A novel DNA vaccine in combination with chemotherapy has demonstrated promising clinical results against a deadly form of ovarian cancer.
The investigational compound Elenagen is an experimental DNA therapy that consists of a circular piece of DNA called a plasmid that includes a gene for a human protein called p62/SQSTM1.
In a new paper, a team of scientists from CureLab Oncology, the NN Alexandrov National Cancer Center and Minsk City Oncology Center have demonstrated a clear clinical benefit of the new biological agent against advanced platinum-resistant ovarian cancer.
The results were derived from a clinical study that evaluated the safety and efficacy of Elenagen as an adjuvant to platinum-based chemotherapy, gemcitabine.
The majority of newly diagnosed ovarian cancer patients are initially treated with platinum-based chemotherapy (such as cisplatin and carboplatin), though most eventually stop responding to treatment.
“Almost one in 80 women will be diagnosed with ovarian cancer during her lifetime, and almost one in 110 will die of it,” said Dr Alex Shneider, founder and CEO of CureLab Oncology. “I doubt that we can significantly change these numbers anytime soon. But these numbers would be less tragic if we could say to a diagnosed woman: ‘We can give you an extended period of a high-quality life.’ Our team has been focused on giving patients diagnosed with platinum-resistant ovarian cancer additional life — a life full of energy and free of pain.”
An unclear mechanism of action
The researchers found that, in response to an intramuscular injection of Elenagen, tumours changed their internal structure, permitting immune cells to enter the tumours more efficiently while making it harder for metastatic cells to exit.
Elenagen also reduced systemic chronic inflammation in the organism, which plays a detrimental role in many diseases, including cancer.
“When we began our study, we were concerned that the mechanism of action of this novel drug is not clear,” said co-author of the study, Professor Sergey Krasny. “In fact, it may be years or even decades before it is entirely understood. Then we thought, what if our predecessors had waited for the mechanism of action of penicillin to be entirely clear in the lab before testing in the clinic? We were also compelled by the strong published evidence of Elenagen’s effects obtained during Phase I clinical studies and in laboratory dogs.”
In the Phase I study, progression-free survival (PFS) for the gemcitabine-treated group was just 2.8 months. However, the group receiving the chemotherapy supplemented with Elenagen demonstrated a PFS of 7.2 months.
Nine out of 20 patients receiving Elenagen did not demonstrate any disease progression, with a longest recorded observation of 24 months. All patients receiving only the chemotherapy had disease progression within less than one year. Surprisingly, patients with elevated CA 125 patients were the most responsive to Elenagen regimens.
CureLab Oncology has submitted its pre-IND package to the FDA and plans to expand the study in the USA as Phase II/III study.