Napo Pharmaceuticals, Inc. Obtains IRB Approval for Phase 3 Clinical Trial Protocol for Crofelemer In HIV/AIDS Diarrhea Assessment

SOUTH SAN FRANCISCO, Calif., March 14 /PRNewswire-FirstCall/ -- Napo Pharmaceuticals, Inc. announces today that it has received approval from the principal independent review board "IRB" overseeing the pivotal, phase 3 ADVENT study of crofelemer for diarrhea in people living with HIV/AIDS.

The ADVENT trial ("Anti-Diarrhea therapy in HIV disease-Emerging treatmeNT concepts) is a randomized, double-blind, parallel-group, placebo-controlled, two-stage, adaptive design study to assess the efficacy and safety of crofelemer 125mg, 250 mg, and 500 mg oral doses twice daily for the treatment of HIV-Associated Diarrhea. Napo previously met with the United States Food and Drug Administration (FDA) on January 16, 2007 under the Special Protocol Assessment Process on this adaptive design of its ADVENT trial. The study will be carried out under an FDA Fast Track designation.

About the ADVENT Trial

The 'adaptive design' trial is executed in two stages. Adaptive trial design has been advocated by the FDA to improve efficiency of clinical trials.* Stage I represents a dose selection stage and Stage II, a dose assessment stage. Four dose groups (placebo, 125 mg, 250 mg, and 500 mg p.o. b.i.d.) will be assessed in Stage I. When 50 subjects per group complete the initial efficacy dosing period (28 days), an interim analysis will be conducted to select an optimal single dose of crofelemer for Stage II. Stage II will continue until an additional 75 subjects are randomized to this dose of crofelemer or placebo, providing for 125 patients on placebo and 125 patients on the selected crofelemer dose. The primary study analysis is planned after all subjects complete the 28-day efficacy period. A full study analysis and final study report will be prepared at that time, which will form the basis of a subsequent New Drug Application (NDA) filing to FDA. Subjects who complete the efficacy part of the study will be allowed to continue into a five-month extension. The purpose of the extension is to provide additional safety and tolerability information about crofelemer in longer tem use.

"The IRB approval of our protocol with the adaptive design is a very important milestone for Napo", said Lisa A. Conte, Chief Executive Officer of Napo. "This represents the ability to proceed efficiently in our Phase 3 study, while gaining the commercial benefits of testing lower doses in the final study prior to filing our NDA for the AIDS diarrhea indication. While these efforts have prolonged the initiation of dosing in the trial, Napo is still aiming to submit an NDA for this indication in the next year, and targeting approval under fast-track designation by mid-2008."

Special Protocol Assessment

The FDA's SPA process was implemented under the Prescription Drug User Fee Act (PDUFA) in November 1997. The FDA agreed to specific performance goals for special protocol assessment and agreement that apply to pivotal efficacy trials. To use this process, companies planning clinical trials designed to support efficacy claims submit a study protocol, as well as related questions. Upon review, the FDA may then agree to the protocol design, execution and analyses and issue a special protocol letter to that effect. Once the FDA agrees in writing to a protocol reviewed under this process, the assessment should be considered binding on the review division of the FDA as long as the protocol is followed, unless substantial scientific issues essential to determining the safety or efficacy of the drug are being identified after the testing has begun.

References * Scott Gottlieb, MD, 2006 Conference on Adaptive Trial Design, July 10, 2006, http://www.fda.gov/oc/speeches/2006/trialdesign0710.html. For more information please contact: Napo Pharmaceuticals, Inc Lisa Conte, Chief Executive Officer 001 + 650 616 1902 Charles Thompson, Chief Financial Officer 001 + 650 616 1903 Buchanan Communications Tim Anderson, Mary-Jane Johnson +44 (0) 20 7466 5000 Noonan Russo David Schull 001 + 858 646 3058 Greg Geissman Nomura Code Securities Limited +44 (0)20 7776 1205 Clare Terlouw About Napo

Napo Pharmaceuticals Inc., focuses on the development and commercialisation of proprietary pharmaceuticals for the global marketplace in collaboration with local partners. Napo was founded in November 2001, and is based in South San Francisco, California, with a subsidiary in Mumbai, India.

Napo's late-stage proprietary gastro-intestinal compound, crofelemer, is in various stages of clinical development for four distinct product indications, including a late-stage Phase 3 program:

-- CRO-HIV for AIDS diarrhea, Phase 3 -- CRO-IBS for diarrhea irritable bowel syndrome ("D-IBS"), Phase 2 -- CRO-ID for acute infectious diarrhea (including cholera), Phase 2 -- CRO-PED for paediatric diarrhea, Phase 1 The FDA has granted fast-track status to CRO-IBS and CRO-HIV.

Crofelemer, a proprietary patented agent, is extracted from Croton lechleri, a medicinal plant which can be sustainably harvested from several countries in South America. Napo also plans to develop an early clinical stage product, NP-500, for the treatment of insulin resistant diseases of Type II diabetes and metabolic syndrome (Syndrome X; pre-diabetic syndrome). Napo also has a plant library of approximately 2,300 medicinal plants from tropical regions and Napo has entered its first screening relationship associated with this collection. Currently, products are based on the chemical and biological diversity derived from plants with medicinal properties, but future products may be in-licensed from other sources.

Napo has partnerships with Trine Pharmaceuticals, Inc. of the United States of America; Glenmark Pharmaceuticals Limited of India; and AsiaPharm Group Ltd. of China. For more information please visit www.napopharma.com.

About Crofelemer

Crofelemer, a proprietary patented agent, is extracted from Croton lechleri, a medicinal plant which can be sustainably harvested from several countries in South America. Crofelemer is in various stages of clinical development for four distinct product indications, one in Phase 3, two in Phase 2 and one in Phase 1.

These products have been tested in trials involving approximately 1500 patients in double-blind placebo-controlled, mostly published trials of AIDS diarrhea, diarrhea-predominant IBS, and acute infectious diarrhea. The products are generally well tolerated and have shown significant anti-diarrheal activities and improvement in gastrointestinal symptoms. Crofelemer produces several effects when administered orally providing for activity in several disease indications. Crofelemer's anti-secretory mechanism reduces excess fluid secreted into the gastro-intestinal tract, while its anti-inflammatory and analgesic activity may provide the rationale for its significant benefit in abdominal pain. Crofelemer acts locally in the intestines, with limited systemic exposure.

Napo Pharmaceuticals, Inc.

CONTACT: Lisa Conte, Chief Executive Officer, +1-650-616-1902, or CharlesThompson, Chief Financial Officer, +1-650-616-1903, both of NapoPharmaceuticals, Inc; or Tim Anderson or Mary-Jane Johnson,+44-20-7466-5000, of Buchanan Communications; David Schull or GregGeissman, both of Noonan Russo, +1-858-646-3058; or Clare Terlouw,+44-20-7776-1205, of Nomura Code Securities Limited, all for NapoPharmaceuticals, Inc.

Web site: http://www.napopharma.com/