Phase I Study of Cantrixil in Patients With Ovarian Cancer, Fallopian Tube Cancer or Primary Peritoneal Cancer.

This study is a progressive design with 2 discrete Parts (Part A: Dose escalation, Part B: Dose expansion. Cycle 1/Part A is a dose-finding assessment (dose escalation) to establish the maximum tolerated dose (MTD) of Cantrixil when administered as a single dose once a week for 3 weeks. Cycle2/Part A continues with 3 additional weekly doses of Cantrixil as a monotherapy before an assessment of disease response. In Cycles 3 to 8/Part A, patients will be administered the same once weekly dose of Cantrixil they tolerated in Cycles 1 and 2 (tolerance defined as no dose limiting toxicities [DLTs] or unacceptable treatment-related adverse events [AEs]) in combination with a limited range of standard chemotherapy agent(s), in order to assess the safety and tolerability of Cantrixil in combination therapy. Standard chemotherapy drugs will be administered at the standard efficacious doses to maintain optimum benefit of known drug combinations for patients.

Once the MTD has been determined in Part A, an additional 12 patients will be recruited in an expansion cohort for Part B. These patients will receive 2 cycles of Cantrixil monotherapy at the MTD, followed by up to 6 cycles of combination therapy.

Patients enrolled into the respective parts of the study may not receive treatments under different parts of the protocol.

To accommodate the intraperitoneal administration of Cantrixil, an in-dwelling, closed catheter or port will be inserted if the patient does not already have one. For intraperitoneal ports, the minimum period between port placement and the first administration of Cantrixil must not be shorter than 7 days.

Patients should begin protocol treatment within a maximum of 28 days of enrolment (i.e., signing of consent form).

Patients will start at Dose Level 0 which is calculated to be the human equivalent of 10% of the severely toxic dose in 10% (STD10) dose in rats (dose that is 1/10 the severely toxic dose in 10% of rats tested). Dose levels -1 and -2 will only be activated if there are 2 DLTs at the Dose Level 0 and -1, respectively. Single patient cohorts will be treated with increasing doses of Cantrixil until an AE is observed that meets the definition of a Dose Limiting Toxicity (DLT) or, in the opinion of the Data Safety Monitoring Committee (DSMC) and the Investigator, is causally related to study treatment and warrants observing additional patients at this dose level; at this point the study will revert to a 3+3 rules based dose escalation study. Once the study enters a 3+3 rules-based design, the study will not revert back to single patient cohorts.

If any unacceptable treatment-related AE or DLT is observed in any cycle, patients may be dose reduced to the next lower dose level of Cantrixil for subsequent doses of therapy. If a second unacceptable treatment-related AE or DLT is observed during any cycle within the same patient, treatment for the patient with Cantrixil will be discontinued. Investigators may continue with the standard chemotherapy at their discretion and if it is considered safe and in the patient's best interest.

If any of the following unacceptable treatment-related AEs or DLTs are observed and unless clearly unrelated to study treatment (e.g., disease progression), treatment at the allocated Cantrixil dose will be discontinued and dose escalation may be considered:

• Hematologic toxicity
• Grade 4 neutropenia, lasting at least 5 days,
• Grade 3 or Grade 4 neutropenia associated with fever >38.5°C,
• Grade 4 thrombocytopenia lasting at least 5 days,
• Grade 3 thrombocytopenia associated with severe bleeding in the opinion of the Investigator,
• Dose delay of ≥3 weeks due to failure to recover counts.
• Any Common Terminology Criteria for Adverse Events (CTCCTCAE) version 4.03 Grade 3 or Grade 4 non haematological toxicity except:
• Alopecia
• Grade 3 abdominal pain deemed related to the port or catheter as determined by the treating physician
• Grade 3 anorexia
• Grade 3 fatigue
• Grade 3 nausea and/or vomiting, or diarrhoea, lasting ≤48 hours with or without maximal medical management.
• Grade 3 dehydration as a result of nausea and vomiting
• Grade 3 constipation
• Grade 3 metabolic abnormalities [hypokalaemia, hypomagnesemia, hypocalcaemia, hypophosphatemia]) that recovers to Grade 1 or less within 48 hours with or without medical management o• Other serious adverse events (SAEs) which, in the opinion of the treating Investigator, are related to investigational product and necessitate temporary or permanent cessation of administration o• Treatment delays of ≥3 weeks due to any treatment-related non-haematological toxicity will constitute a DLT All patients who discontinued from the study (i.e. are now Off Therapy/ End of Therapy) treatment will progress to follow-up unless the patient withdraws consent.

The initiation of each new cycle of Cantrixil will be at the discretion of the Investigator and will depend on the potential or measurable benefit to the patient assuming continued tolerability and adequate organ function.

Cantrixil treatment will be stopped due to RECIST version 1.1 defined disease progression observed after at least 4 cycles of therapy, recurrence of unacceptable toxicity after 1 Cantrixil dose reduction or patient consent withdrawal. Note that patients with progressive disease at the end of 2 cycles of Cantrixil monotherapy will not be taken off therapy if Cantrixil has been well tolerated. Pre-clinical data would suggest that the maximum benefit from Cantrixil will be realised as a combination therapy, hence all patients will have the opportunity to continue receiving Cantrixil as a combination therapy. Additionally, patients receiving combination therapy that are observed to have progressive disease as identified by RECIST version 1.1 criteria but who, in the opinion of the Investigator, continued to derive clinical benefit may continue Cantrixil treatment. Patients may also be discontinued from study treatment if the Investigator considers continuing therapy is not in the patient's best interest. All patients discontinued from study treatment will progress to follow-up unless the patient withdraws consent.

Tumour assessment via radiological imaging will be conducted during screening and every 6 weeks after the start of therapy, i.e. at the end of monotherapy and then after every 2 cycles of combination therapy. Either contrast-enhanced magnetic resonance imaging (MRI) or contrast-enhanced computed tomography (CT) may be used, but once a modality is used at baseline this must be used consistently for that patient throughout their participation on the study. Other imaging is not mandatory, but may be performed if clinically indicated.

Adverse events will be monitored for the duration of the study from the time of informed consent. Blood samples will be collected weekly for standard safety testing, or more frequently if clinically relevant, during the study. Additional volumes of blood will be collected before and after administration of Cantrixil for pharmacokinetic (PK) analysis (4 mL per time point as per the proposed PK schedule and for any exploratory studies (at baseline, end of Cycle 2 and end of treatment, 15 to 20 mL at each time-point).