Global biotechnology company Immutep (ASX: IMM) has announced its Chinese partner EOC Pharma will commence a phase II clinical trial to evaluate the efficacy and safety of lead drug eftilagimod alpha in treating metastatic breast cancer.
The trial follows encouraging results from an ongoing AIPAC (Active Immunotherapy Paclitaxel) phase IIb study launched earlier this year which seeks to evaluate the drug in combination with paclitaxel, a taxane standard of care chemotherapy medication used to treat a variety of cancers.
EOC Pharma is the exclusive licensee of efti for the Chinese market and is required to fund development of the drug in China as part of its licencing agreement with Immutep.
Phase II trial
The phase II clinical trial will enrol up to 152 patients across 20 clinical sites to study the effects of eftilagimod alpha in combination with paclitaxel chemotherapy in HER2-negative/HR-positive metastatic breast cancer patients who have progression after endocrine therapy.
Study endpoints will include progression-free survival, overall survival and response rate.
Breast cancer is the most common cancer in Chinese women, with more than 1.6 million people being diagnosed and 1.2 million dying of the disease each year.
Immutep chief executive officer Marc Voigt said EOC’s trial will build on encouraging data from the AIPAC study.
“AIPAC marks an important milestone for [us] and builds our confidence that efti can be beneficial for many cancer patients, including those with metastatic breast cancer,” he said.
“EOC’s new trial will bring this innovative treatment much closer to market for [these] patients.”
Mr Voigt confirmed EOC had received positive scientific advice from the Chinese National Medical Products Administration enabling the first patient to be enrolled and dosed in the trial in the first quarter of 2021.
Efficacy results released today from the AIPAC study have demonstrated a “statistically-significant overall survival benefit” in metastatic breast cancer patients known to be insensitive to immune checkpoint inhibitor therapy.
The results showed a promising and improving trend in overall survival in the total population; and a median survival benefit of 2.7 months after using efti plus chemotherapy, compared to chemotherapy plus a placebo.
A survival benefit of more than 7.1 months from efti plus chemotherapy was shown in patients under 65 years of age (who represented 66.7% of the efti group), while those with a low starting monocyte count (21.9% of the group) experienced more than 9.4 months survival benefit.
The study also showed a statistically-significant increase in CD8 (cytotoxic) T cells in patients treated with efti plus chemotherapy, correlating with prolonged overall survival and indicating pharmacodynamic activity and proof-of-concept for efti’s mode of action.
Mr Voigt said improving overall survival is a key endpoint when evaluating the benefit of new anti-cancer drugs.
“Notably, we have seen a more material overall survival benefit than [progression-free survival] benefit in this study however we know this is not unusual for some immunotherapies where it can take time for the body’s immune system to be boosted and provide a therapeutic benefit,” he said.
“We are very encouraged by these first [AIPAC] results which – subject to ongoing data collection – warrant a registrational perspective and regulatory interactions towards what we hope will be an important new class of medicines.”
The data supports Immutep’s long-held belief that efti can provide a meaningful benefit to patients in a range of cancer settings by “pushing the gas” on the body’s immune system.
“Through this mechanism, efti is helping a large proportion of patients in the AIPAC study with Her2-negative/HR-positive metastatic breast cancer which is typically a non-immunogenic cancer and is significantly less responsive to modern immune checkpoint inhibitor therapies,” Mr Voigt said.
“As such, chemotherapy remains the standard of care in many instances and there continues to be a large unmet medical need.”