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A model for the homeostasis of glucose through the regulating hormones glucagon and insulin is described. It contains a subsystem that models the internalization of the glucagon receptor. Internalization is a mechanism in cell signaling, through which G-protein coupled receptors are taken from the surface of the cell to the endosome. The model is used to interpret data from a glucagon challenge test in which subjects have been under treatment with a novel glucagon receptor anti-sense drug which is aimed at reducing the number of receptors in the liver. It is shown how the receptor internalization results in tolerance of the blood glucose concentration to glucagon-induced hyperglycemia. We quantify the reduction of the number of receptors using the model and the data before and after treatment. Electronic supplementary material The online version of this article (doi:10.1007/s10928-019-09655-2) contains supplementary material, which is available to authorized users.

Objectives: Advanced vulvar carcinoma typically affects the elderly and treatment options are limited. Moderate antitumor activity of pembrolizumab (ORR, 6%) was noted in a small population of patients (pts) with PD-L1-positive vulvar cancer in the phase 1b KEYNOTE-028 study. KEYNOTE-158 ( ClinicalTrials.gov , NCT02628067) is a larger, nonrandomized, multicohort, open-label, phase 2 study that evaluates pembrolizumab in pts with previously treated advanced cancers irrespective of tumor PD-L1 expression. We report results for pts in the vulvar carcinoma cohort receiving pembrolizumab monotherapy. Methods: Enrolled pts were aged ≥18 y with histologically/cytologically documented advanced vulvar squamous cell carcinoma with prior treatment failure; measurable disease per RECIST v1.1; ECOG performance status ≤1; and tumor samples available for biomarker analysis, including PD-L1. PD-L1 positivity was defined as combined positive score ≥1 with expression evaluated using the PD-L1 IHC 22C3 pharmDx assay (Agilent Technologies, Carpinteria, CA, USA). Pts received pembrolizumab 200 mg Q3W until disease progression, unacceptable toxicity, or completion of 35 treatment cycles. Tumor imaging was performed every 9 weeks for 1 y and every 12 weeks thereafter. Response was assessed per RECIST v1.1 by independent central radiologic review. The primary endpoint was ORR. Secondary endpoints included duration of response (DOR), PFS, OS, and safety. Results: A total of 101 pts were enrolled. As of October 5, 2020, median time from start of treatment to data cutoff was 36.0 (range, 15.4–55.2) months. Median age was 64.0 (range, 31–87) y; 9 (8.9%) pts had no prior therapy, 57 (56.4%) had 1, 23 (22.8%) had 2, and 11 (10.9%) had 3 or more lines of prior therapy. Tumors were PD-L1–positive in 84 pts (83.2%), PD-L1–negative in 7 pts (6.9%), and non-evaluable/not assessed in 10 pts (9.9%). Overall, ORR was 10.9% (95% CI, 5.6–18.7); 1 pt had a CR and 10 pts had PR. Among pts with PD-L1–positive tumors, 8 of 84 (9.5%; 95% CI, 4.2–17.9) had CR or PR; among pts with PD-L1–negative tumors, 2 of 7 (28.6%; 95% CI, 3.7–71.0) had CR or PR. Among pts with a response, median DOR was 20.4 months (range, 2.1+ to 28.0). Among all enrolled pts (n=101), median PFS was 2.1 months (95% CI, 2.0–2.1) and median OS was 6.2 months (95% CI, 4.9–9.4 months). Treatment-related AEs occurred in 51 pts (50.5%), including 12 pts (11.9%) who had grade 3–5 events (no event occurred in >1 pt). There were 2 deaths (2.0%) considered related to treatment (hepatitis, n=1; fulminant hepatitis, n=1). Neither pt had comorbidities or pre-existing liver disease to contribute to these events; no other contributing factors were identified. A total of 5 pts (5.0%) discontinued because of treatment-related AEs. Immune-mediated AEs occurred in 18 pts (17.8%). Conclusions: Pembrolizumab monotherapy was associated with durable responses in a subset of pts with vulvar carcinoma (ORR, 10.9%; median DOR, 20.4 months). Responses occurred in both PD-L1-positive and PD-L1-negative pts.

ISIS 388626 is an antisense sodium-glucose cotransporter 2 (SGLT2) inhibitor designed to treat type 2 diabetes mellitus by induction of glucosuria. ISIS 388626 was demonstrated to be safe and effective in preclinical trails in several species. We undertook the present study to evaluate the safety and efficacy of 13 weekly doses of 50, 100, and 200 mg of ISIS 388626 in humans. ISIS 388626 increased 24-hour urinary glucose excretion dose dependently with 508.9 ± 781.45 mg/day in the 100-mg and 1299.8 ± 1833.4 mg/day in the 200-mg cohort, versus 88.7 ± 259.29 mg/day in the placebo group. ISIS 388626 induced a reversible increase in serum creatinine, with the largest effect after eight doses of ISIS 388626 (200 mg; 0.38 ± 0.089 mg/dl; 44% increase over baseline). Three subjects were discontinued as a result of creatinine increases. The renal clearance test revealed no indications for impairment of glomerular filtration or renal perfusion. The creatinine increases were accompanied by a rise in the levels of urinary renal damage markers [β-2-microglobulin (B2M), total protein, kidney injury molecule (KIM1), α-glutathione S-transferase (aGST), N-acetyl-β-(d)-glucosaminidase (NAG)]. Other treatment-related adverse events included mild injection site reactions occurring in 8-19% of the subjects. In conclusion, ISIS 388626 treatment induced glucosuria at a dose level of 200 mg/week. This intended pharmacological effect was small, amounting to approximately 1% of the total amount of filtered glucose. Changes in serum and urinary markers were indicative of transient renal dysfunction, most probably of tubular origin. Whether the glucosuria is caused by specific SGLT2 inhibition or general tubular dysfunction or a combination remains uncertain.

4020 Background: Patients (pts) with anal squamous cell carcinoma (ASCC) have poor outcomes and few treatment options. We report a pooled analysis of pembrolizumab (pembro) antitumor activity and safety in the ASCC cohorts of the multicohort studies KEYNOTE-028 (NCT02054806; phase 1b) and KEYNOTE-158 (NCT02628067; phase 2), providing a robust sample size and longer follow-up. Methods: Eligible pts were aged ≥18 y with histologically/cytologically confirmed metastatic/unresectable ASCC, had prior failure of/intolerance to standard therapy or no standard therapy options, measurable disease (RECIST v1.1), ECOG PS 0/1, and a tissue sample evaluable for PD-L1/biomarkers (KEYNOTE-028 required PD-L1 positivity). Baseline PD-L1 expression was assessed using a prototype IHC assay (QualTek) in KEYNOTE-028 and the PD-L1 IHC 22C3 pharmDx assay (Agilent Technologies) in KEYNOTE-158. Pts received pembro 10 mg/kg Q2W (KEYNOTE-028) or 200 mg Q3W (KEYNOTE-158) for 2 y or until PD/unacceptable AEs. The primary endpoint in both studies was ORR (per RECIST v1.1). Secondary endpoints were duration of response (DOR), PFS, OS, and safety. Results: 137 pts with ASCC were treated in KEYNOTE-028 (n = 25) or KEYNOTE-158 (n = 112) and were included in this analysis (median age, 61 y; 83.2% women; 73.0% had PD-L1–positive tumors). Median follow-up was 11.7 mo; 124 pts (90.5%) had discontinued treatment. ORR (95% CI) was 10.9% (6.3%–17.4%). 8 pts had CR and 7 had PR. ORR (95% CI) by PD-L1 status was 14.0% (7.9%–22.4%) in the PD-L1 positive group and 3.3% (0.1%–17.2%) in the PD-L1 negative group. Among all treated pts, median DOR was not reached (range, 6.0+ to 57.5+ mo). By Kaplan-Meier estimation, 84.6% of responders had a DOR ≥24 mo. Median PFS was 2.1 mo (95% CI, 2.0–2.1) and median OS was 11.7 mo (95% CI, 8.8–14.5). The 12-mo PFS and OS rates were 14.5% and 47.4%. 85 pts (62.0%) had +1 treatment-related AE, 24 pts (17.5%) with grade 3–4 events (no grade 5 events). 32 pts (23.4%) had immune-mediated AEs; 2 pts (1.5%) had infusion related reactions. Conclusions: In pts with previously treated advanced ASCC, pembro showed durable antitumor activity, particularly in pts with PD-L1–positive tumors, and manageable toxicity. Clinical trial information: NCT02054806 (KEYNOTE-028), NCT02628067 (KEYNOTE-158) .

Lifestyle modifications, including diet, are important in the prevention and management of type 2 diabetes mellitus (T2DM). However, limited information is available on the effects of single doses of meal replacements, particularly with regard to their effect on postprandial glucose. Therefore, a study was performed comparing the effects of a single meal replacement in T2DM patients on postprandial serum glucose, insulin, and glucagon. This randomized, double-blind, partial cross-over study was performed in 36 T2DM patients who continued their oral anti-diabetic medication. Each patient received three out of four treatments separated by 7 days. The treatments were a proprietary casein hydrolysate (insuVida™) alone or with additional leucine, unhydrolyzed casein, or placebo. Blood sampling was done for 4 hr. Treatments were compared using repeated measures ANOVA. Results are given as an estimate of the difference (%) for the 4-hr epoch. Glucose concentrations were lowered by -4.7% by insuVida and insuVida plus added leucine compared to placebo (95% CI: -1.6 to -7.7%), while the effect of unhydrolyzed casein was -1.7% (-4.8 to 1.5%). Addition of leucine to insuVida induced the greatest increase in insulin (i.e., 51.8%; 41.1 to 63.4%). All three treatments increased glucagon concentrations by 14% (8 to 20%) compared to placebo. A single dose of insuVida™ with or without addition of leucine significantly lowered plasma glucose compared to placebo and intact casein in T2DM patients. This is most likely due to an insulinotropic effect of insuVida. The data suggest that this type of intervention may be a viable treatment strategy in T2DM.