By Randall Osborne

Awarded a pair of new patents related to the breast-cancer gene, BRCA1, Myriad Genetics Inc. has filed an infringement lawsuit against genomics competitor Oncormed Inc.

The legal action by Salt Lake City-based Myriad comes two months after Oncormed, of Gaithersburg, Md., fired the first round, suing Myriad for an alleged infringement of a patent on the same gene. (See BioWorld Today, Nov. 19, 1997, p. 1.)

One of the newly issued patents for Myriad covers a predisposition diagnostic test for BRCA1 mutations, which increase a woman's risk of breast and ovarian cancer. This is the patent against which Myriad alleges that Oncormed has infringed. The other patent has to do with diagnostic screening of a tumor sample for an alteration in the gene or its protein.

BRCA1 is one of two genes responsible for most inherited forms of breast cancer. The other is BRCA2. Myriad was at the forefront in discovering the complete sequence of the genes. Both companies have BRCA1 and BRCA2 testing services on the market.

Peter Meldrum, president and CEO of Myriad, refused to comment on the litigation.

Myriad also has discovered three new genes — one of them called CtIP, which is linked to the pathway of BRCA1 and may be necessary for tumor suppression.

Another is MMSC1, which appears to interact directly with the MMAC1 gene, discovered by Myriad a year ago. MMSC1 is believed to function as an interacting partner with MMAC1, which is related to brain and prostate cancer,

"I would say [MMSC1] is especially promising," Meldrum said. "It's farther along down the path toward therapeutic product development." Myriad's collaborator in developing gene therapy based on MMAC1 and small-molecule compounds targeting MMSC1 is Schering-Plough Corp., of Madison, N.J.

The third gene discovered by Myriad is called MKK3, and acts as a tumor suppressor in lung cancer. Therapeutic rights for MKK3 and CtIP belong entirely to Myriad.

Also, Myriad has launched CardiaRisk, its genetic test to identify the 15 to 20 percent of the population at risk for severe hypertension related to the angiotensinogen (AGT) gene. (See BioWorld Today, Nov. 17, 1997, p. 1.)

Hypertensive patients with the variant form of the AGT gene are 42 percent more likely to advance beyond borderline high blood pressure levels, and their hypertension is more likely to occur earlier in life.

Patients with the AGT variant have been shown to be salt-sensitive, with a tendency for their blood pressure to decrease when consumption of sodium is restricted, Meldrum said.

The test sells for $395.

Myriad's stock (NASDAQ:MYGN) closed Tuesday at $25.25, up $0.50. *