IDEC Pharmaceuticals Inc. and Genentech Inc. have reportedpositive final results for a pivotal Phase III trial of IDEC-C2B8, as asingle-agent therapy for relapsed low grade or follicular non-Hodgkin's lymphoma.
"Upon FDA approval, of course, IDEC-C2B8 will be the firstproduct we take to market," Bill Rastetter, president and CEO ofIDEC, told BioWorld Today. "After 10 years, it is pretty exciting."
Rastetter said he has hopes that the product would fall under thePresidential Oncology Initiative, announced earlier this year, whichsuggests the FDA review and approve applications for cancertherapies in a six-month time frame.
"It is our assumption," Rastetter said, "that this product would fallunder this initiative."
IDEC-C2B8 is a chimeric monoclonal antibody that binds to theCD20 antigen present on all B cells and recruits host defenses toattack and kill malignant and normal B cells. The antibody is beingdeveloped for certain lymphomas and leukemias characterized byexcessive B-cell proliferation. Low grade and follicular non-Hodgkin's B-cell lymphomas afflict approximately 150,000 people inthe U.S. with about 20,000 new diagnoses each year.
The Phase III trial, conducted in a total of 166 patients, confirmed theantibody's overall response rate and safety profile. In Phase III open-label, single-arm testing of IDEC-C2B8 as a single agent therapeutic,each of the patients participating at more than 30 trial centers,received four infusions of the antibody on an outpatient basis duringa 22-day period. Of 151 patients, 76 responded to treatment for anoverall response rate of 50 percent.
Nine of these were complete responses or remissions (6 percent) and67 were partial responses (44 percent). At over nine months' medianfollow-up, the median time to disease progression for respondersfollowing treatment with IDEC-C2B8 has not yet been reached. Ofthe responding patients, 70 percent remain in remission. Patientscontinue to be followed.
The adverse events associated with IDEC-C2B8 were mostlyinfusion-related and consisted of mild to moderate flu-like symptomssuch as chills and fever. They occurred more frequently upon initialadministration.
Advantage: No Toxic Side Effects
"These results are significant," Laura Leber, senior director ofcorporate communications at Genentech, of South San Francisco,said, "because they confirm early Phase II results.
"Most importantly," she said, "are the lack of toxic side effects withthis treatment, which provides a huge advantage over other therapies.The next step is to go rapidly to submission of data to the FDA forapproval, which we hope to get in the first half of 1998."
Eric Hecht, an analyst with Morgan Stanley & Co., in New York,said IDEC stock ran up from $18 to $25 last week in anticipation ofthe Phase III results. "This is IDEC's first product to go to marketand the first monoclonal antibody therapy for cancer. It should makethem profitable," Hecht said.
Hecht predicted a sales potential of $300 million based on a $6,500price tag per course of therapy. One course, he said, involved fourweekly infusions at $1,600 per infusion.
"This product's safety profile is going to mean that patients, whohave B-cell lymphoma and must be treated for years, will benefitfrom it as well as those patients resistant to chemotherapy," Hechtsaid.
"We have spoken to a great many clinics who really like theproduct," he said.
Genentech and IDEC, of San Diego, will co-promote the product inthe U.S. and will work with Hoffman-La Roche Ltd. of Switzerland,in Europe and Zenyaku Kogyo Co. Ltd., of Japan.
IDEC and Genentech also are collaborating on the use of IDEC-C2B8 in combination with other therapies for lymphoma andreported positive results in a Phase II open label, single arm trialcombining IDEC-C2B8 with CHOP chemo (a standard regimen ofcyclophosphamide, doxorubicin, vincristine and prednisone).
In this trial, patients with low grade or follicular lymphoma receivedsix doses of IDEC-C2B8 over 21 weeks. Within the same timeperiod, they also received six cycles of CHOP chemotherapy. Of the35 patients completing the treatments, 35 responded to treatment, foran overall response rate of 100 percent. Twenty-two patients (63percent) achieved a complete response and 13 (37 percent) achieveda partial response. Adverse events did not exceed those routinelyobserved with CHOP alone or those associated with IDEC-C2B8alone, indicating compatibility of the two therapies.
IDEC-C2B8 is being developed by Genentech and IDEC under a1995 collaboration agreement in which Genentech provided $9million up front in preferred equity investments and licensing fees,$17.5 million in additional equity funding prior to U.S. approval andapproximately $30.5 million in milestone and option payments. Thepotential value of the deal was approximately $57 million.
In February of this year, IDEC and Genentech expanded theiragreement to include the clinical development and commercializationof IDEC-Y2B8, IDEC's radioconjugate for the treatment of B-Celllymphomas. IDEC-Y2B8 is designed to destroy B-Cell tumors bydelivering a targeted, radiopharmaceutical agent to the cancer cellsand consists of an anti-CD20 antibody coupled to the high-energyradioisotope, yttrium.
IDEC's stock (NASDAQ:IDPH) closed Tuesday at $22.250, down$1.375. n
-- Frances Bishopp
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