By Debbie Strickland
Despite the October launch of its hand-held radioisotope detector, Neoprobe Corp.'s fourth quarter was a rocky one, culminating in last week's FDA request for additional information in support of a biologics licensing application (BLA) for RIGScan CR49, a radiolabeled monoclonal antibody for use with the device in detecting metastatic colorectal cancer.
"We intend to meet with FDA early in January to clarify the scope of the information and what they would like to see," said Judy Barnes, spokeswoman for the Dublin, Ohio, company.
The U.S. delay comes just a month after the European Agency for the Evaluation of Medical Products recommended that Neoprobe submit a new marketing application for the same product. Adding to Neoprobe investors' woes, the firm's worldwide RIGS marketing agreement with U.S. Surgical Corp. dissolved in October.
Wall Street reaction to the latest setback was pronounced: Neoprobe shares (NASDAQ:NEOP) fell about 25 percent, to just over $6.
The company's stock last week was trading at about half its early fall range of $12 to $14, but officials were optimistic.
"We're already in discussions and negotiations with replacement partners that are as strong, if not stronger, than U.S. Surgical," said David Bupp, Neoprobe's president.
As for the regulatory setback, "The information request from the FDA is not unusual," he said. "The agency has not rejected the BLA application; they have indicated that they need more information to make a decision."
In a Phase III study enrolling metastatic colorectal cancer patients at 24 cancer centers and hospitals in the U.S., Europe and Israel, RIGScan CR49 detected cancer in more than 90 percent of patients with known disease. The procedure also helped surgeons find additional cancer in one out of every five evaluable patients.
In August, Neoprobe launched a Phase II multicenter study of RIGScan CR49 in patients with other adenocarcinomas, including ovarian, endometrial, pancreatic and stomach cancers. The company also initiated a compassionate use program for metastatic colorectal cancer to make the product available pending regulatory decisions.
RIGS, or radioimmunoguided surgery, technology includes a radiolabeled agent that targets cancer cells and a hand-held radiation detection probe to locate areas where the targeting agent has accumulated. The company's recently launched detector is being used for intraoperative lymphatic mapping for melanoma patients to detect metastases in the lymph nodes. *