Background: Gastric cancer (GC) with bone marrow metastasis (BMM) and disseminated intravascular coagulation (DIC) constitute a highly aggressive GC (HAGC) sub-type with distinctive features. The prognosis is poor and most HAGC patients die in weeks without effective treatment. Undue concerns about the myelosuppression mitigate against the application of cytotoxics in HAGC which is characterized by thrombocytopenia. Retrospective analysis showed low dose chemotherapy might relieve the DIC and bring with survival benefit but the standard of care (SOC) has not yet been established without a prospective study available. We completed a multi-center phase II trial evaluating the safety and efficacy of infusional fluorouracil and weekly docetaxel as first-line (1L) treatment for HAGC. Methods: This was a single-arm trial. A Simon's two-stage optimal design was applied. Eligible cases were: 18-75 years old, histologically confirmed GC, established BMM, overt DIC, platelet ≤ 50*10⁹/L and Eastern Cooperative Oncology Group (ECOG) performance status (PS) ≤ 3. Fluorouracil 200mg/m²/d continuous infusion on days 1-21 and docetaxel 25mg/m²/d on days 1, 8, 15 were given every four weeks. Hematological response (HeR) was defined as the platelet restored to normal range. The primary end point was HeR rate. Secondary end points were time to HeR (TTHeR), one month mortality (OMM), overall survival (OS), adverse events (AEs) and quality of life (QoL). Results: From Jan 2021 to Sep 2022, 24 HAGC cases from three Chinese centers were enrolled (details shown in table below). 20 HeRs were achieved and the HeR rate was 83.3%. Median TTHeR was 13 days and OMM was 12.5%. Till the data cut-off date (Jul 31, 2023), 3 patients were still alive with a median follow-up of 403 days. The median OS was 242 days. Totally, twelve Grade 3 AEs were recorded in 7 (29.2%) patients, among which stomatitis (4, 16.7%) and aminotransferase elevation (3, 12.5%) were the most frequent. No drug-related grade 4 or 5 AEs were observed. QoL outcomes were significantly improved both during and after the treatment. Conclusions: Anti-cancer treatment is the key point to control DIC of HAGC. The Zhen Long regimen was well tolerated and showed promising efficacy in the 1L setting. It should be considered as the SOC in current practice, but further randomized trials are still needed. Clinical trial information: NCT04547153.