Effects of controlled-release on the pharmacokinetics and absorption characteristics of a compound undergoing intestinal efflux in humans

OBJECTIVE: The number of active pharmaceutical ingredients (API) undergoing inhibitable and saturable intestinal efflux is considerable. As a consequence, absorption and bioavailability may depend on the intestinal concentration profile of the drug and may vary as a function of dose and release rate of the drug from the dosage form. The impact of controlled versus immediate-release on the absorption of P-glycoprotein substrates is currently unknown. Thus, the main focus of the present study was a comparison of the pharmacokinetics of the P-gp model substrate talinolol following administration of immediate-release (IR) and controlled-release (CR) tablets to healthy human volunteers with a particular focus on the absorption characteristics of the active pharmaceutical ingredients. METHODS: Talinolol immediate-release (Cordanum), 100mg), one controlled-release (100mg) and two controlled-release tablets (200mg) were administered as single doses to fasting healthy volunteers in a crossover design with a 1 week washout period between treatments. Sufficient blood and urine samples were drawn and analysed using a specific HPLC method with UV detection to describe the resulting plasma and urinary excretion versus time profiles. RESULTS: The bioavailability of talinolol in term of AUC(0-->infinity) for IR talinolol was approximately twice as high as compared to the administration of the same dose in a controlled-release dosage form. After administration of talinolol IR tablets, the drug was rapidly absorbed and reached maximum concentrations C(max) of 204.5 ng/ml /-121.8 (means /-S.D.) 2h after dosing. The terminal half-life of the drug averaged 19.8h following IR administration in comparison to 32 h under CR dosing conditions. Following administration of the IR dosage form, significant secondary peaks were observed in one healthy subject. Secondary peaks were not clearly apparent in the CR plasma profiles. CONCLUSION: The present study demonstrates a considerable loss of bioavailability of drugs that are substrates of intestinal secretory transporters upon their administration in controlled-release dosage forms

Risankizumab in patients with moderate to severe Crohn's disease: an open-label extension study.

BACKGROUND: Risankizumab, an anti-interleukin 23 antibody, was superior to placebo in achieving clinical and endoscopic remission at week 12 in a randomised, phase 2 induction study in patients with moderately to severely active Crohn's disease. Here we aimed to assess the efficacy and safety of extended intravenous induction and subcutaneous maintenance therapy with risankizumab. METHODS: All patients who completed the 12-week induction phase of the double-blind phase 2 induction study were included in this open-label extension study. Patients who did not achieve deep remission, defined as clinical remission (Crohn's Disease Activity Index [CDAI] 50% CDEIS reduction from baseline); endoscopic remission, as defined previously; mucosal healing; and deep remission. Safety was assessed in patients who received at least one dose of the study drug during the open-label phases of the study. This study is registered with ClinicalTrials.gov, number NCT02031276. FINDINGS: Of the 108 patients who completed the 12-week double-blind induction trial, six patients were in deep remission and entered the 12-week washout phase. 102 patients were not in deep remission, 101 of whom received 12 weeks of 600 mg risankizumab (33 from the original placebo group, 34 from the 200 mg risankizumab group, and 34 from the 600 mg risankizumab group); the other patient declined to continue the study. At week 26, 54 (53%) of 101 patients treated with 600 mg rizankizumab were in clinical remission. Among patients included in the open-label extension trial, clinical remission rates at week 26 versus week 12 were: 18 (55%) versus six (18%) of 33 patients in the original placebo group; 20 (59%) versus seven (21%) of 34 patients in the original 200 mg risankizumab group; and 16 (47%) versus nine (26%) of 34 patients in the original 600 mg risankizumab group. 62 patients received risankizumab maintenance treatment, including the 54 patients who achieved clinical remission at week 26, the six patients who had achieved deep remission at week 12, and one patient because of a protocol violation. At week 52, clinical remission was maintained in 44 (71%) patients; 50 (81%) patients had a clinical response, 22 (35%) patients were in endoscopic remission, and 34 (55%) patients had an endoscopic response. 15 (24%) patients had mucosal healing and 18 (29%) patients achieved deep remission at week 52. Risankizumab was well tolerated with no new safety signals noted. The most frequent treatment-emergent adverse events were arthralgia (25 [22%] of 115 patients), headache (23 [20%]), abdominal pain (21 [18%]), nasopharyngitis (18 [16%]), nausea (18 [16%]), and pyrexia (15 [13%]). Most adverse events were mild or moderate and considered to be unrelated to study treatment. There were no treatment-related deaths. INTERPRETATION: Extended induction treatment with open-label intravenous risankizumab was effective in increasing clinical response and remission rates at week 26. Open-label subcutaneous risankizumab maintained remission until week 52 in most patients who were in clinical remission at week 26. Selective blockade of interleukin 23 warrants further investigation as a treatment for Crohn's disease. FUNDING: Boehringer Ingelheim

Adefovir dipivoxil for wait-listed and post-liver transplantation patients with lamivudine-resistant hepatitis B : final long-term results

Wait-listed (n = 226) or post-liver transplantation (n = 241) chronic hepatitis B (CHB) patients with lamivudine-resistant hepatitis B virus (HBV) were treated with adefovir dipivoxil for a median of 39 and 99 weeks, respectively. Among wait-listed patients, serum HBV DNA levels became undetectable (<1,000 copies/mL) in 59% and 65% at weeks 48 and 96, respectively. After 48 weeks, alanine aminotransferase (ALT), albumin, bilirubin, and prothrombin time normalized in 77%, 76%, 60%, and 84% of wait-listed patients, respectively. Among posttransplantation patients, serum HBV DNA levels became undetectable in 40% and 65% at weeks 48 and 96, respectively. After 48 weeks, ALT, albumin, bilirubin, and prothrombin time normalized in 51%, 81%, 76%, and 56% of posttransplantation patients, respectively. Among wait-listed patients who underwent on-study liver transplantation, protection from graft reinfection over a median of 35 weeks was similar among patients who did (n = 34) or did not (n = 23) receive hepatitis B immunoglobulin (HBIg). Hepatitis B surface antigen was detected on the first measurement only in 6% and 9% of patients who did or did not receive HBIg, respectively. Serum HBV DNA was detected on consecutive visits in 6% and 0% of patients who did or did not receive HBIg, respectively. Treatment-related adverse events led to discontinuation of adefovir dipivoxil in 4% of patients. Cumulative probabilities of resistance were 0%, 2%, and 2% at weeks 48, 96, and 144, respectively. In conclusion, adefovir dipivoxil is effective and safe in wait-listed or posttransplantation CHB patients with lamivudine-resistant HBV and prevents graft reinfection with or without HBIg