1960 - Phase I Study of Intraperitoneal TRX-E-002-1 in Subjects with Persistent or Recurrent Ovarian, Fallopian Tube or Primary Peritoneal Cancer: Three-month Follow-up Results of the Dose Escalation Phase

Background

The poor outcomes associated with current therapies for recurrent epithelial ovarian cancer (EOC) are thought to reflect the existence of drug-resistant ovarian cancer stem cells (OCSCs). TRX-E-002-1 is a novel, third generation benzopyran molecule that induces caspase-dependent and -independent apoptosis in CD44 positive ovarian cancer stem-like cells and CD44 negative ovarian somatic cancer cells. The dose escalation phase of a progressive design trial investigating intraperitoneal (IP)-administered TRX-E-002-1 monotherapy and in combination with standard of care for recurrent EOC (NCT02903771) has been completed with a Maximum Tolerated Dose (MTD) of 5 mg/kg established.

Methods

Women with platinum resistant, persistent or recurrent EOC were enrolled into the dose escalation phase of the study (Part A) in which TRX-E-002-1 monotherapy was administered IP weekly for 2 three-week cycles, after which combination with standard intravenous chemotherapy was allowed to a maximum of 8 cycles. Subjects were followed up for 3 months after the end of treatment. The study objectives were to establish the MTD and to evaluate safety, tolerability, pharmacokinetics and anti-tumour activity of TRX-E-002-1.

Results

A total of 9 subjects were evaluable for efficacy. Four of 9 patients completed 8 cycles (6 months); 2 remained progression-free at the 3-month endpoint post-treatment (9 months). Preliminary data on activity include 1 partial response (during combination treatment) and 5 patients with stable disease on monotherapy per RECIST criteria. The most common drug-related adverse events, not generally dose limiting, were abdominal pain (27%), fatigue (13%), vomiting (10%) and nausea (10%). There was limited accumulation of TRX-E-002-1 with multiple dosing across multiple concentration‐time points. PK profiles were comparable between all subjects with plasma concentrations progressively declining to < 10% maximal concentrations by 24 hours.

Conclusions

IP administered TRX-E-002-1 as a first-in-class, dual acting, anti-cancer therapy has demonstrated preliminary activity for the treatment of platinum resistant ovarian cancer.

Clinical trial identification

NCT02903771.

Editorial acknowledgement

Dr Caroline Markey, Markey Medical Consulting.

Legal entity responsible for the study

Kazia Therapeutics Limited.

Funding

Kazia Therapeutics Limited.

Disclosure

J. Coward: Honoraria (institution): Takeda Pharmaceuticals; Research grant / Funding (self): AstraZeneca; Leadership role, Overseas Trainee Sub-committee member: Royal Australasian College of Physicians. K. Moore: Honoraria (self), Speaker Bureau / Expert testimony, Research grant / Funding (institution): AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution): Clovis; Advisory / Consultancy, Research grant / Funding (institution): Immunogen; Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Tesaro; Advisory / Consultancy: Pfizer; Advisory / Consultancy, Research grant / Funding (self): Merck; Advisory / Consultancy: Aravive; Advisory / Consultancy, Research grant / Funding (institution): OncoMed; Advisory / Consultancy: Samumed; Advisory / Consultancy: Eisai; Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (institution): Genentech/Roche; Advisory / Consultancy: Janssen; Advisory / Consultancy: Cue; Research grant / Funding (self): Lilly; Research grant / Funding (self): PTC Therapeutics; Research grant / Funding (institution): Regeneron; Research grant / Funding (institution): Agenus; Leadership role, Chair: NRG Oncology OVarian Committee; Leadership role, Associate Director: GOG Partners. D. Berg: Full / Part-time employment: Kazia Therapeutics Limited. J. Garner: Leadership role, Shareholder / Stockholder / Stock options, Full / Part-time employment, Officer / Board of Directors: Kazia Therapeutics Limited. D. Dizon: Research grant / Funding (institution): Bristol-Myers Squibb; Research grant / Funding (institution): Kazia Therapeutics; Honoraria (self): AstraZeneca; Honoraria (self), Advisory / Consultancy: Tesaro; Honoraria (self): Regeneron; Advisory / Consultancy: iMab. All other authors have declared no conflicts of interest.