SciClone Pharmaceuticals Inc. said Wednesday that interim datafrom its Phase III trial of Zadaxin in Taiwan showed encouragingtrends in the treatment of hepatitis B.
The company also said analysis of the Phase III U.S. trial of thedrug, also called thymosin alpha 1, has been completed. That datawill be presented at the meeting of the American GastroenterologyAssociation being held in San Diego on May 13 through 19.
The interim results included data on only 75 patients who hadreached the 12-month point of the trial, and about 12 who hadreached 16 months in the 18-month trial, so definitive conclusionscould not be drawn. But the San Mateo, Calif. company is releasinginterim results occasionally because of the importance of the Taiwantrial to the drug's potential to reach market. The drug's efficacy wasput in doubt when former licenser Alpha 1 Biomedicals Inc. releasedpartial U.S. Phase III results last April. (See BioWorld Today, April29, 1994, p. 1.)
Tom Moore, SciClone's CEO, told BioWorld that all patients shouldbe through their 18-month regimen in the first quarter of 1996.Company officials, however, aren't going to wait until then to pushforward on other fronts.
The drug has been approved in Singapore, but SciClone has beenwaiting to launch there in part because of the negative publicitygenerated by the U.S. trial, which was sponsored by Alpha 1Biomedicals. (Alpha 1 later sold rights to most of the world toSciClone.)
The Taiwan study consists of three randomized treatment groups ofabout 53 patients each. One group gets treatment for six months witha 12-month follow-up. The second group gets treatment for 12months with a six-month follow-up. And the third group, anuntreated control, is observed for 18 months.
The company is looking for a response that includes both hepatitis Bvirus (HBV) DNA and hepatitis B e antigen converting to negativestatus. Of 75 patients who had reached the 12-month point in thetrial, 31 percent of those in Group 1 responded to both markers, 24percent responded to both markers in Group 2, and 17 percent inGroup 3.
The results, according to Moore and an analyst, confused the market,resulting in a 19 percent drop in SciClone's stock(NASDAQ:SCLN). The stock fell $1.50 Wednesday, from $7.88 to$6.38 per share.
Charles Engelberg, vice president, senior biotechnology analyst withMontgomery Securities in San Francisco, said investors were lookingfor greater than 50 percent clearance of HBV DNA, but werepresented with "much more rigorous standards" of clearance of thatmarker and e antigen.
"We maintain a buy [on the stock]," Engelberg told BioWorld, "butwe think the market won't be a believer until the results arestatistically significant and the drug is being sold in Singapore,"which he expects to occur around mid-1995.
Release of the HBV DNA data from the U.S. trial in April caused thestocks of both Alpha 1 and SciClone to tumble. SciClone said it isdelaying release of complete U.S. results so investigators can presentit at the meeting, and so the data can later be published.
"It's very important for us to see the publication and presentation ofthis data," Moore said. "We feel that people drew very prematureconclusions based on one set of data." Complete results, he said, willinclude data on the trial protocol and e antigen.
Moore also said that company officials will start talking to doctors inSingapore later this month, to explain trial results and find out whatthey think of Zadaxin.
"We're looking forward to revealing this data to doctors inSingapore, and getting their reaction to prescribing the drug," Mooresaid. The bottom line is, "Are they comfortable prescribing the drugwith this [Taiwan and U.S.] data." n
-- Jim Shrine
(c) 1997 American Health Consultants. All rights reserved.