By Randall Osborne
After an encouraging interim analysis of data from the Phase II trial of its rheumatoid arthritis vaccine, Anergen Inc. plans a larger Phase II trial and is shopping for pharmaceutical collaborators.
Barry Sherman, president and CEO of Redwood City, Calif.-based Anergen Inc., said the interim analysis of the 53-patient study made an important advance in developing the vaccine, known as AnervaX.
"Getting at this approach — inhibiting T cell activation — is something that has been going on for a long time, but we're just beginning to see data like these," Sherman said.
The double-blind, placebo-controlled trial, done on an outpatient basis was designed to further evaluate safety and tolerability and explore biological mechanisms. Patients received one of three dosage levels given on a six-week or eight-week schedule.
More than half the patients injected at six-week intervals showed at least 20 percent improvement, and one-fourth of patients in the eight-week group showed 50 percent improvement or more. None showed evidence of generalized immunosuppression.
Another minor-scale Phase II trial will be conducted to test AnervaX on patients with more serious cases of rheumatoid arthritis, Sherman said. Next year, a larger Phase II trial, enrolling 120 to 150 patients, will begin. The exact date for starting the larger Phase II trial "depends somewhat on our success at partnering with a pharmaceutical company," Sherman said, adding that talks are under way with prospective partners.
Meanwhile, data from the early Phase II trial will be analyzed further.
The peptide vaccine, which stimulates production of antibodies to prevent the autoimmune cascade, targets the DR4 and DR1 HLA (human leukocyte antigen) molecules found in 90 percent of patients with rheumatoid arthritis. Only 15 percent of the general population has these HLA molecules.
Another company working toward development of a rheumatoid arthritis vaccine is Immune Response Corp., of Carlsbad, Calif., which has completed Phase II trials of its IR501. Sherman said the two companies are approaching the vaccine from different angles.
"Our peptide is derived from the HLA molecule; Immune Response is taking a peptide out of the T cell receptor," Sherman said. "Both approaches are trying to interfere with T cell activation, but we're doing it from one side and they're doing it from the other."
Immune Response Vaccine Positive In Phase II
Steven Brostoff, chief scientific officer of Immune Response, said the company has finished a Phase II trial with statistically significant data that were expected to be presented at the meeting today of the American College of Rheumatology (ACR) in Washington. Anergen's data were also expected to be presented at the meeting.
A Phase IIb study by Immune Response will enroll at least 300 patients in about 20 sites, and will have as its endpoints the customary ones for rheumatoid arthritis, Brostoff said. The endpoint criteria are established by the ACR, and include improvements in the number of tender and swollen joints.
Anergen is collaborating with Organon, of Oss, the Netherlands, to develop another T cell inhibitor vaccine, known as AnergiX, for rheumatoid arthritis. Organon is the pharmaceutical unit of the Akzo Nobel Group, in Oss.
In partnership with Novo Nordisk A/S, of Bagsvaerd, Denmark, Anergen is developing AnergiX for multiple sclerosis, myasthenia gravis, and Type I diabetes. Last year, Novo Nordisk extended the pact, which was then three years old, for another two years. (See BioWorld Today, April 2, 1996, p. 1.)
As of June 30, Anergen had $11.43 million in cash — enough to fund operations through next year — with a net loss of $3.94 million for the first six months of 1997.
The company's stock (NASDAQ:ANRG) closed Friday at $3.562, up $0.125. *