Isis Begins Phase III CMV Retinitis Trials

Isis Pharmaceuticals has begun Phase III trials of its antisense compound ISIS 2922, a treatment for cytomegalovirus retinitis in patients with AIDS. About 200 patients are expected to be enrolled into two trials, one of which will compare the efficacy of ISIS 2922 plus Syntex' ganciclovir to ganciclovir alone (the gold standard drug for the condition), while the other will evaluate ISIS 2922 alone in newly-diagnosed patients.

Isis predicts that around 150 patients will be included in the comparative study, all of whom will have failed first-line therapy with ganciclovir or Astra's Foscavir (foscarnet). The combination regimen will be given to patients for three weeks, whereupon those on the antisense drug will continue on that alone to provide a direct comparison of maintenance treatment with the two drugs.

The second trial, which will involve around 50 patients with retinitis at the periphery of their retina, is designed to allow an assessment of progression of the disease treated with ISIS 2922, without endangering patients. The patients will receive either ISIS 2922 or no therapy, although patients will be switched to ISIS 2922 if their symptoms progress. Preliminary results from both these trials are expected by the end of 1995.