A phase I/II study of the safety and anti-cancer activity of IV-administered belinostat (PXD101) plus carboplatin (C) or paclitaxel (P), or both in patients with advanced solid tumors

Abstract

3574 Background: Belinostat (PXD101), a HDAC inhibitor of the hydroxamate class has shown anti-tumor preclinical activity in combination with other standard chemotherapeutic agents. In Ph. I and II clinical trials the MTD for belinostat has been established at 1,000 mg/m2/d. This Ph I/II study assesses safety, and anti-cancer activity of belinostat administered in combination with C and/or P. Methods: Sequential cohorts of 3–6 patients (pts) with advanced solid tumors and PS 0–2 were recruited to determine the MTD of standard dose C and/or P with escalating doses of belinostat administered as a 30-min IV infusion daily for 5 days (d) every 21 d. C and/or P were administered 2–3 hours following infusion of belinostat on d 3. Results: 23 pts have been treated with a mean of 5 cycles (range 1 - 15) at 5 dose levels: C and belinostat (600 mg/m2) (5 pts); P and belinostat (600 mg/m2) (5 pts); C and P and belinostat (600 mg/m2) (3 pts); C and P and belinostat (800 mg/m2) (4 pts); C and P and belinostat (1,000 mg/m2) (6 pts). Possibly drug-related grade 3 or 4 toxicities were thrombocytopenia (2), vomiting (1), sensory neuropathy (1), myalgia (1), and fatigue (1).No DLT was observed. One SAE (grade 1 T-wave morphology change) was graded as possibly drug-related. No QTcf greater than 500ms were reported. There are 2 confirmed PRs: 1 with heavily treated metastatic rectal cancer and 1 with gemcitabine pre-treated metastatic pancreatic cancer. An additional 11[E1] patients had SD for 2–15 cycles, with 4 being SD for >10 cycles. One pt with mixed mullerian cancer of ovarian origin with SD had an 81% reduction in CA-125 to normal levels after 6 cycles. [E1]If you include MMMT pt as SD on radio. Conclusions: Belinostat with standard dose C and/or P is well-tolerated and shows clinical activity in heavily pre-treated patients with advanced metastatic disease. Recruitment to a phase II expansion in pts with recurrent ovarian cancer is ongoing. No significant financial relationships to disclose.

A phase I–II study of the histone deacetylase inhibitor valproic acid plus chemoimmunotherapy in patients with advanced melanoma

“…Conflicting results have been reported about the correlation among VPA dose, plasmatic concentration and changes in histone acetylation, and more data are needed to better define these relationships and the value of these parameters as surrogate end points. The same considerations could apply to other, more potent HDACis, such as vorinostat and belinostat, which appear promising in enhancing the activity of chemotherapy regimens (Ramalingam et al, 2007;Sinha et al, 2007).…”