Ozanimod in Patients With Moderate to Severe Ulcerative Colitis Naive to Advanced Therapies.

BACKGROUND AND AIMS: The pivotal phase 3 True North (TN) study demonstrated the efficacy and safety of ozanimod in patients with moderately to severely active ulcerative colitis. This analysis assessed ozanimod during TN and the ongoing open-label extension (OLE) in patients with active disease who were naive to advanced therapies (ATs). METHODS: TN was a randomized, double-blind, placebo-controlled trial consisting of a 10-week induction period and 42-week maintenance period. Eligible patients could enter the OLE. Symptomatic efficacy was evaluated from induction through the OLE. Clinical, endoscopic, and mucosal outcomes were evaluated at the end of induction (Week [W] 10) and maintenance (W52), and at predefined OLE timepoints (OLE W46 and W94). Safety during TN was reported. RESULTS: This analysis included 616 AT-naive patients. Numerically greater proportions of patients receiving ozanimod than placebo achieved symptomatic response (39% vs 29%, 95% CI [-0.1, 18.8]) by W2, with significant differences (56% vs 39%, 95% CI [6.3, 26.3]) achieved by W4. Patients receiving ozanimod showed significant improvements across efficacy outcomes versus placebo at W10 and W52 (P<0.05, all endpoints). In patients on continuous ozanimod who entered the OLE in clinical response at W52, 91% maintained clinical response through OLE W94, and 74% achieved endoscopic improvement and 57% achieved mucosal healing at OLE W94. In ozanimod-treated patients without clinical response by W10 who received extended induction in the OLE, 62% achieved symptomatic response by OLE W10. Safety outcomes in AT-naive patients were consistent with the total TN population. CONCLUSION: Ozanimod is an effective, durable, and well-tolerated oral therapy for AT-naive ulcerative colitis patients.

Efficacy and Safety of Approximately 3 Years of Continuous Ozanimod in Moderately to Severely Active Ulcerative Colitis: Interim Analysis of the True North Open-label Extension.

BACKGROUNDS AND AIMS: This interim analysis from the True North open-label extension [OLE] study examines efficacy and safety of approximately 3 years of continuous ozanimod treatment in patients with moderately to severely active ulcerative colitis. METHODS: Clinical responders after 52 weeks of ozanimod during the phase 3 True North study, who continued treatment in the OLE, were evaluated. Efficacy, including endoscopic and histological endpoints, was assessed during the OLE for approximately 2 additional years through OLE Week 94, using observed case [OC] and nonresponder imputation [NRI] analyses. Adverse events were monitored from True North baseline through OLE data cutoff and expressed as exposure-adjusted incidence rates. RESULTS: This analysis included 131 patients; 54% had achieved corticosteroid-free remission at True North Week 52. In OC analyses, clinical response, clinical remission, and corticosteroid-free remission were achieved by 91.4%, 69.1%, and 67.9% of patients, respectively, at OLE Week 94 [146 weeks of total treatment]. Similarly, endoscopic improvement, histological remission, and mucosal healing were achieved by 73.3%, 67.3%, and 56.3% of patients, respectively, at OLE Week 94. Efficacy rates were lower using NRI analyses, but maintenance of efficacy was demonstrated through OLE Week 94. No new safety signals emerged from this analysis. Serious infections, malignancy, cardiovascular events, and hepatic events occurred infrequently. CONCLUSIONS: Among patients who achieved clinical response after 1 year of ozanimod treatment during True North, a high percentage sustained clinical and mucosal efficacy over 2 additional years in the OLE. No new safety signals were observed with long-term ozanimod use.

Cardiovascular Safety of Ozanimod in Patients With Ulcerative Colitis: True North and Open-Label Extension Analyses.

BACKGROUND & AIMS: Evaluating cardiovascular safety of sphingosine 1-phosphate (S1P) receptor modulators is warranted due to S1P receptor expression on cardiomyocytes and vascular endothelial cells. This analysis reports the cardiovascular safety of ozanimod, an S1P receptor modulator, in patients with moderately to severely active ulcerative colitis from the phase 3 True North (TN) and open-label extension (OLE). METHODS: All patients who received ozanimod in TN (n = 796) and all eligible TN patients who entered the OLE (n = 823) were included. Cardiovascular-related adverse events were evaluated in patients with up to 146 weeks of ozanimod exposure (2219 patient-years), which included 52 weeks during TN. RESULTS: On TN day 1, first-dose ozanimod resulted in a 0.2 beats per minute mean decrease in heart rate from pretreatment to hour 6; 2 patients experienced bradycardia, which resolved without treatment modification. Mean systolic and diastolic blood pressure increases of 5.1 and 2.2 mm Hg, respectively, were observed at TN week 52. No second-degree Mobitz type II atrioventricular block events were reported; 1 third-degree atrioventricular block unrelated to ozanimod occurred in the OLE. Cardiac and vascular treatment-emergent adverse events were infrequent (3.8% [31 of 823] and 8.5% [70 of 823]); no ozanimod-related cardiovascular deaths occurred. The incidences of deep-vein thrombosis (0.2%; 2 of 823), pulmonary embolism (0.2%; 2 of 823), and ischemic stroke (0.4%; 3 of 823) in the OLE were low. CONCLUSIONS: No new cardiovascular safety signals were identified, consistent with findings from previous ozanimod studies. There were few major adverse cardiovascular events or thromboembolic events, which were unrelated or unlikely related to ozanimod. Ozanimod has a well-tolerated cardiovascular safety profile when prescribed in accordance with the label. Clinical trial registry website and trial numbers: ClinicalTrials.gov numbers: NCT02435992 and NCT02531126.

Ozanimod as Induction and Maintenance Therapy for Ulcerative Colitis.

BACKGROUND: Ozanimod, a selective sphingosine-1-phosphate receptor modulator, is under investigation for the treatment of inflammatory bowel disease. METHODS: We conducted a phase 3, multicenter, randomized, double-blind, placebo-controlled trial of ozanimod as induction and maintenance therapy in patients with moderately to severely active ulcerative colitis. In the 10-week induction period, patients in cohort 1 were assigned to receive oral ozanimod hydrochloride at a dose of 1 mg (equivalent to 0.92 mg of ozanimod) or placebo once daily in a double-blind manner, and patients in cohort 2 received open-label ozanimod at the same daily dose. At 10 weeks, patients with a clinical response to ozanimod in either cohort underwent randomization again to receive double-blind ozanimod or placebo for the maintenance period (through week 52). The primary end point for both periods was the percentage of patients with clinical remission, as assessed with the three-component Mayo score. Key secondary clinical, endoscopic, and histologic end points were evaluated with the use of ranked, hierarchical testing. Safety was also assessed. RESULTS: In the induction period, 645 patients were included in cohort 1 and 367 in cohort 2; a total of 457 patients were included in the maintenance period. The incidence of clinical remission was significantly higher among patients who received ozanimod than among those who received placebo during both induction (18.4% vs. 6.0%, P<0.001) and maintenance (37.0% vs. 18.5% [among patients with a response at week 10], P<0.001). The incidence of clinical response was also significantly higher with ozanimod than with placebo during induction (47.8% vs. 25.9%, P<0.001) and maintenance (60.0% vs. 41.0%, P<0.001). All other key secondary end points were significantly improved with ozanimod as compared with placebo in both periods. The incidence of infection (of any severity) with ozanimod was similar to that with placebo during induction and higher than that with placebo during maintenance. Serious infection occurred in less than 2% of the patients in each group during the 52-week trial. Elevated liver aminotransferase levels were more common with ozanimod. CONCLUSIONS: Ozanimod was more effective than placebo as induction and maintenance therapy in patients with moderately to severely active ulcerative colitis. (Funded by Bristol Myers Squibb; True North ClinicalTrials.gov number, NCT02435992.).

Long-Term Efficacy and Safety of Ozanimod in Moderately to Severely Active Ulcerative Colitis: Results From the Open-Label Extension of the Randomized, Phase 2 TOUCHSTONE Study.

BACKGROUND AND AIMS: This analysis examined the long-term safety and efficacy of ozanimod in patients with moderately to severely active ulcerative colitis [UC] with ≥ 4 years of follow-up in the phase 2 TOUCHSTONE open-label extension [OLE]. METHODS: Patients receiving placebo or ozanimod HCl 0.5 mg or 1 mg during the double-blind period could enter the OLE [ozanimod HCl 1 mg daily]. Partial Mayo score [pMS] clinical response and remission were assessed through OLE week 200 and summarized descriptively using observed cases [OC] and non-responder imputation [NRI]. Endoscopy was required at OLE week 56 and the end of treatment. Parameters associated with endoscopy were summarized at weeks 56 and 104 [OC], and week 56 [NRI]. C-reactive protein and faecal calprotectin were assessed. Adverse events were monitored throughout the study. RESULTS: Of 197 patients receiving double-blind treatment, 170 entered the OLE. Discontinuation rates were 28% at year 1 and 15-18% annually through year 4. Partial Mayo measures indicated clinical response and remission rates at OLE week 200 of 93.3% and 82.7%, respectively, using OC and 41% and 37% with the more conservative NRI analysis. At weeks 56 and 104, respectively, histological remission rates were 46.3% and 38.5%, and endoscopic improvement rates were 46.4% and 46.5% [OC]. No new safety signals were identified during ≥ 4 years of follow-up. CONCLUSIONS: There was a high rate of continued study participation and long-term benefit with ozanimod HCl 1 mg daily based on clinical, histological and biomarker measures in patients with moderately to severely active UC in the TOUCHSTONE OLE. [NCT02531126].

P031 Impact of Prior Biologic Exposure on Response to Ozanimod for Moderate-to-Severe Ulcerative Colitis in the Phase 3 True North Study.

BACKGROUND: Ozanimod, an oral sphingosine 1-phosphate (S1P) receptor modulator selectively targeting S1P1 and S1P5, demonstrated superior efficacy and safety vs placebo for up to 52 weeks in adults with moderately to severely active ulcerative colitis (UC) in a phase 3 study (True North). In this post-hoc analysis, we evaluated the impact of prior biologic exposure on response to ozanimod. METHODS: True North consisted of two cohorts. In cohort 1, patients with UC received double-blind treatment with once-daily ozanimod 0.92 mg (equivalent to ozanimod HCl 1 mg) or placebo. In cohort 2, patients received open-label once daily ozanimod 0.92 mg. Ozanimod responders after a 10-week induction were re-randomized to double-blind maintenance with ozanimod 0.92 mg or placebo through week 52. Outcomes based on prior biologic exposure (biologic-naïve, 1 biologic, and 2+ biologics) and prior biologic type (anti-tumor necrosis factor [TNF] agents, vedolizumab, or both) were analyzed for clinical remission, clinical response, endoscopic improvement, and mucosal healing. Patients exposed to only a JAK inhibitor were excluded from the analysis. RESULTS: A total of 992 patients (n = 213 placebo and n = 426 ozanimod in cohort 1, n = 353 ozanimod in cohort 2) were included in the analysis for induction; 616 were biologic-naïve, 162 had exposure to 1 biologic, and 214 were exposed to 2 or more biologics. At baseline, biologic-exposed patients had more prior corticosteroid use, longer disease duration, and more extensive disease than biologic-naïve patients. During induction, greater therapeutic effects of ozanimod were generally seen in biologic-naïve vs biologic-exposed patients, and ozanimod-treated patients had greater responses on nearly all reported endpoints at week 10 (cohort 1). Clinical remission was achieved in 23% vs 6.6% of patients on ozanimod vs placebo who were biologic naïve, 17.2% vs 8.3% on 1 prior biologic, and 3.7% vs 2.5% on 2 or more biologics. Clinical response was reached in 53% vs 28% of patients on ozanimod vs placebo who were biologic naïve, 50% vs 33% on 1 biologic, and 27% vs 15% on 2 or more biologics. During maintenance, ozanimod-treated patients had greater responses on all endpoints versus placebo, with similar proportions of patients achieving clinical response to ozanimod regardless of prior biologic exposure (61% for biologic naïve, 60% for 1 biologic, and 55% for 2 or more biologics). At week 52, the proportion of patients on ozanimod with clinical remission was similar in the 1-biologic and 2+-biologic exposure groups (28% and 26%, respectively), and proportions of patients on ozanimod with endoscopic improvement and mucosal healing were similar for the 1-biologic and biologic-naïve groups (47% and 50%, 30%, and 33%, respectively). Among patients with inadequate response to prior anti-TNF agents, vedolizumab, or both at baseline, treatment effects favored ozanimod vs placebo on these endpoints in all three groups during both induction and maintenance. CONCLUSION: Ozanimod improved clinical, endoscopic, and histologic outcomes in both biologic-exposed and -naïve patients. Patients with prior biologic use may require additional time to respond to treatment. Outcomes were improved with ozanimod regardless of prior use of anti-TNF agents and vedolizumab.

P035 Ozanimod for Moderate-to-Severe Ulcerative Colitis: North American Population Results During Induction and Maintenance in the Phase 3 True North Study.

BACKGROUND: True North is a phase 3, randomized, double-blind, placebo-controlled trial conducted at 285 sites in 30 countries (NCT02435992). Treatment with once-daily ozanimod (an oral sphingosine 1-phosphate [S1P] receptor modulator selectively targeting S1P1 and S1P5) in patients with moderately-to-severely active ulcerative colitis (UC) showed significant improvements in primary and all key secondary endpoints. Here we report findings on the consistency of clinical and endoscopic endpoints in the global and North American population. METHODS: In True North, patients received either double-blind treatment with ozanimod 0.92 mg (equivalent to ozanimod HCl 1 mg) or matching placebo, or open-label ozanimod 0.92 mg over a 10-week induction period. Patients with clinical response to ozanimod at Week 10 were re-randomized 1:1 to receive double-blind maintenance treatment with ozanimod 0.92 mg or placebo through Week 52. The primary endpoint was proportion of patients in clinical remission at Weeks 10 and 52; key secondary endpoints included clinical response and endoscopic improvement. The global population included 1012 patients who received at least 1 dose of study medication during induction, and 457 who received at least 1 dose of study medication during maintenance. Here, we examine the results from the patients in the North American sites. RESULTS: A total of 247 patients were enrolled in North America, of which 167 received double-blind ozanimod (n=107) or placebo (n=60) during induction. At baseline, 41.1% and 48.3% of patients in the ozanimod and placebo groups, respectively, had previously received a biologic treatment for UC. At Week 10, 15.9% and 3.3% of patients in the ozanimod and placebo groups, respectively, achieved clinical remission. In addition, 46.7% and 15.0% achieved clinical response and 26.2% and 10.0% achieved endoscopic improvement in the ozanimod and placebo groups, respectively. In patients with prior exposure to tumor necrosis factor inhibitor (TNFi), the proportion with clinical response favored ozanimod (35.7%) vs placebo (11.5%), while the proportion with clinical remission and endoscopic improvement did not favor ozanimod. In patients with no prior TNFi exposure, greater responses were seen with ozanimod vs placebo for all 3 endpoints. During maintenance, 105 patients from North America were re-randomized to treatment with ozanimod (n=56) or placebo (n=49). At Week 52, 39.3% and 12.2% of patients in the ozanimod and placebo groups, respectively, achieved clinical remission. In addition, 58.9% and 26.5% achieved clinical response and 50.0% and 16.3% achieved endoscopic improvement in the ozanimod and placebo groups, respectively. The proportion of patients with clinical remission, clinical response, and endoscopic improvement favored ozanimod vs placebo regardless of prior TNFi use. These outcomes from the North American population are generally consistent with those previously reported from the global population. CONCLUSION: In this post-hoc analysis, consistent with the global population, ozanimod treatment for up to 52 weeks in North American patients with moderately-to-severely active UC showed benefits on clinical and endoscopic endpoints.

P037 Effect of Ozanimod Treatment and Discontinuation on Absolute Lymphocyte Count in Moderate-to-Severe Ulcerative Colitis: Results from a Phase 3 Trial.

BACKGROUND: Ozanimod is an oral sphingosine 1-phosphate (S1P) receptor modulator selectively targeting S1P1 and S1P5, which reduces migration of lymphocytes involved in adaptive immunity from lymphoid tissues to blood and inflamed tissues while preserving components of the innate immune response. Ozanimod is approved in multiple countries for the treatment of relapsing forms of multiple sclerosis and in the US for the treatment of moderately-to-severely active ulcerative colitis (UC). The reduction of circulating lymphocytes is expected based on the mechanism of action of ozanimod and thought to be an important driver of efficacy. METHODS: We assessed absolute lymphocyte count (ALC) during ozanimod induction and maintenance, and after ozanimod discontinuation, per protocol, in adults with moderately-to-severely active UC to characterize the time course of ALC reduction and recovery. The analysis included patients who received ozanimod 0.92 mg (equivalent to ozanimod HCl 1 mg) or placebo once daily in True North, a phase 3 randomized trial (NCT02435992). During a 10-week induction period, patients were randomized 2:1 to double-blind treatment with ozanimod or placebo (Cohort 1) or received open-label ozanimod (Cohort 2). Patients from either cohort with a clinical response to ozanimod at week 10 were re-randomized 1:1 to double-blind treatment with ozanimod or placebo during maintenance through week 52. Placebo-treated patients with a clinical response at week 10 continued placebo during maintenance. ALC was assessed at baseline and at visits throughout induction and maintenance. RESULTS: A total of 69 patients received continuous placebo treatment, 230 received continuous ozanimod treatment, and 227 received ozanimod during induction and placebo during maintenance. In patients who received continuous placebo, mean ALC remained stable between 1.8‒2.1 x 109/L over time (normal range: 1.02‒3.36 x 109/L). In ozanimod-treated patients, mean ALC was reduced to 43%‒45% of baseline and 70%‒73% of patients had ALC shifts from normal at baseline to low (9/L) at week 10. In patients who continued ozanimod, mean ALC reductions were sustained at approximately the same level and ALC shifts from normal at baseline to low were maintained in 73%‒89% of patients during maintenance. In patients who received ozanimod induction therapy and then were re-randomized to placebo for maintenance, mean ALC recovered within 8 weeks to levels similar to baseline at induction and the proportion of patients with ALC shifts from normal at baseline to low decreased from 73% at week 10 to 6% at week 52. Fewer than 2% of ozanimod-treated patients had ALC 9/L during either induction or maintenance and ALC generally returned to ≥ 0.2 x 109/L while patients remained on ozanimod. Among those who switched from ozanimod induction to placebo maintenance, there were no occurrences of ALC 9/L at the end of maintenance. No patients with a serious/opportunistic infection had concurrent ALC 9/L. CONCLUSION: Consistent with the mechanism of action of ozanimod, ALC reductions occurred during ozanimod induction and were sustained during maintenance. Incidence of ALC 9/L was low. ALC recovered after switching to placebo and most patients did not require treatment discontinuation because of changes in ALC.

P038 Ozanimod First-Dose Cardiac Effects in Patients with Moderately to Severely Active Ulcerative Colitis and Relapsing Multiple Sclerosis.

BACKGROUND: Ozanimod, an oral sphingosine 1-phosphate (S1P) receptor modulator that selectively targets S1P1 and S1P5, is approved in the US for treating moderately to severely active ulcerative colitis (UC) and in multiple countries for treating relapsing forms of multiple sclerosis (MS). In a Phase 1 study of ozanimod in healthy participants, first-dose cardiac effects were mitigated with gradual dose escalation. Based on these results, an initial 7-day ozanimod dose escalation regimen was implemented in all Phase 2 and 3 UC and MS trials. The objective of this analysis was to evaluate the number of patients who were excluded from ozanimod treatment due to contraindications of pre-existing cardiac disorders and to evaluate the incidence of cardiac-related treatment-emergent adverse events (TEAEs) following first-dose ozanimod administration in all patients and patients with a history of non-exclusionary cardiac disorders in the UC and MS clinical trials. METHODS: For UC, the analysis included pooled data from the Phase 2 Touchstone (NCT01647516) and Phase 3 True North (NCT02435992) trials. For MS, the analysis included pooled data from the Phase 3 Radiance (NCT02047734) and Sunbeam (NCT02294058) trials. Patients with clinically relevant cardiac conditions or clinically significant electrocardiogram (ECG) disorders were excluded from the trials. On Day 1, all patients received ozanimod 0.23 mg (equivalent to ozanimod HCl 0.25 mg). Day 1 cardiac monitoring included collection of vital signs (including heart rate) prior to dosing and hourly for at least 6 hours after dosing, and ECG prior to dosing and at Hour 6 after dosing. RESULTS: Among patients screened, 26/2178 (1.2%) in the UC studies and 47/3351 (1.4%) in the MS studies were excluded due to protocol-defined pre-existing cardiac disorders. Of 496 patients who received ozanimod in the UC studies, 1 (0.2%) experienced a cardiac-related TEAE on Day 1 (asymptomatic bradycardia). Of 1774 patients who received ozanimod in the MS studies, 11 (0.6%) experienced a cardiac-related TEAE on Day 1. In both the UC and MS studies, no cases of second- or third-degree AV block were observed. A decrease in mean heart rate from baseline (UC, 0.7 bpm; MS, 1.2 bpm) was observed at first-dose that reached a nadir at Hour 5 and returned to baseline by Hour 6. Among 496 patients with UC who received ozanimod, 34 (6.9%) had a known history of cardiac disorders, of whom 1 experienced a cardiac-related TEAE on Day 1 (asymptomatic bradycardia). Among the 1774 patients with MS who received ozanimod, 96 (5.4%) had a known history of cardiac disorders, of whom 2 experienced symptomatic bradycardia on Day 1. CONCLUSION: In clinical trials of ozanimod, the number of patients with UC or MS who failed screening because of exclusionary cardiac disorders was low. Most patients with a history of cardiac disorders who were enrolled in ozanimod clinical trials did not have Day 1 cardiac events, and the events that occurred were manageable.

Targeting of rifamycin SV to the colon for treatment of travelers' diarrhea: a randomized, double-blind, placebo-controlled phase 3 study.

BACKGROUND: Rifamycin SV is under development for treatment of travelers' diarrhea (TD) in a new oral formulation, Rifamycin SV MMX (RIF-MMX; Santarus Inc., San Diego, CA, USA), which targets its delivery to the colon, making it a unique rifamycin drug. METHODS: This was a randomized, double-blind, phase 3 study of adult travelers to Mexico or Guatemala experiencing acute diarrhea. A total of 264 patients received RIF-MMX (2 × 200 mg twice daily for 3 days, n = 199) or placebo (n = 65) in a 3 : 1 ratio. The primary endpoint was the length of time between the administration of first dose of study drug and passage of the last unformed stool (TLUS; after which clinical cure was declared). Other endpoints included eradication of pathogens from the stools, pathogen minimum inhibitory concentration (MIC), and adverse events (AEs). RESULTS: TLUS was significantly shorter in the RIF-MMX group (median: 46.0 hours) compared with placebo (median: 68.0 hours; p = 0.0008) and a larger percentage of RIF-MMX treated patients (81.4%) achieved clinical cure compared with placebo patients (56.9%). TLUS was significantly shorter in the subgroups of patients with enteroaggregative, enterotoxigenic, or diffusely adherent Escherichia coli infections (p = 0.0035) with nonsignificant activity against invasive bacteria (p = 0.3804). Overall pathogen eradication rates were numerically higher in the RIF-MMX group (67.0%) compared with placebo (54.8%) but the difference did not reach significance (p = 0.0836). In vitro resistance to rifamycin SV was observed in some bacteria remaining after treatment of patients with RIF-MMX but was not associated with lower efficacy in them. AEs appeared to be more frequent with placebo (38.5%) than with RIF-MMX (29.6%). CONCLUSIONS: RIF-MMX shortened the duration of TD in patients with a broad range of pathogens and was well tolerated. The unique pharmacokinetic properties of the drug offer evidence that TD pathogens work at the level of the colon.

Pharmacokinetics of nelfinavir in subjects with hepatic impairment.

HIV-seronegative subjects with hepatic impairment (6 mild, 6 moderate) and 12 matched healthy controls received nelfinavir 1250 mg every 12 hours with food for 2 weeks. Mild impairment did not significantly change nelfinavir or major metabolite (M8) steady-state exposures compared with controls. In subjects with moderate impairment, steady-state area under the plasma concentration time-curve over the dosing interval and maximum observed plasma concentrations were 62% and 22% higher for nelfinavir than for controls, and for M8 were 46% and 35% of control values. With increasing degree of impairment, no trend toward increase in unbound nelfinavir was observed, but there was an increase in unbound M8 levels. Nelfinavir was safe and well tolerated. One subject with moderate impairment was discontinued because of transient leucopenia. Observed changes are unlikely to affect nelfinavir efficacy or markedly influence safety. Dose reduction of nelfinavir does not appear necessary for subjects with mild/moderate impairment. Further long-term evaluations of nelfinavir pharmacokinetics and safety in HIV-seropositive subjects with hepatic impairment may be useful.

In vitro antiviral activity and single-dose pharmacokinetics in humans of a novel, orally bioavailable inhibitor of human rhinovirus 3C protease.

(E)-(S)-4-((S)-2-{3-[(5-methyl-isoxazole-3-carbonyl)-amino]-2-oxo-2H-pyridin-1-yl}-pent-4-ynoylamino)-5-((S)-2-oxo-pyrrolidin-3-yl)-pent-2-enoic acid ethyl ester (Compound 1) is a novel, irreversible inhibitor of human rhinovirus (HRV) 3C protease {inactivation rate constant (Kobs/[I]) of 223,000 M-1s-1}. In cell-based assays, Compound 1 was active against all HRV serotypes (35 of 35), HRV clinical isolates (5 of 5), and related picornaviruses (8 of 8) tested with mean 50% effective concentration (EC50) values of 50 nM (range, 14 to 122 nM), 77 nM (range, 72 to 89 nM), and 75 nM (range, 7 to 249 nM), respectively. Compound 1 inhibited HRV 3C-mediated polyprotein processing in infected cells in a concentration-dependent manner, providing direct confirmation that the cell-based antiviral activity is due to inhibition of 3C protease. In vitro and in vivo nonclinical safety studies showed Compound 1 to be without adverse effects at maximum achievable doses. Single oral doses of Compound 1 up to 2,000 mg in healthy volunteers were found to be safe and well tolerated in a phase I-ascending, single-dose study. Compound 1 estimated free observed maximum concentration in plasma (Cmax) for 500-, 1,000-, and 2,000-mg doses were higher than the protein binding-corrected EC50 required to inhibit 80% of the HRV serotypes tested. Treatment of HRV 52-infected cells with one to five 2-h pulses of 150 nM Compound 1 (corresponding to the Cmax at the 500-mg dose) was sufficient to effect a significant reduction in viral replication. These experiments highlight Compound 1 as a potent, orally bioavailable, irreversible inhibitor of HRV 3C protease and provide data that suggest that Cmax rather than the Cmin might be the key variable predicting clinical efficacy.

Greater reversal of CD4+ cell abnormalities and viral load reduction after initiation of antiretroviral therapy with zidovudine, lamivudine, and nelfinavir before complete HIV type 1 seroconversion.

In a prospective open-label study, 41 male subjects received nelfinavir, zidovudine, and lamivudine stratified as either: early stage (ES; negative/indeterminate Western blot; n = 19) or late stage (LS; positive Western blot; n = 22) primary HIV-1 infection. Despite higher median baseline HIV-1 RNA levels and lower CD4(+) cell numbers in the ES subjects, a significantly greater decline in viral load (-3.46 vs. -2.83 log(10) copies/ml; p = 0.023) and increase in CD4(+) cell number (+85 vs. +41 cells/month increase, p = 0.01) were observed over the first 3 months of therapy such that both groups had comparable results at 1 year. The proportion with HIV-1 RNA < 50 copies/mL at 1 year was similar (9 of 19 ES subjects and 11 of 22 LS subjects by intention-to-treat analysis). Memory CD4(+) cell numbers, and activated CD4(+) percentages, were also significantly improved in ES subjects. Despite poorer prognostic markers at baseline ES subjects achieved responses similar to those of LS subjects after 1 year of treatment.