Metreleptin therapy for nonalcoholic steatohepatitis: Open-label therapy interventions in two different clinical settings

Abstract

Background: Recombinant leptin therapy reverses nonalcoholic steatohepatitis (NASH) in leptin-deficient lipodystrophy. We inquired if leptin therapy would improve nonalcoholic steatohepatitis in more common forms of this heterogeneous condition.

Methods: Nine male patients with relative leptin deficiency (level < 25th percentile of body mass index- and gender-matched United States population) and biopsy-proven NASH and 23 patients with partial lipodystrophy and NASH were recruited for two distinctive open-label trials. Participants received leptin therapy in the form of metreleptin for 12 months. The primary endpoints were the global nonalcoholic steatohepatitis scores from paired liver biopsies scored blindly.

Findings: Of 9 participants recruited in the relative leptin deficiency treatment study, 7 completed 12-months of therapy. Mean global NASH scores were reduced from 8 ± 3 to 5 ± 2 (range: from 1 to 6, P = 0.004). In the partial lipodystrophy study, 19 of 22 subjects completed 12 months of treatment, and 18 completed a second liver biopsy. Global NASH scores also reduced significantly from 6 ± 2 to 5 ± 2 (range: from -2 to 4, P = 0.008). In both studies, the predominant changes were in steatosis and hepatic injury scores.

Conclusion: Our findings show that patients with NASH associated with both relative leptin deficiency and partial lipodystrophy have reductions in hepatic steatosis and injury in response to exogenous leptin therapy. Moreover, leptin deficiency may have regulatory effects in mediating fat deposition and ensuing injury in the liver.TRIAL REGISTRATION. ClinicalTrials.gov NCT00596934 and NCT01679197.

Keywords: Fatty Liver Disease; Insulin Resistance; Leptin; Obesity; Partial Lipodystrophy.

Figures

Figure 1.. Correlation of circulating leptin levels with adiposity in patients with NASH, the RLD study design, and the effect of metreleptin therapy on metabolic parameters in the RLD study.

(A) Serum leptin levels against total body fat percentage determined by DEXA scan in 50 NASH patients. F = females (r = 0.540, P = 0.010), M = males (r = 0.430, P = 0.030). Blue symbols show 11 patients with RLD; (B) The RLD study design. For metabolic and body composition parameters, data carried forward. For liver related parameters, a decision was made to only conduct completer analysis since liver biopsy was done only at baseline and at month 12; and withdrawal reasons may have confounded the observations; (C) Effect of metreleptin therapy on leptin levels throughout the study period. Note that levels after month 3 may be confounded by circulating anti-drug antibodies; (D) Changes from baseline in weight; (E) fat percentage; (F) lean body mass percentage; (G) glucose; and (H) HOMA-IR studied at the indicated times. We report the F-statistic and P value from a repeated-measures ANOVA. *These P values are marked if they are significant versus baseline with post hoc paired sample t-test after multiplicity correction. Paired t-test was used to compare month-12 values to baseline (without multiplicity correction) as the change at 12 months vs. baseline was a prespecified endpoint. ▲ shows specific data points where the last observation was carried forward.

Figure 2.. Effect of metreleptin therapy on liver parameters in the RLD study.

Effect of metreleptin on (A) aspartate aminotransferase (AST); (B) alanine aminotransferase (ALT); and (C) liver fat percentage as determined by MRI over time; (D) individual NASH scores at baseline and 12 months. We report the F-statistic and P value from a repeated-measures ANOVA. *These P values are marked if they are significant versus baseline with post hoc paired sample t-test after multiplicity correction. Paired t-test was used to compare month-12 values to baseline (without multiplicity correction) as the change at 12 months vs. baseline was a prespecified endpoint. (E) H&E stains of liver biopsies before and after 1 year of therapy with leptin. Note the marked improvement in steatosis on biopsy and magnetic resonance images and spectroscopy (15 % fat at baseline vs. 5 % fat after treatment with metreleptin); (F) Components of NASH score at 12 months compared to baseline; (G) Percent change in different free fatty acid species relative to total free fatty acid levels compared to baseline after 6 months of metreleptin therapy. *P < 0.05 and **P < 0.01 versus baseline.

Figure 3.. Leptin levels, study design, and the effect of metreleptin on metabolic parameters and liver enzymes over the 12-month treatment period in the PL study.

(A) Leptin levels throughout the PL study period. Leptin levels were measured from three samples measured 30 minutes apart at baseline, and 3, 6, 9, and 12 months after metreleptin. The levels shown are average leptin levels. The F-statistic and P value are reported from a repeated-measures ANOVA. *These P values are marked if they are significant versus baseline with post hoc paired sample t-test after multiplicity correction. Paired t-test was used to compare month-12 values to baseline (without multiplicity correction) as the change at 12 months vs. baseline was a prespecified endpoint; (B) Patient progression through the PL study. A total of 23 patients with partial lipodystrophy were enrolled and 22 had biopsy-proven NASH. Of the 22 patients, 3 withdrew from the study and 19 completed 1 year of metreleptin treatment. 18 patients completed the 12-month post-treatment biopsy; (C) Triglycerides; (D) HbA1c; (E) ALT; and (F) AST levels in subjects with partial lipodystrophy treated with metreleptin for 1 year. The F-statistic and P value are reported from a repeated-measures ANOVA. *These P values are marked if they are significant versus baseline with post hoc paired sample t-test after multiplicity correction. Paired t-test was used to compare month-12 values to baseline (without multiplicity correction) as the change at 12 months vs. baseline was a prespecified endpoint. Tests are run on log transformed data for triglycerides, ALT and AST. Triglycerides are shown geometric mean with 95 % confidence intervals (CI), otherwise, the data are reported as mean ± SD. The last observed non-missing values (month 6) is used to fill in missing values at month 9 visit in one subject (subject ID: 21) who missed month 9 visit but completed the study protocol.

Figure 4.. Liver fat quantification and histopathological features of NASH after 1-year of metreleptin therapy in subjects with PL.

A) Liver fat quantification, using magnetic resonance (MR) Dixon method, decreased from baseline 13 ± 7 % to 8 ± 5 % after 12 months of metreleptin in subjects who completed 1 year of follow up (n = 19; P = 0.001). Liver fat of 18 subjects with paired liver biopsies showed a reduction from baseline 13 ± 7 % to 8 ± 5 % after 12 months of metreleptin (n = 18, P = 0.001); (B) NASH score comparisons at baseline and after 12 months of metreleptin therapy of 18 subjects with 1-year biopsies show a decrease in global NASH scores from 6 ± 2 to 5 ± 2 (P = 0.008); (C) During the 1 year follow up, NAS scores also decreased from 5 ± 1 to 4 ± 1 (P < 0.001); (D) Different components of the NASH score before and after metreleptin treatment. P values are obtained with Wilcoxon matched-pairs signed rank test; (E) H&E staining of the liver biopsy specimens from a 14-year-old female participant. I. Baseline biopsy at 200x magnification. II. 12-month biopsy at 200X magnification. III. Baseline biopsy at 100x magnification. IV.12-month biopsy at 100x magnification. Note the marked steatosis and hepatocyte ballooning at baseline state, which significantly improve by 12 months; (F) Components of NASH score at 12 months compared to baseline in the PL study (n =18); (G) Metabolic parameters before and after metreleptin in PL patients with baseline and 12-month liver biopsies. Energy intake is reported in 17 patients. *Total intake includes food, water and other beverages. Levels are compared by using paired sample t-test. #Tests are run on log-transformed data. Data are presented as mean ± standard deviation (SD). Triglycerides are reported.as geometric mean and 95% confidence intervals (CI).