Recombinant Human C1 Esterase Inhibitor for the Management of Adverse Events Related to Intravenous Immunoglobulin Infusion in Patients With Common Variable Immunodeficiency or Polyneuropathy: A Pilot Open-Label Study.

It has been hypothesized that low levels of C1 esterase inhibitor (C1-INH), a key inhibitor of the complement pathway, may play a role in the occurrence of adverse events (AEs) associated with intravenous immunoglobulin (IVIG) therapy. This open-label pilot study evaluated C1-INH replacement, with recombinant human C1-INH (rhC1-INH), as a potential therapy for adults requiring IVIG and experiencing AEs. Patients received two rounds of IVIG infusion [pre-treatment phase (no rhC1-INH), 4-8 weeks] and then three rounds of one dose of intravenous rhC1-INH 50 U/kg (maximum, 4,200 U) with subsequent IVIG infusion (treatment phase, 6-12 weeks). Nineteen adults completed the study; all had an autoimmune condition linked to common variable immunodeficiency (CVID) or polyneuropathy, and 57.9% had low baseline C1-INH levels. Mean ± SD total scores improved significantly with the Headache Impact Test (from 62.8 ± 6.2 at pre-treatment to 57.7 ± 9.1 after treatment; mean Δ, -5.0; p = 0.02) and Modified Fatigue Impact Scale (from 59.3 ± 13.1 to 51.2 ± 15.4; mean Δ, -8.1; p = 0.006). Significant improvements in the Migraine Disability Assessment were observed for three of five items (p ≤ 0.002). Mean ± SD C1-INH level increased from 26.8 ± 5.9 mg/dl after the second round of IVIG (pre-treatment) to 32.1 ± 7.8 mg/dl after the third rhC1-INH treatment; functional C1-INH levels increased from 115.8 ± 34.7% to 158.3 ± 46.8%. Future research is warranted to explore the benefit of C1-INH therapy for reduction of IVIG-related AEs, as well as the role of C1-INH in patients with CVID and autoimmune disease. Clinical Trial Registration: ClinicalTrials.gov, identifier NCT03576469.

Efficacy of recombinant human C1 esterase inhibitor across anatomic locations in acute hereditary angioedema attacks.

BACKGROUND: Hereditary angioedema (HAE) may occur at or spread to multiple anatomic locations during an acute attack. Recombinant human C1 esterase inhibitor (rhC1-INH) is approved for treating acute HAE attacks. OBJECTIVE: To examine the time to the beginning of symptom relief with rhC1-INH by attack location. METHODS: Data for patients ≥12 years of age with an acute HAE attack who received rhC1-INH 50 IU/kg or placebo were pooled from two double-blind clinical trials with open-label extensions. The time to the beginning of symptom relief was defined as the first time point that the visual analog scale severity score at an attack location decreased by ≥20 mm versus baseline, with persistence. Data were reported as median time values (95% confidence interval [CI]). RESULTS: For abdominal attacks, the median time to the beginning of symptom relief was 60.0 minutes (95% CI, 47.0-62.0 minutes; n = 194 attacks) with rhC1-INH versus 240.0 minutes (95% CI, 45.0-720.0 minutes; n = 15 attacks) with placebo. The median time to the beginning of symptom relief for peripheral attacks was 105.0 minutes (95% CI, 90.0-120.0 minutes; n = 169 attacks) with rhC1-INH versus 303.0 minutes (95% CI, 180.0-720.0 minutes; n = 17 attacks) with placebo. For oro-facial-pharyngeal-laryngeal attacks or urogenital attacks, the median time to the beginning of symptom relief with rhC1-INH was 64.5 minutes (95% CI, 60.0-120.0 minutes; n = 36 attacks) and 119.0 minutes (95% CI, 40.0-270.0 minutes; n = 13 attacks), respectively, versus 306.0 minutes (95% CI, 30.0-495.0 minutes; n = 6 attacks) and 320.0 minutes (n = 1 attack) with placebo. CONCLUSION: In shortening the median time to the beginning of symptom relief of acute HAE attacks, rhC1-INH 50 IU/kg was efficacious, regardless of attack location.

Efficacy of recombinant human C1 esterase inhibitor for the treatment of severe hereditary angioedema attacks.

BACKGROUND: Severe attacks of hereditary angioedema (HAE) are debilitating and potentially life threatening, and can increase anxiety and the use of medical resources. OBJECTIVE: This post hoc assessment evaluated recombinant human C1 esterase inhibitor (rhC1-INH) used to treat acute severe HAE attacks. METHODS: In a double-blind, randomized-controlled trial (RCT), patients with an HAE attack (baseline visual analog scale score of ≥50 mm, with severe attacks defined as ≥75 mm) were randomly assigned to receive rhC1-INH (50 IU/kg for patients who weighed <84 kg; 4200 IU for patients who weighed ≥84 kg) or placebo. Also, in an open-label extension (OLE) study of rhC1-INH, oropharyngeal-laryngeal attacks were analyzed. Rescue therapy with rhC1-INH 50 IU/kg (≤4200 IU) was permitted after 4 hours or for life-threatening symptoms (in the RCT) or after 1 hour (in the OLE study). The primary end point measured the time to the beginning of symptom relief by using the Treatment Effects Questionnaire. RESULTS: Of 75 adults in the RCT, 43 had severe attacks and received either rhC1-INH (n = 24) or placebo (n = 19). The median (95% confidence interval) time to the onset of symptom relief totaled 90.0 minutes (95% confidence interval, 47.0-120.0 minutes) versus 334.0 minutes (95% confidence interval, 105.0 to not calculable minutes; hazard ratio, 2.5; p = 0.02), for rhC1-INH and placebo, respectively. Open-label rhC1-INH rescue therapy was administered to 1 of 24 in the rhC1-INH group (4.2%) and 10 of 19 in the placebo group (52.6%). During the OLE study, the median onset of symptom relief with rhC1-INH for eight oropharyngeal-laryngeal HAE attacks was 69.0 minutes (95% confidence interval, 59.0-91.0 minutes). CONCLUSION: In the current study, rhC1-INH was efficacious in resolving severe HAE attacks, including oropharyngeal-laryngeal attacks. The rhC1-INH rescue treatment rapidly improved symptoms for patients who received placebo and who experienced worsening or sustained symptoms.

Recombinant human C1 esterase inhibitor for acute hereditary angioedema attacks with upper airway involvement.

BACKGROUND: Recombinant human C1 esterase inhibitor (rhC1-INH) is approved for treatment of hereditary angioedema (HAE) in adolescents and adults. HAE attacks that involve the upper airway can be life threatening, and data on the administration of rhC1-INH for these types of attacks are currently limited. OBJECTIVE: To evaluate the efficacy and safety of rhC1-INH for treatment of acute HAE attacks with upper airway involvement. METHODS: A pooled analysis of data from three clinical trials with open-label extensions examined rhC1-INH for treatment of acute HAE attacks with upper airway involvement. Patients with functional plasma C1 esterase inhibitor <50% of normal who had experienced an acute upper airway HAE attack and received rhC1-INH were identified retrospectively based on severity of breathing or swallowing symptoms. The primary end point was the time to beginning of relief (time at which the overall visual analog scale score [0-100 mm] decreased from baseline by ≥20 mm for two consecutive time points [persistence]). RESULTS: Of 683 acute HAE attacks treated with rhC1-INH, data for 45 attacks with upper airway involvement were included. The median time to the beginning of symptom relief was 67 minutes (95% confidence interval, 60-120 minutes) and did not differ by attack number or by baseline breathing or swallowing symptom severity. Most attacks (91.1%) achieved the beginning of relief within 4 hours of rhC1-INH treatment. All attacks resolved without the need for any additional medication, and no patients required intubation or tracheostomy. Treatment with rhC1-INH was well tolerated, with no adverse events reported in more than one patient (except HAE reported as an adverse event [n = 2]). CONCLUSION: This pooled analysis of clinical trial data supports the efficacy of rhC1-INH for treatment of acute HAE attacks with upper airway involvement.

Long-Term Safety and Efficacy of Subcutaneous Methylnaltrexone in Patients with Opioid-Induced Constipation and Chronic Noncancer Pain: A Phase 3, Open-Label Trial.

OBJECTIVE: Methylnaltrexone, a peripherally acting µ-opioid receptor antagonist, alleviates opioid-induced constipation. Understanding its long-term safety and efficacy profile in patients with chronic noncancer pain is warranted given the persistence of opioid-induced constipation. METHODS.: In this phase 3, multicenter, open-label trial, adults with chronic noncancer pain (N = 1034) received subcutaneous methylnaltrexone 12 mg once daily for 48 weeks. RESULTS: The most common adverse events were gastrointestinal related (e.g., abdominal pain, diarrhea, nausea) and were mild to moderate in intensity. Only 15.2% of patients discontinued because of an adverse event. Serious cardiac-related adverse events occurred in nine patients. Of the seven instances of major adverse coronary events reported, three were adjudicated after external review; all instances occurred in patients with cardiovascular risk factors. Methylnaltrexone elicited a bowel movement within four hours in 34.1% of the injections throughout the 48-week treatment period. CONCLUSIONS: Change from baseline in mean weekly bowel movement rate, Bowel Movement Straining Scale score, Bristol Stool Scale score, and mean percentage of patients with complete evacuation from baseline to week 48 were significantly improved ( P < 0.001 for all). Long-term subcutaneous methylnaltrexone was well tolerated, with no new safety concerns, and provided consistent opioid-induced constipation relief in patients with chronic noncancer pain.

Recombinant human C1 esterase inhibitor for prophylaxis of hereditary angio-oedema: a phase 2, multicentre, randomised, double-blind, placebo-controlled crossover trial.

BACKGROUND: Hereditary angio-oedema is a recurrent, oedematous disorder caused by deficiency of functional C1 inhibitor. Infusions of plasma-derived C1 esterase inhibitor deter attacks of hereditary angio-oedema, but the prophylactic effect of recombinant human C1 esterase inhibitor has not been rigorously studied. We aimed to assess the efficacy of recombinant human C1 esterase inhibitor for prophylaxis of hereditary angio-oedema. METHODS: We conducted this phase 2, multicentre, randomised, double-blind, placebo-controlled crossover trial at ten centres in Canada, the Czech Republic, Israel, Italy, Macedonia, Romania, Serbia, and the USA. We enrolled patients aged 13 years or older with functional C1-inhibitor concentrations of less than 50% of normal and a history of four or more attacks of hereditary angio-oedema per month for at least 3 months before study initiation. Patients were randomly assigned centrally (1:1:1:1:1:1), via an interactive response technology system with fixed allocation, to receive one of six treatment sequences. During each sequence, patients received intravenous recombinant human C1 esterase inhibitor (50 IU/kg; maximum 4200 IU) twice weekly, recombinant human C1 esterase inhibitor once weekly and placebo once weekly, and placebo twice weekly, each for 4 weeks with a 1 week washout period between crossover. All patients, investigators, and study personnel who participated in patient care were masked to group allocation during the study. The primary efficacy endpoint was the number of attacks of hereditary angio-oedema observed in each 4 week treatment period. Attack symptoms were recorded daily. The primary efficacy analysis was done in the intention-to-treat population. Safety was assessed in all patients who received at least one injection of study medication. This study is registered with ClinicalTrials.gov, number NCT02247739. FINDINGS: Between Dec 29, 2014, and May 3, 2016, we enrolled 35 patients, of whom 32 (91%) underwent randomisation (intention-to-treat population) and 26 (81%) completed the study. The mean number of attacks of hereditary angio-oedema over 4 weeks was significantly reduced with recombinant human C1 esterase inhibitor twice weekly (2·7 attacks [SD 2·4]) and once weekly (4·4 attacks [3·2]) versus placebo (7·2 attacks [3·6]), with mean differences of -4·4 attacks (p<0·0001) and -2·8 attacks (p=0·0004), respectively. We recorded adverse events in ten (34%) of 29 patients given twice-weekly recombinant human C1 esterase inhibitor, 13 (45%) of 29 patients given the once-weekly regimen, and eight (29%) of 28 patients given placebo. Headache (twice-weekly treatment) and nasopharyngitis (once-weekly treatment) were the most common adverse events. Two (7%) adverse events (fatigue and headache) were deemed possibly related to treatment with recombinant human C1 esterase inhibitor, but both resolved without additional treatment. No thrombotic or thromboembolic events, systemic allergic reactions (including anaphylaxis), or neutralising antibodies were reported. INTERPRETATION: Prophylaxis with recombinant human C1 esterase inhibitor provided clinically relevant reductions in frequency of hereditary angio-oedema attacks and was well tolerated. In view of the pharmacokinetic profile of recombinant human C1 esterase inhibitor, our results suggest that efficacy of C1-inhibitor replacement therapy might not be a direct function of plasma trough concentrations of C1 inhibitor. FUNDING: Pharming Technologies.

Sustained response of recombinant human C1 esterase inhibitor for acute treatment of hereditary angioedema attacks.

BACKGROUND: Symptoms of hereditary angioedema (HAE) attacks can recur soon after initial treatment; the durability of response for recombinant human C1 esterase inhibitor (rhC1INH) treatment is unknown. OBJECTIVE: To examine the efficacy and durability of rhC1INH for acute HAE attacks. METHODS: In this pooled post hoc analysis of 2 trials, patients with type I or II HAE (functional C1INH levels <50% of normal) and a baseline visual analog scale score of at least 50 mm were included if they had received at least 1 intravenous dose of 50 IU/kg of rhC1INH. Response was defined as symptom relief within 4 hours after treatment with persistence (≥20-mm decrease in visual analog scale scores [0 mm {"no symptoms at all"} to 100 mm {"extremely disabling"}] at 2 consecutive time points) during the 4 hours. Durability was the response without an increase of at least 20 mm in the minimum post-treatment visual analog scale score up to 24 hours. Recurrence and new attack symptoms were determined for patients with 72-hour post-treatment data. RESULTS: Data were analyzed for 127 patients treated with 50 IU/kg of rhC1INH in 2 studies. Most attacks (90.7%) responded within 4 hours, with differences in response rates among attack locations (61.5%-94.4%). The median time to the beginning of symptom relief was 75.0 minutes (95% confidence interval 65.0-80.0). No relapse occurred during 24 hours for attacks that initially responded. Only 7.1% of attacks were associated with symptom recurrence within 72 hours of initial rhC1INH treatment. CONCLUSION: This integrated analysis supports the efficacy of rhC1INH for treatment of acute HAE across multiple attacks, with a sustained response for at least 3 days. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT00225147 and NCT00262301.

Recombinant Human C1-Esterase Inhibitor to Treat Acute Hereditary Angioedema Attacks in Adolescents.

BACKGROUND: Recombinant human C1-esterase inhibitor (rhC1-INH) is efficacious and well tolerated for managing hereditary angioedema (HAE) attacks in adults. However, there are insufficient data on its efficacy and safety in adolescents. OBJECTIVE: To evaluate the efficacy and safety profiles of rhC1-INH for acute HAE attacks in adolescents. METHODS: Adolescents (aged 12-18 y) with HAE enrolled in 2 randomized controlled trials and 2 open-label extension trials were included and received intravenous rhC1-INH for acute attacks. Times to the beginning of sustained symptom relief (visual analog scale change from baseline ≥20 mm) and minimal symptoms (visual analog scale score of <20 mm across locations) were assessed. Safety parameters included hypersensitivity reactions, anti-rhC1-INH antibodies, and host-related impurities. RESULTS: Sixteen adolescents (50 attacks, aged 14-18 y) received rhC1-INH. Attacks were managed with single-dose rhC1-INH 50 U/kg (46.0%) and single-dose rhC1-INH 2100 U (16%), and 32.0% were treated with additional doses after receiving an initial rhC1-INH 2100 U dose (total dose, 4200-6300 U). Most attacks (88.0%) occurred at a single location; 59.1% (26 of 44) were abdominal. Across the first 5 attacks, median times to the beginning of symptom relief ranged from 19.0 to 78.5 minutes; median times to minimal symptoms ranged from 120 to 190 minutes. Pharmacokinetics showed that rhC1-INH restored functional plasma C1-esterase inhibitor levels to the normal (>70%) range for almost all evaluable patients. No severe or drug-related adverse events or hypersensitivity reactions occurred. No treatment-emergent antibodies to rhC1-INH or host-related impurities were observed. CONCLUSIONS: rhC1-INH is efficacious and well tolerated among adolescents with HAE.

Randomized, Double-Blind Trial of Oral Methylnaltrexone for the Treatment of Opioid-Induced Constipation in Patients with Chronic Noncancer Pain.

BACKGROUND: Subcutaneous methylnaltrexone, a peripherally acting µ-opioid receptor antagonist, improves opioid-induced constipation (OIC) in patients with chronic noncancer pain. An oral methylnaltrexone formulation has been developed. METHODS: In this phase 3, double-blind trial, adults with chronic noncancer pain receiving opioid doses of ≥ 50 mg/day oral morphine equivalents with OIC were randomly assigned to oral methylnaltrexone (150, 300, or 450 mg) or placebo once daily (QD) for 4 weeks followed by as-needed dosing for 8 weeks. Patients who had ≥ 3 rescue-free bowel movements (RFBMs)/week, with an increase of ≥ 1 RFBM/week from baseline for ≥ 3 of 4 weeks during the QD period, were responders. RESULTS: Overall, 803 patients were included in the analyses. A significantly greater percentage of patients had an increase in mean percentage of dosing days resulting in an RFBM within 4 hours of dosing during weeks 1 through 4 (QD period; primary endpoint) with methylnaltrexone (300 mg/day [24.6%; P = 0.002] and 450 mg/day [27.4%; P < 0.0001]) vs. placebo (18.2%). The percentage of responders (49.3% for 300 mg [P = 0.03] and 51.5% for 450 mg [P = 0.005] vs. 38.3% with placebo) and change from baseline in mean number of weekly RFBMs (difference vs. placebo, 0.5 for 300 mg [P = 0.03] and 0.5 for 450 mg [P = 0.02]) was significantly greater with methylnaltrexone 300 and 450 mg/day vs. placebo during the QD period. All dosages of oral methylnaltrexone were well tolerated. CONCLUSIONS: Oral methylnaltrexone was efficacious and well tolerated for OIC in patients with chronic noncancer pain, particularly the 450-mg dose.

Baseline Oral 5-ASA Use and Efficacy and Safety of Budesonide Foam in Patients with Ulcerative Proctitis and Ulcerative Proctosigmoiditis: Analysis of 2 Phase 3 Studies.

BACKGROUND: Rectal budesonide foam is a second-generation corticosteroid efficacious for active mild to moderate ulcerative proctitis and ulcerative proctosigmoiditis. This subgroup analysis examined the impact of baseline oral 5-aminosalicylic acid (5-ASA) on the efficacy and safety of budesonide foam in patients with mild to moderate ulcerative proctitis or ulcerative proctosigmoiditis. METHODS: Patients received budesonide foam 2 mg/25 mL twice daily for 2 weeks, then once daily for 4 weeks, or placebo, with or without continued stable dosing of baseline oral 5-ASAs, for remission induction at week 6 (primary endpoint) in 2 identically designed, randomized, double-blind, phase 3 studies. RESULTS: Of the 267 and 279 patients randomized to treatment with budesonide foam or placebo (pooled population), 55.1% and 55.2%, respectively, reported baseline 5-ASA use. A significantly greater percentage of patients achieved remission with budesonide foam versus placebo, either with (42.2% versus 31.8%, respectively; P = 0.03) or without (40.0% versus 14.4%; P < 0.0001) baseline 5-ASA use at week 6. A significantly greater percentage of patients achieved a Modified Mayo Disease Activity Index rectal bleeding subscale score of 0 at week 6, regardless of baseline 5-ASA use (5-ASA, 50.3% versus 35.7%; P = 0.003: no 5-ASA, 45.8% versus 19.2%; P < 0.0001). The frequency of adverse events was comparable between groups, regardless of baseline 5-ASA use. CONCLUSIONS: Budesonide foam was efficacious and safe for induction of remission of mild to moderate ulcerative proctitis and ulcerative proctosigmoiditis in patients receiving oral 5-ASA at baseline and those who were not (Clinicaltrials.gov: NCT01008410 and NCT01008423).