Research Update

    Attention Business/Health Editors:

    YM Biosciences announces independent Data Safety Monitoring Board

    recommends tesmilifene pivotal trial continue as planned

 

    MISSISSAUGA, ON, June 26 /CNW/ - YM BioSciences Inc. (AMEX:YMI, TSX:YM,

AIM:YMBA), a company engaged in the acquisition, development and

commercialization of oncology and acute care products, today announced that

the independent Data Safety Monitoring Board (DSMB) for the pivotal Phase III

trial of tesmilifene in metastatic and recurrent breast cancer has completed

its first planned interim safety and efficacy analysis and concluded that the

trial continue as planned. The interim analysis was based on 215 events

(deaths) which occurred as of June 8th. The second of three planned interim

analyses is designed to occur after 256 events and is expected to occur in the

calendar third quarter of 2006. YM remains blinded to the study data.

    "The next interim analysis for our trial is expected to occur shortly

and, as per the statistical plan and design of the trial, at each subsequent

analysis the level of survival improvement tesmilifene must demonstrate is

lowered. Thus the probability of success improves with each interim analysis,"

said David Allan, Chairman and CEO of YM BioSciences. "We are pleased that

tesmilifene continues to display a good safety profile and remain optimistic

based on the efficacy results tesmilifene produced in its first Phase III

trial."

    The pivotal Phase III trial compares the overall survival of patients

treated with tesmilifene combined with epirubicin/cyclophosphamide to

epirubicin/cyclophosphamide alone in women with rapidly progressing metastatic

and recurrent breast cancer. The trial completed enrollment of 723 patients in

September 2005, is the subject of a Special Protocol Assessment by the FDA,

and is being conducted according to a sequential adaptive clinical design. The

sequential adaptive design allows for three interim analyses prior to a final

fourth analysis. Therefore, a total of four analyses are possible without

statistical penalty. In addition, YM has received FDA Fast Track designation

for tesmilifene in advanced breast cancer.

    The study is statistically powered to detect a 33% improvement in overall

survival based on 384 events at the final analysis. The trial will be

considered positive if the tesmilifene arm is superior to the control arm with

an improvement in overall survival ranging from 50% initially (first interim

analysis) to 33% at the final analysis.

 

    About YM BioSciences

    YM BioSciences Inc. is a company engaged in the acquisition, development

and commercialization of oncology and acute care products. In addition to

tesmilifene, YM BioSciences is developing nimotuzumab, an anti-EGFr humanized

monoclonal antibody, in a number of indications and AeroLEF(TM), a unique

inhaled delivery of free and liposome encapsulated fentanyl, to treat acute

pain including cancer pain. YM BioSciences is also developing its anti-GnRH,

anti-cancer vaccine, Norelin(TM), and owns a portfolio of preclinical

compounds.

 

    Except for historical information, this press release may contain forward-

looking statements, which reflect the Company's current expectation regarding

future events. These forward-looking statements involve risk and

uncertainties, which may cause but are not limited to, changing market

conditions, the successful and timely completion of clinical studies, the

establishment of corporate alliances, the impact of competitive products and

pricing, new product development, uncertainties related to the regulatory

approval process and other risks detailed from time to time in the Company's

ongoing quarterly and annual reporting.

 

    For further information: Thomas Fechtner, The Trout Group LLC, Tel.

[phone] x31, Fax [phone], Email: tfechtner(at)troutgroup.com;

James Smith, the Equicom Group Inc., Tel. [phone] x 229,

Fax [phone], Email: jsmith(at)equicomgroup.com

    (YMBA)



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