Arpida Receives Approval From US FDA to Initiate a Phase II Trial With iclaprim in Hospital-Acquired, Ventilator and Healthcare-Associated Pneumonia

REINACH and BASEL, Switzerland, June 21 /PRNewswire-FirstCall/ -- Arpida Ltd. announced today that it has received approval from the US Food and Drug Administration for a Phase II trial with intravenous iclaprim in the treatment of patients with hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP) or healthcare-associated pneumonia (HCAP) suspected or confirmed to be due to Gram-positive pathogens.

According to US data, pneumonia accounts for approximately 15% of all hospital-associated infections and 27% of all infections acquired in the intensive care unit; moreover it has a high mortality rate. The number of treatment options in this field is currently very limited, particularly for infections caused by methicillin-resistant Staphylococcus aureus (MRSA). This has given rise to a large and urgent medical need for safe drugs which are efficacious against these resistant pathogens.

Results of a special Phase I study, conducted in 2005, have shown that iclaprim achieves high concentrations in the specific compartments of the lung where clinically relevant pathogens, including MRSA, are most commonly found and could therefore become an efficacious drug for the treatment of pneumonia.

The Phase II trial is designed as a multi-centre, randomised, double-blind, comparative study. The efficacy and safety of two different dosing regimens of iclaprim will be compared to the current standard of care vancomycin. More than 130 patients will be enrolled. Patients will be treated for 7-14 days and a Test-of-Cure (TOC) visit will be performed 7-14 days after the end of therapy. The primary endpoint will be the clinical cure rate at the TOC visit. Enrolment is expected to start in the second half of 2007.

Intravenous iclaprim is also being developed for complicated skin and skin structure infections (cSSSI). In this indication the drug candidate has completed patient enrolment in two pivotal Phase III trials. The first of the two studies has already been evaluated and shows a good efficacy in cSSSI as well as excellent safety. Top-line data of the second trial are expected shortly. If these confirm the strong results of the first trial, an NDA filing can be expected before the end of this year.

Dr. Paul Hadvary, Head of Development of Arpida Ltd, commented: "Based on our positive results with iclaprim in cSSSI trials and on its good tissue distribution particularly to the key lung compartments, we feel that this compound could demonstrate good efficacy in hospital-acquired, ventilator- and healthcare-associated pneumonia. I am pleased that the US FDA has consented that we initiate studies in these seriously ill patients as I believe that iclaprim could add a potent weapon to the clinicians' armamentarium to combat this potentially life-threatening infection."

About Arpida Ltd.

Arpida is a biopharmaceutical company with research facilities near Basel, Switzerland and in the USA. It focuses on the discovery and development of novel drugs that seek to overcome the growing problem of microbial resistance.

Arpida's leading product candidate is intravenous iclaprim, a broad-spectrum antibiotic that targets severe infections requiring hospital treatment, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). In November 2006, intravenous iclaprim has successfully completed its first Phase III trial in the treatment of cSSSI (complicated skin and skin structure infections). In March 2007, patient enrolment into the Phase III programme was completed. The US Food and Drug Administration have granted fast track status to intravenous iclaprim for the treatment of cSSSI.

An oral formulation of iclaprim has successfully completed three Phase I trials: an ADME study (absorption, distribution, metabolism and excretion) with radiolabelled compound, a Phase I bioavailability trial with a solution and one with a capsule formulation. Arpida believes that the availability of an oral formulation could potentially fulfil an important clinical medical need for the treatment of serious bacterial infections, particularly those caused by MRSA. Iclaprim could be offered not only as an intravenous therapy for hospital use in acute situations, but also as an oral formulation, allowing early patient discharge followed by outpatient treatment. This switch should be a valuable instrument in reducing healthcare costs and enhancing patient comfort.

Arpida's third most advanced programme, AR-709, targets upper and lower respiratory tract infections acquired in the community setting. AR-709 exhibited potent activity against a collection of 611 pneumococcal clinical isolates from Europe, the USA and Asia irrespective of the mechanisms of resistance to currently used drugs. Promising results of "first-in-man" studies with AR-709 were published in March 2007.

An additional compound, AR-2474, has achieved in vivo proof of concept. AR-2474 has been shown to be highly effective in eradicating MRSA in preclinical models of skin infection and nasal carriage.

Moreover, the company has several other leads in optimisation and additional discovery programmes derived from its own discovery platform at various research stages.

This press release contains specific forward-looking statements, e.g. statements including terms like believe, assume, expect or similar expressions. Such forward-looking statements are subject to known and unknown risks, uncertainties and other factors which may result in a substantial divergence between the actual results, financial situation, development or performance of the company and those explicitly or implicitly presumed in these statements. Against the background of these uncertainties readers should not place undue reliance on forward-looking statements. The company assumes no responsibility to update forward-looking statements or to adapt them to future events or developments.

Arpida contacts: Dr Khalid Islam, President and CEO Tel: +41-61-417-96-60 Harry Welten, MBA, CFO and Senior Vice President Tel: +41-61-417-96-65 Paul Verbraeken, Head of Corporate Communications Tel: +41-61-417-96-83

CONTACT: Arpida contacts: Dr Khalid Islam, President and CEO, Tel:+41-61-417-96-60; Harry Welten, MBA, CFO and Senior Vice President, Tel:+41-61-417-96-65; Paul Verbraeken, Head of Corporate Communications, Tel:+41-61-417-96-83