leronlimab
PRO140

Standard Dose
One weekly subcutaneous (under the skin) injection of 350 mg used in clinical trials.See package insert when available for more complete information on potential side effects and interactions.
Manufacturer
CytoDyn, Inc.cytodyn.com
AWP
Not yet established.Potential Side Effects and Toxicity
In general, no treatment-related serious side effects have been reported and injection site reactions that occurred during studies have been mostly mild and self-resolving. The most common adverse reactions associated with either placebo or leronlimab included diarrhea, headache, swollen lymph nodes, and high blood pressure. Administration-site reactions occurring in more than 5% of participants were induration (hardening or thickening of the skin), pain, and irritation.
Potential Drug Interactions
Drug-drug interactions associated with leronlimab are currently unknown. Tell your provider or pharmacist about all medications, herbals, and supplements you are taking or thinking of taking, prescribed or not.
More Information
Leronlimab received FDA Fast Track designation in May of last year. The approval is given to investigational medications for serious or life-threatening conditions and which meet an unmet need. Leronlimab is being studied as part of an HIV drug combination for people with multi-drug resistant virus. Leronlimab is also being studied as a single-drug maintenance therapy for people who have achieved undetectable viral load on a stable HIV regimen. The company developing the drug, CytoDyn, reported no drug resistance observed in people taking leronlimab for up to four years. A tropism test is needed to determine if this medication will work for you. Results of a phenotypic tropism test may take up to a month to complete. Genotypic tests are also available and may provide a faster and less expensive alternative. Leronlimab targets CCR5-tropic virus. Viral tropism refers to the types of HIV that a person can have, CCR5 (R5), CXCR4 (X4), or Dual-Mix Tropic (R5 and X4). Leronlimab blocks CCR5, a receptor on the outside of a CD4 cell, and shuts down this point of entry for the virus. Most people are infected with R5 virus initially, and then over time, X4 and mixed viruses may predominate. Leronlimab is an immunoglobulin (also called an antibody). The injections can be self-administered. The company developing this drug, CytoDyn, is also studying it for cancer treatment. For a short YouTube video on the drug’s mechanism of action, go to youtube.com/watch?v=sCMwoVYeRA0.
Doctor Comments
Dr. Ross Slotten says:
Leronlimab is a CCR5 inhibitor currently in Phase 2/3 trials, so it has not yet been approved by the FDA for clinical use. Like maraviroc (Selzentry), it can only be prescribed to individuals with a CCR5-tropic virus, and it is intended as an alternative agent in the setting of resistance to other entry and fusion inhibitors. Leronlimab is also being tested for safety and efficacy as a single agent (monotherapy) against HIV, once undetectability has been achieved in combination with other anti-retroviral medications. In my view, its main drawback is that it must be given as a subcutaneous injection, like the ill-fated Fuzeon. So far, side effects noted have been diarrhea, headache, swollen lymph nodes, and high blood pressure, which will not necessarily pose limitations on its use, unless those side effects are common. One study reported that 65.4% of participants experienced at least one side effect, but only one participant dropped out because of side effects. That study was small and included only 52 people. Injection site reactions were said to be mild and temporary. Perhaps if this medication could be given orally as monotherapy, I might barnstorm for it. Otherwise, it’s not a breakthrough and will be yet another niche agent.
Activist Comments
Activist Bridgette Picou says:
Still in investigational studies, leronlimab, also known as PRO 140 in trials, is an HIV drug (CCR5 antagonist) whose mechanism of action is to attach to the CD4 cell receptor and block it, preventing entry of the HIV virus. Leronlimab is also unique as it is intended to be used as monotherapy without the use of other HIV meds. It is an injectable medication given subcutaneously once a week and intended for those with multi-drug-resistant strains of virus.