By Lisa Seachrist
WASHINGTON — In light of Phase II/III clinical data, Oxigene Inc. has focused its ongoing Phase III study of Neu-Sensamide, a radiation sensitizer, on a subset of patients who have non-small cell lung cancer (NSCLC).
The Lund, Sweden-based company will limit testing of the product to the 50 percent of patients with NSCLC who have squamous cell carcinoma and increase the trial size from 220 patients to 350 patients to ensure the trial can adequately show safety and efficacy.
"Based on our Phase II/III study, this is the patient group that is most likely to benefit from the combination of Neu-Sensamide and radiation," said Bjorn Nordenvall, chairman, president and CEO of Oxigene. "The decision to limit the study to these patients will allow us move Neu-Sensamide forward."
In a Phase II/III study presented Tuesday at the meeting of the European Society of Therapeutic Radiology and Oncology, in Edinburgh, Scotland, treatment with Neu-Sensamide was shown to provide no statistically significant benefit in either survival or tumor response compared to patients receiving radiation alone.
However, the investigators identified a patient sub-group — those with squamous cell carcinoma — for whom Neu-Sensamide in combination with radiation appears of benefit.
The ongoing Phase III study, which is being conducted entirely in Europe, already has 150 patients enrolled. The company is changing its enrollment criteria to stipulate that only those patients with squamous cell carcinoma may enter. The study design has been altered to increase the number of patients by 130, to a total of 350.
Nordenvall noted the change in plan is not a shock, because the other major type of NSCLC, adenocarcinoma, tends to rapidly metastasize, rendering local radiotherapy less effective. In the U.S., the standard of care for NSCLC is a combination of radiotherapy and chemotherapy, so the company has decided not to continue recruiting U.S. patients for the Phase III study.
Instead, U.S. patients are being recruited to participate in a Phase II study of Neu-Sensamide, in combination with radiation and chemotherapy, as a means of enhancing these therapies in the treatment of all forms of NSCLC.
Neu-Sensamide increases a cancer cell's susceptibility to cytotoxic therapies by inhibiting its ability to initiate DNA repair, forcing the cell to undergo programmed cell death or apoptosis. The drug is given as an injection one hour before radiation therapy to render the cells more susceptible to the radiation damage. Oxigene is also testing the drug as an adjunct to radiation in the brain cancer glioblastoma.
Nordenvall said that, because Neu-Sensamide is associated with central nervous system side effects when given in high doses, the company is rapidly developing its next generation of radiation and chemotherapy sensitizers. Oxi-104 is currently being tested as a chemosensitizer in patients with advanced cancers.
"With Neu-Sensamide, we can't administer doses high enough to use it for many cancers," Nordenvall said. "Oxi-104 doesn't have those side effects, so it has the potential to be used in higher dose and have a more general effect."
In addition to therapy sensitizers, Oxigene is developing Combretastatin, an anti-angiogenic that also attacks existing vascular systems within tumors. The company expects the drug to enter clinical trials by the end of this year. Cordycepin, a nucleoside analog, is in Phase I studies in patients with TdT-positive leukemia.
Oxigene's stock (NASDAQ:OXGN) closed Tuesday at $6.375, down $0.125. *