Sintilimab plus chemotherapy for patients with EGFR-mutated non-squamous non-small-cell lung cancer with disease progression after EGFR tyrosine-kinase inhibitor therapy (ORIENT-31): second interim analysis from a double-blind, randomised, placebo-controlled, phase 3 trial.

BACKGROUND: In the first interim analysis of the ORIENT-31 trial, compared with chemotherapy alone, sintilimab plus bevacizumab biosimilar IBI305 plus chemotherapy (pemetrexed and cisplatin) significantly improved progression-free survival in patients with EGFR-mutated non-squamous non-small-cell lung cancer (NSCLC) who progressed on EGFR tyrosine-kinase inhibitor treatment. However, the benefit of anti-PD-1 or PD-L1 antibody added to chemotherapy in this patient population remains unclear, with no prospective evidence from phase 3 trials globally. We report the results from the prespecified second interim analysis of progression-free survival between sintilimab plus chemotherapy and chemotherapy alone, the updated results of sintilimab plus IBI305 plus chemotherapy, and preliminary overall survival results. METHODS: This double-blind, randomised, placebo-controlled, phase 3 trial was done at 52 centres across China and included patients aged 18-75 years with locally advanced or metastatic (stage IIIB, IIIC, or IV according to the American Joint Committee on Cancer, eighth edition) EGFR-mutated non-squamous NSCLC, disease progression after EGFR tyrosine-kinase inhibitor treatment (according to the Response Evaluation Criteria in Solid Tumours version 1.1 [RECIST 1.1]), and at least one measurable lesion (according to RECIST 1.1). Patients were randomly assigned (1:1:1), using an interactive web response system, to receive sintilimab (200 mg) plus IBI305 (15 mg/kg) plus pemetrexed (500 mg/m2) and cisplatin (75 mg/m2), sintilimab plus chemotherapy, or chemotherapy alone on day 1 of each 3-week cycle for four cycles, followed by maintenance therapy of sintilimab, IBI305, and pemetrexed. All study drugs were administered intravenously. The primary endpoint was progression-free survival in the intention-to-treat population assessed by an independent radiographic review committee. Data cutoff was March 31, 2022, unless otherwise specified. The study is registered at ClinicalTrials.gov, NCT03802240 (ongoing). FINDINGS: Between July 11, 2019, and March 31, 2022, 1011 patients were screened and 476 were randomly assigned (158 to the sintilimab plus IBI305 plus chemotherapy group, 158 to the sintilimab plus chemotherapy group, and 160 to the chemotherapy alone group). The median follow-up duration for progression-free survival was 12·9 months (IQR 8·2-17·8) in the sintilimab plus IBI305 plus chemotherapy group, 15·1 months (8·0-19·5) in the sintilimab plus chemotherapy group, and 14·4 months (9·8-23·8) in the chemotherapy alone group. Sintilimab plus chemotherapy significantly improved progression-free survival compared with chemotherapy alone (median 5·5 months [95% CI 4·5-6·1] vs 4·3 months [4·1-5·3]; hazard ratio [HR] 0·72 [95% CI 0·55-0·94]; two-sided p=0·016). Significant progression-free survival benefit was sustained with sintilimab plus IBI305 plus chemotherapy compared with chemotherapy alone (median 7·2 months [95% CI 6·6-9·3]; HR: 0·51 [0·39-0·67]; two-sided p<0·0001). As of data cutoff (July 4, 2022), the median overall survival was 21·1 months (95% CI 17·5-23·9) for sintilimab plus IBI305 plus chemotherapy (HR 0·98 [0·72-1·34]) and 20·5 months (15·8-25·3) for sintilimab plus chemotherapy group (HR 0·97 [0·71-1·32]) versus 19·2 months (15·8-22·4) for chemotherapy alone; after adjusting for crossover, the HR for sintilimab plus IBI305 plus chemotherapy to chemotherapy alone ranged from 0·79 (0·57-1·09) to 0·84 (0·61-1·15) and the HR for sintilimab plus chemotherapy to chemotherapy alone ranged from 0·78 (0·57-1·08) to 0·84 (0·61-1·16). The safety results were generally consistent with those in the first interim analysis; in particular, treatment-related adverse events of grade 3 or worse occurred in 88 (56%) of 158 patients in the sintilimab plus IBI305 plus chemotherapy group, 64 (41%) of 156 patients in the sintilimab plus chemotherapy group, and 79 (49%) of 160 patients in the chemotherapy alone group. INTERPRETATION: This is the first prospective phase 3 trial to show the benefit of anti-PD-1 antibody plus chemotherapy in patients with EGFR-mutated NSCLC who progressed on treatment with tyrosine-kinase inhibitors. Compared with chemotherapy alone, sintilimab combined with pemetrexed and cisplatin showed significant and clinically meaningful improvement of progression-free survival with an optimal safety profile. Sintilimab plus IBI305 plus chemotherapy continued to show progression-free survival benefit compared with chemotherapy alone in this second interim analysis with an additional 8-month follow-up. FUNDING: National Natural Science Foundation of China, Shanghai Municipal Science & Technology Commission Research Project, and Innovent Biologics. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Sintilimab plus bevacizumab biosimilar IBI305 and chemotherapy for patients with EGFR-mutated non-squamous non-small-cell lung cancer who progressed on EGFR tyrosine-kinase inhibitor therapy (ORIENT-31): first interim results from a randomised, double-blind, multicentre, phase 3 trial.

BACKGROUND: VEGF inhibitors can enhance the efficacy of immunotherapy. However, despite high initial response rates, almost all patients eventually develop treatment resistance to EGFR tyrosine-kinase inhibitors. We aimed to evaluate the efficacy and safety of sintilimab with or without IBI305 plus pemetrexed and cisplatin, compared with pemetrexed and cisplatin alone, for the treatment of patients with locally advanced or metastatic EGFR-mutated non-small-cell lung cancer (NSCLC) who had disease progression after receiving EGFR tyrosine-kinase inhibitor therapy. METHODS: This randomised, double-blind, multicentre, phase 3 trial was conducted at 52 hospitals in China. Eligible participants were adults aged 18-75 years with locally advanced or metastatic NSCLC and EGFRmut who progressed after receiving a EGFR tyrosine-kinase inhibitor, had an Eastern Cooperative Oncology Group performance status of 0 or 1 with at least one measurable lesion, and an estimated life expectancy of at least 3 months. Participants were randomly assigned (1:1:1) to receive sintilimab (200 mg) plus IBI305 (15 mg/kg) plus pemetrexed (500 mg/m2) and cisplatin (75 mg/m2), sintilimab plus pemetrexed and cisplatin, or pemetrexed and cisplatin (chemotherapy alone) using block randomisation with stratification according to sex and presence or absence of brain metastases. All study drugs were administered intravenously on day 1 of each cycle, once every 3 weeks. Except for cisplatin, which was only given in the first four cycles, treatment was given for 24 months or until disease progression, intolerable toxic effects, withdrawal of consent, death, or other protocol-specified conditions, whichever occurred first. The primary endpoint was progression-free survival in the intention-to-treat population. We herein report the first planned interim analysis, with progression-free survival results for the comparison between sintilimab plus IBI305 plus chemotherapy versus chemotherapy alone. The progression-free survival results for the sintilimab plus pemetrexed and cisplatin group are immature and not reported here. This study is registered with ClinicalTrials.gov, NCT03802240 (recruiting). FINDINGS: Between July 11, 2019, and July 31, 2021, 936 patients were screened and 444 were randomly assigned (148 to the sintilimab plus IBI305 plus chemotherapy group, 145 to the sintilimab plus chemotherapy group, and 151 to the chemotherapy alone group). Data cutoff for this interim analysis was July 31, 2021. After a median follow-up of 9·8 months (IQR 4·4-13·3), progression-free survival was significantly longer in the sintilimab plus IBI305 plus chemotherapy group versus the chemotherapy alone group (median 6·9 months [95% CI 6·0-9.3] vs 4·3 months [4·1-5·4]; hazard ratio 0·46 [0·34-0·64]; p<0·0001). The most common grade 3 or 4 treatment-related adverse events were decreased neutrophil count (30 [20%] in the sintilimab plus IBI305 plus chemotherapy group vs 26 [18%] in the sintilimab plus chemotherapy group vs 27 [18%] in the chemotherapy alone group), decreased white blood cell count (17 [11%] vs 12 [8%] vs 13 [9%]), and anaemia (18 [12%] vs ten [7%] vs 15 [10%]). Potentially treatment-related deaths occurred in six patients (intestinal obstruction, gastrointestinal haemorrhage, and myelosuppression in one patient each, and three deaths of unknown cause) in the sintilimab plus IBI305 plus chemotherapy group, and in one patient in the chemotherapy alone group (unknown cause). INTERPRETATION: In this interim analysis, sintilimab plus IBI305 plus cisplatin and pemetrexed was generally efficacious and well tolerated in patients with EGFR-mutated NSCLC who progressed after receiving EGFR tyrosine-kinase inhibitor therapy. FUNDING: Innovent Biologics and the National Natural Science Foundation of China. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Furmonertinib (AST2818) versus gefitinib as first-line therapy for Chinese patients with locally advanced or metastatic EGFR mutation-positive non-small-cell lung cancer (FURLONG): a multicentre, double-blind, randomised phase 3 study.

BACKGROUND: Furmonertinib (AST2818) is an irreversible, selective, third-generation EGFR tyrosine-kinase inhibitor. We aimed to investigate the efficacy and safety of furmonertinib versus the first-generation EGFR tyrosine-kinase inhibitor gefitinib as first-line treatment in patients with EGFR mutation-positive locally advanced or metastatic non-small-cell lung cancer (NSCLC). METHODS: The FURLONG study is a multicentre, double-blind, randomised, phase 3 study done in 55 hospitals across mainland China. We enrolled patients who were aged 18 years or older and had histologically confirmed, locally advanced or metastatic, stage IIIB, IIIC, or IV unresectable NSCLC with EGFR exon 19 deletions or exon 21 Leu858Arg mutation on tissue biopsy confirmed by a central laboratory. Eligible patients were stratified according to EGFR mutation (exon 19 deletions or exon 21 Leu858Arg) and CNS metastases (with or without) and randomly assigned (1:1) to receive either oral furmonertinib (80 mg/day) or oral gefitinib (250 mg/day) in 21-day cycles until disease progression, the occurrence of intolerable toxicities, withdrawal of consent, or other discontinuation reasons judged by the investigators. Investigators, clinicians, participants, independent review centre (IRC) members, the sponsor, and those analysing the data were all masked to treatment allocation. The primary endpoint was IRC-assessed progression-free survival and, along with safety, was analysed in the full analysis set, which comprised all randomly assigned patients who had received at least one dose of study drug. This study is registered with ClinicalTrials.gov, NCT03787992, and is ongoing for survival follow-up. FINDINGS: Between May 30, 2019, and Dec 5, 2019, 750 patients were screened, of whom 358 were randomly assigned to receive either furmonertinib and gefitinib-matching placebo (n=178) or gefitinib and furmonertinib-matching placebo (n=180). 178 patients randomly assigned to furmonertinib and 179 patients randomly assigned to gefitinib were treated and were included in the full analysis set. Median follow-up was 21·0 months (IQR 18·0-23·5) in the furmonertinib group and 21·0 months (18·0-23·5) in the gefitinib group. Median IRC-assessed progression-free survival was 20·8 months (95% CI 17·8-23·5) in the furmonertinib group and 11·1 months (9·7-12·5) in the gefitinib group (hazard ratio 0·44, 95% CI 0·34-0·58; p<0·0001). Treatment-related adverse events of a grade 3 or more occurred in 20 (11%) of 178 patients in the furmonertinib group and in 32 (18%) of 179 patients in the gefitinib group. Treatment-related serious adverse events were reported in ten (6%) patients in the furmonertinib group and in 11 (6%) patients in the gefitinib group. Ten (6%) patients in the furmonertinib group and three (2%) patients in the gefitinib group died due to adverse events, which were all judged to be possibly unrelated to study treatment by the investigators. INTERPRETATION: Furmonertinib showed superior efficacy compared with gefitinib as first-line therapy in Chinese patients with EGFR mutation-positive NSCLC, along with an acceptable safety profile without new signals. Furmonertinib is a new potential treatment option for this population. FUNDING: Shanghai Allist Pharmaceuticals and the China National Major Project for New Drug Innovation. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

High Visceral Fat in Female Breast Cancer Patients Correlates with the Risk of Progression after Adjuvant Chemotherapy.

RATIONALE: Clinical and epidemiological evidence indicate that obesity is associated with the risk and progression of breast cancer. Body mass index (BMI) as a measure of adiposity does not precisely describe individual body composition and adipose tissue distribution. We aimed to investigate the association between body composition and the efficiency of adjuvant chemotherapy as well as post-treatment progress among female breast cancer patients. METHODS: Participants included 199 females with stage I-III breast cancer. Body composition, including body fat mass, visceral fat level, and skeletal muscle mass, was assessed based on the bioelectrical impedance analysis (BIA). The Kaplan-Meier survival curves, log-rank test, and Cox proportional-hazards model were used to estimate the effects of body composition as prognostic factors on survival. RESULTS: Postmenopausal women had a higher proportion of visceral fat compared to premenopausal women (64% vs. 33.87%, P < 0.001). Compared with those with normal visceral fat level, patients with high visceral fat level were older (P < 0.001), had higher body fat mass (p < 0.001), skeletal muscle mass (P = 0.013), minerals (P = 0.011), protein (P = 0.036), triglycerides (P = 0.038), cholesterol (P = 0.022), and low-density lipoprotein cholesterol (LDL-C) (P = 0.015). A more prolonged disease-free survival (DFS) was noted in patients with a normal visceral fat level as compared to patients with a high visceral fat level (hazard ratio [HR] 1.9, 95% CI 1-3.5; adjusted HR 1.77, 95% CI 0.932-3.36). CONCLUSIONS: A high visceral fat level in female patients with breast cancer is associated with a shorter DFS after adjuvant chemotherapy. Body composition alongside BIA provides a quick and noninvasive approach to identify breast cancer patients with a higher risk of cancer progression.

The clinical application value of the extracellular-water-to-total-body-water ratio obtained by bioelectrical impedance analysis in people with advanced cancer.

OBJECTIVES: Body-composition analysis using bioelectrical impedance analysis is gradually becoming more widely used in clinical practice. The ratio of extracellular water (ECW) to total body water (TBW) is thought to be related to the prognosis of a variety of diseases. However, its performance in people with advanced cancer deserves further discussion. METHODS: A retrospective analysis was performed on 784 people with advanced cancer. Anthropometric indicators, serologic indicators, nutritional status, health-related quality of life, and body composition were analyzed. Participants were grouped into two groups according to ECW/TBW ratio. We used t tests and χ2 tests to analyze differences between the groups. Univariate and multivariate Cox regressions were conducted to analyze the factors influencing overall survival. Logistic regression was used to analyze the related factors of malnutrition, and linear regression for factors of health-related quality of life. RESULTS: Age, body mass index, Patient-Generated Subjective Global Assessment score, Karnofsky Performance Status questionnaire score, skeletal muscle mass index, and fat-free mass index were statistically different between the non-overhydrated and overhydrated groups. Univariate and multivariate Cox regression models showed that an ECW/TBW ≥ 0.40 is a risk factor for poor prognosis in people with advanced cancer (hazard ratio = 1.511; 95% confidence interval, 1.103-2.070; P = 0.010). Subgroup analyses were next conducted according to tumor type, with ECW/TBW ≥ 0.40 emerging as a risk factor for poor prognosis for people with advanced breast cancer and advanced gastric cancer. Logistic regression showed that ECW/TBW ≥ 0.40 is a risk factor for malnutrition in people with advanced cancer (odds ratio = 1.988; 95% confidence interval, 1.049-3.767; P = 0.035). The univariate and multivariate linear regression models showed that the ECW/TBW ratio is an influencing factor for health-related quality of life in the domains of physical functioning, role functioning, and constipation. CONCLUSION: We found that in people with cancer, an ECW/TBW ≥ 0.40 was a risk factor for malnutrition and lower health-related quality of life, and in people with advanced cancer, it was a risk factor for poor prognosis.

Sintilimab plus a bevacizumab biosimilar (IBI305) versus sorafenib in unresectable hepatocellular carcinoma (ORIENT-32): a randomised, open-label, phase 2-3 study.

BACKGROUND: China has a high burden of hepatocellular carcinoma, and hepatitis B virus (HBV) infection is the main causative factor. Patients with hepatocellular carcinoma have a poor prognosis and a substantial unmet clinical need. The phase 2-3 ORIENT-32 study aimed to assess sintilimab (a PD-1 inhibitor) plus IBI305, a bevacizumab biosimilar, versus sorafenib as a first-line treatment for unresectable HBV-associated hepatocellular carcinoma. METHODS: This randomised, open-label, phase 2-3 study was done at 50 clinical sites in China. Patients aged 18 years or older with histologically or cytologically diagnosed or clinically confirmed unresectable or metastatic hepatocellular carcinoma, no previous systemic treatment, and a baseline Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 were eligible for inclusion. In the phase 2 part of the study, patients received intravenous sintilimab (200 mg every 3 weeks) plus intravenous IBI305 (15 mg/kg every 3 weeks). In the phase 3 part, patients were randomly assigned (2:1) to receive either sintilimab plus IBI305 (sintilimab-bevacizumab biosimilar group) or sorafenib (400 mg orally twice daily; sorafenib group), until disease progression or unacceptable toxicity. Randomisation was done using permuted block randomisation, with a block size of six, via an interactive web response system, and stratified by macrovascular invasion or extrahepatic metastasis, baseline α-fetoprotein, and ECOG performance status. The primary endpoint of the phase 2 part of the study was safety, assessed in all patients who received at least one dose of study drug. The co-primary endpoints of the phase 3 part of the study were overall survival and independent radiological review committee (IRRC)-assessed progression-free survival according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 in the intention-to-treat population. The study is registered with ClinicalTrials.gov, NCT03794440. The study is closed to new participants and follow-up is ongoing for long-term outcomes. FINDINGS: Between Feb 11, 2019 and Jan 15, 2020, we enrolled 595 patients: 24 were enrolled directly into the phase 2 safety run-in and 571 were randomly assigned to sintilimab-bevacizumab biosimilar (n=380) or sorafenib (n=191). In the phase 2 part of the trial, 24 patients received at least one dose of the study drug, with an objective response rate of 25·0% (95% CI 9·8-46·7). Based on the preliminary safety and activity data of the phase 2 part, in which grade 3 or worse treatment-related adverse events occurred in seven (29%) of 24 patients, the randomised phase 3 part was started. At data cutoff (Aug 15, 2020), the median follow-up was 10·0 months (IQR 8·5-11·7) in the sintilimab-bevacizumab biosimilar group and 10·0 months (8·4-11·7) in the sorafenib group. Patients in the sintilimab-bevacizumab biosimilar group had a significantly longer IRRC-assessed median progression-free survival (4·6 months [95% CI 4·1-5·7]) than did patients in the sorafenib group (2·8 months [2·7-3·2]; stratified hazard ratio [HR] 0·56, 95% CI 0·46-0·70; p<0·0001). In the first interim analysis of overall survival, sintilimab-bevacizumab biosimilar showed a significantly longer overall survival than did sorafenib (median not reached [95% CI not reached-not reached] vs 10·4 months [8·5-not reached]; HR 0·57, 95% CI 0·43-0·75; p<0·0001). The most common grade 3-4 treatment-emergent adverse events were hypertension (55 [14%] of 380 patients in the sintilimab-bevacizumab biosimilar group vs 11 [6%] of 185 patients in the sorafenib group) and palmar-plantar erythrodysaesthesia syndrome (none vs 22 [12%]). 123 (32%) patients in the sintilimab-bevacizumab biosimilar group and 36 (19%) patients in the sorafenib group had serious adverse events. Treatment-related adverse events that led to death occurred in six (2%) patients in the sintilimab-bevacizumab biosimilar group (one patient with abnormal liver function, one patient with both hepatic failure and gastrointestinal haemorrhage, one patient with interstitial lung disease, one patient with both hepatic faliure and hyperkalemia, one patient with upper gastrointestinal haemorrhage, and one patient with intestinal volvulus) and two (1%) patients in the sorafenib group (one patient with gastrointestinal haemorrhage and one patient with death of unknown cause). INTERPRETATION: Sintilimab plus IBI305 showed a significant overall survival and progression-free survival benefit versus sorafenib in the first-line setting for Chinese patients with unresectable, HBV-associated hepatocellular carcinoma, with an acceptable safety profile. This combination regimen could provide a novel treatment option for such patients. FUNDING: Innovent Biologics. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

A Pilot Phase 1 Study of Intrathecal Pemetrexed for Refractory Leptomeningeal Metastases From Non-small-cell Lung Cancer.

Objectives: We aim to determine the feasibility, safety, maximally tolerated dose (MTD), recommended dose and potential anti-tumor activity of intrathecal pemetrexed (IP). Materials and Methods: Lung adenocarcinoma patients with recurrent or progressive leptomeningeal metastases (LM) after intrathecal chemotherapy were recruited. IP dose was escalated from 10 mg. A minimum of three patients and a maximum of six were enrolled in each cohort. Schedule protocol was IP twice per week for 2 weeks in induction therapy, followed by once per week for 4 weeks in consolidation therapy. Serial samples of plasma and cerebrospinal fluid (CSF) were obtained for pharmacokinetic studies. Results: Thirteen patients were enrolled between March 2017 and July 2018. EGFR driver oncogene was identified in most of the patients. Severe adverse events (AEs) were encountered in 31% (4/13) of the cases, including myelosuppression, radiculitis, and elevation of hepatic aminotransferases (EHA). Study protocol was revised due to lethal myelosuppression. Following protocol revision, vitamin B12 and folic acid supplementation was given at the beginning of treatment, and myelosuppression was well-controlled. Dose-limiting toxicities (DLT) were myelosuppression, radiculitis, and EHA. Two patients (2/2) developed dose-limiting myelosuppression at 15 mg level. One patient (1/6) experienced dose-limiting radiculitis and EHA at 10 mg level. MTD was 10 mg. Response rate was 31% (4/13) and disease control rate was 54% (7/13). The drug concentration showed a decreasing trend in serial CSF samples following each IP. After IP, the peak plasma concentration was reached at 4 h in two cases, 6 h in two cases, 9 h in one case, and 12 h in one case, respectively. Conclusion: Pemetrexed was appropriate for intrathecal administration. IP at 10 mg dose in combination with vitamin supplementation on the schedule of 1-2 times per week showed controllable toxicity and good efficacy. This regimen paves the way for subsequent clinical trial. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT03101579.

Low-dose radiation induces renal SOD1 expression and activity in type 1 diabetic mice.

PURPOSE: Oxidative stress plays a critical role in the pathogenesis of diabetic nephropathy (DN). As an antioxidant, superoxide dismutase (SOD)-1 deficiency exacerbates but SOD1 supplementation prevents diabetes-induced renal damage. Previously, we have demonstrated that repetitive exposure to low-dose radiation (LDR) at 25 mGy significantly prevents DN. Whether this prevention is related to SOD1 expression and activity remains unknown. The aim of the present study was to explore the effects of different methods of LDR treatment on SOD1 expression and activity in the kidneys of diabetic mice. MATERIALS AND METHODS: C57BL/6J mice were induced with type 1 diabetes using streptozotocin (STZ). Diabetic mice were irradiated with whole-body X-rays at either a single dose of 25 mGy or 75 mGy, or three doses of 25 mGy and then sacrificed at different times. Body weight, blood glucose level, and renal SOD1 expression and activity were measured. RESULTS: LDR had no impact on the body weights or blood glucose levels of the mice in either the normal or diabetic groups. A single exposure of LDR at 25 mGy did not preserve renal SOD1 expression and activity in diabetic mice, but a single exposure of LDR at 75 mGy or three exposures of LDR at 25 mGy could preserve them. CONCLUSION: The stimulation of renal SOD1 expression and activity by a single or cumulative LDR of 75 mGy may be one of the preventive mechanisms of DN observed in the previous study.

Antitumor effects of a purified polysaccharide from Rhodiola rosea and its action mechanism.

In the last three decades, numerous polysaccharides and polysaccharide-protein complexes have been isolated from plant or animal and used as a promising source of therapeutic agents for cancer. In this study, we prepared a homogeneous polysaccharide (RRP-ws) from Rhodiola rosea and tested its immunomodulation and anti-cancer activity in vitro and in vivo experiments using Sarcoma 180 (S-180) cells. Preliminary physicochemical analysis identified that RRP-ws was composed of Glc, Gal, Man and Rha with a relative molar ratio of 4.2:2.4:1.6:1.0, and contained 95.14% of total carbohydrate, 2.08% of protein and no sulfate. In vitro experiment showed that RRP-ws exerted a direct cytotoxic effect on the growth of S-180 cells. In vivo experiment, RRP-ws could inhibit tumor growth of S-180 tumor transplanted in mice, and increase the relative spleen/thymus indexes and body weight. Furthermore, RRP-ws also increased the production of IL-2, TNF-α and IFN-γ in serum, and elevated the ratio of CD4+/CD8+ on peripheral blood T-lymphocyte in tumor bearing mice. The overall findings indicated that RRP-ws could be used as a novel promising immunotherapeutic agent in cancer treatment.