Oncothyreon Announces Presentation of Data from Phase 1Trial of ONT-10

    Oncothyreon Announces Presentation of Data from Phase 1Trial of ONT-10

PR Newswire

SEATTLE, Nov. 8, 2013

SEATTLE, Nov. 8, 2013 /PRNewswire/ - Oncothyreon Inc. (NASDAQ: ONTY) today
announced the presentation of preliminary results from an ongoing Phase 1
trial of ONT-10, a therapeutic vaccine targeting the tumor-associated antigen
MUC1, at the Annual Meeting of the Society for Immunotherapy of Cancer in
National Harbor, Maryland. The trial is a first-in-man dose escalation trial
in patients with advanced, previously treated malignancies of types associated
with the expression of MUC1. ONT-10 was administered either weekly or every
other week over an 8 week period. Patients with stable disease for at least
twelve weeks after starting treatment with ONT-10 were eligible for a separate
maintenance protocol in which the same dose of the vaccine was administered
every six weeks until tumor progression.

The dose  escalation  portion of  the  trial  has enrolled  33  patients  with 
advanced malignancies, including ovarian  cancer (10), pancreatic cancer  (5), 
endometrial cancer  (4), colorectal  cancer  (4) lung  cancer (3)  and  breast 
cancer (3), who had received extensive prior lines of therapy (median 3, range
1-11). ONT-10 was administered at doses from 250 µg up to 1000 µg weekly, and
from 250 µg up to 2000 µg every other week. To date, 19 patients have entered
the maintenance protocol. ONT-10 has been well-tolerated in this trial,  with 
no   treatment-related   serious    adverse   events.    The   most    common 
treatment-related  adverse  events  have  been  fatigue  and  injection   site 
reactions,  all  of  which  have  been   mild  to  moderate  in  severity.   A 
dose-limiting toxicity has  not been  identified, and  patients are  currently 
being enrolled in a 2000 µg weekly cohort.

A significant endpoint of the trial was to determine if ONT-10 stimulates  the 
production of MUC1-specific antibodies as seen in preclinical animal  models. 
At the  time  of the  presentation,  sera were  available  for testing  in  30 
patients treated  at  doses up  to  1000 µg  weekly.  IgM and  IgG  anti-MUC1 
antibodies were  observed in  the majority  of patients  at titers  frequently 
exceeding 1:50,000. The data support a  dose and schedule response, with  the 
greatest IgG response occurring at 1000 µg weekly.

Thirty-one patients were evaluated for anti-tumor activity by RECIST (Response
Evaluation  Criteria  in  Solid  Tumors)  1.1.  Twenty  patients  (65%)  were 
progression free at the time of first tumor assessment at week 9 or 10,  while 
progressive disease occurred in  11 patients (35%).  Eight patients have  been 
progression free for  6 months or  greater (range  6 to 18  months). Three  of 
these 8 patients were reported to have a history of progressive disease  prior 
to the initiation of  ONT-10, while an additional  patient had a rising  tumor 
marker. A decrease in the size of nodal disease was seen in two patients with
ovarian cancer.

"Our early experience with ONT-10  is encouraging" said John Nemunaitis,  M.D. 
Executive Medical Director  at Mary Crowley  Cancer Research Centers,  Dallas, 
Texas and  principal  investigator for  this  study. "The  lack  of  observed 
toxicity, the  immune  response  to  the vaccine,  and  the  delayed  time  to 
progression of  greater than  6  months in  advanced  stage patients  are  all 
supportive of the expansion of ONT-10 into later stage trials."

"We are excited by the strong antibody response to ONT-10 we have seen in this
trial," said Scott Peterson, Ph.D.  Chief Scientific Officer of  Oncothyreon. 
"In preclinical models treatment with ONT-10  was associated with both a  high 
titer antibody response and significant  anti-tumor activity. As our  studies 
with ONT-10 progress, we are looking forward to evaluating the correlation  of 
antibody levels with potential anti-tumor activity in man."

"Upon completion of the  dose-escalation portion of  this trial, we  currently 
plan to enroll  one or  more disease-specific expansion  cohorts," said  Diana 
Hausman, M.D., Chief Medical Officer of Oncothyreon. "We intend to use  these 
results to guide our plans for the further development of ONT-10."

About ONT-10

ONT-10 is a  therapeutic vaccine  targeting MUC1,  a tumor-associated  antigen 
present on  many types  of  human malignant  tumors, including  lung,  breast, 
colorectal, prostate  and  ovarian  cancer.  ONT-10  contains  a  glycosylated 
antigen designed to mimic the hypoglycosylated state of tumor-associated  MUC1 
and intended to  stimulate both the  humoral and cellular  arms of the  immune 
response. Preclinical  results  demonstrated  that  administration  of  ONT-10 
produces a robust antibody response in  mice specific for human tumor MUC1,  a 
strong cellular  immune  response  directed  to  the  target  and  significant 
anti-tumor activity. Additionally, the adjuvant component of ONT-10, PET-Lipid
A, a  fully  synthetic toll  like  receptor  4 (TLR4)  agonist  discovered  by 
Oncothyreon, was  shown to  have  enhanced potency  compared to  the  marketed 
adjuvant monophosphoryl lipid A (MPL®).

About Oncothyreon

Oncothyreon is  a biotechnology  company specializing  in the  development  of 
innovative therapeutic  products for  the treatment  of cancer.  Oncothyreon's 
goal is to  develop and  commercialize novel synthetic  vaccines and  targeted 
small molecules that have the potential  to improve the lives and outcomes  of 
cancer patients. For more information, visit www.oncothyreon.com.

Forward-Looking Statements

In order  to provide  Oncothyreon's  investors with  an understanding  of  its 
current results and  future prospects, this  release contains statements  that 
are forward-looking. Any statements contained  in this press release that  are 
not statements  of  historical  fact  may  be  deemed  to  be  forward-looking 
statements. Words  such  as  "believes,"  "anticipates,"  "plans,"  "expects," 
"will,"  "intends,"  "potential,"  "possible"  and  similar  expressions   are 
intended  to  identify   forward-looking  statements.  These   forward-looking 
statements include Oncothyreon's  expectations regarding clinical  development 

Forward-looking  statements  involve  risks   and  uncertainties  related   to 
Oncothyreon's business and the general economic environment, many of which are
beyond its control. These risks,  uncertainties and other factors could  cause 
Oncothyreon's actual  results to  differ materially  from those  projected  in 
forward-looking statements, including  those predicting  the timing,  duration 
and results of clinical trials, the timing and results of regulatory  reviews, 
the safety and  efficacy of our  product candidates, and  the indications  for 
which our product  candidates might be  developed. There can  be no  guarantee 
that the results of preclinical studies or clinical trials will be  predictive 
of either safety or efficacy  in future clinical trials. Although  Oncothyreon 
believes that the forward-looking statements contained herein are  reasonable, 
it  can   give  no   assurance  that   its  expectations   are  correct.   All 
forward-looking statements are expressly qualified  in their entirety by  this 
cautionary statement. For  a detailed description  of Oncothyreon's risks  and 
uncertainties, you  are encouraged  to  review the  documents filed  with  the 
securities regulators in the  United States on EDGAR  and in Canada on  SEDAR. 
Oncothyreon  does  not  undertake  any  obligation  to  publicly  update   its 
forward-looking statements based  on events  or circumstances  after the  date 

SOURCE Oncothyreon Inc.


Additional Information

Additional information relating to Oncothyreon can be found on EDGAR
atwww.sec.gov and on SEDAR atwww.sedar.com.

Investor and Media Relations Contact:

Julie Rathbun
Rathbun Communications
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