LAVAL, QUEBEC, CANADA and LILLE, FRANCE--(Marketwire - May 3, 2012) -ProMetic Life Sciences Inc. (TSX:PLI) ("ProMetic or the "Corporation ") and Macopharma SA ("Macopharma") announced today the publication of the final results of the Prion-filtered vs. standard Red cells in Surgical and Multi-transfused patients ("PRISM") study by the UK Advisory Board for the Safety of Blood Tissues and Organs ("SaBTO").

The final conclusions of the study were that following administration of P-Capt® filtered red cells to patients:

• None of the antibodies found in study patients were attributable to use of the filter;
  
  
• There was no significant difference in the number of definite and probable adverse events in patients receiving P-Capt® filtered red cells and controls patients who received standard red cells;
  
  
• The use of the P-Capt® filter does not reduce the overall safety of transfusion (i.e. the filter is safe to use);
  
  
• If implemented, the use of P-Capt® filters would require post-marketing surveillance to assess continued safety in large populations of transfused patients.
  
  

"We are greatly encouraged by the completion of this clinical evaluation on patients," stated Mr. Ronald De Lagrange, President and CEO of MacoPharma. "The results demonstrate that not only is the product effective in reducing the risk of transmission of variant Creutzfeldt-Jakob disease ("vCJD") by blood transfusion, there is also no impact of the treatment on red cell quality."

In 2009 SaBTO noted that it was "satisfied that there is now sufficient evidence that this particular filter reduces infectivity" and it recommended "that filtered red cells be provided to those born since 1^st January 1996, subject to satisfactory completion of the PRISM clinical trial". The SaBTO committee also noted that "if implemented, the continuing requirement for prion filtration should be reviewed in the event that further data on prevalence or efficacy of the filters becomes available".

However, SaBTO decided to "put on-hold its 2009 recommendation and requested further specific information to allow a decision on the recommendation to be made when this is available". The further information requested includes data from prion infectivity studies in hamsters conducted by the Health Protection Agency ("HPA") on behalf of the UK Blood Services, infectivity studies in sheep conducted at the Roslin Institute and the final results of the current IHC human appendix prevalence study (due in autumn 2012). The HPA hamster infectivity study is similar in its objectives to a study already performed and reported by ProMetic/PRDT in the Lancet; sheep infectivity models have not been proven to be good models for vCJD in human blood nor have sheep prions been proven to bind to the P-Capt® filter with the same avidity as human prions. Therefore, the reason for delaying a decision on P-Capt® adoption until data from these new investigations is available is unclear.

Dr Steve Burton, CEO of ProMetic's UK subsidiary, ProMetic Biosciences Ltd stated, "We are of course very pleased that the long-awaited results of the PRISM study confirm the safety of the P-Capt® filter in use, however it is disappointing that this study took much longer to complete than was originally anticipated and that SaBTO have again deferred a final recommendation on P-Capt® implementation until later this year". "The PRISM study results are consistent with the positive results of a previous human volunteer study undertaken by Macopharma/ProMetic/PRDT and multiple patient studies undertaken by the Irish Blood Transfusion Service", noted Dr Burton.

Mr Pierre Laurin, President and CEO of ProMetic said "once again the safety of the P-Capt® filter has been demonstrated and in combination with multiple studies confirming the effectiveness of ProMetic's technology for capturing infectious prions from blood there is now a compelling case for the immediate implementation of the P-Capt® filter in the UK to protect the population against future cases of vCJD through transfusion of contaminated red cells". "ProMetic and Macopharma continue to add to the impressive body of data on P-Capt® filter's performance and we anticipate the publication of new data in the near future from an animal infectivity model much more relevant to humans compared to our previous studies and on-going investigations conducted on behalf of the UK Blood Services. We continue to liaise with NHS Blood and Transplant ("NHSBT") and members of the UK Government regarding the adoption of the P-Capt® filter as per SaBTO's recommendation in November 2009 and hope that the decision makers attach greater importance to protecting future generations from this fatal disease rather than the implementation costs" added Mr Laurin.

In the published minutes of its meeting of 9^th March 2012, SaBTO describes a revised model for predicting future cases of vCJD by red cell transfusion which is based on current assumptions of factors such as vCJD prevalence in the UK and the amount of infectivity in human blood but which also assumes all previous cases of vCJD transmitted by blood transfusion have been identified and not missed or misdiagnosed. As a consequence the new model assumes a very low amount of infectivity in human blood (1 infectious dose per unit of red cells pre-leucodepletion) in order to make the model fit the actual number of vCJD transfusion transmission cases reported. Even with these revised assumptions discounting the possible missed and or misdiagnosed cases, the new model indicates future vCJD transmission is very likely to occur and could therefore be prevented. The potential for miss-diagnosis of vCJD is a real possibility as the majority of cases to date have been individuals with the MM genotype with very few cases identified for persons with MV or VV genotype. It has been postulated that persons with different genotypes may show different symptoms and rather worryingly the total number of cases of all forms of CJD reported by the UK CJD Surveillance Unit have increased progressively over the last two decades with no apparent explanation.

A redacted analysis of the cost effectiveness of prion-filtration was posted by SaBTO on its website. This analysis considers children to benefit the most from the implementation of prion filtration with approximately 40 life years saved per clinical case. However the report notes the cost per life year saved for children "falls well above the threshold of £25,000" but that if prion filtration was implemented universally in the UK "the overall unit cost would reduce substantially" though all intervention scenarios considered in the report exceed the cost effectiveness threshold of £25,000 per Quality Adjusted Life Years ("QALY") gained.

About PRISM

The PRISM study was undertaken on behalf of the UK blood services (NHSBT) with the objective of independently assessing whether the administration of P-Capt® filtered red cells to patients causes the formation of antibodies which react specifically with prion filtered cells or increases pan-reactive antibodies which react with all red cells or increases the rate of alloimmunisation to clinically significant red cell antigens. Secondly, the PRISM study sought to establish whether the administration of P-Capt® filtered red cells to patients increases the rate of known transfusion reactions or caused a new type of transfusion reaction. The PRISM study commenced during 2007.

About variant Creutzfeldt-Jakob Disease

Variant Creutzfeldt-Jakob Disease ("vCJD") is characterized by the accumulation of large deposits of misfolded prion protein in the brain and the nervous system and the appearance of sponge-like holes in the brain causing a fatal degenerative CNS disorder. Such abnormal prion proteins may be sufficient to transmit the disease. Although some people's genetic make-up may protect them, at least 89% of the population may be susceptible to vCJD. vCJD was initially transmitted to humans from BSE infected cows presumably by the consumption of BSE contaminated meat, but a secondary route of transmission by the transfusion of blood units from asymptomatic vCJD individuals threatens to increase the prevalence of the fatal disease.

About P-Capt^®

P-Capt^® is a single-use sterile device which was awarded CE mark approval in September 2006. Red blood cells are passed through the filter under gravity and a highly specific affinity adsorbent material captures and removes any vCJD prion protein.

P-Capt^® is the only approved product proven to be effective for the removal of prion infectivity from red blood cell concentrate prior to transfusion. It has been evaluated extensively by the UK Blood Services (including the National Blood Service, the Northern Irish Blood Transfusion Service, the Welsh Blood Service, and the Scottish National Blood Transfusion Service), the Irish Blood Transfusion Service and the Health Protection Agency since production of the first batches in 2006 and to date has achieved all of the required performance and safety requirements and met all bench marks. The P-Capt^® filter incorporates the prion-specific affinity resin developed by PRDT and supplied by ProMetic to MacoPharma and it is manufactured under licence and distributed by MacoPharma.

About Macopharma SA

Macopharma SA ("Macopharma") ([ www.macopharma.com ]) is an innovator in global healthcare with expertise in the fields of transfusion and infusion. It has become the largest supplier of in-line leucoreduction filtration sets in Europe and is expanding its efforts into the cellular therapy field by developing products for cell expansion, in addition to cell/organ processing and freezing. Headquartered in the Lille metropolitan area (France), MacoPharma has three manufacturing facilities in Europe and their products are sold into more than 70 countries worldwide.

About ProMetic Life Sciences Inc.

ProMetic Life Sciences Inc. ("ProMetic") ([ www.prometic.com ]) is a biopharmaceutical company specialized in the research, development, manufacture and marketing of a variety of commercial applications derived from its proprietary Mimetic Ligand™ technology. This technology is used in large-scale purification of biologics and the elimination of pathogens. ProMetic is also active in therapeutic drug development with the mission to bring to market effective, innovative, lower cost, less toxic products for the treatment of hematology and cancer. Its drug discovery platform is focused on replacing complex, expensive proteins with synthetic "drug-like" protein mimetics. Headquartered in Laval (Canada), ProMetic has R&D facilities in the UK, the U.S. and Canada, manufacturing facilities in the UK and business development activities in the U.S., Europe, Asia and in the Middle-East.

Forward Looking Statements

This press release contains forward-looking statements about ProMetic's objectives, strategies and businesses that involve risks and uncertainties. These statements are "forward-looking" because they are based on our current expectations about the markets we operate in and on various estimates and assumptions. Actual events or results may differ materially from those anticipated in these forward-looking statements if known or unknown risks affect our business, or if our estimates or assumptions turn out to be inaccurate. Such risks and assumptions include, but are not limited to, ProMetic's ability to develop, manufacture, and successfully commercialize value-added pharmaceutical products, the availability of funds and resources to pursue R&D projects, the successful and timely completion of clinical studies, the ability of ProMetic to take advantage of business opportunities in the pharmaceutical industry, uncertainties related to the regulatory process and general changes in economic conditions. You will find a more detailed assessment of the risks that could cause actual events or results to materially differ from our current expectations on page 24 of ProMetic's Annual Information Form for the year ended December 31, 2011, under the heading "Risk Factors". As a result, we cannot guarantee that any forward-looking statement will materialize. We assume no obligation to update any forward-looking statement even if new information becomes available, as a result of future events or for any other reason, unless required by applicable securities laws and regulations. All amounts are in Canadian dollars unless stated otherwise.