Characterizing Tumor Responses From RAINBOW, a Randomized Phase III Trial of Ramucirumab (RAM) Plus Paclitaxel (PAC) vs Placebo (PBO) Plus PAC in Patients (pts) With Previously Treated Advanced Gastric or Gastroesophageal Junction (GEJ) Adenocarcinoma Abstract 45 Bodoky G, Gil-Delgado M, Cascinu S, Lipatov ON, Cunningham D, Van Cutsem E, Muro K, Chandrawansa K, Liepa AM, Carlesi R, Ohtsu A, Wilke H
Background In the RAINBOW trial, patients with gastric/ gastoesophageal (GEJ) adenocarcinoma being treated with ramucirumab + paclitaxel (RAM + PAC) had significantly longer overall survival (OS; median 9.6 vs 7.4 monhts, hazard ratio [HR] 0.81, [95% CI 0.68-0.96]; P =.017) and progression-free survival (PFS) (4.4 vs 2.9 months, HR 0.64, 95 CI 0.54-0.75; P<.0001) versus patients in the placebo + paclitaxel (PBO + PAC) arm 1 Objective response rate was also significantly improved 1 Wilke H, et al. Lancet Oncol. 2014;15(11):1224-1235.
Methods RAINBOW Study Design
Tumor Response Rates (ITT)
Background Cont d Tumor response is a possible indicator of anticancer treatment activity, although the correlation with a survival benefit is uncertain Tumor response is also the outcome most frequently assessed at the individual patient level in routine clincal practice and may help guide treatment decisions This report will further charecterize the time to response, duration of response, and quality-of-life (QoL) outcomes in patients with a measurable response from the RAINBOW trial
Methods Cont d Assessments Tumor: Radiographic assessment of disease per RECIST v1.1 at baseline and every 6 weeks for the first 6 months and every 9 weeks thereafter QoL: Assessed with the EORTC QLQ-C30 v3 at baseline, every 6 weeks, and at end of therapy
Methods Cont d Analysis Time to response (tr) was the time from randomization to first tumor response (complete or partiel) Duration of response (DoR) was the time from first tumor response to disease progression A swimmer plot of DoR, survival, and status at study end was developed Time-to-event curves were generated using the Kaplan-Meier method Hazard ratios (HRs) for TtR and DoR were generated from a stratified Cox model QoL scores were classified as improved or worsened if change from baseline was 10 points (100-point scale), otherwise considered stable
Results Demographic and Baseline Characteristics of Tumor Response ECOG PS, Eastern Cooperative Oncology Group performance status; PD, progressive disease; SD, standard deviation
Time to Response Kaplan-Meier (ITT)
Time to Response Cont d Box Plot (Responders)
Duration of Response for Tumor Responders
Swimmer Plots of Tumor Responders Ramucirumab + Paclitaxel
Swimmer Plots of Tumor Responders Placebo + Paclitaxel
Time to Response and Durability of Response 53/92 (58%) RAM + PAC and 33/54 (61%) PBO + PAC patients responded by 6 weeks - 19/53 (36%) RAM + PAC and 6/33 (18%) PBO + PAC patients maintained their response 6 months - 6/53 (11%) RAM + PAC and 2/33 (6%) PBO + PAC patients maintained their response 1 year 79/92 (86%) RAM + PAC and 47/54 (87%) PBO + PAC patients responded by 12 weeks - 38/79 (48%) RAM + PAC and 11/47 (23%) PBO + PAC patients maintained their response 6 months - 10/79 (13%) RAM + PAC and 3/47 (6%) PBO + PAC patients maintained their response 1 year
Improved/Stable QoL for Select Scales at 6 Weeks for ITT and Responders Similar results were seen for other QoL scales and at other assessment times
Conclusions Patients with advanced gastric/gej cancer not only showed an improved response rate with RAM + PAC, but responses were also more durable For the majority of patients, response occurred within the first 6 weeks of therapy Regardless of treatment arm, patients who experienced a tumor response were more likely to report improved or stable QoL, including in dimensions related to disease symptoms