ESMO Congress 2023 | OncologyPRO

Abstract 644P

Background

Rivoceranib (Rivo) is a novel oral TKI that potently and selectively inhibits vascular endothelial growth factor receptor-2 (VEGFR2). Selective inhibition of VEGFR2 has been shown to enhance the efficacy of chemotherapy. Herein, we present safety and efficacy results of the phase 1b portion of this study evaluating Rivo in patients (pts) with previously treated metastatic colorectal cancer.

Methods

In phase 1b of the study, a 3+3+3 dose-escalation was conducted to identify the recommended phase 2 dose (RP2D) of Rivo to be used in combination trifluridine/tipiracil. The phase 2 portion will evaluate the RP2D of Rivo PO QD (Days 1-28) in combination with trifluridine/tipiracil 35 mg/m² PO BID (Days 1-5, 8-12 Q28 days).

Results

As of September 2022, 29 pts received treatment with Rivo. The median age was 54 yrs (range, 30-80), most pts were male (55.2%) and White (86.2%), ECOG PS was 0 (55.2%) or 1 (44.8%), and most pts received 3 (24.1%) or 4 (24.1%) prior lines of systemic therapy. Efficacy results at each dose level are summarized in the table. Dose limiting toxicities included myelosuppression, nausea, diarrhea, fatigue, asthenia, anorexia, proteinuria and arrythmia. No treatment-related deaths occurred. The patient who received the longest duration of treatment (>26 cycles) continues to receive treatment with rivoceranib.

Table: 644P

Efficacy results (intent-to-treat population)

	300 mg (n=7)	400 mg (n=7)	500 mg (n=8)	600 mg (n=7)
ORR, n (%)	0	0	1 (12.5)	0
BOR per RECIST v1.1
PR, n (%)	0	0	1 (12.5)	0
SD, n (%)	4 (57.1)	5 (71.4)	4 (50.0)	1 (14.3)
PD, n (%)	2 (28.6)	1 (14.3)	3 (37.5)	4 (57.1)
NE, n (%)	1 (14.3)	1 (14.3)	0	2 (28.6)
mPFS, mo (95% CI)	3.9 (0.9,8.3)	4.2 (1.8,NE)	3.6 (1.8,14.6)	2.1 (1.2, NE)
mOS, mo (95% CI)	13.4 (1.9, 26.9)	6.7 (3.1, NE)	11.3 (3.3, NE)	7.6 (5.2, NE)
OS at 12 mo (95% CI)	57.1 (17.2,83.7)	42.9 (9.8,73.4)	50.0 (15.2,77.5)	33.3 (4.6,67.6)

Conclusions

Rivo 400 mg PO QD is the RP2D to be used in combination with trifluridine/tipiracil 35 mg/m² PO BID.

Clinical trial identification

NCT04073615.

Editorial acknowledgement

The Phillips Group Oncology Communications, Inc.

Legal entity responsible for the study

Elevar Therapeutics.

Funding

Elevar Therapeutics.

Disclosure

C.H. Park, X. Meng, S.H. Jang: Financial Interests, Personal, Full or part-time Employment: Elevar Therapeutics; Financial Interests, Personal, Stocks or ownership: Elevar Therapeutics. All other authors have declared no conflicts of interest.