Abstract 64P
Background
REG is an oral multikinase inhibitor approved for pretreated patients with mCRC. Anecdotal evidence from oncologists suggests a subgroup of patients (pt) have prolonged response to REG. We conducted an SLR of published studies to obtain a comprehensive understanding of the proportion of patients who experience long-term response (LTR) (defined as progression-free survival [PFS] or duration of treatment [DoT] ≥4, ≥5, and ≥6 months).
Methods
We searched MEDLINE, MEDLINE in-process, and Embase on March 5, 2024, to identify studies published from 2019 onward. English language publications (pubs) were included if they reported relevant data for REG monotherapy in case reports or in observational studies/randomized-controlled clinical trials (RCTs) with ≥20 patients. The proportion of patients with LTR was extracted from text or determined using Kaplan-Meier (KM) curves that presented the number of patients on treatment or at risk of progression at various timepoints of interest.
Results
Among the 1,419 unique publications identified, 41 met inclusion criteria (13 case reports, 6 RCTs, 22 observational studies). As shown in the table, a high proportion of patients treated with REG achieved LTR in RCTs and observational studies. Among the 13 case reports (12 patients), most (75%) patients who received REG monotherapy in real-world clinical settings maintained progression-free status for 8-30 months. Notably, three cases reported exceptionally long PFS of 30 months, 41 months, and up to nine years. Table: 64P
| PFS (months) | ≥4 | ≥5 | ≥6 | ≥9 | ≥12 |
| Observational [# pubs] % pt (n/N) | [4] 19.4% (7/36)–41.3% (33/80) | [4] 10.3% (6/58)–21.9% (21/96) | [8] 10.5% (14/133)–25.7% (18/70) | [6] 3.8% (5/133)–10% (7/70) | [8] 1.5% (2/133)–6.3% (8/128) |
| RCTs [# pubs] % pt (n/N) | [1] 26.8% (30/112) | – | [3] 12.9% (13/101)–16.1% (18/112) | [2] 5% (5/20)–7.8% (7/90) | [2] 5.6% (5/90)–7.1% (8/112) |
| DoT (months) | ≥4 | ≥5 | ≥6 | ≥9 | ≥12 |
| Observational [# pubs] % pt (n/N) | [1] 22% (512/2326) | [1] 15% (349/2326) | – | – | – |
| RCTs [# pubs] % pt (n/N) | – | – | [1] 4.7% (2/43)–15.7% (8/51) | – | [1] 7.8% (4/51) |
Conclusions
It is evident that there are patients who show LTR to REG treatment. Further insights are required to enhance our understanding of patient characteristics and determinants that influence the effectiveness of REG treatment in heavily pretreated patients with mCRC.
Legal entity responsible for the study
Bayer HealthCare Pharmaceuticals.
Funding
Bayer HealthCare Pharmaceuticals.
Disclosure
M. Peeters: Financial Interests, Personal, Invited Speaker: Amgen, Sanofi, Servier, Merck, BMS, Sirtex Medical; Financial Interests, Personal, Advisory Board: Bayer, Qurin; Financial Interests, Personal, Other, Consulting: Remedus; Financial Interests, Personal, Member of Board of Directors: Qurin; Financial Interests, Personal, Stocks/Shares: Bimini. X. Pan: Financial Interests, Institutional, Full or part-time Employment: Bayer. M. Koufopoulou: Financial Interests, Institutional, Full or part-time Employment: Cencora. M. Arregui: Financial Interests, Personal, Full or part-time Employment, I am an employee of Cencora, a consulting firm which provides consulting and other research services to pharmaceutical and related organizations: Cencora. E. Wissinger: Financial Interests, Personal and Institutional, Full or part-time Employment, employees of Cencora, a consulting firm which provides consulting and other research services to pharmaceutical and related organizations: Cencora; Financial Interests, Personal and Institutional, Stocks/Shares: Cencora. H. Ostojic: Financial Interests, Personal, Full or part-time Employment: Bayer Consumer Care. F. Pisa: Financial Interests, Personal, Full or part-time Employment: Bayer AG. R.D. Kim: Financial Interests, Personal, Advisory Board: Servier, Roche, Taiho, Ipsen, Lilly, Bayer, Pfizer, AbbVie; Financial Interests, Personal, Other, Speaker Bureau: Incyte.