The efficacy, effectiveness, and safety of lanreotide autogel for the treatment of GEP-NETs in Caucasian and non-Chinese Asian populations have been well established [17, 18, 27, 28, 31]. However, there remains a lack of such data in patients of Chinese ethnicity. This retrospective study therefore aimed to describe the clinical effectiveness and safety of lanreotide autogel 120 mg in patients of Chinese ethnicity with GEP-NETs in routine clinical practice.

In this study, lanreotide autogel showed good PFS rate. The primary endpoint of PFS rate at 48 weeks was 0.82 (95% CI 0.53–0.94) and median PFS was not met in the effectiveness population. These results align with those from earlier studies demonstrating the antitumoral effect of lanreotide autogel in patients with GEP-NETs, in Caucasian, Japanese, and Korean patients [17, 18, 27, 28]. In the CLARINET trial, median PFS was not reached at 96 weeks in Caucasian patients [17], and, in patients who continued to receive lanreotide autogel during the OLE, median PFS was 38.5 months (95% CI 30.9–59.4 months) [18]. A phase II study in Japanese patients with grade 1 or grade 2 NETs treated with lanreotide autogel for 48 weeks resulted in a median PFS of 36.3 weeks (9.1 months; 95% CI 24.1–53.1 weeks) [27], while a retrospective analysis of Korean patients with GEP-NETs who were treated with lanreotide autogel showed a median PFS of 16.4 months (95% CI 9.5–23.3 months) [28]. Given that earlier studies were only performed in Caucasian and non-Chinese Asian populations, this study provides novel evidence for the antitumoral effects of lanreotide autogel in patients of Chinese ethnicity.

Serum CgA is a useful biomarker for the assessment of tumor burden and treatment response in GEP-NETs, and decreases in serum CgA have previously been demonstrated to be associated with a reduction in disease progression [32,33,34]. Therefore, the large decrease in mean serum CgA levels observed in this study suggests a biochemical response to a reduction in tumor burden and overall response to lanreotide autogel 120 mg [34]. However, in the current study, serum CgA levels were only assessed in ten patients and demonstrated high interpatient variability. Therefore, the results reported here should be interpreted with caution.

The efficacy of lanreotide autogel in controlling NET symptoms has also been previously demonstrated in Caucasian patients with carcinoid syndrome in the phase III ELECT trial and its OLE [19, 22]. In ELECT, lanreotide autogel-treated patients demonstrated significantly lower percentage of days with octreotide rescue medication and with moderate-to-severe diarrhea and/or flushing versus placebo, irrespective of prior SSA treatment [19, 22]. Similarly, in the present study, no rescue medication use was reported and, of patients with symptoms at index (N = 9), only two continued to have symptoms at week 48. However, it should be noted that ten patients overall had NET-related symptoms at week 48, eight of whom reported an absence of symptoms or unknown symptom status at index.

The safety and tolerability profile of lanreotide autogel is well described from its use in clinical trials and practice in numerous countries worldwide [17, 19, 27, 28, 35]. In the safety population of this study, a total of 20 (74.1%) patients reported TEAEs and 8 (29.6%) patients reported drug-related TEAEs. The majority of AEs, including treatment-related TEAEs, were mild or moderate (grade 1 or grade 2) and no serious TEAEs or deaths were reported. These findings align with those from studies with both Caucasian and non-Chinese Asian patients treated with lanreotide autogel in clinical and real-world settings [17,18,19, 27, 28, 35]. A retrospective analysis of Korean patients with metastatic, well-differentiated GEP-NETs treated with lanreotide in routine practice settings showed that 40.5% of patients reported an AE, all of which were grade 1 and grade 2, and the most common AE was abdominal pain (16.2%) [28]. In a phase II study of Japanese patients with unresectable or metastatic well-differentiated NETs, the most frequent AEs were injection site induration (28.1%) and pale feces (18.8%) [27]. Similarly, in a prospective, noninterventional study of patients with locally advanced, metastatic GEP-NETs in a real-world community setting in the USA, 19.2% of patients reported TEAEs, the majority of which were gastrointestinal disorders [36]. Altogether, results from the present study are in line previously published findings which found that gastrointestinal disorders, general disorders, and administration site conditions were the most frequently experienced TEAEs. These results indicate that lanreotide autogel 120 mg is generally well tolerated by patients of Chinese ethnicity in a real-world setting, with these patients typically experiencing mild or moderate AEs.

This study also provides real-world evidence for the effectiveness and safety of lanreotide autogel 120 mg in NET types that are prevalent in Asian populations but have previously been underrepresented in studies in Caucasian populations. Pancreatic NETs were the most common primary tumor type in this study, comprising 73.9% of the effectiveness population. This proportion is higher than that typically observed in Western populations, in which other primary tumor sites, such as the small intestine or midgut, are more common [37, 38]. For example, of 64,971 patients with NETs in the USA, primary tumor sites with the highest incidence were the lung (1.49 per 100,000 persons) and small intestine (1.05 per 100,000 persons); incidence of pancreatic NETs was 0.48 per 100,000 persons [38]. Whereas, in a hospital-based, nationwide, multicenter, retrospective study of Chinese patients with GEP-NETs, the most common primary sites were the pancreas (31.5%) followed by the rectum (29.6%) [39]. Similarly, in a retrospective study of Korean patients in routine practice settings and in a phase II study of Japanese patients, 48.9% and 42.9% of tumors were of pancreatic origin, respectively [27, 28]. While there is a higher proportion of pancreatic tumors in our study versus other studies in Asian populations, the results of our study nevertheless reinforce the epidemiologic differences of NETs between Asian and Caucasian populations and provides a more accurate representation of the Chinese patient population observed in clinical practice, compared with randomized controlled trials.

The present study was subject to some limitations. Firstly, the retrospective design and real-world nature of this study may have overestimated PFS rates compared with randomized controlled trials, as no central reviews of radiological images by independent physicians were performed, and criteria used to assess disease progression were not standardized between study sites. Secondly, the long-term effectiveness of lanreotide autogel could not be ascertained given the short follow-up time of 48 weeks. Furthermore, due to the small number of patients in this study, conclusions could not be drawn for subgroups of patients stratified by age, gender, tumor grade, and functional status. However, subgroup analyses are pertinent since median overall survival in patients with NETs have been reported to vary significantly according to age at diagnosis, tumor site, grade, and stage [38].