Phase 1b Study of the Safety, Pharmacokinetics, and Disease-related Outcomes of the Matrix Metalloproteinase-9 Inhibitor Andecaliximab in Patients With Rheumatoid Arthritis.

PURPOSE: Andecaliximab (GS-5745) is a highly selective monoclonal antibody against matrix metalloproteinase-9 (MMP9), a proteolytic enzyme implicated in the pathogenesis of rheumatoid arthritis (RA). This study assessed the safety and pharmacokinetic (PK) parameters of andecaliximab in patients with RA and evaluated the effects of andecaliximab treatment on exploratory disease biomarkers. METHODS: In this double-blind, Phase 1b trial, patients with active RA were randomized (4:1) to receive 400-mg andecaliximab or placebo every 2 weeks for a total of 3 intravenous infusions. The primary and secondary end points were safety and the PK parameters of andecaliximab, respectively. Data were summarized by using descriptive statistics. FINDINGS: A total of 18 patients were randomized; 15 received andecaliximab (participants with confirmed RA diagnosis without current administration of a biologic DMARD a biologic DMARD (disease-modifying antirheumatic drug), aged 18 to 70 years old, weighing >45 to <120 kg). No deaths, serious adverse events, or study discontinuations occurred. All reported adverse events were grade 1 or grade 2 in severity. Mean plasma andecaliximab exposure was 587 d · µg/mL and 878 d · µg/mL at days 1 and 29, respectively, suggesting moderate accumulation. The median terminal t1/2 was 5.65 days; mean volume of distribution at steady state was 4560 mL. Mean MMP9 coverage (the percentage of total plasma MMP9 bound by therapeutic antibody) was maintained at ~80% after the first administration of andecaliximab. IMPLICATIONS: Andecaliximab administered as 3 infusions over 29 days was generally safe and well tolerated in patients with RA. The majority of total plasma MMP9 was bound by andecaliximab after the first administration. Clinical studies of increased treatment duration in larger patient cohorts are warranted. ClinicalTrials.gov identifier: NCT02176876. Registered on 25 June 2014.

Inhibition of lysophosphatidic acid acyltransferase beta disrupts proliferative and survival signals in normal cells and induces apoptosis of tumor cells.

Lysophosphatidic acid acyltransferase beta (LPAAT-beta) is an intrinsic membrane protein that catalyzes the synthesis of phosphatidic acid (PA) from lysoPA. Given that PA is a cofactor in a number of signaling cascades that are constitutively active in tumors, we evaluated the role of PA produced by LPAAT-beta in Xenopus oocyte meiotic maturation assays and an isoform-specific inhibitor of LPAAT-beta in mammalian cell assays. We found that ectopic overexpression of LPAAT-beta cooperates in activation of the Ras/Raf/Erk pathway in Xenopus oocytes and that inhibition of LPAAT-beta inhibits signaling in both the Ras/Raf/Erk and PI3K/Akt pathways. When LPAAT-beta activity is suppressed by CT32228 (N-(4-bromo-phenyl)-6-(5-chloro-2-methyl-phenyl)-[1,3,5]triazine-2,4-diamine), an isoform-specific noncompetitive inhibitor, tumor cells undergo mitotic catastrophe while most normal cells simply arrest or become quiescent. The data presented here suggest that PA produced by LPAAT-beta plays an important role in signaling pathways critical to tumor cell survival.