RUTI: a new therapeutic vaccine to shorten the latent tuberculosis infection treatment Authors: Cristina Vilaplana, Sergio Pinto, Eva Montané, Mahavir Singh, Vicenç Ausina, Joan Costa, Pere-Joan Cardona
The Rationale
The Latent Tuberculosis Infection (LTBI). The continuous reactivation requires a prolonged chemotherapy: 9 months 7 6 5 4 3 2 macrophage population necrosis population INH treatment (9 months) A log 0 CFUs 0 7 6 5 4 3 2 B Cardona PJ 2006 0 0 50 00 50 200 250 300 350 400 450 500 days
The LTBI. Cardona et al 2000, 2003, 2004 A B C D E
RUTI restimulates the immune response after the short-term chemotherapy, against a high number of M. tuberculosis antigens, not only against the growing bacilli. Treatment with Qx+RUTI Treatment with Qx 5 A B 5 4 4 log IFN-γ pg /ml 3 2 3 2 log CFUs/mL IFN-γ production CFUs IFN-γ production CFUs 2 6 8 9 2 6 8 9 weeks
The poliantigenic Response against Growing/ resting bacilli no spots/0 6 cells 400 350 300 250 200 50 00 50 0 40 20 00 80 60 40 20 0 ESAT-6 N.S. BCG 40 MPT-64 Ag85B 20 00 80 60 40 20 0 N.D. 9 3 PPD CFP-0 6 kda 9 kda 9 3 38 kda weeks 9 3 N.D. 40 kda aer Infected Infected+Qx w3-9 Infected + Qx w3-9 + RUTI 9 3 Qx (RIF+INH) RUTI 3 9 23 weeks hsp65 N.D. 9 3
Efficacy of RUTI in the murine model (Cardona et al Vaccine 2005) C57BL/6 DBA/2 6 5 4 A B $ 6 Log 0 CFUs/mL 3 2 6 5 4 3 C INH + RIF $ INH + RIF D LUNG SPLEEN Log 0 CFUs/mL 5 4 3 2 2 INH + RIF 0 3 9 7 22 0 3 9 7 22 Weeks INH + RIF Control Chemotherapy Chemotherapy + RUTI IN Chemotherapy + RUTI SC $ H+R RUTI 0 3 9 7 9 222 weeks
Efficacy of RUTI in the guinea pig model (Guirado et al 2005) 3.5 log 0 CFUs/lung 3.0 2.5 2.0 Ct i.n. s.c. week 6 00 Control RUTI i.n. RUTI s.c. 000 RUTI RUTI weight 900 800 700 INH+RIF RUTI INH+RIF RUTI RUTI INH+RIF RUTI 600 500 4 6 8 0 2 4 6 4 6 8 0 2 4 6 4 6 8 0 2 4 6 weeks
RUTI will reduce the LTBI treatment period 7 6 5 4 9 month of INH treatment 3 2 log0cfus 0 0 50 00 50 200 250 300 350 400 450 500 7 6 5 month of INH treatment + 2 RUTI doses 4 3 2 0 0 50 00 50 200 250 300 350 400 450 500 days
Short-term chemotherapy removes foamy macrophages
Foamy macrophages are a source of immunodepression (Cardona et al 2003) UTE0423R 6 BAL 4,0 inos 3,2 4 H-2 d H-2b 2,4 2,6 0 0 3 9 8 22 Lung DBA/2 Spleen C57BL/6 0 3 9 8 22 0 3 9 8 22 0,8 0,0 0 3 9 8 22
NO Foamy macrophages are a source of immunodepression (Cardona et al 2003)
Objectives To demonstrate the lack of toxicity of RUTI in healthy volunteers (Phase I trial). To follow up the immunological response induced after the inoculation of RUTI
Methods () Healthy volunteers have been recruited (HIV-, Hepatitis B and C -, and absence of latent tuberculosis infection (LTBI) through T-SPOT assay They are included in a random double blind assay controlled with placebo. Increasing doses of RUTI are administered (5, 25, 00 and 250 μg) in 4 groups of 6 volunteers. Two of them will be inoculated with placebo and 4 with the real vaccine. 2 inoculations of RUTI are administered 4 weeks a part in each case, once lack of toxicity is certified after the first inoculation
Methods (2) Toxicity is monitored for 68 days through regular clinical examinations (0,, 3, 7, 2, 28, 29, 3, 35, 56, 2 and 68 days post first inoculation); and haematological and biochemical determinations in peripheral blood samples (at 0, 7, 2, 28, 35, 56, 2 and 68 day post first inoculation) Immunological monitoring will be done from peripheral blood samples. Cellular immunity will be followed looking at IFN-γ production through an ELISPOT assay and whole blood assay against antigens ESAT-6, CFP-0, 6 kda, MPT-64, Ag85B, 38 kda, hsp 65, PPD and BCG; CD4+ CD25 high regulatory T cells; and γδ T cells proliferation. Whole blood bactericidal activity will be also followed, as well as humoral response.
Phase I trial
Phase I trial d0 d7 d2 d28 d35 d56 d2 d68
Results So far, the second inoculation of the third RUTI dose (00 μg) has been already inoculated without showing any toxic effects and an increasing immunological response with dose.
Phase I trial d0 d7 d2 d28 d35 d56 d2 d68 Table. Recorded Adverse Events (possibly or probably related to the vaccination) Local Twiching 2 Pain Vesiculated lesions Systemic Fever AE Number of subjects (n=2)
ELISPOT IFN-γ AT D7: ONE WEEK AFTER THE FIRST RUTI INOCULATION 40 ESAT-6 85 B SFU/2 0e5 PBMCs 30 20 0 0 50 00 50 0 5µg FCMtb PPD 25µg FCMtb 00µg FCMtb 5µg FCMtb BCG 25µg FCMtb 00µg FCMtb V V2 V3 V4 V5 V6 V7 V8 V9 V0 V V2 V3 V4 V5 V6 V!7 V8 5µg FCMtb 25µg FCMtb 00µg FCMtb
Future perspectives Phase IIa trials are planned for the end of 2008 in HIV- and HIV+ people in Europe. A Phase IIa trial in HIV- and HIV+ people will be started at the second half of 2009 in Africa. A Phase IIb trial in coinfected HIV+ people in Europe and Africa will start at 200 to demonstrate the efficacy of the month INH treatment plus 2 inoculations of RUTI vs 6 month INH treatment.
Future perspectives
RUTI will reduce the LTBI treatment period 7 6 5 4 9 month of INH treatment 3 2 log0cfus 0 0 50 00 50 200 250 300 350 400 450 500 7 6 5 month of INH treatment + 2 RUTI doses 4 3 2 0 0 50 00 50 200 250 300 350 400 450 500 days