A randomized phase II study of PX-12, an inhibitor of thioredoxin in patients with advanced cancer of the pancreas following progression after a gemcitabine …
RK Ramanathan, J Abbruzzese, T Dragovich… - Cancer chemotherapy …, 2011 - Springer
RK Ramanathan, J Abbruzzese, T Dragovich, L Kirkpatrick, JM Guillen, AF Baker…
Cancer chemotherapy and pharmacology, 2011•SpringerPurpose This study evaluated PX-12, a novel small molecule inhibitor of the proto-oncogene
(Trx-1), in patients with previously treated advanced pancreatic cancer (APC). Methods PX-
12 (54 or 128 mg/m 2) was administered by 3-hour IV infusion daily× 5 days every 21 days
(n= 17). Patients were randomized to either 54 or 128 mg/m 2 and then stratified based on
CA 19-9 level (≥ 1,000 vs.< 1,000 U/ml) and SUV values on PET scans (≥ 7.0 vs.< 7.0).
The primary endpoint was based on a progression-free survival (PFS) at 4 months in≥ 40 …
(Trx-1), in patients with previously treated advanced pancreatic cancer (APC). Methods PX-
12 (54 or 128 mg/m 2) was administered by 3-hour IV infusion daily× 5 days every 21 days
(n= 17). Patients were randomized to either 54 or 128 mg/m 2 and then stratified based on
CA 19-9 level (≥ 1,000 vs.< 1,000 U/ml) and SUV values on PET scans (≥ 7.0 vs.< 7.0).
The primary endpoint was based on a progression-free survival (PFS) at 4 months in≥ 40 …
Purpose
This study evaluated PX-12, a novel small molecule inhibitor of the proto-oncogene (Trx-1), in patients with previously treated advanced pancreatic cancer (APC).
Methods
PX-12 (54 or 128 mg/m2) was administered by 3-hour IV infusion daily ×5 days every 21 days (n = 17). Patients were randomized to either 54 or 128 mg/m2 and then stratified based on CA 19-9 level (≥1,000 vs. <1,000 U/ml) and SUV values on PET scans (≥7.0 vs. <7.0). The primary endpoint was based on a progression-free survival (PFS) at 4 months in ≥40% of patients, and required 40 patients in each arm. An amendment required elevated Trx-1 levels (>18 ng/ml) as an entry criteria after the first 17 patients were accrued.
Results
Plasma Trx-1 levels were elevated in 3/28 (11%) patients screened for study. The grade of the expired metabolite odor was higher in the 128 mg/m2 arm. Therapy was well tolerated, and Grade ≥3 adverse events were uncommon. The best response was stable disease in 2 patients. There was no consistent decrease in SUV, Trx-1 levels or CA 19-9 levels with therapy. No patients had a PFS of >4 months. Median PFS and survival were 0.9 months (95% CI 0.5–1.2) and 3.2 months (95% CI 2.4–4.2), respectively.
Conclusions
Due to the lack of significant antitumor activity and unexpectedly low baseline Trx-1 levels, the study was terminated early. PX-12 does not appear to be active in unselected patients with previously treated APC.
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