CytoDyn has been cleared by an institutional review board to start a Phase 2 trial testing its investigational therapy leronlimab (PRO 140) to treat about 22 different solid cancers, including ovarian cancer.
Leronlimab is an antibody that blocks C-C motif chemokine receptor 5 (CCR5), a protein present in high levels in several cancers. CCR5 acts like a navigation system for tumor cells which allows them to migrate to other areas of the body (metastasize).
The upcoming Phase 2 trial will be a basket trial, a type of clinical trial where a single investigational therapy or therapy combinations will be evaluated across multiple cancer populations.
It will include patients with cancers of the ovary, brain, throat, lung, stomach, colon, breast, testicle, uterus, pancreas, bladder, among others. The primary endpoint of the trial will be the length of time that patients live without disease worsening.
“Our current basket trial focuses on method of action (MOA) rather than a specific cancer type,” Nader Pourhassan, PhD, president and CEO of CytoDyn, said in a press release.
“We are extremely pleased the central [institutional review board] provided approval to proceed with the trial in a matter of weeks. This process can often take two months or more,” he added.
The study will include 30 patients, whose cancers are locally advanced or metastatic and positive for the CCR5 factor. They will receive 350 mg leronlimab, once weekly, via under-the-skin injections, and will be able to continue the standard-of-care chemotherapy prescribed by the treating physician.
The trial will be carried out at multiple sites across the U.S. Preliminary results on each patient are expected within three to four weeks after starting treatment with leronlimab.
“We currently have more than 70 patients eagerly waiting to participate in this basket trial,” said Pourhassan. “Enrollment of the trial could be completed in as little as 30 to 60 days, as this is a 30-patient trial.”
In pre-clinical studies, leronlimab was shown to block CCR5 and reduce tumour cell migration and metastases in animal models of aggressive breast and prostate cancer. In a mouse model of breast cancer, it reduced metastasis by more than 98%.
Based on these results, CytoDyn is currently conducting a Phase 1b/2 clinical trial (NCT03838367) of leronlimab treatment in combination with the chemotherapy agent carboplatin, in patients with metastatic triple-negative breast cancer (mTNBC).
A second patient with metastatic breast cancer (MBC) was also dosed with leronlimab under an emergency investigational new drug (EIND) application granted by the U.S. Food and Drug Administration (FDA) in September 2019.
So far, results of “peripheral blood sampling from Patient #1 in the mTNBC trial, who has been on leronlimab for approximately five months, revealed no cancer cells or cancer associated cells,” said Bruce Patterson, MD, CEO and founder of IncellDx, a diagnostic partner and advisor to CytoDyn.
“Patient #2, who has been on leronlimab for almost 3 months in the MBC study, with brain metastasis, continues to show in the latest CT scan, stable lesions that are now described as scar-like suggesting repair in the metastatic tumors,” he said.
The findings led the FDA to grant leronlimab fast track status for the treatment of mTNBC. The designation aims to support the development and speed up the review and approval of therapies to treat serious conditions that respond to an unmet medical need.
CytoDyn has also asked the FDA to grant leronlimab with a breakthrough therapy designation as an adjuvant treatment for mTNBC. The status is given to therapies that treat a serious or life-threatening condition, with preliminary clinical evidence showing that they may provide clinical benefits over available therapies.
“If leronlimab proves to be as effective in this basket trial, as we have seen in our mTNBC and MBC patients, this opens up a strong potential for CytoDyn to file for another breakthrough therapy designation for the 22 cancer indications being evaluated in this trial,” Pourhassan said.