Miravant Medical Technologies Inc. suffered a 75.6 percent stock drop Monday on negative Phase III data of an investigational drug to treat vision loss.

“Obviously, we’re disappointed,” said Laurens Lichty, Miravant’s manager of corporate communications. “But we are still very positive on our technology, and we’ll continue evaluation of the clinical trial results.”

The Santa Barbara, Calif.-based company saw its stock (NASDAQ:MRVT) plummet $7.31 to close Monday at $2.44. The company reported a cash position of $12 million to $14 million, Lichty said.

“That includes cash on hand, and [an] approximate $3 million line of credit that we have under our current agreements [with Pharmacia Corp.],” she added, referring to a $20 million financing arrangement finalized with Pharmacia on May 30.

Miravant reported a $4.9 million loss in the third quarter ended Sept. 30.

Trial results indicated that SnET2 (tin ethyl etiopurpurin) did not meet its primary efficacy endpoint. SnET2 is an investigational photodynamic therapy for sub-foveal choroidal neovascularization, also known as the wet form of AMD. While AMD is the leading cause of severe vision loss in people older than 50, the wet form is the most severe, affecting only 10 percent of those with the disease but accounting for 90 percent of the blindness caused by AMD. Annually, approximately 400,000 new cases of wet AMD are diagnosed in the U.S. and Europe.

The investigational drug was developed in collaboration with Pharmacia, of Bridgewater, N.J., for the wet form of age-related macular degeneration (wet AMD).

“As of now, we’re continuing to work with Pharmacia on the full analysis of the data under the Phase III study,” Lichty said.

Under original terms of the deal, Pharmacia made a $19 million equity investment and provided a $22.5 million line of credit. In conjunction with the line of credit, Pharmacia received up to 360,000 warrants to purchase Miravant common stock. (See BioWorld Today, Jan. 20, 1999.)

The Phase III trials involved two randomized, double-masked studies, enrolling a total of 933 patients with wet AMD at 59 U.S. centers. Patients were treated with SnET2 at varying dose levels (0.5 mg/kg and 0.75 mg/kg) or received placebo, and a diode laser using 664nm wavelength.

“We have noted all the way along, including at our recent analyst meeting at the end of November, that this was a high-risk project with high hurdles,” Pharmacia spokesman Paul Fitzhenry said. “We are disappointed with the results.”

Despite the SnET2 trial setback, Miravant continues to work with its PhotoPoint technology, a procedure that uses light-activated drugs to destroy fast-dividing cells.

“We’re very much committed to the technology of photodynamic therapy, which we have branded PhotoPoint,” Lichty said. “We have ongoing clinical trials that we initiated this month in dermatology for treating psoriasis patients [and] we have a very active cardiovascular research program in looking at restenosis as well as atherosclerosis. And we also have preclinical studies under way in oncology.”

The Phase II study for psoriasis, as well as the cardiovascular and oncology programs, are using Miravant’s unlicensed molecules, Lichty said.

“We’re getting very promising results in these programs, and we’re going to continue to support them.”