SK'F's RIDAURA (AURANOFIN) U.S. INDICATION AIMED AT USE IN ADULT ARTHRITIS WHERE INITIAL THERAPY IS UNSATISFACTORY, FIRM TELLS FDA ARTHRITIS CMTE.

SmithKline's Ridaura (auranofin) is being proposed for marketing for use in arthritis where initial drug therapy is unsatisfactory. The firm defined the indication in a presentation to FDA's Arthritis Drugs Advisory Cmte. meeting Oct. 25-26. SmithKline VP-Medical and Regulatory Affairs Michael Young, MD/PhD, told the cmte. that Ridaura "is indicated in the management of adults with active classical or definite rheumatoid arthritis who have an insufficient therapeutic response to, or are intolerant of, an adequate trial of a baseline or 'first step' therapeutic program, including among other measures, full doses of one or more nonsteroidal anti-inflammatory drugs." The Oct. 26 meeting was the second time SmithKline has presented data to the cmte. on Ridaura.In January 1982 the cmte. recommended the drug be approved for remission of rheumatoid arthritis, pending satisfactory completion of a statistical analysis of the one pivotal study SmithKline presented. At the Oct. 26 meetiong, SmithKline reported the results of a second pivotal U.S. trial, as well as the results of a one-year double-blind comparative study conducted in Germany and Austria and 16 other internatl. comparative trials. In the second randomized, controlled, double-blind pivotal study of 299 patients, SmithKline VP-R&D Philip Schein reported that "82% of auranofin patients versus 67% of GST [parenteral gold sodium thiomalate] treated cases were able to complete the 21-week course of gold therapy." He said "withdrawals due to adverse reactions occurred four times more frequently with GST than with auranofin therapy." Further, "the difference between the two gold regimens was not statistically significant." The advisory cmte. did not make any formal recommendations on the SmithKline data.FDA requested that the cmte. simply discuss the current status of auranofin, noting in the meeting agenda that: "The issues that we will be discussing pertain to the basic approvability of auranofin. They are what are the risk/benefit ratios of auranofin versus parenteral gold, short term and long term." FDA added that the issues under discussion "do not need for you to critically review any data on auranofin but rather to draw on your training and experience with parental gold." [For a list of questions presented to the cmte., see box, p. 7.] One of the concerns reflected in FDA's questions is whether the increased convenience of oral Ridaura vs. injectable gold could lead to a greater incidence of adverse reactions. FDA asked the cmte. to discuss the question: "If auranofin's only unique property is that it is a gold that can be given orally rather than parenterally, it carries a mixed blessing." FDA said although the drug offers greater convenience for patients "it increases the likelihood that many patients will be followed less closely and some may suffer avoidable serious adverse effects." SK&F Plans To Detail MDs Familiar With Injectable Use; Patient Labeling Discussed Cmte. consultant and former cmte. chairwoman Bonnie Hepburn, MD, Rutgers, questioned whether monthly lab monitoring was sufficient in early treatment. "Some of us, I think, are troubled by the laboratory monitoring" tests and the recommendation that they be done monthly, Hepburn said. She asked if monthly monitoring is "really adequate during the induction period with [Ridaura]?" She noted that the cmte. hasn't "really seen much in the way of severe immunological reactions in the data presented thus far." She added, however, "if we think about this drug the same way we think about injectable gold, then I think its clear that we do see some severe reactions early on in therapy, and we can protect against those, I would think, in . . . monitoring early on." Cmte. members concurred that monitoring should be more frequent. FDA Office of Drug Research & Review Director Robert Temple, MD, asked the cmte. what it thought of the suggestion that the box warning on Ridaura include a statement that patients should be limited to a one month supply of the drug. "This is a little over rigid, perhaps," Temple added. In draft labeling for Ridaura, FDA and SmithKline attempted to address the concern that patients receiving oral auranofin may not be as adequately monitored as patients receiving an injection from a physician. The draft labeling states: "Before each Rx of Ridaura, results of laboratory work that is recommended to be done on a monthly basis should be reviewed and the patient seen to determine the presence or absence of adverse effects." In response to FDA's question about use of gold by primary care physicians before sending their rheumatoid arthritis patients to a rheumatologist, Hepburn said she would "look at anything that delays the arrival of the patient at the rheumatologist office as a detriment to the patient." She added that if auranofin is "marketed and labeled in a way that encourages such a delay, I think that would be most unfortunate." SmithKline will be promoting Ridaura to MDs who have used injectable gold. According to SmithKline's Michael Young, the company intends to introduce Ridaura "to physicians who are experienced in the treatment of rheumatoid arthritis, and more than that, are used to introducing second step rheumatoid therapy." Young noted that SmithKline also intends, through its sales force, to monitor who is given any information on the product and to institute a program to obtain "feedback on who is using the drug and what the outcome is." FDA Anti-inflammatory Drugs Group Leader John Harter, MD, said it would be "useful" for patients receiving Ridaura to have "some written form." SmithKline VP-R&D Philip Schein, said the firm intends to make patient information available for distribution by the physician and pharmacist, but said SmithKline opposed "making such information, or a reference to it, a formal part of the package insert."