Interneuron Licenses Topical Compound From HeavenlyDoor.com --Formerly Procept, Inc.-- for Use Against HIV And Other Sexually Transmitted Diseases.

Business Editors and Health/Medical Writers

LEXINGTON, Mass.--(BW HealthWire)--June 15, 2000

Interneuron Pharmaceuticals, Inc. (NASDAQ: IPIC) and HeavenlyDoor.com, Inc. (NASDAQ Small Cap: HVDC) today announced that Interneuron has licensed exclusive worldwide development and commercialization rights to PRO 2000, a candidate topical microbicide that has been shown, in animal studies and in vitro, to prevent infection by the human immunodeficiency virus (HIV) and other sexually transmitted pathogens. A vaginally applied gel formulation, PRO 2000 Gel is currently being evaluated in an early stage human clinical trial supported by the National Institutes of Health (NIH).

As set forth in its agreement with HeavenlyDoor.com, formerly Procept, Inc., which developed PRO 2000, Interneuron gains exclusive worldwide rights to PRO 2000 in exchange for an upfront license fee, clinical trial milestone payments and royalties on net sales. Interneuron is responsible for all remaining pre-clinical development, clinical testing, regulatory review and commercialization activities in connection with PRO 2000.

The National Institute of Allergy and Infectious Diseases (NIAID) is sponsoring a Phase 1/2 clinical trial of PRO 2000 Gel in the U.S. and South Africa. Initiated in July 1999, this trial is designed to evaluate the safety, tolerance and acceptability of PRO 2000 Gel in healthy, sexually active women and in sexually abstinent HIV-infected women. In addition, two Phase 1 clinical trials with PRO 2000 Gel have been completed, demonstrating its safety and tolerability in healthy, sexually abstinent women. One of these trials was supported by the Medical Research Council of the United Kingdom (MRC), which is also discussing Phase 2 safety studies with the Company.

"Interneuron's acquisition of PRO 2000 adds a compound with significant peer-reviewed and published pre-clinical data and early clinical stage findings, as well as the attention of regulatory agencies in the U.S. and the U.K.," said Glenn L. Cooper, president and chief executive officer of Interneuron. "PRO 2000 has secured previous clinical trial support from the NIH and the MRC, and we believe it is well positioned to participate in larger Phase 3 clinical trials that these agencies may conduct to demonstrate protective efficacy and safety."

"We are enthusiastic to have found a larger corporate partner like Interneuron with the financial resources and experienced drug development team necessary to expedite the development of PRO 2000 Gel," said John F. Dee, vice chairman of HeavenlyDoor.com. "We welcome Interneuron's commitment to the continued development of the program and remain excited about its very large market potential."

Independent surveys conducted by the Alan Guttmacher Institute and the European Union (through Hillmark Consulting, Ltd.) showed that women in the U.S. and 11 other countries have a high level of interest in vaginal microbicides. The worldwide market opportunity for such agents has been estimated at significantly greater than $1 billion annually.

In a study published in the June 2000 issue of the Journal of Virology (vol. 74, pp. 5577-5586), researchers from St. George's Hospital Medical School in London found that PRO 2000 was the most effective of three microbicides in protecting cultured human cervical tissue against HIV infection. The researchers compared three such agents: nonoxynol-9, gramicidin and PRO 2000. PRO 2000 was found to prevent infection completely, while nonoxynol-9 and gramicidin were at best only partially effective, even when each was present at its highest nontoxic concentration.

Additional findings based on research at the Children's Hospital Medical Center in Cincinnati, Ohio and presented at the World AIDS Conference in 1998 showed that PRO 2000 Gel can protect mice completely from vaginal herpes simplex infection. Unlike many other compounds, PRO 2000 provided significant protection even when applied up to an hour before exposure to the virus.

Furthermore, in a study coordinated by the MRC, PRO 2000 Gel was shown to protect female rhesus monkeys from infection by an HIV-like virus (a hybrid simian/human immunodeficiency virus). Because it contains HIV elements, the use of a hybrid virus in these studies, rather than a pure simian virus, may provide a better indication of PRO 2000's potential effectiveness against the human virus.

In laboratory studies, PRO 2000 was shown to be effective in preventing HIV infection of cultured T cells, macrophages and dendritic cells, which are believed to be the first cells infected during sexual transmission. Preclinical studies also showed that PRO 2000 is active against other sexually transmitted agents, including genital herpes simplex virus type 2 and Chlamydia trachomatis.

PRO 2000 was originally discovered by Procept scientists in a search for compounds that inhibit the first steps in the HIV infection process. It is believed that PRO 2000 coats the envelope protein of HIV, thereby preventing the entry of the virus into susceptible human cells.

Interneuron Pharmaceuticals is engaged in the development and commercialization of a portfolio of products and product candidates for central nervous system and other disorders, including multiple compounds in late-stage clinical development.

HeavenlyDoor.com, Inc. (NASDAQ Small Cap: HVDC) is a publicly traded Internet company whose objective is to provide products and services for the elderly and aging baby boomer population, with an initial focus on the pre-planning of funerals, and ultimately the long-term care, assisted living and financial/estate planning industries. The Company, through its subsidiary d/b/a Procept, Inc., is developing and seeks to outlicense O6-benzylguanine, which currently has substantial government support for its ongoing Phase 2 trials.

Except for the descriptions of historical facts contained herein, this press release contains forward-looking statements that involve risks and uncertainties that could cause the Company's actual results and financial condition to differ materially from those anticipated by the forward looking statements. These risks and uncertainties are set forth in the Company's filings under the Securities Act of 1933 and the Securities Exchange Act of 1934 under "Risk Factors" and elsewhere, and include, but are not limited to, risks relating to the Redux-related litigation, including risk relating to the finalization of the proposed settlement of the product liability litigation; uncertainties relating to clinical trials and regulatory approvals; need for additional funds and corporate partners; history of operating losses and expectation of future losses; product liability; dependence on third parties for manufacturing and marketing; the early stage of products under development; government regulation, patent risks and competition.