National Editor

The FDA's decision to lift a longstanding clinical hold on NeoRx's Targeted Skeletal Radiotherapy program for myeloma - allowing talks about a new Phase III trial to move forward - proved to be stock-jolting news for the company and sent its shares skyrocketing 86.8 percent Thursday.

Jack Bowman, chairman of Seattle-based NeoRx, said the stock jump probably was due to the agency's action along with news earlier this week of a deal that gained $10 million for the company.

"We've got about $21 million, and we can certainly get started on the [Phase III] clinical trial," he told BioWorld Today, estimating the company will start treating patients near the end of the year.

NeoRx's stock (NASDAQ:NERX) ended the day at $3.10, up $1.44.

It won't be the first time NeoRx has started a Phase III trial with TSR, noted Brian Rye, analyst with Raymond James & Associates. A Phase II study finished in the summer of 2000, and "in October, they wanted to do a Phase III, but about a month [after the Phase II], they started seeing side effects in a handful of people," he said.

"They've had to go back and decide what the issue was and how best to address it. They had to go back to square one."

Or almost square one. A dosimetry study was conducted and the results submitted to the FDA in February. NeoRx, which met with the FDA in March regarding results from that study, has been waiting since then for the agency to lift the clinical hold.

Since the problems arose, "in a very tough market, they did a prudent job of whittling the company down to focus on this core program," Rye said. "They were able to find some good buyers for some patents they just didn't need anymore."

Late last year, NeoRx raised $7.9 million by selling intellectual property as well as certain license and option rights to IDEC Pharmaceuticals Corp., of San Diego. (See BioWorld Today, Nov. 14, 2002.)

And earlier this week, the company entered into an agreement with Boston Scientific Corp., of Natick, Mass., for certain cardiovascular intellectual property and got a $9 million payment in exchange. BSC paid NeoRx another $1 million for an exclusive license to use other, device-related intellectual property.

"They've given themselves some cushion financially, taken themselves off the death [watch] and put themselves back on solid ground," Rye told BioWorld Today.

"There's really never been a question as to whether or not [TSR] has demonstrated efficacy," Rye said. "It has."

TSR is designed to deliver high doses of radiation to tumor sites throughout the skeleton with minimal damage to organs outside the bone, targeting bone and adjacent marrow with a small-molecule agent known as DOTMP, combined with the radionuclide holmium-166.

Bowman said the company probably won't start treating patients in the new Phase III trial until the end of the year, with a plan very different from the first.

"We were using much higher doses before, and using a rather complicated dosing scheme," he said. "That's been greatly simplified. We're going to restrict ourselves to a dosage at which we did not see any of the serious side effects."

The main side effect consisted of hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura, he said.

"It's kind of a complicated [condition] in which people get a fever and kidney problems and marrow suppression," he said. The problem developed six months to nine months after treatment, he added.

"We had started treating people in a Phase III trial when the Phase II patients developed" the condition, Bowman said, and the FDA asked the company to stop. The later dosimetry trial focused on measuring the dose of radiation to the kidneys, and Bowman said he believes its findings have resolved the earlier problem.

With cash in hand, the company is ready to move forward.

"We're intending to partner [TRS], but we have to be farther along," Bowman said. "I want to have some patients in Phase III."

If more cash is needed, he said, "we still have over 100 patents we consider noncore. A lot of it is in cardiovascular [indications], where we no longer have an effort."