By Randall Osborne
West Coast Editor
After SuperGen Inc.'s shares toppled 29 percent Thursday on news that the filing of a new drug application (NDA) for its cancer drug rubitecan could be delayed several months past the original target date, the company said in a press release that it "continues to enjoy a strong collaborative relationship" with Abbott Laboratories Inc., which signed a potential $150 million development deal for rubitecan last year.
But it's not so simple, said analyst Peter Drake, of Prudential Vector Healthcare in Deerfield, Ill., who said SuperGen was having "significant" problems managing the trial. Drake downgraded SuperGen's stock to "hold" status, and is credited with sending its price into a tailspin.
"We cast a very broad net, as we always do, and we brought up information from multiple sources that suggests there are clinical trial control issues surrounding the story," Drake told BioWorld Today on Friday. "This is a big issue."
Joseph Rubinfeld, chairman and CEO of SuperGen, said Drake "shot from the hip and jumped the gun" in writing his research note. The pact with Abbott, of Abbott Park, Ill., entered late last year, remains solid, he said.
"Whoever his secret sources are, he hasn't talked to anybody in authority," Rubinfeld said. "He's misread the tea leaves, that's all."
Drake declined to identify his sources, but said in a research note that SuperGen had hired a major contract research organization to oversee the trial for the oral cancer chemotherapy drug.
Rubinfeld acknowledged as much, and conceded the CRO was hired in response to a letter from Abbott.
"[The CRO is] not managing the project; they're only entering data," Rubinfeld told BioWorld Today. "It has nothing to do with the progress of the trial. That letter from Abbott is not a concern at all. It listed goals to accomplish in the next month, and we did that. There's nothing dramatic, or out of the ordinary."
Rubinfeld said the NDA, first planned for the first quarter of next year, might not be filed until mid-2001. The Phase III pancreatic cancer trials have been delayed, but he noted such delays are not unusual in large-scale trials.
Rubitecan, a topoisomerase I inhibitor extracted from the bark and leaves of the camptotheca acuminata tree in China, showed in a Phase II study that median survival among responders exceeded 18 months.
Analyst Jerry Treppel, of Banc of America Securities in New York, issued a note Friday, saying the sell-off of SuperGen shares was not warranted, and reiterated his firm's "buy" rating.
SuperGen's Phase III pancreatic cancer study is the largest ever, with about 1,800 patients expected to be enrolled, Treppel said. About 1,400 are enrolled already. The three-arm study involves 1,000 patients in one part and 400 each in two others. SuperGen said the two smaller parts are expected to reach enrollment by December and the 1,000-patient part by January 2001.
Drake's claim that 10 percent to 15 percent of trial patients are "currently ineligible from study inclusion due to protocol violations" is wrong, Treppel said.
What's true, Treppel said, is that management says 10 percent to 15 percent of pancreatic cancer patients who want to enter the trials do not meet the protocols.
"Even if they're behind in one arm [of the study], they can file with data from one of the others," Treppel added.
He called the plunge in SuperGen's stock price "bizarre," and attributed it to Drake's downgrade, which, "in the absence of any other information," damaged the share price.
"This sort of came out of nowhere," Treppel said.
Not so, Drake said.
"You and I aren't going to know if I'm right or not for another six-plus months, but the stock market voted," he said. "Four-plus million shares have traded. Somebody's making a bet, one way or another."
SuperGen's shares (NASDAQ:SUPG) have not shown great recovery, he added. The stock closed Friday at $20.718, up $1.031.
"If the stock was up 5 [points] today, I'd be going back to my sources," Drake said, adding that he expects SuperGen will not submit its NDA until the fourth quarter of 2001.
SuperGen also is testing rubitecan in 11 other tumor types, with clinical trials under way for ovarian, head and neck, colorectal, breast, lung, cervical, prostate and gastric cancers. Rubitecan has shown promise in a Phase II study in patients with hematological diseases. At scientific meetings in November, SuperGen is expected to present some data on rubitecan against refractory pancreatic cancer.
Another SuperGen drug is Nipent, a small-molecule purine analogue for hairy cell leukemia that acts by blocking the enzyme adenosine deaminase in cells, and doesn't require the presence of surface receptors. In March 1999, SuperGen filed a supplemental new drug application requesting approval of Nipent for treating mature T-cell lymphomas, primarily cutaneous T-cell lymphoma and peripheral T-cell lymphoma.