Study of CB-839 in Combination w/ Paclitaxel in Patients of African Ancestry and Non-African Ancestry With Advanced TNBC

CX-839-007 is an open-label Phase 2 study of the combination of CB-839 with paclitaxel in
patients of African ancestry and non-African ancestry with advanced triple negative breast
cancer. Multiple single-arm cohorts will be enrolled in which 800 mg BID CB-839 will be
administered in combination with the full approved dose of paclitaxel.

Patients will be enrolled into 4 cohorts, as follows:

- Cohort 1: patients of African ancestry with 2 or more lines of prior therapy for
metastatic disease

- Cohort 2: patients of African ancestry with no prior lines of therapy for metastatic
disease

- Cohort 3: same as cohort 1 but in patients of non-African ancestry

- Cohort 4: same as cohort 2 but in patients of non-African ancestry

Key Inclusion Criteria:

- Meets criteria for 1 of the 4 defined study cohorts

- TNBC defined as ER and PR negative (<1%) and HER-2 negative (FISH negative or IHC
0-1+)

- Metastatic disease or locally-advanced disease not amenable to curative intent
treatment

- Adequate hepatic, renal, cardiac, and hematologic function

- ECOG performance status 0-1

- Recovery to baseline or ≤ Grade 1 CTCAE ver.4.0

Key Exclusion Criteria:

- Known brain metastases or CNS cancer unless adequately treated with radiotherapy
and/or surgery and stable for ≥ 2 mo

- Unable to receive oral medications

- Known hypersensitivity to Cremophor®-based agents

- Major surgery within 28 days of C1D1