A phase I, randomized, ascending-dose study to assess safety, pharmacokinetics, and activity of GDC-8264, a RIP1 inhibitor, in healthy volunteers.

Receptor-interacting protein 1 (RIP1) is a key regulator of multiple signaling pathways that mediate inflammatory responses and cell death. RIP1 kinase activity mediates apoptosis and necroptosis induced by tumor necrosis factor (TNF)-α, Toll-like receptors, and ischemic tissue damage. RIP1 has been implicated in several human pathologies and consequently, RIP1 inhibition may represent a therapeutic approach for diseases dependent on RIP1-mediated inflammation and cell death. GDC-8264 is a potent, selective, and reversible small molecule inhibitor of RIP1 kinase activity. This phase I, randomized, placebo-controlled, double-blinded trial examined safety, pharmacokinetics (PKs), and pharmacodynamics (PDs) of single- (5-225 mg) and multiple- (50 and 100 mg once daily, up to 14 days) ascending oral doses of GDC-8264 in healthy volunteers, and also tested the effect of food on the PKs of GDC-8264. All adverse events in GDC-8264-treated subjects in both stages were mild. GDC-8264 exhibited dose-proportional increases in systemic exposure; the mean terminal half-life ranged from 10-13 h, with limited accumulation on multiple dosing (accumulation ratio [AR] ~ 1.4); GDC-8264 had minimal renal excretion at all doses. A high-fat meal had no significant effect on the PKs of GDC-8264. In an ex vivo stimulation assay of whole blood, GDC-8264 rapidly and completely inhibited release of CCL4, a downstream marker of RIP1 pathway activation, indicating a potent pharmacological effect. Based on PK-PD modeling, the GDC-8264 half-maximal inhibitory concentration for the inhibition of CCL4 release was estimated to be 0.58 ng/mL. The favorable safety, PKs, and PDs of GDC-8264 support its further development for treatment of RIP1-driven diseases.

Genetic variation associated with thyroid autoimmunity shapes the systemic immune response to PD-1 checkpoint blockade.

Activation of systemic immune responses using PD-1 checkpoint inhibitors is an essential approach to cancer therapy. Yet, the extent of benefit relative to risk of immune related adverse events (irAE) varies widely among patients. Here, we study endocrine irAE from 7 clinical trials across 6 cancers where atezolizumab (anti-PD-L1) was combined with chemotherapies and compared to standard of care. We show that atezolizumab-induced thyroid dysfunction is associated with longer survival. We construct a polygenic risk score (PRS) for lifetime risk of hypothyroidism using a GWAS from the UK Biobank and apply this PRS to genetic data collected from 2,616 patients of European ancestry from these trials. Patients with high PRS are at increased risk of atezolizumab-induced thyroid dysfunction and lower risk of death in triple negative breast cancer. Our results indicate that genetic variation associated with thyroid autoimmunity interacts with biological pathways driving the systemic immune response to PD-1 blockade.

Safety and efficacy of atezolizumab in patients with autoimmune disease: Subgroup analysis of the SAUL study in locally advanced/metastatic urinary tract carcinoma.

AIM: Patients with pre-existing autoimmune disease (AID) are typically excluded from clinical trials of immune checkpoint inhibitors, and there are limited data on outcomes in this population. The single-arm international SAUL study of atezolizumab enrolled a broader 'real-world' patient population. We present outcomes in patients with a history of AID. METHODS: Patients with locally advanced/metastatic urinary tract carcinoma received atezolizumab 1200 mg every 3 weeks until loss of clinical benefit or unacceptable toxicity. The primary end-point was safety. Overall survival (OS) was a secondary end-point. Subgroup analyses of AID patients were prespecified. RESULTS: Thirty-five of 997 treated patients had AID at baseline, most commonly psoriasis (n = 15). Compared with non-AID patients, AID patients experienced numerically more adverse events (AEs) of special interest (46% versus 30%; grade ≥3 14% versus 6%) and treatment-related grade 3/4 AEs (26% versus 12%), but without relevant increases in treatment-related deaths (0% versus 1%) or AEs necessitating treatment discontinuation (9% versus 6%). Pre-existing AID worsened in four patients (11%; two flares in two patients); three of the six flares resolved, one was resolving, and two were unresolved. Efficacy was similar in AID and non-AID patients (median OS, 8.2 versus 8.8 months, respectively; median progression-free survival, 4.4 versus 2.2 months; disease control rate, 51% versus 39%). CONCLUSIONS: In 35 atezolizumab-treated patients with pre-existing AID, incidences of special- interest and treatment-related AEs appeared acceptable. AEs were manageable, rarely requiring atezolizumab discontinuation. Treating these patients requires caution, but pre-existing AID does not preclude atezolizumab therapy. TRIAL REGISTRATION: NCT02928406.

Polygenic risk for skin autoimmunity impacts immune checkpoint blockade in bladder cancer.

PD-1 and PD-L1 act to restrict T cell responses in cancer and contribute to self-tolerance. Consistent with this role, PD-1 checkpoint inhibitors have been associated with immune-related adverse events (irAEs), immune toxicities thought to be autoimmune in origin. Analyses of dermatological irAEs have identified an association with improved overall survival (OS) following anti-PD-(L)1 therapy, but the factors that contribute to this relationship are poorly understood. We collected germline whole-genome sequencing data from IMvigor211, a recent phase 3 randomized controlled trial comparing atezolizumab (anti-PD-L1) monotherapy to chemotherapy in bladder cancer. We found that high vitiligo, high psoriasis, and low atopic dermatitis polygenic risk scores (PRSs) were associated with longer OS under anti-PD-L1 monotherapy as compared to chemotherapy, reflecting the Th17 polarization of these diseases. PRSs were not correlated with tumor mutation burden, PD-L1 immunohistochemistry, nor T-effector gene signatures. Shared genetic factors impact risk for dermatological autoimmunity and anti-PD-L1 monotherapy in bladder cancer.

Cerebrovascular accidents in patients treated for choroidal neovascularization with ranibizumab in randomized controlled trials.

PURPOSE: To analyze cerebrovascular accidents (CVAs) pooled from large, randomized, controlled clinical trials of ranibizumab treatment for neovascular age-related macular degeneration. METHODS: Events in five trials (FOCUS, MARINA, ANCHOR, PIER, and SAILOR) were analyzed using a standard safety monitoring process. Exact methods, stratified by study, were used to test for treatment differences based on odds ratios. A stepwise logistic regression model was fit to classify subjects' risk for CVA based on medical history. Treatment differences in CVA rates at 1 year or 2 years were evaluated within risk groups using stratified exact methods. RESULTS: Pooled 2-year CVA rates were <3%; odds ratios (95% confidence intervals) for CVA risk were 1.2 (0.4-4.4) for ranibizumab 0.3-mg versus control, 2.2 (0.8-7.1) for 0.5 mg versus control, and 1.5 (0.8-3.0) for 0.5-mg versus 0.3-mg ranibizumab. No substantial increased risk of CVA for 0.5 mg versus 0.3 mg was identified in pooled analyses or any of the individual trials. In pooled analyses, the difference between 0.5-mg ranibizumab and control was larger (7.7 [1.2-177]) among high-risk CVA patients. CONCLUSION: This analysis provided some evidence, although not definitive, of a potential increased risk of CVA with ranibizumab versus control or with 0.5-mg versus 0.3-mg ranibizumab. Continued monitoring for CVA within clinical trials seems warrented.