Background and Aims: Human T-lymphotropic virus type 1 (HTLV-1), is as a type C retrovirus, which was first isolated from a patient with Adult T-cell leukemia/lymphoma (ATLL). Approximately 10-20 million people are infected by HTLV-1 virus worldwide, but only 5-10% of them develop clinical manifestations such as Acute-T lymphoma (ATL), HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), uveitis, and infective dermatitis. Indinavir was the first protease inhibitor used for treating HIV-1. It has some activity on HTLV-1, but it is not fully able to inhibit the HTLV-1 protease. Nowadays, design and construction of novel pharmacophore compounds can serve as an appropriate replacement for Indinavir. 
Materials and Methods: In the present research, we used bioinformatics studies, to evaluate the potential role of four novel pharmacophres with inhibitory function on HTLV-1 protease, so called KMI pharmacophores (Keikha Modified Indinavir).
Results: After a detailed structural analysis of each of them, it seems all four designed phamacophores, (especially KMI-3) could be more effective on HTLV-1 protease than Indinavir.
Conclusions: According to exact in silico evaluations of each four pharmacophores, KMI-3 demonstrated a potential for its use on treatment of HTLV-1 infections.