Biotechnology company Cytodyn has submitted the pivotal clinical trial protocol for its investigational HIV monotherapy leronlimab to the US Food and Drug Administration (FDA).

Leronlimab is a humanised IgG4 mAb designed to block the CCR5 cellular receptor that is believed to play multiple roles with implications in HIV infection, tumour metastases and immune signalling.

The new Phase III trial is designed to evaluate the treatment strategy and clinical safety of 700mg weekly subcutaneous leronlimab as a single-agent induction therapy followed by a 525mg or 700mg dose as maintenance therapy.

This regimen is intended for the chronic suppression of CCR5-tropic HIV-1 infection.

Trial participants will be administered with existing retroviral regimen plus 700mg leronlimab for four weeks in the overlap phase. Patients will then be shifted to the monotherapy induction phase, involving 700mg weekly dose of the drug for ten weeks.

Subjects will later receive either a 525mg or 700mg dose during a 36-week monotherapy maintenance phase.

CytoDyn president and CEO Nader Pourhassan said: “A monotherapy with leronlimab, if approved, may allow patients with pill fatigue to maintain a disciplined compliance regimen.

“In addition, it may provide patients concerned about the possibility of developing one or more drug class resistances, to potentially maintain a suppressed viral load without the typical side effects or toxicity associated with HAART.”

If successful, the Phase III trial is expected to support the filing of a biologics license application (BLA) for label expansion in case the drug secures FDA approval as a combination therapy with HAART in HIV.

The US regulator awarded fast track designation to leronlimab plus HAART combination to treat HIV-infected patients and for metastatic triple-negative breast cancer.