Prima BioMed Receives Positive Scientific Advice From the European Medicines Agency for Its Lead Product, IMP321 - Seite 2

About Scientific Advice

Scientific Advice is a procedure offered by the EMA to pharmaceutical industry participants for clarification of questions arising during development of medicinal products. Scientific Advice is prospective in nature and it focuses on development strategies rather than pre-evaluation of data to support a Marketing Authorisation Application (MAA). Scientific Advice is legally non-binding and is based on the current scientific knowledge which may be subject to future changes. Nevertheless, the advice provided is taken into consideration during MAA and any deviations from the advice given need to be well justified.

About AIPAC (Active Immunotherapy PAClitaxel)

AIPAC is the acronym for Prima's planned multicenter, Phase IIb, randomized, double blinded, placebo-controlled clinical trial in HER-2 negative metastatic breast cancer patients receiving IMP321 or placebo as adjunctive to the standard-of-care chemotherapy drug paclitaxel. In a Phase IIa trial, IMP321 was able to increase the response rate (as per the RECIST criteria) at six months in these patients from the 25% expected of paclitaxel² to 50% for IMP321 plus paclitaxel³. The primary purpose of the AIPAC trial is to determine the clinical benefit of IMP321 in terms of Progression-Free Survival in this patient population (power 80%). Details of the AIPC study will be posted on www.clinicaltrials.gov in due course.

About IMP321 and cancer immunotherapy

IMP321 is a cancer immunotherapy agent currently in mid-stage clinical development with Prima BioMed, where it is the company's lead compound. Immunotherapy is a process whereby a disease such as cancer is treated either by activating or suppressing components of the immune system to generate a response. LAG-3, or Lymphocyte Activation Gene 3, is able to stimulate and in other cases inhibit an immune response, through involvement in a number of immune pathways. IMP321 is a soluble LAG-3Ig fusion protein which works by binding to MHC class II molecules on APCs such as dendritic cells to activate them. The APCs are important for showing cancer antigens to T cells and activating them to destroy cancer cells. IMP321 is a first-in-class APC activator.