Arpida Provides Further Comments on the Pivotal Phase III Trials

REINACH, Switzerland, April 11 /PRNewswire-FirstCall/ -- Further to the press release published on 9 April, Arpida Ltd. (SWX: ARPN) today elaborates on some additional elements of the clinical programme with intravenous iclaprim in complicated Skin and Skin Structure Infections (cSSSI). Extensive data on ASSIST-1 has been presented at last year's ICAAC and IDSA meetings. Data on ASSIST-2 will be presented at the upcoming 18th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) which takes place in Barcelona, 19-22 April 2008.

As reported in November 2006 and July 2007, intravenous iclaprim achieved its pre-specified primary endpoint in both of the pivotal Phase III trials: ASSIST-1 and ASSIST-2. Generally, two independent trials are preferred by regulatory authorities to confirm the robustness of the data. ASSIST-1 and ASSIST-2 were similarly designed and importantly used the same comparator (i.e. linezolid) which could allow regulators to pool and further analyse the data. Noteworthy to say, that linezolid has been shown to be superior to vancomycin in cSSSI for patients with MRSA infections (Weigelt et al, AAC, June 2005, page 2260-2266).

The aim of these trials is to provide an unbiased assessment of the treatment effect and takes into account all populations; particularly relevant are the Intent-to-Treat (ITT) and the Per-Protocol (PP) population. It is essential and standard practice in any study to remove any significant imbalances, in order to properly analyse the results. As reported in July 2007, imbalances were noted in the ASSIST-2 trial - in particular due to the use of prohibited antibiotics. The correction for this imbalance in the PP population results in the Modified Clinically Evaluable ("MCE") population and shows that the MCE population is in close agreement with the ITT population. The pre-specified primary endpoint for both trials required that the lower bound of the confidence interval for treatment difference remain within minus 12.5%, which was met in all relevant populations.

As is usual in this indication, the pivotal Phase III trials were designed to demonstrate non-inferiority to a comparator. The relevance of this trial design was recently debated at an Anti-infective Drug Advisory Committee meeting discussing Community-Acquired Pneumonia (CAP) in which the panel unanimously confirmed the importance of non-inferiority trials and full evaluation of benefit and risk.

Based on the Phase III results and on those of other studies carried out, Arpida is confident that intravenous iclaprim has compelling properties, both in terms of efficacy and safety. In both pivotal Phase III trials, a high percentage of patients had MRSA infections and iclaprim showed high eradication rates (in the ASSIST-2 trial the eradication rates were 74% versus 75% for linezolid).

Iclaprim has been shown to be well tolerated in patients suffering from cSSSI. In general, iclaprim was better tolerated than linezolid, with fewer patients reporting adverse events in all categories, both in ASSIST-1 and ASSIST-2. Similarly, a small, transient QTc prolongation was observed in both trials. No cardiovascular events related to QTc elevation were reported.

About Arpida Ltd.

Arpida (SWX: ARPN) is a biopharmaceutical company with research facilities in Reinach, 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. The most advanced compounds include an antibacterial under regulatory review and an antifungal in Phase III.

Arpida's leading product candidate is intravenous iclaprim, a potent antibacterial that targets severe infections requiring hospital treatment, including those caused by methicillin-resistant Staphylococcus aureus (MRSA). The clinical programme for the first indication, complicated skin and skin structure infections (cSSSI), has been completed. The submission of the NDA to the US FDA was completed in March 2008.

In December 2007, Arpida announced the enrolment of the first patients in a Phase II clinical study with intravenous iclaprim in the treatment of patients with hospital-acquired pneumonia (HAP), ventilator-associated pneumonia (VAP) or healthcare associated pneumonia (HCAP).

In January 2008, the US FDA granted authorisation to progress oral iclaprim into a Phase II 'intravenous-to-oral' switch trial. 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 could be a valuable instrument in reducing healthcare costs and enhancing patient comfort.

Arpida's fourth most advanced antibiotic programme, AR-709, targets upper and lower respiratory tract infections acquired in the community setting. AR-709 exhibited potent activity against a large panel of pneumococcal clinical isolates including those resistant 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 effective in eradicating pathogens in preclinical models of skin infection and nasal carriage.

Apart from the antibiotic programmes, Arpida has an innovative antifungal therapy (TLT) which is in Phase III clinical trials in Europe, targeting onychomycosis.

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.

SOURCE Arpida Ltd.