Clinical and immunological effects of a 6 week immunotherapy cycle with murabutide in HIV-1 patients with unsuccessful long-term antiretroviral treatment

In an effort to evaluate the potential of non-specific immunotherapy in restoring global immunity, we have examined the clinical tolerance and biological effects of a 6 week administration of the immunomodulator, murabutide, in chronically infected HIV-1 patients. Forty-two subjects, presenting weak immune reconstitution and ineffective virus suppression following long-term highly active antiretroviral therapy (HAART), were randomized to receive, or not, murabutide 7 mg/day on five consecutive days/week. Clinical and immunological parameters were monitored before and after the immunotherapy period. Administration of murabutide was generally well tolerated, although some grade III adverse events, reversible on treatment cessation, were observed. Interestingly, in comparison with pre-inclusion levels, at 1 week after the immunotherapy cycle, only murabutide recipients presented a significant increase in CD4 cells, platelet counts, and in the percentage of patients with undetectable viral loads (<50 copies/mL). Statistical significance between the two groups was only evident with the latter parameter. Some of these clinical changes were maintained even up to 12 weeks after murabutide administration, and were accompanied by an increased ability to mount cellular responses to active immunization with a recall antigen, and by a significant increase in the percentage of patients presenting positive lymphoproliferative responses to the viral antigen gp160. These results warrant further evaluation of extended periods or cycles of murabutide immunotherapy as adjunct to HAART.

A phase I study of a six-week cycle of immunotherapy with Murabutide in HIV-1 patients naive to antiretrovirals

BACKGROUND

Limitations in the use of antiretroviral therapy suggest the need for additional approaches to enhance immune restoration and the control of HIV-1 replication. Therefore, we evaluated the clinical tolerance and biological effects of immunotherapy with the synthetic immunomodulator Murabutide in 9 treatment-naive HIV-1 patients presenting with CD4+ lymphocyte counts >500 cells/mm3 and plasma viral loads <30.000 copies/ml.

MATERIAL/METHODS

Murabutide was administered at a daily dose of 7 mg on 5 consecutive days per week, for a period of 6 weeks. The study duration extended over 22 weeks, and clinical, virological, and immunological evaluations were carried out on 2 occasions before, during, and after immunotherapy.

RESULTS

With acceptable clinical tolerance and only 2 reversible grade III adverse events, clinical and virological parameters remained highly stable throughout the study period. However, maintained or improved lymphoproliferative responses to several recall and HIV-1 antigens, as well as modest but significant increases in the percentages of naive cells were noted during or/and after immunotherapy. These changes could not be demonstrated in an observation group of 9 additional patients who were identically followed for a 22-week period.

CONCLUSIONS

Our results suggest that non-specific immunotherapy targeting dysfunctions in innate immunity could bring about restoration of immune responses in HIV disease.