June 17, 2015
By Riley McDermid, BioSpace.com Breaking News Sr. Editor
BioSpace learned Wednesday at the BIO International conference that DelMar Pharmaceuticals has filed an S-1 form with the U.S. Securities and Exchange Commission to raise up to $8 million in base financing via stock offering, with a separate $10 million backing the warrants.
Maxim Group and Roth Capital Partners will act as co-book runners on the offering. Jeffrey A. Bacha, president and CEO of DelMar Pharmaceuticals, Inc, issued a statement.
“We believe that we have reached an exciting time during the clinical trials for VAL-083 that demonstrate progress in our drug development programs, and look forward to the registration trials needed to take us through the next milestone,” Bacha told BioSpace.
The company also noted in the filing that its rapid production of patents also lead it to the fundraising.
“Since March 31, 2015, we have filed a total of 10 patent applications which are being prosecuted in the United States and in international jurisdictions; five U.S. patents and one international patent have been allowed to date,” it said.
DelMar has been closely watched since the data it presented at the American Society of Clinical Oncology (ASCO)’s two weeks ago showed VAL-083 is a promising therapy for patients with a brutal form of brain cancer that may not be able to undergo resection and chemotherapy.
That was particularly exciting because of the effect it has on extending survival time for animals with glioblastoma multiforme (GBM), a type of brain cancer.
“The overall survival of nine months demonstrated at the higher doses in our clinical trial for GBM patients that have failed both temozolomide (TMZ) and Avastin is clinically meaningful for these patients who have no available therapy and a very poor prognosis,” Bacha told BioSpace.
Glioblastomas (GBM) are tumors formed from the supportive tissue of the brain. Highly malignant, they are usually found in the cerebral hemispheres of the brain, and reproduce quickly and they are supported by a large network of blood vessels. Because they often contain different types of cells, they are usually difficult to treat, leaving biotech companies frustrated at the still-high mortality rates for patients and lack of new products.
The data demonstrated that VAL-083 may be effective against GBM, boosting median survival time for animals treated with 4 mg/kg VAL-083 to 72 days compared to 48 days for controls (p<0.0001). Median survival time for 3 mg/kg VAL-083 was 54 days.
In the second in vivo model (BT74) reported at ASCO, the additional data showed that VAL-083 treatment increased survival time in animals bearing intracranial BT74 tumors compared to untreated control. BT74 tumors are traditionally resistant to TMZ.
“VAL-083 is an alkylating agent whose cytotoxic anti-cancer mechanism is believed to be via the formation of DNA crosslinks at N7 position of guanine. Because these N7 adducts appear not to be subject to MGMT-mediated repair, VAL-83 may be an effective chemotherapeutic in the treatment of TMZ-resistant GBM,” said the company in a statement. “VAL-083 has been demonstrated to cross the blood brain barrier and accumulate in brain tumor tissue. Previous studies show that TMZ activity is similar in cancer stem cells (CSC) and their paired non-CSC from primary GBM tissues independent of their MGMT expression.”
Bacha said patients with poor prognoses would likely benefit the most from the data, including those unable to undergo the standard existing treatment, which is surgical resection followed by TMZ and radiation therapy.
“Clinicians who reviewed our data at ASCO were encouraged by the potential of VAL-083 in this population,” he said, adding the company will soon be rolling the drug into late-stage trials later this year.
“We also were pleased to confirm that we have initiated a 14 patient Phase II expansion cohort, which we expect to report on later this year as we advance VAL-083 toward a registration-directed Phase II/III in refractory GBM,” said Bacha. “We are targeting to initiate the Phase II/III trial in the second half of 2015.”
In February, Bacha told BioSpace that despite a marked lack of progress in new therapies to treat glioblastoma tumors, a type of brain cancer, the science is finally catching up and the next year will be an exciting one for new therapies and patients.
Bacha said that the drug that was approved, Avastin, for refractory patients in 2009 offers “some improvement in quality of life, but doesn’t improve survival.” Prior to that, Temodar was approved as front-line therapy, and although it’s more convenient for patients and has fewer side-effects than the drugs it replaced, survival outcomes were really no better. The median survival for GBM patients is still well under two years.
“That said, a lot of the recent excitement in the cancer field has been focused on immunotherapies. Immunotherapy or ‘immuno-oncology’ centers on the principal of harnessing our own immune system to destroy tumor cells,” he told BioSpace. “Science is finally allowing us to scratch the surface of this opportunity and it holds huge promise. “
But Bacha said Del Mar is very excited about their new GBM drug, VAL-083, which is a chemotherapy that has the potential to offer a real solution. There are caveats for the field in general, though, said Bacha.
“An important thing to keep in mind is that a key component of an immunotherapy regimen is an active chemotherapy, so it’s really ‘chemo-immunooncology’ that we’re talking about as the multi-modal approach that could truly change the landscape of cancer care. That’s where VAL-083 comes in,” he said.
Chemotherapy causes cancer cell-death through apoptosis, which can increase tumor antigen presentation or decrease expression of immune checkpoint molecules in the tumor micro-environment, potentially benefiting the activity of an immunotherapy, said Bacha. He added that because immunotherapies are also, in general, pro-inflammatory, they may render tumors more susceptible to traditional chemotherapies.
“What’s exciting for DelMar is that VAL-083 should be an ideal agent of choice for strategically integrating with potential immune-based therapies,” he told BioSpace.
“You see, while there is evidence of synergy between chemotherapy and immunotherapy, it’s not that simple. The interaction between chemotherapy and the immune system is complex and could actually be antagonistic in some cases,” said Bacha. “A chemotherapy could actually suppress the anti-tumor immune response, by decreasing lymphocytes or inhibiting lymphocyte function.”
He said that based on the NCI’s experience Del Mar’s own clinical trial, the dose-limiting toxicity with VAL-083 will be myelosuppression, but it is platelet related rather than lymphocyte related, which means the mechanism should not conflict with the activity of an immunotherapy.
“This is particularly exciting in GBM where the majority of patients are resistant to the available chemotherapies,” said Bacha. “Our data shows that VAL-083’s unique anti-tumor mechanism works where current chemotherapies fail and may be more potent where they are active. So, we’ve got an exciting drug candidate that should be really well positioned as the era of chemo-immunooncology evolves.”
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