Clinical Bridging From Prefilled Syringe to On-body Injector for Risankizumab in Crohn's Disease.

PURPOSE: This article describes the clinical development bridging strategy and key data to support the marketing application of the risankizumab on-body injection (OBI) system for the treatment of moderately to severely active Crohn's disease (CD), even though the OBI was not evaluated directly in the pivotal Phase III studies in CD. METHODS: Three studies were conducted as part of the clinical bridging strategy. The pilot pharmacokinetics (PK) study was a Phase I, single-dose, 4-arm, open-label, randomized, parallel-group exploratory PK and tolerability study that assessed the effect of rate and volume of administration on the bioavailability (BA) of risankizumab and the extent of injection site-related pain after subcutaneous (SC) administration in healthy subjects. The pivotal BA/bioequivalence (BE) study was a relative BA/BE bridging study in healthy subjects to assess the relative BA of the to-be-marketed risankizumab OBI compared with the prefilled syringe (PFS) used in the Phase III CD studies. The OBI adhesive study was a randomized, open-label, non-drug interventional study in healthy subjects to assess the OBI adhesive effectiveness and skin tolerability at 2 different locations (abdomen and upper thigh) over different periods of time (5 and 30 minutes). FINDINGS: The pilot PK study showed that risankizumab exposures were similar across different rates/volumes of SC administration in healthy subjects, thereby supporting further development of the OBI. Second, a pivotal BA/BE study showed comparability between the OBI and Phase III PFS with bioequivalent risankizumab AUCs and no clinically meaningful difference for Cmax based on the wide therapeutic window of risankizumab. In both studies, no new safety risks were identified. No impact of immunogenicity on PK profile or safety was observed for the OBI. Third, an adhesive OBI (without risankizumab) study showed that there were no differences in adhesion/skin tolerability observed over time (up to 30 minutes) or for location of adhesion, and the OBI device adhesion was well tolerated at both the abdomen and thigh locations. IMPLICATIONS: These results supported the risankizumab OBI presentation approval in CD.

Pharmacokinetic Comparability of Risankizumab Formulations in Prefilled Syringe and Auto-injector for Subcutaneous Injection.

PURPOSE: Risankizumab is a humanized immunoglobulin G1 monoclonal antibody that inhibits the p19 subunit of interleukin 23 from interacting with its receptor for the treatment of moderate to severe plaque psoriasis. The aim of this Phase I biopharmaceutics bridging study was to evaluate the pharmacokinetic comparability, immunogenicity, and tolerability of the risankizumab 90 mg/mL prefilled syringe (PFS) and the risankizumab 150 mg/mL PFS and auto-injector (AI) in healthy subjects. METHODS: Healthy subjects received one 150-mg dose of risankizumab in 1 of 3 ways (226 subjects randomized 3:3:1 to 3 treatment arms): 150 mg/mL by PFS × 1 SC injection, 90 mg/mL by PFS × 2 SC injections, or 150 mg/mL by AI × 1 SC injection, and were followed up for 140 days after dosing for the collection of pharmacokinetic, immunogenicity, and tolerability data. FINDINGS: Risankizumab concentration-time profiles overlapped with comparable pharmacokinetic parameters across all treatment arms, indicating similar pharmacokinetic characteristics. The CIs with both formulations and forms of administration were within the bioequivalence range of 0.80-1.25 across all measures of exposure. The prevalence of treatment-emergent anti-drug antibodies and the percentages of subjects who reported at least 1 treatment-emergent adverse event were comparable across all treatment arms. IMPLICATIONS: Bioequivalence was established between risankizumab 150 mg/mL PFS and 90 mg/mL PFS, and between 150 mg/mL PFS and AI, along with comparable immunogenicity profiles across all 3 treatment arms. Risankizumab 150 mg SC delivered by PFS or AI was well tolerated, with comparable safety profiles across all treatment arms, and no new safety risks were identified.

A Randomized, Double-Blind, Placebo-Controlled, Crossover Study of the T-Type Calcium Channel Blocker ABT-639 in an Intradermal Capsaicin Experimental Pain Model in Healthy Adults.

OBJECTIVE: This randomized, double-blind, placebo-controlled, crossover trial evaluated the pharmacodynamic effects of a single 100-mg dose of ABT-639, a peripherally active, selective T-type Cav3.2 channel blocker, with the intradermal capsaicin pain model using pregabalin 300 mg as a positive control. SUBJECTS: Healthy adult males (aged 21 to 55 years) were randomly assigned to receive single oral doses of ABT-639, pregabalin, and placebo. METHODS: Serial measurements for area (cm2) of hyperalgesia, allodynia, and flare response were performed over a 20-minute period after each capsaicin injection at 1 and 4 hours post-dose. Capsaicin injections were administered in different arms as determined by random assignment. Serial measurements for spontaneous pain and elicited pain were performed over a 60-minute period at 1 and 4 hours post-dose using a 100-mm visual analog scale. Standard safety evaluations were performed. RESULTS: Nineteen participants were randomized and included in the analysis. No significant differences were observed between ABT-639 and placebo in spontaneous pain, elicited pain, and areas of allodynia, hyperalgesia, and flare after intradermal capsaicin injection at 1 and 4 hours post-dose. In contrast, pregabalin demonstrated significant reductions in spontaneous pain at 1 and 4 hours post-dose, and elicited pain and areas of allodynia and hyperalgesia at 4 hours post-dose compared with placebo. ABT-639 demonstrated acceptable safety and tolerability; somnolence and euphoric mood were the most commonly reported adverse events. CONCLUSIONS: These data indicate that a single 100-mg dose of ABT-639 had no effect on experimental pain induced by intradermal capsaicin injection.

Efficacy and safety of the α4ß2 neuronal nicotinic receptor agonist ABT-894 in patients with diabetic peripheral neuropathic pain.

Preclinical and clinical studies suggest that neuronal nicotinic receptor (NNR) agonists may be a novel and effective therapy for numerous painful conditions. Analgesic efficacy and safety of the highly selective α(4)ß(2) NNR agonist ABT-894 was evaluated in 2 separate randomized, double-blind, multicenter, placebo-controlled clinical trials in patients with diabetic peripheral neuropathic pain (DPNP). Study 1 (280 patients randomized) tested 1, 2, and 4 mg ABT-894 twice daily compared with placebo and 60 mg duloxetine once per day over 8 weeks of treatment. Study 2 (124 patients randomized) tested 6 mg ABT-894 twice daily vs placebo for 8 weeks. The primary efficacy outcome measure in both studies was the weekly mean of the 24-hour average pain score recorded in each patient's diary. In both trials, none of the ABT-894 dose groups showed efficacy compared with placebo, whereas duloxetine achieved a statistically significant improvement over placebo in Study 1. All dose levels of ABT-894 were well tolerated, and no significant safety issues were identified. These results are in contrast to the outcome of a previously reported study of DPNP using the less selective α(4)ß(2) NNR agonist ABT-594, which demonstrated efficacy compared with placebo, albeit with significant tolerability limitations. The failure of the highly selective α(4)ß(2) NNR agonist ABT-894 indicates that it may not be possible to define a therapeutic index for this mechanism or that selectively targeting α(4)ß(2) NNRs may not be a viable approach to treating neuropathic pain.

Oral and cutaneous thermosensory profile of selective TRPV1 inhibition by ABT-102 in a randomized healthy volunteer trial.

The capsaicin receptor (TRPV1) antagonist ABT-102 demonstrates efficacy in multiple preclinical pain models. However, evolving clinical data for this compound class suggest potentially profound drug-induced thermosensory impairment. Safety and tolerability of ABT-102 were assessed in a multiple-dose, double-blind, placebo-controlled, randomized healthy volunteer trial. Thirty-six participants were randomized in a 2:1 ratio to ABT-102:placebo in 3 dose groups (1 mg, 2 mg, and 4 mg twice a day) and confined to an inpatient research unit for a 7-day treatment period and 3 follow-up days. Outcome measures included: oral and cutaneous cold detection, warm detection (WDT), and heat pain thresholds (HPT); oral perceived heat intensity (oral liquid test); time to hand withdrawal (water bath test); and cutaneous pain intensity (long thermal stimulus). Significant dose-dependent (placebo- and baseline-adjusted) increases in HPT and reduced painfulness of suprathreshold heat were present from days 1-7. For ABT-102 4 mg twice a day, model-based mean differences from placebo (95% confidence interval) were as follows: oral HPT, day 1=2.5°C (0.6-4.4), day 5=4.4°C (2.5-6.3); cutaneous HPT, day 2=3.3°C (1.4-5.3), day 5=5.3°C (3.3-7.2); oral WDT, day 1=2.6°C (0.5-4.7), day 5=2.7°C (0.6-4.9); cutaneous WDT, day 2=1.3 (0.0-2.6), day 5=1.6 (0.3-2.8) (all P<0.05). Oral liquid test and water bath test results followed a similar pattern. There was no effect on cutaneous cold detection. All effects were fully reversed by day 10. There were no other relevant safety findings. Core body temperature remained below 39°C in all participants. In conclusion, ABT-102 potently and reversibly increased HPT and reduced painfulness of suprathreshold oral/cutaneous heat.

The stimulation of HSD17B7 expression by estradiol provides a powerful feed-forward mechanism for estradiol biosynthesis in breast cancer cells.

Our laboratory has previously cloned and purified an ovarian protein found to be a novel 17ß-hydroxysteroid dehydrogenase type 7 enzyme (HSD17B7) (formerly prolactin receptor-associated protein) that converts the weak estrogen, estrone, to the highly potent estradiol. The regulation of this enzyme has not yet been explored. In this report, we show high expression of HSD17B7 in human ductal carcinoma and breast cancer cell lines and present evidence for a strong up-regulation of this enzyme by estradiol at the level of mRNA, protein expression, and promoter activity in MCF-7 cells. The effect of estradiol is mediated by estrogen receptor (ER)α, whereas ERß prevents this stimulation. ER antagonists, ICI 182,780 and 4-hydroxytamoxifen, prevent estradiol-induced stimulation of the endogenously expressed HSD17B7, suggesting that these inhibitors not only block estradiol action but also its production. We have identified a -185-bp region of the hsd17b7 promoter that is highly conserved among rat, mouse, and human and confers regulation by estradiol in MCF-7 cells. This region is devoid of a classical estradiol-response element but contains a nuclear factor 1 (NF1) site that is essential for estradiol action. We found that estradiol stimulates the recruitment and DNA binding of NF1 to this region of the hsd17b7 promoter. Furthermore, knockdown of NF1 family members, NF1B, NF1A, and NF1X, completely prevents induction of this gene by estradiol. In summary, our findings demonstrate that estradiol stimulates HSD17B7 transcriptional activity in breast cancer cells through a novel mechanism requiring NF1 and strongly suggest a positive feedback mechanism to increase local estradiol synthesis causing growth of estrogen-dependent breast cancers.

A randomized, double-blind, placebo-controlled trial evaluating the efficacy and safety of ABT-594 in patients with diabetic peripheral neuropathic pain.

ABT-594 is a neuronal nicotinic acetylcholine receptor (NNR) agonist that exhibits potent analgesic activity in preclinical models of acute, chronic, and neuropathic pain. The purpose of this phase 2, randomized, multicenter, double-blind, placebo-controlled study was to evaluate the safety and analgesic efficacy of ABT-594 in patients with diabetic peripheral neuropathic pain (DPNP). A total of 266 DPNP patients were randomized 1:1:1:1 to receive placebo, ABT-594 150 microg BID, ABT-594 225 microg BID, or ABT-594 300 microg BID. Patients were titrated to a fixed-dose of ABT-594 over 7 days and remained at this dose for another 6 weeks. Compared to placebo, all three ABT-594 treatment groups showed significantly greater decreases on the average diary-based 0-10 Pain Rating Scale (PRS) score from baseline to final evaluation, the primary efficacy measure (placebo, -1.1; 150 microg BID, -1.9; 225 microg BID, -1.9; 300 microg BID, -2.0). The proportion of patients achieving at least a 50% improvement in the average diary-based PRS was greater in all three ABT-594 treatment groups. However, adverse event (AE) dropout rates were significantly higher in all three ABT-594 treatment groups (28% for 150 microg BID, 46% for 225 microg BID, and 66% for 300 microg BID) than for the placebo group (9%). Consistent with the expected side-effect profile of NNR agonists, the most frequently reported AEs were nausea, dizziness, vomiting, abnormal dreams, and asthenia. This study establishes proof of concept for NNR agonists as a new class of compounds for treating neuropathic pain.