Campath

Levoxyl

(levothyroxine sodium, King Pharmaceuticals)

A synthetic thyroid hormone for treating hypothyroidism and suppressing thyroid-stimulating hormone. This is the second thyroid hormone product approved by the Food and Drug Administration under a 1997 requirement that manufacturers of all marketed levothyroxine products file new drug applications by Aug. 14, 2001. These products were available before 1962, so they were never formally approved and did not undergo a full review.

* Recommended Dosage: Available in tablets ranging in strength from 25 [micro]g to 300 [micro]g.

* Special Considerations: Side effects of levothyroxine "are usually due to over-dosage and include nervousness, weight loss, tachycardia, irritability, and anxiety," the FDA stated in August 2000 in approving Unithroid, the first such product approved under the new requirements.

* Comment: The approval establishes that the FDA considers Levoxyl effective and in compliance with standards for manufacturing purity, potency, and stability. Product recalls related to problems with stability and potency led to the 1997 FDA requirement. The products of companies that fail to meet the Aug. 15 deadline will be "subject to regulatory action as an unapproved drug," according to the FDA.

More than 70 millions prescriptions for synthetic thyroid replacement drugs were dispensed last year, making such drugs the eighth most commonly dispensed prescription drug category in 2000, according to IMS America, a pharmaceutical market research firm. More than 60% of those prescriptions were for Synthroid, the third most commonly dispensed drug in 2000.

At press time, Synthroid manufacturer Abbott Laboratories had not yet submitted the application to the FDA, but the company stated in early June that it planned to submit a new drug application "within the FDA's timeline" and sought to reassure patients and physicians that extensive research had verified the safety and efficacy of Synthroid.

The Abbott statement was released amid rumors that the FDA might withdraw Synthroid from the market. An FDA spokesperson told this newspaper that the agency does not intend to "abruptly" withdraw any levothyroxine sodium.

Campath

(alemtuzumab, Berlex)

A humanized monoclonal antibody for treating B-cell chronic lymphocytic leukemia in people who have been treated with alkylating agents and have failed treatment with fludarabine.

* Recommended Dosage: Administered via 2-hour infusions, three times a week for up to 12 weeks, under supervision of physicians experienced in using antineoplastic agents.

* Special Considerations: Side effects of Campath in trials included infections, hematologic toxicities, and infusion-related events, including some that were fatal.

* Comment: Campath is a humanized monoclonal antibody that binds to the CD52 antigen on B lymphocytes, causing lysis of cancerous B lymphocytes. Gampath "provides a new option for refractory patients who have no other approved therapeutic options available," Dr. Kanti Rai, chief of the division of hematology and oncology, Long is land Jewish Medical Center, New Hyde Park, N.Y., said in a statement issued by Millennium Pharmaceuticals, a codeveloper of Campath. He was a principal investigator in clinical trials of Campath.

In a study of 93 chronic lymphocytic leukemia patients aged 32-68 years who had been treated previously with alkylating. agents and had failed treatment with fludarabine (70% had advanced disease), 31 (33%) of the patients bad a complete or partial remission lasting a median of 7 months with use of Campath; 7 additional patients had a complete or partial remission that lasted for more than 1 year. These data were presented by Berlex at an FDA Oncologic Drugs Advisory Committee meeting earlier this year. The committee voted 14-1 to back accelerated approval of this agent. The typical median survival of such patients is 3-10 months following failure of fludarabine therapy and initiation of salvage therapy, according to Millennium.

During or within 6 months of completing this study, 28 subjects died; half of the fatalities were attributed to disease progression, and the other half were "due to complications related to Campath therapy," Millennium said in a statement.

COPYRIGHT 2001 International Medical News Group
COPYRIGHT 2001 Gale Group