and nitrofurantoin macrocrystals were found to be safe and effective as prophylaxis against recurrent urinary tract infections. Women given placebo had 2.8 infections per patient-year during the six-month study period, while women given TMP, TMP-SMZ, or nitrofurantoin had significantly lower infection rates (0.015 per patient-year). The effect of prophylaxis appeared to be limited to the period when the agents were taken. Only one patient had a TMP-resistant coliform isolated from cultures obtained during prophylaxis and six months afterwards. The sole factor associated with the recurrence of infection after prophylaxis was a history of three or more infections in the year preceding prophylaxis. Thirty-one of the 60 women in the trial were monitored for a mean of 6.1 years before and 3.2 years after they entered the study. Analysis of infection rates indicated that about half these women were experiencing an infection cluster when they entered the study and that the prestudy baseline infection rate correlated with the poststudy rate. Thus, prophylaxis did not appear to exert a long-term effect on the baseline infection rate. Urinary prophylaxis generally appears to become cost-effective when the baseline infection rate exceeds two per patient-year.

Is antimicrobial prophylaxis of urinary tract infections cost effective?

Antimicrobial prophylaxis prevents recurrent urinary tract infections in susceptible women, but its cost effectiveness has not been studied. In a recent placebo-controlled trial of urinary prophylaxis, we also assessed cost effectiveness using a decision analysis model. In our hospital the direct cost of 1 patient year of urinary prophylaxis approximates the cost of treating one episode of cystitis. In women with a baseline infection rate of three per patient year, the annual cost of prophylaxis ($85.82) was less than treatment of acute episodes of infection ($392.30). Sensitivity analyses showed that in women with three infections per year, prophylaxis became cost effective when charges per episode exceeded $42.00. In women with frequent episodes of cystitis, prophylaxis will be cost effective in most practice settings.

Antimicrobial prophylaxis of recurrent urinary tract infections: a double-blind, placebo-controlled trial

To study once-daily antimicrobial prophylaxis of urinary tract infections, we gave trimethoprim-sulfamethoxazole (40 mg/200 mg), trimethoprim (100 mg), nitrofurantoin macrocrystals (100 mg), or placebo to 60 women for 6 months. During prophylaxis, infections per patient year were comparable in the groups receiving trimethoprim (0.0), nitrofurantoin (0.14), or trimethoprim-sulfamethoxazole (0.15) and occurred less frequently than in patients receiving placebo (2.8; P less than 0.001, placebo versus each drug regimen). The effectiveness of prophylaxis was limited to the 6 months that antimicrobials were given, and infections were more likely to develop after prophylaxis in women who had three or more infections in the year before prophylaxis (P less than 0.005). Further, women whose preprophylaxis infection was positive for antibody-coated bacteria were more likely to have same-strain relapse when infections recurred (P = 0.001). Emergence of trimethoprim-resistant Escherichia coli was rare, but non-E. coli infections occurred more often after prophylaxis (P less than 0.05). Prophylaxis with these drugs is effective, well tolerated, and did not produce emergence of resistant E. coli but may predispose to non-E. coli urinary tract infections after its discontinuation.