Development of an Interleukin-1β Vaccine in Patients with Type 2 Diabetes

Abstract

Interleukin-1β (IL-1β) is a key cytokine involved in inflammatory illnesses including rare hereditary diseases and common chronic inflammatory conditions as gout, rheumatoid arthritis, and type 2 diabetes mellitus, suggesting reduction of IL-1β activity as new treatment strategy. The objective of our study was to assess safety, antibody response, and preliminary efficacy of a novel vaccine against IL-1β. The vaccine hIL1bQb consisting of full-length, recombinant IL-1β coupled to virus-like particles was tested in a preclinical and clinical, randomized, placebo-controlled, double-blind study in patients with type 2 diabetes. The preclinical simian study showed prompt induction of IL-1β-specific antibodies upon vaccination, while neutralizing antibodies appeared with delay. In the clinical study with 48 type 2 diabetic patients, neutralizing IL-1β-specific antibody responses were detectable after six injections with doses of 900 µg. The development of neutralizing antibodies was associated with higher number of study drug injections, lower baseline body mass index, improvement of glycemia, and C-reactive protein (CRP). The vaccine hIL1bQb was safe and well-tolerated with no differences regarding adverse events between patients receiving hIL1bQb compared to placebo. This is the first description of a vaccine against IL-1β and represents a new treatment option for IL-1β-dependent diseases such as type 2 diabetes mellitus (ClinicalTrials.gov NCT00924105).

Figures

Figure 1

Characterization of the immune response to IL1bQb in rhesus monkeys. To assess immune response in rhesus monkey, 24 animals were injected subcutaneously six times every 14 days (day 1, 15, 29, 43, 57, and 71, see arrows) with a rhesus monkey version (rmIL1bQb, n = 12) or a human version (hIL1bQb, n = 12) of the IL-1β vaccine. Rhesus monkeys developed anti-IL-1β IgG antibody responses after one injection and neutralizing antibody responses after three to four injections. Anti-IL-1β IgG titers and neutralization titers are expressed as the reciprocals of the serum dilutions needed to achieve half-maximal signal in enzyme-linked immunosorbent assay (ELISA) or half-maximal inhibition of the IL-6 response in the cellular assay, respectively. (a) Two weeks after the last injection (day 84), animals were challenged with an intravenous injection of rhesus IL-1β. IL-6 concentrations were determined in serum collected after 3, 6, and 9 hours. Control animals treated with the virus-like particles carrier Qb showed pronounced IL-6 levels, while immunization with rmIL1bQb and hIL1bQb completely protected against the IL-1β challenge (b).

Figure 2

Enrollment and outcomes of phase 1 clinical trial. A total of 94 type 2 diabetic patients were screened in four participating centers. Of those, 46 of patients were not eligible according to entry criteria, most often due to a positive TB-specific test. Forty-eight patients were randomly assigned to active treatment (hIL1bQb) or placebo in ascending treatment groups. All patients completed the study and were analyzed according to the intention-to-treat approach.

Figure 3

Induction of IgG antibody responses in type 2 diabetic patients. There was a moderate, dose-dependent anti-IL-1β IgG antibody response in the first 5 dose groups as measured by ELISA assay (inset a). Substantially higher antibody titers were measured in the highest treatment group (a). Decay phase of the anti-IL-1β IgG antibody response shown in (a) with logarithmic y-axis. Half-lives of anti-IL-1β antibodies were about 7 weeks in treatment groups 5 and 6, while in the lower treatment groups half-lives were 2·6-2·9 weeks (b). There was a tight correlation between anti-IL-1β and anti-Qβ IgG antibody titers at week 14 (R2 = 0·71), indicating that the lack of an anti-IL-1β antibody response in some subjects was most likely not due to an IL-1β-specific limitation in the antibody response, but rather due to levels below the detection limit (c). Anti-IL-1β and anti-Qβ IgG antibody titers are expressed as the reciprocal of the serum dilutions needed to achieve half maximal absorbance in ELISA.

Figure 4

Neutralizing capacity is dependent on strong IL-1β antibody responses. Anti-IL-1β IgG antibody titers measured by ELISA (solid lines) and neutralizing antibody responses (dashed lines) for individual patients in the 900 µg treatment group are shown (open squares for individual subjects with neutralizing response=responders (a–c); closed squares for individual subjects without neutralizing response=nonresponders (d–f)). Anti-IL-1β IgG antibody titers are expressed as outlined in the legend to Figure 1. Neutralizing responses are expressed as % decrease of the absorbance signal detected in the IL-6 quantification assay, when comparing supernatants from HeLa cells incubated with 25 pg/ml IL-1β in the presence of immune sera to supernatants of HeLa cells incubated with 25 pg/ml IL-1β in the presence of the corresponding preimmune serum at a 1:5 dilution. Anti-IL-1β IgG antibody responses measured by ELISA were substantially higher in responders compared to nonresponders. Neutralizing antibody responses were delayed compared to the overall anti-IL-1β IgG antibody response measured by ELISA. (g) Geometric means of anti-IL-1β IgG titers (solid line) and % neutralization (dashed line) are shown for grouped responders (open squares) and nonresponders (closed squares).

Figure 5

Changes in metabolic and inflammatory parameters. Secondary outcome measures HbA1c, glucose, and C-reactive protein (CRP) were compared in the highest-dose group (6−8 × 900 μg) as neutralizing responses only developed with this dose level. Changes in neutralization responses are depicted on the x-axis, while changes in HbA1c-levels from baseline (screening and baseline average) to the end of the core study (average for weeks 16, 20, 24) are plotted on the y-axis (a). Changes in fasting glucose levels were related to changes in neutralization in participants from baseline to the end of the core study (average of weeks 14, 16, 20, 24 (b)). Changes in CRP levels were related to changes in neutralization in study participants from baseline to the end of the core study (average of weeks 14, 16, 20, 24 (c)). CRP levels above 30 mg/dl or >3-fold increased compared to baseline as well as HbA1c and glucose levels at time points of increased CRP were not included in the analysis. Colors indicate individual subjects. Nonresponders: closed squares; responders: open squares.