GBM data goes to print
CHARLOTTESVILLE, Va.—Clinical-stage biopharmaceutical company Diffusion Pharmaceuticals Inc. is enjoying increased attention to go with recent positive results for its lead product with the announcement that it had clinical results published in the February print edition of the Journal of Neurosurgery.
Data from its Phase 1/2 clinical trial assessing the safety and efficacy of trans sodium crocetinate (TSC) in newly diagnosed glioblastoma multiforme (GBM) was published in a paper titled “Trans sodium crocetinate with temozolomide and radiation therapy for glioblastoma multiforme.” The trial looked at the combination of TSC and radiation therapy with the drug temozolomide beginning either after surgery or biopsy of the tumor. The data showed that of 59 patients, 36.3 percent of those who received the full dose of TSC were alive at two years, compared to a historical two-year survival rate of 27 percent to 30 percent. Many patients saw significant tumor shrinkage, and 11 patients saw their tumors disappear completely.
“The publication of the article in the JNS provides peer-reviewed validation and raises the visibility of Diffusion across key stakeholder audiences,” said David Kalergis, chairman and CEO of Diffusion Pharmaceuticals. “The very encouraging data from our Phase 1/2 clinical trial supports our strategy to advance into Phase 3 clinical development.”
Hypoxia, or oxygen deprivation, is the result of rapid tumor growth, in which the tumor outgrows its blood supply. Tumor cells thrive with hypoxia, and changes in the tumor microenvironment result in resistance to chemotherapy and radiation therapy. As Diffusion explains on its website, “when the tumor tissue becomes oxygen-deprived (hypoxic), it is up to three times more resistant to the cancer-killing power of standard therapies.” TSC counteracts tumor hypoxia and related treatment resistance by re-oxygenating tumor tissue, which in turn increases cancer cells’ vulnerability to radiation therapy and chemotherapy. Because oxygen levels in normal tissue are not affected by TSC administration, this approach avoids off-target side effects.
A further difficulty stems from the fact that cancer DNA can repair radiation damage, Diffusion notes on its website, but that damage can be made permanent if oxygen is present.
The current standard of care in treating GBM is surgical removal of the tumor, followed by radiation therapy and chemotherapy with temozolomide. Clinical trials have shown that the median overall survival for patients receiving combination therapy is 14.6 months, three months more than radiotherapy alone. This combination approach was found to increase two-year survival from 10.4 percent to 26.5 percent.
Diffusion notes that “This improvement in survival demonstrates that it is possible to achieve improved results by combining other treatment modalities with radiation therapy. However, it also demonstrates the substantial remaining unmet medical need, with almost three out of four patients dead within two years of diagnosis.”
A Phase 2 clinical program of 59 patients with newly diagnosed glioblastoma multiforme showed a favorable safety and efficacy profile for TSC combined with standard of care. Diffusion reached an agreement with the U.S. Food and Drug Administration in the second half of 2015 regarding guidance on the design of a Phase 3 trial in newly diagnosed GBM, and additional studies may include a Phase 2 trial in pancreatic cancer and a study in brain metastases. Given its mechanism of action, Diffusion is optimistic that TSC has therapeutic potential in other hypoxia-related indications such as stroke and neurodegenerative diseases.
Diffusion has received Orphan Drug Designation for TSC for the potential treatment of GBM and brain metastasis, and reportedly expects to gain Orphan Drug Designation for pancreatic cancer as well in the near future, according to its website.