Three‐Year Follow‐Up of the Phase II Trial for Resectable Non‐Small‐Cell Lung Cancer Treated With Perioperative Sintilimab and Neoadjuvant Anlotinib Plus Chemotherapy: TD‐NeoFOUR Trial

ABSTRACT

Background

Lung cancer is a leading cause of cancer‐related deaths. Perioperative therapies, including neoadjuvant chemo‐immunotherapy, have improved outcomes, but combining them with antiangiogenic drugs may offer further benefits. This study evaluated the 3‐year efficacy and safety of neoadjuvant sintilimab, anlotinib, and chemotherapy in resectable NSCLC patients from the TD‐NeoFOUR trial.

Methods

The study included 45 patients who received neoadjuvant treatment with anlotinib, sintilimab, and platinum‐based chemotherapy. The primary endpoint was overall survival (OS), and the secondary endpoint was event‐free survival (EFS). The Kaplan–Meier method was used to estimate survival curves, and the log‐rank test was used to compare survival rates between subgroups.

Results

As of November 11, 2024, all 45 patients had been followed up for a median of 35.7 months. The estimated 3‐year EFS rate was 84.3%, and the estimated 3‐year OS rate was 86.7%. Subgroup analysis showed that patients achieving pathological complete response (pCR) and major pathological response (MPR) had significantly higher 3‐year EFS and OS rates compared to patients with non‐pCR and non‐MPR. No new treatment‐related adverse events (TRAEs) occurred during the 3‐year follow‐up, indicating the long‐term safety of the treatment regimen.

Conclusions

The combination of neoadjuvant chemo‐immunotherapy and antiangiogenic drugs significantly improved long‐term survival outcomes in patients with resectable NSCLC. This treatment regimen is a promising option for improving prognosis in this patient population.

This three‐year survival follow‐up of resectable NSCLC patients in the TD‐NeoFOUR trial showed that neoadjuvant anlotinib, sintilimab, and chemotherapy achieved an estimated 3‐year EFS rate of 84.3% and an OS rate of 86.7%, demonstrating significant improvement over conventional neoadjuvant chemoimmunotherapy. These findings provide high‐level evidence supporting the clinical efficacy of this innovative quadruplet neoadjuvant regimen in resectable NSCLC.

1. Introduction

Lung cancer is still the most commonly diagnosed cancer and the leading cause of cancer death worldwide. Lung cancer accounted for nearly 12.5% of new cancer cases and 18.7% of cancer deaths globally in 2022 [1]. The situation is similar in China. According to the latest data released by the National Cancer Center in 2024, lung cancer still tops the list of cancer incidence and mortality rates in China [2].

Although surgery is acknowledged as the preferred therapeutic approach for non‐small cell lung cancer (NSCLC), only 25%–30% of patients are deemed eligible for potentially curative surgical resection [3]. Furthermore, it has been observed that more than 50% of patients experienced either local recurrence or distant metastasis within a 5‐year postoperative period [4]. Therefore, perioperative systemic treatment of NSCLC assumes significant importance.

Early studies have demonstrated that neoadjuvant chemo‐immunotherapy significantly improved pCR and MPR rates, and also evidenced favorable outcomes in improving patients' survival duration [5, 6]. For instance, the TD‐FOREKNOW trial achieved a pCR rate of 32.6% and an MPR rate of 65.1% [7]; the CheckMate‐816 trial showed pCR and MPR rates of 24% and 36.9% [8]; the KeyNote‐671 trial reported 18.1% and 30.2% [9]. In terms of survival rates, the 3‐year EFS rates for CheckMate‐816 and KeyNote‐671 were 56% [8] and 54% [10], while the 3‐year OS rates were 73% [8] and 71% [10], respectively. However, the therapeutic efficacy of the treatment under discussion exhibits significant potential for enhancement [11].

Pathological tumor vasculature is a hallmark of cancer [12], facilitating tumor metastasis, immunosuppression, and drug resistance [13]. The combination of immune checkpoint inhibitors (ICIs) with antiangiogenic drugs exhibits synergistic effects [14], offering significant therapeutic benefits across solid tumors such as renal cell carcinoma [15], hepatocellular carcinoma [16], endometrial carcinoma [17], and ovarian cancer [18].

TD‐NeoFOUR trial was the first phase II clinical trial using an antiangiogenic drug in patients with resectable NSCLC in combination with neoadjuvant chemo‐immunotherapy. The pCR rate and MPR rate of the intention‐to‐treat (ITT) population were 57.8% and 66.7%, respectively; these were significantly improved compared with the previous neoadjuvant immunotherapy alone [19]. In order to verify the permanence and stability of the therapeutic effect, we conducted this 3‐year follow‐up of the ITT population from the TD‐NeoFOUR trial.

2. Materials and Methods

2.1. Patients and Study Design

Eligible patients were all 45 participants from the ITT population in TD‐NeoFOUR. Inclusion and exclusion criteria have been previously described [10]. Briefly, eligible participants were adults aged 18–75 with histologically confirmed resectable NSCLC. Patients must have adequate organ function, an ECOG performance status of 0 or 1, and at least one measurable lesion according to RECIST 1.1. Adequate lung function was deemed necessary for resection. Exclusion criteria included patients with unresectable or metastatic disease, ROS1/ALK genetic alterations, active autoimmune diseases (except stable endocrine disorders or localized skin conditions), recent immunosuppressive therapy use, or prior chemotherapy/immunotherapy/antiangiogenic treatment. The study was conducted in accordance with the Declaration of Helsinki and Good Clinical Practice. All participants provided written informed consent before enrollment, and the study followed the CONSORT reporting guidelines. The trial was registered on ClinicalTrials.gov with the number NCT05400070.

Patients received anlotinib (Chia Tai Tianqing Pharmaceutical Group Co.) 10 mg orally once on Days 1–14 of each treatment cycle in combination with sintilimab (Innovent [Suzhou] Biopharmaceutical Co. Ltd., China) 200 mg intravenously every 3 weeks (administered on Day 1 of each cycle for 3 cycles), along with concurrent standard neoadjuvant platinum‐based doublet chemotherapy. Surgery was performed within 4–6 weeks after the last neoadjuvant treatment, followed by sintilimab maintenance therapy (200 mg every 3 weeks) initiated within 6 weeks postoperatively for up to 1 year. During treatment, anlotinib was discontinued in cases of hemoptysis; for ≥ Grade 3 treatment‐related adverse events (TRAEs), the anlotinib dose was reduced to 8 mg/day and chemotherapy doses were decreased by 25%, while sintilimab dose adjustments were prohibited. If a single drug was suspended due to adverse events (AEs), other medications were continued. Treatment persisted until intolerable toxicity occurred or patient consent was withdrawn. Patients with disease progression could undergo surgery or receive standard chemoradiotherapy (SOC‐CRT) (note: All timepoints were calculated based on Day 1 of each treatment cycle).

2.2. Efficacy

The main contents of the follow‐up included the progression of the disease and the results of recent examinations. The primary endpoint was overall survival (OS) and the secondary endpoint was EFS. OS was defined as the time from enrollment to death from any cause. EFS was defined as the interval from enrollment to the earliest occurrence of disease progression, local, or distant recurrence.

2.3. Safety

AEs were assessed using National Cancer Institute Common Terminology Criteria for AEs version 5.0. TRAE were AEs considered by the investigator to be related to chemotherapy, sintilimab, or anlotinib. Immune‐related AEs (irAEs) were defined as drug‐related adverse reactions that are associated with immune mechanisms, including immune‐related pneumonitis, myocarditis, and endocrine diseases. AEs were evaluated 30 days after the final dose.

2.4. Statistical Analysis

Kaplan–Meier method was used to calculate OS and EFS, and to estimate the survival curve. The chi‐square test was used to evaluate the relationship between the tumor microenvironment (TME) and irAEs, Grade 3–4 TRAEs. Log‐rank test was used to compare the OS and EFS rate between the subgroups. The p values were two‐sided; 0.05 was considered as the significance level. All statistical analyses were performed using SPSS software (version 27.0; IBM Corp., Armonk, NY, USA).

3. Results

3.1. Patients Baseline and Treatment Characteristics

The ITT population comprised 45 patients, including 28 (62.2%) aged over 60 years, 41 males (91.1%), 34 squamous cell carcinoma (SCC) cases (75.6%), and 37 current or former smokers (82.2%). Detailed demographic and baseline characteristics are shown in Table 1.

TABLE 1.

Demographics and baseline characteristics of the intention‐to‐treat population (N = 45).

Variable	Value
Age (years)
Median (range)	60 (52–74)
≥ 60	28 (62.2)
Sexual
Male	41 (91.1)
Female	4 (8.9)
Histological status
Squamous cell carcinoma	34 (75.6)
Adenocarcinoma	10 (22.2)
Sarcomatoid carcinoma	1 (2.2)
Smoking situation	1 (2.8)
Smoker	36 (80)
Nonsmoker	9 (20)
Clinical stage
II A	4 (8.8)
II B	8 (17.8)
III A	15 (33.3)
III B	18 (2.2)

Note: Data are expressed as number (%) unless otherwise specified.

During neoadjuvant treatment, one patient discontinued therapy due to Grade 3 transaminase elevation and Grade 4 myelosuppression, while three patients refused surgery. Among the 41 patients in the per‐protocol (PP) population, 33 completed all three planned cycles of neoadjuvant therapy, and 8 underwent surgery after two cycles. Six patients discontinued adjuvant treatment due to AEs.

3.2. Efficacy

As of November 11, 2024, all patients from the ITT population had been followed up. The minimum follow‐up duration was 20.3 months. The median follow‐up duration was 35.7 months. Among these 45 patients, 6 of them passed away. Four patients were lost to follow‐up. Four patients developed progressive diseases. And 35 people are in stable condition with no disease progression. The three‐year estimated EFS rate of the ITT population was 84.3% (95% confidence interval [CI], 69.7%–92.2%) (Figure 1A). And the estimated 3‐year OS rate was 86.7% (95% CI, 71.1%–94.2%) (Figure 1B). The median EFS and OS were both not reached.

FIGURE 1.

Kaplan–Meier survival curve of the ITT population. (A) Kaplan–Meier curve of EFS in the ITT population. (B) Kaplan–Meier curve of OS in the ITT population. EFS, event‐free survival; ITT, intention‐to‐treat; OS, overall survival.

3.3. Subgroup Analysis

The pathological response may serve as a predictive biomarker. We categorized the patients into pCR and non‐pCR groups, as well as MPR and non‐MPR groups, based on their postoperative pathological results. In the ITT population, 26 patients achieved pCR and 30 achieved MPR. Among the pCR group, one patient died of COVID‐19 infection. Concurrently, two fatalities were observed in the MPR group, with one of the deceased having experienced disease progression prior to death. The estimated 3‐year EFS rate and OS rate were 96.2% (95% CI, 75.1%–99.5%) in the pCR group, and 93.3% (95% CI, 75.6%–98.3%) in the MPR group. Meanwhile, the non‐pCR group had an estimated three‐year EFS rate of 68.0% (95% CI, 42.1%–84.2%) and an estimated 3‐year OS rate of 73.7% (95% CI, 47.9%–88.1%) (Figure 2A,B). For the non‐MPR group, the estimated 3‐year EFS rate was 66.0% (95% CI, 36.5%–84.3%), and the estimated 3‐year OS rate was 64.2% (95% CI, 33.3%–83.7%) (Figure 2C,D). Patients with pCR exhibited significantly higher estimated three‐year EFS and OS rates compared to non‐pCR (EFS, log‐rank p = 0.010; OS, log‐rank p = 0.027). Similar results were observed for patients with MPR and non‐MPR (EFS, log‐rank p = 0.018; OS, log‐rank p = 0.020). Overall, patients who achieved pCR and MPR exhibited a favorable prognosis.

FIGURE 2.

EFS and OS of subgroups with different pathological responses. (A) The EFS in patients with pCR and non‐pCR. (B) The OS in patients with pCR and non‐pCR. (C) The EFS in patients with MPR and non‐MPR. (D) The OS in patients with MPR and non‐MPR. EFS, event‐free survival; MPR, major pathological response; OS, overall survival; pCR, pathological complete response.

We also conducted subgroup analyses based on patients' age, pathological type, smoking status, and TNM staging. Among the ITT population, 28 individuals aged 60 or older and 17 under 60; 34 with SCC, 10 with adenocarcinoma (ADC), and 1 with sarcomatoid carcinoma; 36 were smokers and 9 were nonsmokers; 12 were in Stage IIA or IIB, and 33 were in Stage IIIA or IIIB. We found that patients over 60 years old had a significantly higher estimated 3‐year OS rate than those under 60 years old (log‐rank, p = 0.044) (Figure 3B). However, the estimated 3‐year EFS rate showed no statistical difference between patients over and under 60 years old. Also, no statistically significant differences were observed in the estimated 3‐year EFS and OS rates between SCC and ADC, smokers and nonsmokers, Stage II and Stage III disease (Figure 3A,C–H).

FIGURE 3.

EFS and OS of subgroups defined by demographics and baseline characteristics within the ITT population. (A) The EFS in patients older than 60 and younger than 60. (B) The OS in patients older than 60 and younger than 60. (C) The EFS in patients with SCC and ADC. (D) The OS in patients with SCC and ADC. (E) The EFS in smoking and nonsmoking patients. (F) The OS in smoking and nonsmoking patients. (G) The EFS in patients with TNM Stages II and III. (H) The OS in patients with TNM Stages II and III. ADC, adenocarcinoma; EFS, event‐free survival; ITT, intention‐to‐treat; MPR, major pathological response; OS, overall survival; pCR, pathological complete response; SCC, squamous cell carcinoma.

3.4. Safety

During the neoadjuvant treatment period, 100.0% (45/45) of patients experienced treatment‐TRAEs of any grade, including 25 patients with Grade 3 or 4 TRAEs and 7 patients with immune‐related adverse events (irAEs). In the adjuvant treatment period, irAEs occurred in 14 patients, including Grade 3 irAEs in 7 patients. In addition, no new TRAEs occurred in the 3‐year follow‐up. The relationship between TME of baseline samples and irAEs and Grade 3–4 TRAEs was mainly concerned.

3.5. TME Modulation and Treatment Safety

TD‐NeoFOUR trial revealed that the TME was significantly modulated in patients achieving pCR, with decreased infiltration of Tregs and increased infiltration of CD8+ T cells and M1 macrophages [19]. To investigate whether TME modifications correlate with AEs occurrence, we performed an expanded safety analysis incorporating TME profiling data. Vascular normalization indicators (VEGF+ cells, CD31+/NG2+ cell ratio and perivascular CD8+ or CD4+ T cells) and immune cell indicators (Treg cells, M1 macrophages, M2 macrophages, PD‐1 + CD8+ T cells and CD39 + CD8+ T cells) were analyzed. However, the association between indicators and Grade 3–4 AEs (Table 2) or irAEs (Table 3) was not found (p > 0.05, chi‐square test).

TABLE 2.

Association analysis between tumor microenvironment and Grade 3–4 AEs in baseline samples.

	TRAEs (Grade 3 or 4)		p
	Yes	No
VEGF‐positive cells (n = 9)			0.524
High	4	1
Low	2	2
CD31+/NG2+ cell ratios (n = 14)			0.266
High	6	1
Low	3	4
Perivascular infiltration of CD4+ T cells (n = 16)			0.608
High	4	4
Low	6	2
CD39+CD8+ T cells (n = 9)			0.524
High	2	2
Low	4	1
M1 macrophage (n = 12)			1.000
High	4	2
Low	4	2
PD1+CD8+/CD8+ T cells (n = 8)
High	3	1	1.000
Low	2	2
CD4+Foxp3+ Treg cells (n = 11)			0.545
High	3	3
Low	4	1
Perivascular infiltration of CD8+ T cells (n = 8)			1.000
High	3	1
Low	3	1
M2 macrophage (n = 12)			1.000
High	4	2
Low	3	3

TABLE 3.

Association analysis between tumor microenvironment and irAEs in baseline samples.

	irAEs		p
	Yes	No
VEGF‐positive cells (n = 9)			NA
High	1	4
Low	0	4
CD31+/NG2+ cell ratios (n = 14)			0.266
High	4	3
Low	1	6
Perivascular infiltration of CD4+ T cells (n = 16)			1.000
High	2	6
Low	3	5
CD39+CD8+ T cells (n = 9)			1.000
High	1	3
Low	1	4
M1 macrophage (n = 12)			1.000
High	2	4
Low	2	4
PD1+CD8+/CD8+ T cells (n = 8)			NA
High	1	3
Low	0	4
CD4+Foxp3+ Treg cells (n = 11)			1.000
High	2	4
Low	1	4
Perivascular infiltration of CD8+ T cells (n = 8)			1.000
High	1	3
Low	1	3
M2 macrophage (n = 12)			0.545
High	3	3
Low	1	5

4. Discussion

In this study, we have evaluated the efficacy of the combination of neoadjuvant chemo‐immunotherapy and antiangiogenic drugs in patients with resectable NSCLC and, for the first time, provided a mean follow‐up of 35.7 months.

In previously conducted neoadjuvant anti‐PD‐1/PD‐L1 immunotherapy clinical trials, the 3‐year EFS rates were 56% in CheckMate‐816, 54.3% in KeyNote‐671, and 60.1% in AEGEAN [20]. Meanwhile, the 3‐year OS rate achieved in CheckMate‐816, KeyNote‐671, and NADIM was 73%, 71.3%, and 81.9% [21]. In this 3‐year follow‐up study, we evaluated clinical outcomes for all patients from the ITT population. The estimated 3‐year EFS rate reached 84.3%, and the estimated 3‐year OS rate was 86.7%, demonstrating significant improvement compared to previous clinical trials using neoadjuvant immunotherapy combined with chemotherapy. These results indicate that relevant NSCLC patients can achieve substantial clinical benefits from this novel neoadjuvant anti‐angiogenesis therapy combined with chemoimmunotherapy, representing both an innovation and breakthrough in NSCLC neoadjuvant treatment approaches.

Among the 26 patients with pCR, one died from COVID‐19 infection without any disease progression related to lung cancer. The remaining 25 pCR patients had no disease progression or death. Two patients died in the MPR subgroup, of which one patient was the former one and another patient developed metastasis to the subaortic lymph nodes at 8.7 months and died at 10.9 months. Subgroup analysis revealed that patients achieving pCR and MPR exhibited significantly superior survival rates compared to patients with non‐pCR and non‐MPR. This might suggest that better postoperative pathological response may be associated with better prognosis in patients and also highlights the potential of postoperative pathological response as a clinical predictive indicator. In subgroup analyses encompassing age, histological type, smoking status, and TNM staging, besides the observation that the OS rate was higher in patients over 60 years old compared to those under 60, no other statistically significant differences were identified based on the current data. This may be attributable to the relatively small number of patients enrolled in the trial.

The IMpower150 trial employed the combination of atezolizumab with bevacizumab, carboplatin, and paclitaxel (ABCP regimen) for the treatment of advanced or metastatic NSCLC, and revealed a significant improvement in patient survival compared to the regimen comprising bevacizumab, carboplatin, and paclitaxel (BCP regimen), with particularly notable efficacy in patients who were EGFR mutation‐negative and had PD‐L1 expression ≥ 1% [22]. Among the three EGFR‐mutated patients included in TD‐NeoFOUR, one developed lumbar metastasis after 22.5 months and has survived to date following radiotherapy, while the other two have not experienced disease progression or death. Due to the limited number of EGFR‐mutated patients included, this follow‐up was unable to conduct a subgroup analysis of EGFR mutations. Additionally, due to the lack of data on PD‐L1 expression levels in patients, this follow‐up was unable to analyze its relationship with patient survival.

Antiangiogenic drugs improve tumor vasculature structure and function, promoting vascular normalization to enhance immune cell infiltration and reduce immunosuppressive cell infiltration; thereby altering the TME and boosting the efficacy of chemo‐immunotherapy [23]. Some studies suggested that the abundance of immune‐related cells such as CD68+ macrophages, CD8+ T cells, and regulatory T cells in TME following antiangiogenic therapy may be associated with patient prognosis, implying their potential as biomarkers for predicting clinical outcomes [24]. In this follow‐up, due to the lack of key data, we did not analyze the association between survival and immune cells in TME. The optimal predictive biomarkers remain to be further explored.

In terms of safety, no additional TRAEs occurred during the 3‐year follow‐up; indicating the long‐term safety of the combination of chemo‐immunotherapy and antiangiogenic drugs.

Several limitations existed in this 3‐year follow‐up study. The single‐arm design of the TD‐NeoFOUR trial precluded direct analysis of the relative contributions of perioperative sintilimab and neoadjuvant anlotinib, as survival rates in the ITT population can only be compared with data from other trials. The limited number of participants enrolled in the trial may impact the statistical results during subgroup analysis. The absence of key data has hindered our analysis of the correlation between predictive biomarkers of response and survival outcomes. Additionally, the trial's inclusion of only three patients with EGFR mutations and exclusion of those with ALK translocations limits the insights into these specific genetic alterations.

Based on the 3‐year follow‐up, we present the first long‐term survival data for patients with resectable NSCLC receiving neoadjuvant antiangiogenesis plus chemo‐immunotherapy. This indicates the efficacy and feasibility of the combination therapy, which could offer a new treatment option for patients with resectable NSCLC.

Author Contributions

Zhiyuan Gao: software, validation, writing – review and editing. Yajie Mao: software, validation, writing – review and editing. Yichen Sun: software, validation, writing – review and editing. Liping Tong: data curation, methodology. Honggang Liu: data curation, methodology. Tianhu Wang: data curation, formal analysis, resources. Changjian Shao: investigation, methodology, project administration, supervision, validation. Hongtao Duan: investigation, methodology, project administration, resources, supervision, validation, writing – review and editing. Xiaolong Yan: funding acquisition, methodology, project administration, resources, supervision, validation, writing – review and editing.

Conflicts of Interest

The authors declare no conflicts of interest.

Gao Z., Mao Y., Sun Y., et al., “Three‐Year Follow‐Up of the Phase II Trial for Resectable Non‐Small‐Cell Lung Cancer Treated With Perioperative Sintilimab and Neoadjuvant Anlotinib Plus Chemotherapy: TD‐NeoFOUR Trial,” Thoracic Cancer 16, no. 16 (2025): e70149, 10.1111/1759-7714.70149.

Data Availability Statement

Data will be available upon reasonable request to the corresponding author.