Jyunichiro Nasu

Background: Platinum-based doublets are standard first-line therapy for advanced gastric cancer (GC) in the Western Pacific region, but oxaliplatin frequently induces persistent peripheral sensory neuropathy (PSN). Whether residual PSN compromises the feasibility and efficacy of subsequent paclitaxel (PTX)-based therapy remains unclear. Methods: The IVY study was a prospective, multicenter observational trial conducted across 16 Japanese institutions. Patients with advanced GC progressing after fluoropyrimidine–platinum therapy received second-line PTX ± ramucirumab. Baseline PSN was assessed by CTCAE, PNQ, and FACT/GOG-Ntx. The primary endpoint was the incidence of grade ≥ 3 PSN during second-line therapy. Secondary endpoints included progression-free survival (PFS), overall survival (OS), time to treatment failure (TTF), tumor response, and patient-reported outcomes. Results: Among 156 patients (90 PSN-positive, 66 PSN-negative), grade ≥ 3 PSN occurred more frequently in the PSN-positive group (16.7% vs. 4.5%; p = 0.02). Median PFS was 4.0 vs. 3.9 months (p = 0.20), and median OS was 10.3 vs. 8.1 months (p = 0.04). In multivariable analysis, residual PSN was not an independent predictor of OS (HR = 0.68 for PSN-positive vs. PSN-negative, 95% CI [0.46–1.01]; p = 0.06). Patient-reported instruments captured greater and earlier QoL impairment in PSN-positive patients, though trajectories stabilized by 12 weeks. Conclusions: Residual PSN increases the risk of clinically relevant neurotoxicity—particularly in patients with baseline grade ≥ 2—but, in this cohort, did not appear to preclude paclitaxel-based second-line therapy when monitoring and dose modification were available. The apparent survival difference was exploratory and, after adjustment for baseline imbalance, should not be interpreted as a benefit attributable to residual PSN. Residual neuropathy should therefore prompt structured baseline assessment and early-cycle monitoring rather than routine reassurance.

Paclitaxel is used in second-line conventional chemotherapies to manage patients with unresectable advanced gastric cancer (GC). Paclitaxel-induced peripheral neuropathy is a known adverse event leading to treatment discontinuation. Additionally, oxaliplatin which causes irreversible peripheral neuropathy is now commonly used in first-line chemotherapy for advanced GC in Japan. Thus, examining the incidence of peripheral neuropathy with paclitaxel after oxaliplatin is necessary to improve the quality of life and outcomes of patients with advanced GC in the second-line treatment setting. This prospective observational multicenter study, (which we named IVY study), will evaluate the degree of chemotherapy-induced peripheral neuropathy (CIPN) and the efficacy of second-line chemotherapy for unresectable advanced GC. A patient neurotoxicity questionnaire (PNQ) and the Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx) will be used to assess CIPN during the second-line treatment. The key eligibility criteria are as follows: 1) unresectable or recurrent GC histologically confirmed to be primary adenocarcinoma of the stomach, 2) age over 20 years, 3) Eastern Cooperative Oncology Group performance status score of 0–2, 4) written informed consent following full study information is provided to the patient, 5) progression or intolerance for first-line chemotherapy comprising fluorinated pyrimidine and platinum anticancer drugs (cisplatin or oxaliplatin) for advanced GC. 6) presence of evaluable lesions as confirmed using a computed tomography (CT) or magnetic resonance imaging. A total of 200 patients is considered to be appropriate for inclusion in this study. The results of this study will provide some information on CIPN with the sequential usage of oxaliplatin as first-line chemotherapy to paclitaxel as second-line chemotherapy in clinical practice. This trial is registered in the University Hospital Medical Information Network’s Clinical Trials Registry with the registration number UMIN000033376 (Registered 11 July 2018).