Immunogenicity of pembrolizumab in patients with advanced tumors.

BACKGROUND: Pembrolizumab is a potent, humanized, monoclonal anti-programmed death 1 antibody that has demonstrated effective antitumor activity and acceptable safety in multiple tumor types. Therapeutic biologics can result in the development of antidrug antibodies (ADAs), which may alter drug clearance and neutralize target binding, potentially reducing drug efficacy; such immunogenicity may also result in infusion reactions, anaphylaxis, and immune complex disorders. Pembrolizumab immunogenicity and its impact on exposure, safety, and efficacy was assessed in this study. PATIENTS AND METHODS: Pembrolizumab immunogenicity was assessed in 3655 patients with advanced or metastatic cancer treated in 12 clinical studies. Patients with melanoma, non-small cell lung cancer, head and neck squamous cell carcinoma, colorectal cancer, urothelial cancer, and Hodgkin lymphoma were treated with pembrolizumab at 2 mg/kg every 3 weeks, 10 mg/kg every 2 weeks, 10 mg/kg every 3 weeks, or 200 mg every 3 weeks. An additional study involving 496 patients with stage III melanoma treated with 200 mg adjuvant pembrolizumab every 3 weeks after complete resection was analyzed separately. RESULTS: Of 3655 patients, 2000 were evaluable for immunogenicity analysis, 36 (1.8%) were treatment-emergent (TE) ADA-positive; 9 (0.5%) of these TE-positive patients had antibodies with neutralizing capacity. The presence of pembrolizumab-specific ADAs did not impact pembrolizumab exposure, nor did pembrolizumab immunogenicity affect the incidence of drug-related adverse events (AEs) or infusion-related reactions. There was no clear relationship between the presence of pembrolizumab-specific ADAs and changes in tumor size across treatment regimens. Of the 496 patients treated with pembrolizumab as adjuvant therapy, 495 were evaluable, 17 (3.4%) were TE ADA-positive; none had neutralizing antibodies. CONCLUSIONS: The incidence of TE (neutralizing positive) ADAs against pembrolizumab was low in patients with advanced tumors. Furthermore, immunogenicity did not appear to have any clinically relevant effects on the exposure, safety, or efficacy of pembrolizumab. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01295827 (February 15, 2011), NCT01704287 (October 11, 2012), NCT01866319 (May 31, 2013), NCT01905657 (July 23, 2013), NCT02142738 (May 20, 2014), NCT01848834 (May 8, 2013), NCT02255097 (October 2, 2014), NCT02460198 (June 2, 2015), NCT01953692 (October 1, 2013), NCT02453594 (May 25, 2015), NCT02256436 (October 3, 2014), NCT02335424 (January 9, 2015), NCT02362594 (February 13, 2015).

Pharmacokinetics and Pharmacodynamics of the BACE1 Inhibitor Verubecestat (MK-8931) in Healthy Japanese Adults: A Randomized, Placebo-Controlled Study.

ß-site amyloid precursor protein cleaving enzyme 1 (BACE1) is required for the production of ß-amyloid (Aß) peptides and is considered a potential treatment target for Alzheimer's disease (AD). To support Japan's participation in the global clinical development program, we characterized the safety, pharmacokinetics (PKs), and pharmacodynamics of the BACE1 inhibitor verubecestat (MK-8931) in 24 healthy Japanese adults in a two-part, single-center, randomized, placebo-controlled phase I trial (protocol MK-8931-007) and compared the results with historical data from non-Japanese subjects. Both single (20, 100, and 450 mg) and multiple (80 and 150 mg once daily for 14 days) doses of verubecestat were well tolerated. Verubecestat's PK profile was similar in Japanese and non-Japanese subjects. Verubecestat also reduced mean cerebrospinal fluid concentrations of the Aß proteins Aß40, Aß42, and soluble ß fragment of amyloid precursor protein; the level of reduction was comparable between Japanese and non-Japanese subjects. These results support the continued global development of verubecestat as a potential disease-modifying agent for Japanese and non-Japanese subjects who are at risk for developing AD.

Tildrakizumab, a novel anti-IL-23 monoclonal antibody, is unaffected by ethnic variability in Caucasian, Chinese, and Japanese subjects.

OBJECTIVE: To evaluate the effect of ethnicity on the pharmacokinetics (PK) of tildrakizumab, a novel anti-IL-23 monoclonal antibody for the treatment of psoriasis. MATERIALS AND METHODS: This was an open-label, 2-part study in healthy adult subjects. In part 1, Japanese subjects and matched Caucasian and Chinese subjects (to Japanese) were assigned to 1 of 3 cohorts and administered tildrakizumab 50, 200, or 400 mg subcutaneously (SC). In part 2, Japanese subjects received tildrakizumab 10 mg/kg IV. Pre- and post-treatment antidrug antibodies were assessed. Safety and tolerability were assessed throughout the study. RESULTS: 59 subjects were enrolled; 53 in part 1 and 6 in part 2. Overall geometric mean AUC∞ was 6.15, 6.05, and 6.32 day×µg/mL/mg in Japanese, Caucasian, and Chinese subjects, respectively, after administration of a single SC dose. Bioavailability was ~92%. Six out of 58 evaluable subjects were positive for post-treatment ADA; 2 of these positive subjects had reduced tildrakizumab exposure. Most AEs were mild in intensity and the most frequent treatment-related AEs were injection site hematoma (15%), injection site pain (10%), and injection site erythema (8%). CONCLUSIONS: The pharmacokinetics of tildrakizumab were similar in Japanese, Caucasian, and Chinese subjects. Tildrakizumab exposure increased proportionally with dose in the range of 50-400 mg. A single SC dose of 50, 200, and 400 mg or a single IV dose of 10 mg/kg was generally well tolerated.

Literature mining for the discovery of hidden connections between drugs, genes and diseases.

The scientific literature represents a rich source for retrieval of knowledge on associations between biomedical concepts such as genes, diseases and cellular processes. A commonly used method to establish relationships between biomedical concepts from literature is co-occurrence. Apart from its use in knowledge retrieval, the co-occurrence method is also well-suited to discover new, hidden relationships between biomedical concepts following a simple ABC-principle, in which A and C have no direct relationship, but are connected via shared B-intermediates. In this paper we describe CoPub Discovery, a tool that mines the literature for new relationships between biomedical concepts. Statistical analysis using ROC curves showed that CoPub Discovery performed well over a wide range of settings and keyword thesauri. We subsequently used CoPub Discovery to search for new relationships between genes, drugs, pathways and diseases. Several of the newly found relationships were validated using independent literature sources. In addition, new predicted relationships between compounds and cell proliferation were validated and confirmed experimentally in an in vitro cell proliferation assay. The results show that CoPub Discovery is able to identify novel associations between genes, drugs, pathways and diseases that have a high probability of being biologically valid. This makes CoPub Discovery a useful tool to unravel the mechanisms behind disease, to find novel drug targets, or to find novel applications for existing drugs.