Attend this session at the ASCO Annual Meeting! Session: Genitourinary Cancer (Prostate)
Type: Oral Abstract Session
Time: Tuesday June 5, 9:45 AM to 12:45 PM
Location: E Arie Crown Theater
Personalize your Annual Meeting experience with a suggested or customized itinerary! Author(s): Kim N. Chi, Sebastien J. Hotte, Susan Ellard, Joel Roger Gingerich, Anthony Michael Joshua, Evan Y. Yu, Martin Edwin Gleave; British Columbia Cancer Agency, Vancouver, BC, Canada; Juravinski Cancer Centre, Hamilton, ON, Canada; Cancer Centre for Southern Interior, Kelowna, BC, Canada; University of Manitoba, Winnipeg, MB, Canada; Princess Margaret Hospital, Toronto, ON, Canada; Fred Hutchinson Cancer Research Center, Seattle, WA; Vancouver Prostate Centre, Vancouver, BC, Canada
Background: Heat Shock Protein 27 (Hsp27) is a multi-functional chaperone protein that regulates cell signaling and survival pathways implicated in cancer progression. In prostate cancer models, Hsp27 complexes with androgen receptor (AR) and enhances transactivation of AR-regulated genes. OGX-427 is a 2nd generation antisense oligonucleotide that inhibits Hsp27 expression with in vitro and in vivo efficacy and was well tolerated with single agent activity in phase I studies. Methods: Chemotherapy-naïve pts with no/minimal symptoms were randomized to receive OGX-427 600 mg IV x 3 loading doses then 1000 mg IV weekly with P 5 mg PO BID or P only. Primary endpoint was the proportion of pts progression free (PPF) at 12 weeks (PCWG2 criteria). A 2-stage MinMax design (H0 = 5%, HA >20%, α=0.1, β=0.1) with 32 pts/arm provides 70% power to detect the difference at 0.10 1-sided significance. Secondary endpoints include PSA decline, measurable disease response, and circulating tumour cell (CTC) enumeration. Results: 38 pts have been enrolled; 1st stage of accrual completed with 2nd stage accruing. In the 1st 32 pts randomized (17 to OGX-427+P, 15 to P), baseline median age was 71 years (53-89), ECOG PS 0 or 1 in 66% and 34% of pts, median PSA 66 (6-606), metastases in bone/lymph nodes/liver or lung was 75/56/9%, 31% had prior P treatment, and 93% had ≥5 CTC/7.5 ml. Predominantly grade 1/2 infusion reactions (chills, diarrhea, flushing, nausea, vomiting) occurred in 47% of pts receiving OGX-427+P. One pt on OGX-427+P developed hemolytic uremic syndrome. A PSA decline of ≥50% occurred in 41% of pts on OGX-427+P, and 20% of pts treated with P. A measurable disease partial response was seen in 3/8 (38%) evaluable pts on OGX-427+P and 0/9 pts on P. CTC conversion from ≥5 to <5/7.5 ml occurred in 50% of pts on OGX-427+P and 31% treated with P. Thus far, in 26 evaluable pts the PPF at 12 weeks was 71% (95% CI: 42-92) in OGX-427+P treated pts and 33% (95% CI: 10-65) in pts on P. Conclusions: These data provide clinical evidence for the role of Hsp27 as a therapeutic target in prostate cancer and support continued evaluation of OGX-427 for pts with CRPC. Funded by a grant from the Terry Fox Research Institute.
Thanks for posting that. These results seem identical to the data previously presented at the ASCO Genitourinary Cancers symposium in early February. That's probably because this abstract must have been submitted awhile ago. Looks like we'll have to wait for OGXI's presentation on June 5 for the updated data they've promised they'll provide.