Panel Recommends Approval of Talc for Malignant Pleural Effusions

BETHESDA, Md--The Oncologic Drugs Advisory Committee (ODAC) hasrecommended that Sclerosol (sterile aerosol talc) be approvedfor use in relieving fluid around the lungs (malignant pleuraleffusion) of patients with cancer. The sponsor for Sclerosol,Bryan Corporation (Woburn, Mass), presented nine controlled trials(six articles and three abstracts), with an average of 12 patientseach, in support of the talc.

In his presentation for Byran, John F. Beamis, MD, head, Pulmonaryand Critical Care Medicine, Lahey Hitchcock Clinic, Burlington,Mass, cited his study of 11 patients, showing a 90% success rate,defined as no return of fluid after 30 and 90 days based on chestx-rays. None of the patients had recurrence of malignant pleuraleffusion after 1 month.

When asked about the talc's origins and freedom from asbestos,Frank Abrano, president of Bryan Corporation, said that the talccomes from a mine in France and is chemically tested in Massachusettsto be sure that it is asbestos-free. He added that this talc isalso used in food processing in the United States. Dr. Beamissaid that not only is the talc sterile but it is delivered directlyinto the chest during thoracoscopy, with no systemic distributionto other organs.

Lydia Larson, PharmD, speaking for the FDA, said that the talchas been used as a pleural sclerosing agent since the 1950s. Itsuse declined with the availability of injectable tetracycline,then increased again when tetracycline was taken off the market.

Dr. Larson searched three databases and found 12 controlled clinicaltrials of the talc, covering a variety of tumors, including lung,ovarian, and breast. In all articles except one, a single doseof the talc was administered.

The success rate, defined as no re-accumulation of fluid on 3to 12 months' follow-up by x-ray, was 90% to 100% with the talcvs 40% to 50% with other therapies. The symptomatic relief ratewith the talc was 9 of 9 in one study, and 6 of 7 in another.Adverse effects included a 23% incidence of fever or pain andup to a 1% incidence of infection.

Although the data on Sclerosol were mostly literature-based, andthe trials had small sample sizes and a variability of doses,Dr. Larson pointed out that four of the trials were prospectiverandomized studies, and that the trials showed an objective measureof success in the form of chest x-rays and a consistency of resultsover time.

The panel voted 7 to 0 with one abstention that the submittedclinical trials were adequate and well controlled. It decidedunanimously that the trials provided substantial evidence of efficacyof Sclerosol in the treatment of malignant pleural effusions andthat a single administration of 4 g to 8 g of talc is both safeand acceptable.

Finally, the committee voted 8 to 0 that Sclerosol is approvablefor the palliative treatment of malignant pleural effusions.