Dose Escalation and Dose Expansion Study of CPO-100 in Patients With Advanced Solid Tumors

The study has three parts. Part A-1 is a dose-escalation phase with a modified "3+3" design in patients with metastatic or unresectable advanced solid tumors to evaluate the safety, tolerability and pharmacokinetics (PK) as a single agent. Two patients will be enrolled at each of the first 2 dose levels and observed for safety during the first cycle. If there are no ≥Grade 2 treatment emergent adverse events (TEAE) that are clinically significant and attributed to the study drug as assessed by the investigator during Cycle 1 for any of the patients in the first two dose levels, the 3rd dose level and beyond will follow the traditional 3+3 design. Dose escalation during the "3+3" period for each subsequent cohort of patients will be guided by the incidence of CPO-100-related adverse events (AE) as graded by National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) CTCAE v5.0 in the first 4 weeks of dosing \[the Dose Limiting Toxicity (DLT) evaluation period\]. In Part A-2, the starting dose for this part will be 45 mg/m2. This dose was established in Part A-1 as being that dose at which the use of Granulocyte-colony stimulating factor ()G-CSF is indicated given that the only Grade 3 treatment-related adverse events noted were related to neutropenia and was well managed with G-CSF support. Prophylactic use of G-CSF will be permitted in Cycle 1 based on the investigator judgement. This additional intervention of primary prophylaxis will be explored in order to determine if the risk of febrile neutropenia (FN) under these circumstances is reduced. Dose escalation during the 3+3 period for each subsequent cohort of patients will be guided by the incidence of CPO-100-related adverse events (AE) as graded by National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v5.0 in the first 4 weeks of dosing (the DLT evaluation period). After the Maximum Tolerated Dose (MTD) of weekly dosing schedule has been established, a recommended Phase 2 dose will be selected based on evaluation of the PK, and safety and tolerability profile on all available Part A study data by the Safety Review Committee (SRC). The selection of the Recommended Phase 2 Dose (RP2D) will consider all available clinical and non-clinical CPO-100 data as well as relevant docetaxel published data. Part B expansion phase will further evaluate the safety and tolerability as well as the preliminary antitumor activity at the selected RP2D. Four cohorts of patients are included in Part B: * Cohort 1: taxane naïve advanced/metastatic gastric, head and neck, lung, and ovarian cancers * Cohort 2: taxane naïve advanced/metastatic breast cancer * Cohort 3: taxane naïve advanced /metastatic prostate cancer * Cohort 4: advanced/metastatic breast or ovarian cancer who have either progressed on a taxane or have developed progressive disease within 6 months of receiving a taxane. The taxane naïve patient population is defined as patients who have not received taxane or taxane-based therapies for their metastatic diseases or patients who had suboptimal taxane exposure defined as having received less than 2 cycles of taxane or taxane-based therapies due to intolerability for their metastatic diseases. Patients who have received taxane or taxane-based therapies for their neoadjuvant treatment or patients who have received taxane or taxane-based therapies for their adjuvant treatment without disease progression during treatment are also considered taxane naïve, as long as they have not received taxane or taxane-based therapies to treat the metastatic diseases. It is estimated that approximately 60 patients can be enrolled in Parts A-1 and A-2. The exact number of patients will depend on the number of dose levels tested. A total of 60 patients, 15 patients in each cohort will be enrolled in Part B. The total duration of the study is estimated to be approximately 5 years. Patients may continue receiving CPO-100 until criteria for withdrawal are met. Patients deriving clinical benefit may continue to receive study medication for as long as they are benefiting from treatment. In the event the study closes or terminates while patients are still benefiting from and receiving CPO-100, every effort will be made to continue drug supply.