TNBC Patient Given Investigative Antibody, Leronlimab, Under Emergency Exception

A metastatic triple-negative breast cancer (TNBC) patient is being treated with CytoDyn’s investigational leronlimab (PRO 140) under an emergency investigational new drug (IND) application granted by the U.S. Food and Drug Administration,

An emergency IND can be used by physicians to request permission to give an investigational medication to a person with a life-threatening condition, provided no satisfactory alternative therapy is available.

The treatment is being administered by Jacob Lalezari, MD, chief executive officer of Quest Clinical Research and an investigator in other leronlimab clinical trials, which are testing it as an anti-retroviral therapy for people with HIV.

“This patient has a particularly aggressive type of mTNBC [metastatic TNBC],” Lalezari said in a press release. “I believe that leronlimab represents a new potentially therapeutic modality in mTNBC.”

Leronlimab is a human antibody designed to block the CCR5 surface receptor protein, whose levels are increased in several cancers, including TNBC. Previous studies have shown that, by blocking CCR5, leronlimab works to stop breast cancer cell invasiveness and to enhance the killing of tumor cells by chemotherapy.

CCR5 is also found at the surface of a subset of immune cells, where it works as an anchor for the entry of the human immunodeficiency virus (HIV). It plays a key role in modulating immune cell trafficking to sites of inflammation. CCR5 antagonists, like leronlimab, are under investigation for their immune-modulating effects and potential to block HIV infection.

The FDA placed leronlimab on fast track status when used in combination with carboplatin, a chemotherapy, to treat patients with CCR5-positive metastatic TNBC in May 2019.

The person’s treatment under the emergency IND runs in parallel with a Phase 1b/2 trial (NCT03838367) testing leronlimab plus carboplatin in treatment-naïve metastatic TNBC patients whose tumors are positive for CCR5.

The open-label study, which is enrolling up to 48 people, is being conducted under the supervision of Massimo Cristofanilli, MD, professor of medicine at Northwestern University Feinberg School of Medicine.

It will be running at Quest Clinical Research in San Francisco, along with four additional trial sites: Northwestern University Medical School, Methodist Houston, Vanderbilt University and the Sidney Kimmel Cancer Center. Enrollment information can be found here.

In addition to determining the optimal dose of leronlimab, the trial will measure how long patients go without disease worsening, their response rate and overall survival, among other outcomes.

Results of the Phase 1b/2 trial will inform CytoDyn’s next steps for leronlimab, which may include seeking FDA’s breakthrough therapy designation and accelerated approval as a metastatic TNBC treatment.

“Today marks a milestone in our Company’s history, a first step into the oncology space,” said Nader Pourhassan, PhD, president and CEO of CytoDyn.

“Leronlimab has already completed eight successful clinical trials and has been dosed in over 800 patients in our HIV programs, without any drug-related serious adverse events (SAEs),” Pourhassan said. “With results from multiple preclinical studies in various cancer indications … we are optimistic about the potential of leronlimab to provide a new therapeutic option to many patients.”