Corixa Corp.’s stock took a dive Wednesday after the FDA said in a “complete review letter” that the company failed to provide sufficient evidence of safety and clinical benefit in its biologics license application for the non-Hodgkin’s lymphoma drug Bexxar.
Furthermore, the FDA said additional clinical studies likely would be necessary to prove Bexxar (tositumomab, iodine-131) is worthy of approval.
Corixa’s stock (NASDAQ:CRXA) closed Wednesday at $6.15, down $3.48, or 36.1 percent.
In response, Steven Gillis, chairman and CEO of Seattle-based Corixa, released a prepared statement saying, “We are extremely disappointed with the FDA’s decision and intend to promptly pursue resolution with our partner, GlaxoSmithKline [plc, of London], and the agency. We are formally requesting a meeting with the FDA and hope to reach mutual agreement on the specific steps still necessary for approval. We will provide additional guidance as to the regulatory pathway for Bexxar after further discussions with GlaxoSmithKline and the FDA.”
Bexxar, Corixa’s lead drug candidate, is a radioimmunotherapy for the treatment of low-grade or transformed low-grade non-Hodgkin’s lymphoma.
The FDA’s complete review letter received by Corixa on March 12 in compliance with the Prescription Drug User Fee Act (PDUFA) deadline also indicated that Corixa has not provided sufficient evidence to win an accelerated approval classification. To receive this, an applicant must show that a drug addresses an unmet medical need, but the classification has no bearing on whether the drug receives regulatory approval.
Now, Corixa is faced with four options: amending its biological license application, notifying the agency of the intent to amend it, withdrawing the application, or asking for a hearing.
“We have not made a determination as to which of the four options we will pursue,” Jim DeNike, Corixa’s director of corporate communications, told BioWorld Today. “Within the next 10 days we’ll have more of a clear understanding of the direction, once we have time to meet with the partner. We will request a meeting with the FDA. We expect it to occur within the next 45 days.”
Furthermore, DeNike restated Gillis’ disappointment in the contents of the letter, adding, “We have a different opinion than the FDA.”
Corixa likely will end up notifying the FDA of its intent to file an amendment, according to a research note released by Michael Wood, vice president of Lehman Brothers Equity Biotechnology Research.
Wood said he does not expect Corixa to amend in the next 10 days because the company does not have data necessary to answer the agency’s questions.
“In our view, this news means that Bexxar could be further delayed by up to two years, depending on whether deficiencies in the filing can be met by ongoing trials, or whether a completely new pivotal trial is required,” Wood said. “We now believe a launch in 2004 or 2005 is more likely vs. our previous estimate of fourth-quarter 2002.”
This isn’t the first time Corixa suffered a setback on Bexxar, a product inherited in late 2000 when Corixa took over San Francisco-based Coulter Pharmaceuticals Inc. in a stock swap valued at the time at more than $900 million. (See BioWorld Today, Oct. 17, 2000.)
Bexxar is an antibody specific to the CD20 antigen on B cells conjugated to radioactive iodine-131. It attaches to a protein found only on the surface of B cells, including non-Hodgkin’s lymphoma B cells.
Coulter and then-partner SmithKline Beecham plc submitted a BLA in September 2000. The agency accepted it in November of that year, and then ended up asking for additional safety and efficacy data a year ago. (See BioWorld Today, March 20, 2001.)
Corixa complied, sending a tremendous volume of information in September 2001.
The FDA’s Oncologic Drugs Advisory committee (ODAC) in January said it would be unable to hear Corixa’s application at the February meeting because the agency’s reviewers had failed to make it through the “extensive amount of material” submitted by the company. (See BioWorld Today, Jan. 11, 2002.)
And even though the company reassured investors and the media that ODAC’s announcement had nothing to do with whether Bexxar was an approvable drug, the company’s stock suffered. Comparatively, the hit wasn’t that bad the stock closed at $12.38, down $2.39, or 16.2 percent, that day.
To clarify, on Wednesday, DeNike told BioWorld Today that ODAC had never actually scheduled a meeting to hear the case for Bexxar. “There was an assumption that we would be on the February panel, but we never indicated that,” he said.
One of Corixa’s competitors, San Diego-based IDEC Pharmaceuticals Corp., is expected to launch Zevalin, an investigational agent for non-Hodgkin’s lymphoma, fairly soon.
Corixa recently was granted FDA approval on the design of a second Phase III trial for its melanoma vaccine, Melacine. (See BioWorld Today, March 1, 2002.)
The company has 16 programs in clinical development and 22 in preclinical development.