Male sex, n (%)	13 (56.5)
Age, median (range), yr	59 (18–79)
Age group, n (%)
<65 yr	14 (60.9)
≥65 yr	9 (39.1)
Race, n (%)
Black	5 (21.7)
White	18 (78.3)
ECOG Performance Status, n (%)
0	4 (17.4)
1	19 (82.6)
Primary tumor site, n
Colon	14 (60.9)
Rectum	8 (34.8)
Unknown	1 (4.3)
Primary tumor side, n (%)
Left	17 (73.9)
Right	5 (21.7)
Unknown	1 (4.3)
Prior surgery, n (%)	22 (95.7)
Prior radiotherapy, n (%)	8 (34.8)
Prior systemic therapy, n (%)	23 (100)
Neoadjuvant	6 (26.1)
Adjuvant	15 (65.2)
Locally advanced setting	1 (4.3)
Metastatic setting	23 (100)
1 regimen	1 (4.3)
2 regimens	3 (13.0)
≥3 regimens	19 (82.6)
Cancer Types or Histologic Subtypes	Colon, 14; rectum, 8; unknown, 1
Outcome Notes
A total of 23 patients were enrolled (7 patients in phase Ia, 16 patients in phase Ib) and received at least one dose of study drug. Of these patients, 16 (70%) discontinued study treatment because of progressive disease (PD). Other causes for discontinuation of study treatment were physician decision (3 patients [13%]; 1 due to clinical decline, 1 due to cancer worsening, and 1 due to nonradiologic progression), withdrawal by patient (2 patients [9%]), TEAE (1 patient [4%], grade 4 cholestatic hepatitis), and death due to study disease (1 patient [4%]). The median (range) OS follow‐up time was 15.3 months (0.4–15.3). All patients had received prior systemic therapy in the metastatic setting, with a median (range) of 4 (1–10) prior regimens. The most common (received by ≥7 patients) prior systemic anticancer therapies in the metastatic setting were irinotecan (22 patients [96%]), 5 FU/capecitabine (22 patients [96%]), bevacizumab (18 patients [78%]), oxaliplatin (17 patients [74%]), cetuximab/panitumumab (13 patients [57%]), regorafenib (8 patients [35%]), and TAS 102 (7 patients [30%]). Exposure and dose modifications are summarized in Table 2. One patient had a ramucirumab dose reduction due to a TEAE of weight decreased. One patient each had a merestinib dose reduction due to TEAEs of blood bilirubin increased and fatigue, respectively. No patients underwent a postdiscontinuation surgical procedure. One patient (4.3%) received radiotherapy and four patients (17.4%) received a postdiscontinuation systemic therapy with investigational antineoplastic agents.