By Randall Osborne

Five months into its partnership with Schering-Plough Corp., Myriad Genetics Inc. has reached its first milestone in the deal, which is worth a total of as much as $60 million.

Salt Lake City-based Myriad has characterized the MMAC1 (mutated in multiple advanced cancers) gene and delineated its biochemical pathway, prompting a $2 million license payment from Schering-Plough, said Myriad spokesman William Hockett.

Myriad's stock (NASDAQ:MYGN) closed Monday at $26.875, up $0.625.

"This is not the prostate cancer gene we're looking for," Hockett said, but it's "looking like a very good tumor suppressor." The MMAC1 was only recently found by mapping DNA sequence deletions in brain cancers, he added. "We found it in 90 percent of glioblastomas and many cases of advanced cancer. Schering had an option on it, and we were pleasantly surprised they took it up."

Schering-Plough has licensed therapeutic rights to the gene, but Myriad keeps worldwide molecular diagnostic rights.

Myriad signed the deal with Schering-Plough, of Madison, N.J., in April. It calls for a three-year research program, which may be extended for two more one-year periods. Five genes are targeted for development. (See BioWorld Today, April 24, 1997, p. 1.)

"There's a major effort for prostate [cancer], and that's our primary effort with that collaboration," Hockett said.

The MMAC1 tumor suppressor is one of the first such genes to show a well-defined enzymatic activity. It dephosphorylates proteins that are phosphorylated on serine, threonine or tyrosine residues, which means it could work against cancer directly through gene therapy or by way of a small molecule approach, modulating what could be a novel signal transduction pathway.

Myriad also sells a genetic test for determining predisposition to breast cancer, devised after the complete sequences were discovered of the breast cancer genes BRCA1 and BRCA2. *