West Coast Editor
Viragen Inc. said 158 patients in its Phase II/III trial with natural interferon as an adjuvant treatment for melanoma showed no statistically significant increase in overall survival, but they tolerated the treatment well and the chance of relapse-free survival after five years was more than doubled in the treated patients.
“The endpoint was relapse-free survival,” said Douglas Calder, director of communications for Plantation, Fla.-based Viragen. “For overall survival, it’s too early to tell. We’ll have to continue evaluating those results.” Calder couldn’t say how long the company will follow the patients, and Viragen’s clinical expert was traveling and could not be reached.
The company’s shares (AMEX:VRA) closed at 92 cents, down 1 cent. Viragen first tipped investors to the news in late February, but did not offer details from the trial, conducted at 20 sites in Germany, until the Fourth International Conference on the Adjuvant Therapy of Malignant Melanoma in London.
In the study, patients’ melanoma was surgically removed and then treated with Viragen’s natural alpha interferon after dacarbazine (DTIC), which is believed to have a therapeutic effect in advanced melanoma.
Earlier studies had shown adjuvant treatment with high-dose recombinant interferon alpha 2b upped relapse-free survival in patients with high-risk primary or regionally metastatic melanoma. Viragen wanted to find out whether low-dose natural interferon alpha which contains a number of interferon-alpha subtypes, some of which had benefits in vitro different from those seen with the recombinant version would work.
Patients were enrolled after complete tumor surgery and randomized to get either two courses of DTIC followed by six months of treatment with low-dose interferon alpha (82 patients), or no adjuvant treatment (76 patients). Measures were relapse-free survival, overall survival, and safety, with a median follow-up time of 5.3 years.
Nineteen patients withdrew early, 79 received adjuvant treatment and 60 served as controls. Completing treatment were 91 percent of the patients, 70 percent of those without modifications in their dosages.
Estimated five-year relapse-free survival rates, treatment vs. controls, were 42 percent and 17 percent, respectively, with a significant prolonging of median relapse-free survival from 174 days to 552 days. In a subgroup of lymph node-positive melanoma, relapse-free survival also increased significantly in treatment vs. controls, 43 percent and 19 percent, respectively.
But no significant effect on overall survival came out of the study. Still, Viragen concluded for now that adjuvant low-dose natural interferon-alpha therapy following DTIC could be an “effective and tolerable approach” for high-risk melanoma.
Natural interferon is “already approved in eight countries, seven of them as a second-line therapy for those who fail recombinant therapy for two forms of leukemia,” Calder noted. “In Sweden, [it’s] approved for any disease where patients fail the recombinant interferon regimen.”
The drug is showing promise in other areas as well, Calder said.
“We’re getting ready to start a Phase III trial in Taiwan, for hepatitis C,” he told BioWorld Today. “That will start in the second calendar quarter of this year.” About 200 million people around the world are affected by hepatitis C, he noted 4 million in the U.S., 5 million in Europe and about 100 million in Southeast Asia.