Hyper-radiation sensitivity is enhanced in cells with mutant p53, which is ubiquitous in high grade serous ovarian cancer (HGSOC). Preclinical data suggests LDWART is a “chemosensitizer” and enhances paclitaxel cytotoxicity. We evaluated the safety and activity of LDWART concurrent with wP (LDWART+wP) in PROC.
Patients (pts) with PROC (progressive disease (PD) < 6 mth from last platinum therapy) were enrolled in a 3 + 3 dose de-escalation (part A) design, combining wP concurrent with fixed dose LDWART in 60 cGy fractions (twice daily on D1-2 of each week of wP), for 6 continuous weeks. Planned dose levels of wP were 80mg/m2, 70mg/m2, 60mg/m2. After 6 weeks of LDWART+wP, pts received wP chemotherapy alone until PD. Dose expansion (part B) with up to 10 HGSOC pts at maximum tolerated dose (MTD) of LDWART+wP, proceeded to confirm toxicity and activity.
As of 30/4/2019, 10 pts were enrolled (3 part A, 7 part B). All part B pts had HGSOC. Median lines of prior therapy was 5 (range 1-8), including prior wP in 70%, and prior bevacizumab (bev) in 50% of pts. There was no dose-limiting toxicity (DLT) at wP 80mg/m2 (DLT period = 1st 3 weeks of LDWART+wP), which was deemed the MTD. 6/10 pts completed 6 weeks of LDWART+wP. Discontinuations were due to PD (3/10) or pt withdrawal (1/10). Common related all-grade adverse events (AEs) were nausea (60%), neutropenia (60%), fatigue (60%), neuropathy (40%), diarrhea (30%); common related grade ≥3 AEs were neutropenia (50%) and anemia (20%). Median progression free survival was 3.2 mth and overall survival was 13.5 mth. 9 pts were evaluable for response. 44.4% (4/9) of pts achieved biochemical response, defined as CA125 decrease >50% from baseline, 2/4 were confirmed. 1 pt had partial response (PR) despite PD on prior wP, and 5 pts had stable disease (SD), giving an overall response rate of 11.1% (1/9) and disease control rate (PR + SD > 6 weeks) of 66.7% (6/9). 3 pts had durable disease control, and completed 12, 18 and 21 weeks of wP respectively.
LDWART+wP (80mg/m2) for 6 weeks was safe and tolerable. Encouraging efficacy was seen in this heavily pre-treated population and LDWART+wP may be useful in the context of PROC where bev is contraindicated.
NCT02545010.
The authors.
RIE2015 National Medical Research Council, National University Cancer Institute Singapore (NCIS) Centre Grant – NCIS Seed Funding.
D.S. Tan: Honoraria (self): Roche; Honoraria (self), Research grant / Funding (self): Bayer; Honoraria (self): MSD; Honoraria (self): Genmab; Honoraria (self), Research grant / Funding (self): AstraZeneca; Honoraria (self): Merck Serono; Honoraria (self): Tessa Therapeutics; Honoraria (self): Novartis; Research grant / Funding (self): Karyopharm. All other authors have declared no conflicts of interest.