ALFACELL Announces Phase II Malignant Mesothelioma Results.

BLOOMFIELD, N.J.--(BUSINESS WIRE)--March 23, 1999--

Data on ONCONASE as a single agent presented in Italy

On Friday, March 19, 1999, ALFACELL Corporation (NASDAQ: ACEL) presented the results of its Phase II clinical trial testing its flagship product Onconase in patients with unresectable malignant mesothelioma. The results were presented at the Malignant Pleura Mesothelioma Conference in Lignano- Sabbiadoro, Italy. The multicenter Phase II trial was one of the largest trials conducted in this indication, involving 105 patients. Alfacell is conducting a randomized Phase III trial comparing ONCONASE to doxorubicin for the same indication, with preliminary results expected later this year.

Malignant mesothelioma is found in the lining of the lungs or the abdomen, and is most often associated with asbestos exposure. The majority of patients with unresectable malignant mesothelioma die within one year of diagnosis. No FDA approved therapy exists for this disease, which strikes approximately 3,500 Americans each year.

Of the 105 patients in the Phase II trial, 39% demonstrated evidence of clinical activity (tumor reduction or stabilization of the disease). One year survival from the beginning of ONCONASE treatment was 34.3% and two year survival was 21.1%. The median survival time (MST) was approximately six months. At the time of this analysis, 18% of the patients were still alive, ranging up to 4+ years from the start of ONCONASE treatment. The drug appeared to be well tolerated, with only five patients discontinuing treatment due to drug intolerance.

Of the 105 patients in the trial, 39% had failed previous therapy prior to study entry, and 48% had epithelioid histology. Sub-population survival analysis revealed a clinical benefit for patients with epithelioid histology, abdominal involvement, or patients who demonstrated evidence of clinical activity. For patients who demonstrated clinical activity, the MST was 17.1 months, with a one year survival of 61% and a 2-year survival of 31.7 %. Patients with abdominal involvement had a MST of 12 months, with one-year survival of 48% and a 2-year survival of 35.6%. Patients with epithelioid histology had a MST of 9.6 months, with a one-year survival of 42% and a 2-year survival of 25.7%.

ALFACELL Corporation is a leader in the development of ribonucleases (RNases) for therapeutic applications. ONCONASE, an antitumor agent, is currently being investigated in Phase III clinical trials in patients with malignant mesothelioma. Onconase is being evaluated by scientists at the National Institutes of Health (NIH) for its preclinical anticancer activity in a variety of tumor systems. ALFACELL is located in Bloomfield, New Jersey, and the Company's common stock is traded on NASDAQ SmallCap under the symbol "ACEL".