Systemic and Antigen-Specific Immune Responses in Patients Treated With Cancer Vaccine BPX-101 Correlate With Clinical Response
Interim Phase I/II Results Presented at AACR 2010 Annual Meeting
HOUSTON, April 19 /PRNewswire/ -- Bellicum Pharmaceuticals,
Inc., a company developing therapeutic cancer vaccines, today
announced the presentation of interim Phase I/II efficacy data for
BPX-101, a novel dendritic cell vaccine for metastatic castrate
resistant prostate cancer (mCRPC), in a Late Breaking poster at the
American Association for Cancer Research (AACR) 101st Annual
Meeting 2010 held in Washington, D.C.
Guru Sonpavde, M.D., Principal Investigator at The University of
Texas Health Science Center-Houston, presented interim Phase I/II
data that suggest a correlation between dose-related variations in
levels of inflammatory serum markers and measurable clinical
response in patients treated with BPX-101. Correlative PSA
declines, suppression of serum IL-6, and antigen-specific immune
responses were also reported.
The trial was designed to establish the safety and maximum
tolerated dose of BPX-101 in combination with activating agent
AP1903, administered every other week for six doses. Exploratory
efficacy endpoints include radiological and biochemical assessments
of clinical response, and assessments of serum and biopsy samples
for systemic and antigen-specific immunological responses.
Interim data from six subjects shows the combination of BPX-101
and AP103 to be safe and well tolerated at low and mid doses of
BPX-101, with no unexpected drug-related adverse events reported.
Clinical responses were evident within the first 12 weeks of
treatment, in both low and mid dose cohorts:
-- Four of six subjects had Stable Disease (SD) per RECIST 1.1 at the end of 12 weeks, and three of three who have been on study at least six months remain stable, including one subject who experienced a 20% decline in measurable disease after 12 weeks, improving further to a 25% decline at six months, tracking towards a Partial Response (PR). -- Four of six subjects achieved a maximal serum PSA decline of at least 10% from baseline, including the subject tracking towards a PR as reported above, who achieved a maximal serum PSA decline approaching 50%. -- Five of six subjects experienced a significant increase in PSA doubling time (PSADT) by 12 weeks, including two subjects with PSA levels below baseline and three subjects with PSADT increases of 80-300%, relative to the pre-treatment PSADT. -- Four of six subjects achieved declines in serum IL-6, a putative biomarker of metastatic prostate cancer, of 75-99% from baseline.
Systemic immunological responses were determined by assessment
of a panel of chemokines and cytokines at each dose and one week
after each dose. Clinically responding subjects tended to exhibit
dramatic and consistent increases in these serum markers one week
after each dose, returning to baseline the following week. Antigen
specific immune responses, measured in injection site reaction
biopsies taken after three doses, were detected in four of four
assessable subjects, including two clear TH1-biased
The apparent dose-response correlation between clinical and
immunological responses will be further investigated in six
subjects now enrolling in the final, high dose cohort.
Bellicum Founder, President and Chief Medical Officer, Kevin M.
Slawin, M.D., stated, "We are very excited and encouraged by this
early data, which appears to contradict the prevailing belief that
while cancer vaccines can prolong overall survival, they do not
elicit measurable clinical or biomarker responses in the near term.
We look forward to completing our trial later this year and
initiating Phase II trials in 2011."
About Bellicum Pharmaceuticals
Bellicum Pharmaceuticals, Inc. is developing next generation
therapeutic vaccines for the treatment of cancer and infectious
diseases. The company's pharmacologically regulated DeCIDe(TM)
vaccines are designed to kill targeted cells by inducing a potent,
durable, fully activated antigen-specific TH1 immune response. Lead
product BPX-101, an autologous DeCIDe(TM) vaccine, is in clinical
development for patients with metastatic castrate resistant
prostate cancer (mCRPC). For more information, visit http://www.bellicum.com/
Source: Bellicum Pharmaceuticals, Inc.
CONTACT: Tom Farrell, Chief Executive Officer of Bellicum
Pharmaceuticals, Inc., +1-713-341-6472, firstname.lastname@example.org; or Joleen
Schultz of Mentus, Life Science, +1-858-455-5500, ext. 215,
email@example.com, for Bellicum Pharmaceuticals, Inc.
Web Site: http://www.bellicum.com/
Posted: April 2010