Pharmacotherapeutic group: Antidiarrheals, intestinal antiinflammatory/antiinfective agents, corticosteroids acting locally, ATC code: A07EA06
Mechanism of action
The intended action of Kinpeygo is the suppression of mucosal B-cells, located in the Peyer's patches in the ileum where the majority of galactose-deficient IgA1 antibodies (Gd-IgA1) are produced. The inhibition of their proliferation and differentiation into plasma cells is expected to lower the occurrence of Gd-IgA1 antibodies and hence the formation of immune complexes in the systemic circulation, therefore preventing the downstream effects of glomerular mesangial deposition of immune complexes containing Gd-IgA1, manifesting as glomerulonephritis and loss of renal function.
Pharmacodynamic effects
Kinpeygo is an oral, modified‑release hard capsule formulation of budesonide which combines a delayed capsule disintegration with a prolonged release of the active substance budesonide in the ileum. By directing the release of budesonide to the ileum, where Peyer's patches reside in high density, a local pharmacological effect is anticipated.
Clinical efficacy
Primary IgA nephropathy
The efficacy of Kinpeygo has been evaluated in 2 randomised, double-blind, placebo-controlled studies of patients with primary IgAN, who were receiving optimised dose (maximum allowed dose or maximum tolerated dose) of Renin‑Angiotensin System (RAS) inhibitor therapy as a standard of care (SOC). The effect of Kinpeygo on kidney function decline based on estimated glomerular filtration rate (eGFR) and proteinuria reduction based on urine protein creatinine ratio (UPCR) was assessed in a randomised, double-blind, multicentre phase 3 study in patients with biopsy proven IgAN. 364 patients in the Full Analysis Set were randomised 1:1 to either Kinpeygo 16 mg once daily or placebo and treated for 9 months followed by a 2-week taper phase of 8 mg and 15 months of observational follow-up.
The final analysis of the study demonstrated that over the 2-year period, a 9-month treatment course of Kinpeygo (Nefecon) 16 mg/day reduced the loss of kidney function at 2 years in patients with primary IgAN in a statistically significant manner. The eGFR benefit accrued by the end of 9 months of treatment was maintained during 15 months of observational follow-up (Figure 1).
Figure 1: Mean absolute change in eGFR from baseline in Phase 3 NefIgArd Study
The treatment effect eGFR difference at 2 years was 6.00 mL/min/1.73 m2 using the MMRM analysis without explicit missing data assumptions (MAR assumption) and was statistically significant. The change from baseline in eGFR at 24 months was -7.50 mL/min/1.73 m2 in the Kinpeygo group compared to -13.50 mL/min/1.73 m2 in the placebo group; there was a treatment benefit of 6.00 mL/min/1.73 m2 (95% CI: 2.76 to 10.08) with Kinpeygo treatment compared to placebo (Table 2).
A supplementary analysis of 2-year eGFR total slope using a linear spline mixed effects analysis method to account for the acute (baseline to 3 months) and chronic (from 3 months onwards) phases estimated an overall treatment benefit of 2.62 mL/min/1.73 m2 per year (95% CI 1.23 to 4.00) in favour of Kinpeygo (Table 2).
Table 2: Analysis of eGFR at 24 months in Phase 3 NefIgArd Study
| eGFR (CKD-EPI) (mL/min/1.73 m2) a | Kinpeygo 16 mg (N=182) | Placebo (N=182) |
| Mean change from baseline (mL/min/1.73 m2) at 24 months (15 months after Kinpeygo treatment ended) b | -7.50 | -13.50 |
| Kinpeygo 16 mg versus Placebo: (95% CI) Change from baseline in eGFR at 24 months (mL/min/1.73 m2) b 2-year eGFR total slope (mL/min/1.73 m2 per year) c | 6.00 (2.76 to 10.08) 2.62 (1.23 to 4.00) |
a Including all observed eGFR data recorded after use of prohibited medication.
b Adjusted geometric least squares mean ratio of eGFR relative to baseline analysed using mixed model repeated measures analysis. Mean changes derived directly from the analysis performed on a log scale.
c Linear-spline mixed effects model in which eGFR was modelled simultaneously and separately over the acute (baseline to 3 months) and chronic (from 3 months onwards) phases and then combined to estimate the overall total slope. Data not log-transformed and including all observed eGFR data regardless of the use of prohibited medications or starting dialysis or having a renal transplant.
CI: confidence interval; eGFR (CKD-EPI): estimated glomerular filtration rate based on Chronic Kidney Disease Epidemiology Collaboration calculation
The 2-year eGFR treatment effect was consistent across all key subgroups, including key demographic (such as age, sex, race) and baseline disease (such as baseline proteinuria) characteristics.
The time to a confirmed 30% reduction in eGFR or end-stage renal disease (defined as renal-related death, renal transplantation, dialysis, or sustained eGFR <15 mL/min/1.73 m2) was delayed in patients who received Kinpeygo compared with those who received placebo (HR 0.45; 95% CI 0.26 to 0.75). The proportion of patients with a confirmed event over the 2-year study period was 11.5% in the Kinpeygo group versus 21.4% of patients in the placebo group.
The final analysis of treatment effect on proteinuria at 2 years was consistent with that observed at the end of the 9 months course of Kinpeygo treatment. However, in the Kinpeygo treatment arm proteinuria increased after a peak reduction at 12 months (Table 3). The UPCR treatment effect at 9 months was highly consistent across subgroups, including key demographic (such as age, sex, race) and baseline disease (such as baseline proteinuria) characteristics. A similarly consistent pattern in UPCR across subgroups was observed at 2 years.
Table 3: Proteinuria reduction at 9, 12, and 24 months and averaged over 12 to 24 months in Phase 3 NefIgArd Study
| Percentage reduction from baseline in UPCR g/g a, b | Kinpeygo 16 mg (N=182) | Placebo (N=182) |
| At 9 months c | 34% | 5% |
| At 12 months (3 months after Kinpeygo treatment ended) | 51% | 3% |
| At 24 months (15 months after Kinpeygo treatment ended) | 31% | 1% |
| Kinpeygo 16 mg versus placebo: Average UPCR percentage reduction over 12 to 24 months compared to baseline d (95% CI) | 41% (32% to 49%) |
a Excluding UPCR data recorded after use of prohibited medication.
b Adjusted geometric least squares mean ratio of UPCR relative to baseline were based on a longitudinal repeated measures model.
c Percent reduction in UPCR was previously evaluated in the first 199 patients randomised (p=0.0003). The final analysis in all 364 patients confirmed a 30% reduction in UPCR at 9 months with Kinpeygo compared with placebo (95% CI 20% to 39%).
d Average UPCR percentage reduction during follow-up (over 12 to 24 months) based on longitudinal repeated measures model.
CI: confidence interval; UPCR: urine protein creatinine ratio.
A supportive phase 2b study with a similar study design was conducted in a total of 153 randomised patients who received Kinpeygo 16 mg, Kinpeygo 8 mg, or placebo, once daily for 9 months followed by a 2-week taper phase and 3 months of observational follow-up, while continuing to receive RAS inhibitor therapy.
The primary objective was met at an interim analysis that compared Kinpeygo to placebo and showed a statistically significant reduction in UPCR at 9 months for the combined Kinpeygo 16 mg/day and 8 mg/day dose groups compared to placebo (p=0.0066).
Using the same statistical methodology as in the phase 3 study, a statistically significant 26% reduction in the primary endpoint UPCR was shown at 9 months for the 16 mg dose of Kinpeygo versus placebo (p=0.0100) and a 29% reduction at 12 months (p=0.0027).
The difference in eGFR CKD-EPI (serum creatinine) for the 16 mg dose of Kinpeygo versus placebo was 3.57 mL/min/1.73m2 at 9 months (p=0.0271), and 4.46 mL/min/1.73 m2 at 12 months (p=0.0256). The improvement in 1-year eGFR slope was estimated to be 5.69 mL/min/1.73 m2 per year with Kinpeygo 16 mg once daily compared to placebo (p=0.0007).
Clinical efficacy of re-treatment (Nef-301 OLE)
Primary IgA nephropathy
The efficacy of re-treatment with Kinpeygo has been evaluated in an open-label extension (OLE) study for patients who had completed the pivotal phase 3 study, either on Kinpeygo or on placebo, and who continued to be treated with a stable dose of RAS inhibitor therapy (angiotensin-converting enzyme inhibitors and/or angiotensin II type I receptor blockers). Patients who had previously received Kinpeygo in the phase 3 study received re-treatment, whereas patients who previously received placebo received Kinpeygo as a first course. 119 patients were enrolled in total (62.2% of which were previously on placebo and were treated with Kinpeygo for the first time) and received Kinpeygo 16 mg/day for a 9-month period, with a possibility for reduction to 8 mg/day if clinically relevant and causally related adverse events developed.
In order to enter Nef-301 OLE patients must have had proteinuria based on two consecutive measurements separated by at least 2 weeks showing either ≥1 g/day (≥1000 mg/day) or UPCR ≥0.8 g/gram (≥90 mg/mmol). Patients must also have had eGFR ≥30 mL/min per 1.73 m2 using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula.
The final analysis of the open-label extension study demonstrated a similar treatment benefit in both primary endpoints (eGFR and UPCR) after 9 months of treatment with Kinpeygo regardless of whether patients received Kinpeygo or placebo in the previous Phase 3 study. At 9 months, the absolute change from baseline in eGFR was -1.28 mL/min/1.73 m2 (95% CI -3.20 to 0.72) for patients previously treated with Kinpeygo 16 mg and -1.53 mL/min/1.73 m2 (95% CI -3.07 to 0.05) for patients previously on placebo. After 9 months of treatment with Kinpeygo 16 mg/day, UPCR was reduced from baseline by 33.3% (95% CI -44.4 to -19.9) in patients previously treated with Kinpeygo 16 mg and by 31.0% (95% CI -40.2 to -20.2) in patients previously treated with placebo.
Paediatric population
Kinpeygo has not been studied in the paediatric population.