Isis Pharmaceuticals Inc. will be able to go forward with lowerdosages in a Phase III trial of its antisense drug for cytomegalovirusretinitis, after discontinuing patient accrual last week due to adverseevents.

Isis, of Carlsbad, Calif., will file a protocol amendment to includedosages lower than the 300 micrograms that were being used in twoPhase III studies. The company will use the same investigators, butthe data already collected probably will be of no use, Lynne Parshall,senior vice president and chief financial officer for Isis, saidWednesday.

On Friday, Isis said it was discontinuing patient accrual in the trialsbecause of adverse events _ retinal pigmented epithelial stippling _seen in three to five of the 20 patients who had been treated to date.(See BioWorld Today, May 15, 1995, p. 1.) It still is unclear whatcaused the spotting effect in the retina, and whether it was related tothe drug, ISIS 2922.

Parshall told BioWorld that Isis discussed the matter with the FDATuesday, and was told the agency had no problems with the trialgoing forward with a lower dose of ISIS 2922. The company expectsto test more than one dose, and should have the new formulations outin the field in two to four weeks, she said.

About 200 patients are expected to be enrolled in the two studies.One, involving patients whose CMV retinitis has progressed despiteprevious treatments, is comparing ISIS 2922 and ganciclovir againstganciclovir alone. The other is evaluating ISIS 2922 as amonotherapy in newly diagnosed patients.

The company's stock (NASDAQ:ISIP) has recovered most of the 9.6percent drop it experienced after Friday's announcement, when it fell88 cents to $8.25 per share. It closed Wednesday at $8.88, up 88cents. _ Jim Shrine

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