STUDY SHOWS SENETEK'S INVICORP EFFECTIVE IN TREATING IMPOTENCE

This press release is transmitted on behalf of Senetek PLC

New York, May 27, 1998 - Senetek PLC announced today that, in a recently concluded clinical study, its new drug therapy for treating erectile dysfunction (ED) in males - INVICORP(TM), a unique neurotransmitter combination-drug therapy administered with a proprietary state-of-the-art autoinjector - was nearly 70 per cent effective in treating patients with pharmaco-resistant erectile dysfunction.

These patients were consecutive erectile clinic attenders who had previously failed therapy with intracavernosal 20 mg of prostaglandin E1 (PGE1), also known as alprostadil - currently the only regulatory-approved intracavernosal drug therapy available in the marketplace for treating male patients with organic erectile dysfunction (impotence) - and 30 mg of papaverine in combination with 1mg of phentolamine mesylate. Forty-seven of the 70 patients achieved erections suitable for sexual intercourse, initially under clinical supervision and subsequently during home use of INVICORP.

The primary minor side effect associated with use of INVICORP was transient facial flushing in 37 out of 70 patients (53 per cent). None of the patients who were administered INVICORP reported priapism or other serious adverse events.

Wallace Dinsmore, M.D., of the Department of Genito Urinary Medicine at Royal Victoria Hospital, Belfast, Northern Ireland, conducted the study, and will be presenting his clinical data at the ''2nd Meeting of the European Society for Impotence Research (ESIR)'' in Madrid, Spain, October 1-4, 1997.

Last month Senetek PLC announced that it filed a Product Licensing Application (PLA) with the United Kingdom's Medicines Control Agency (MCA) seeking approval to market INVICORP to treat moderate-to-severe, organic-based erectile dysfunction (ED) in males.

The PLA submission included data from Phase III clinical trials involving more than 700 men among eight sites in the United Kingdom. The data from the pivotal studies suggested that INVICORP was 81 per cent effective in treating male patients with organic-based ED - patients who previously could not function sexually - enabling them to have an erection suitable for intercourse. Of particular note involving the pivotal studies: 59 per cent of the patients treated successfuly with INVICORP had previously been treated with alternative pharmacotherapies, including prostaglandin (PGE1), papaverine and yohimbine, but had withdrawn from treatment either due to lack of effectiveness (45 per cent) or side effects or other reasons (55 per cent). Eighty-two per cent responded successfully to INVICORP, whereas previous pharmacotherapy had failed to be satisfactory. The primary side effect associated with INVICORP was short-term facial flushing.

INVICORP is an injectable formulation of vasoactive intestinal polypeptide (VIP) in combination with the adrenergic drug phentolamine. VIP, in combination with phentolamine and sexual stimulation, is expected to provide a new and effective alternative for ED patients that is essentially free of the troublesome side effects and cumbersome delivery methods limiting the use of other pharmacologic preparations. INVICORP can be delivered using Senetek's novel and patented Auto Injector - which renders the self-injection process exceptionally easy and unobtrusive to perform and helps ensure accurate, safe delivery of medication.

Senetek PLC is a biotechnology company providing technologies and solutions for aging-related health problems.