Hazard ratio of progression-free survival is an excellent predictor of overall survival in phase III randomized controlled trials evaluating the first-line chemotherapy for extensive-disease small-cell lung cancer

How is overall survival assessed in randomised clinical trials in cancer and are subsequent treatment lines considered? A systematic review

BACKGROUND

Overall survival is the "gold standard" endpoint in cancer clinical trials. It plays a key role in determining the clinical- and cost-effectiveness of a new intervention and whether it is recommended for use in standard of care. The assessment of overall survival usually requires trial participants to be followed up for a long period of time. In this time, they may stop receiving the trial intervention and receive subsequent anti-cancer treatments, which also aim to extend survival, during trial follow-up. This can potentially change the interpretation of overall survival in the context of the clinical trial. This review aimed to determine how overall survival has been assessed in cancer clinical trials and whether subsequent anti-cancer treatments are considered.

METHODS

Two searches were conducted using MEDLINE within OVID© on the 9th of November 2021. The first sought to identify papers publishing overall survival results from randomised controlled trials in eight reputable journals and the second to identify papers mentioning or considering subsequent treatments. Papers published since 2010 were included if presenting or discussing overall survival in the context of treating cancer.

RESULTS

One hundred and thirty-four papers were included. The majority of these were presenting clinical trial results (98, 73%). Of these, 45 (46%) reported overall survival as a (co-) primary endpoint. A lower proportion of papers including overall survival as a (co-) primary endpoint compared to a secondary endpoint were published in recent years. The primary analysis of overall survival varied across the papers. Fifty-nine (60%) mentioned subsequent treatments. Seven papers performed additional analysis, primarily when patients in the control arm received the experimental treatment during trial follow-up (treatment switching).

DISCUSSION

Overall survival has steadily moved from being the primary to a secondary endpoint. However, it is still of interest with papers presenting overall survival results with the caveat of subsequent treatments, but little or no investigation into their effect. This review shows that there is a methodological gap for what researchers should do when trial participants receive anti-cancer treatment during trial follow-up. Future research will identify the stakeholder opinions, on how this methodological gap should be addressed.

Identification of a novel therapeutic target for lung cancer: Mitochondrial ribosome protein L9

Lung cancer has a high fatality rate and incidence rate. At present, the initial and progress mechanism of lung cancer has not been completely elucidated and new therapeutic targets still need to be developed. In this study, the screening process was based on lung cancer expression profile data and survival analysis. Mitochondrial ribosome protein L9 (MRPL9) was upregulated in lung cancer tissues and related to the poor overall survival rate and recurrence-free survival rate of lung cancer patients. Knockdown of MRPL9 inhibited the proliferation, sphere-formation, and migration ability of lung cancer cells. MRPL9 was associated with the c-MYC signaling pathway, and lung cancer patients with high expression of both MRPL9 and MYC had a poor prognosis. Furthermore, c-MYC was associated with the epithelial-mesenchymal transition (EMT) regulatory protein zinc finger E-box binding homeobox 1 (ZEB1) by bioinformatics analysis. The relationship between ZEB1 and c-MYC was further confirmed by interfering with c-MYC expression. MRPL9 is a potential therapeutic target for lung cancer and exerts its biological functions by affecting the transcription factor c-MYC thereby regulating the EMT regulator ZEB1.

Consideration of Surrogate Endpoints for Overall Survival Associated With First-Line Immunotherapy in Extensive-Stage Small Cell Lung Cancer

Background

The combination of immune checkpoint inhibitors (ICIs) and chemotherapy is known to improve overall survival (OS) in patients with extensive-stage small cell lung cancer (ES-SCLC). ICIs have different response patterns and survival kinetics characteristics from those of the traditional chemotherapy. In first-line treatment for ES-SCLC, there is an urgent need for surrogate endpoints for the early and accurate prediction of OS. This study aimed to assess progression-free survival (PFS), milestone OS rate, milestone restricted mean survival time (RMST), overall response rate (ORR), and disease control rate (DCR) as proposed surrogate endpoints for OS in ES-SCLC for first-line immunotherapy trials.

Methods

Between January 1, 2013, and December 2020, published articles on randomized clinical trials of ICIs plus chemotherapy in patients with ES-SCLC as first-line therapy were searched in PubMed. Abstracts from the ESMO, ASCO, and WCLC, reported from 2018 onwards, were also searched. A weighted regression analysis based on the weighted least squares method was performed on log-transformed estimates of treatment effect, and the determination coefficient (R²) was calculated to evaluate the association between treatment effect on the surrogate endpoint and OS.

Results

Seven trials, representing 3,009 patients, were included to make up a total of 16 analyzed arms. The ratio of the 12-month OS milestone rate (r = −0.790, P = 0.011, R² = 0.717) and 12-month OS milestone RMST (r = 0.798, P = 0.010, R² = 0.702) was strongly correlated with the hazard ratio (HR) for OS. The strongest association was observed between the ratio of the 24-month OS milestone RMST and the HR for OS (r = 0.922, P = 0.001, R² = 0.825). No associations were observed between the HR for OS and PFS and the RR for ORR and DCR.

Conclusions

The results suggested a strong correlation among the ratio of OS milestone rates at 12 months, ratios of OS milestone RMSTs at 12 and 24 months, and HR for OS. The results indicate that OS milestone rates and OS milestone RMSTs could be considered surrogate endpoints of OS in future first-line immunotherapy trials for ES-SCLC.

Apatinib with etoposide capsules as a third- or further-line therapy for extensive-stage small cell lung cancer: an open-label, multicenter, single-arm phase II trial

Background

Patients with extensive-stage small-cell lung cancer (ES-SCLC) have a particularly poor prognosis. And the treatment options for patients with relapsed or refractory ES-SCLC are limited. Thus, we conducted an open-label, multicenter, single-arm phase II clinical trial to assess the efficacy and safety of apatinib plus etoposide capsules as the third- or further-line treatment in ES-SCLC patients.

Methods

Patients with ES-SCLC who experienced disease progression following 2 to 3 previous therapies from 11 medical centers in China were enrolled to receive apatinib (250 mg/d, continuously) and etoposide capsules (50 mg/d, on day 1–21, per 28 days). The treatment continued until disease progression, treatment intolerance, or death. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), overall survival (OS), and safety.

Results

Fifty-six patients with relapsed or refractory ES-SCLC were enrolled from January 2018 to February 2020 and 53 of them were eventually included in the evaluation population. The median follow-up was 9.8 months. At the data cut-off time (March 5, 2020), 39 patients (74%) had died and 44 (83%) had progressed. The median PFS was 3.0 months (95% CI, 2.1–3.9) and the median OS was 5.0 months (95% CI, 3.6–6.4). No complete responses were seen. Eleven patients (21%) showed a best response of partial response and 37 (70%) patients achieved stable disease. The ORR was 20.8% (11/53), and the disease control rate (DCR) was 90.6% (48/53). The 6-month OS rate was 40.1% (95% CI, 26.2–54). After 12 months, the OS rate was 18.4% (95% CI, 4.7–32.1). Possible treatment-related grade III/IV adverse events included leukopenia [8 (15.1%)], neutropenia [7 (13.2%)], anemia [4 (7.4%)], and hand-foot syndrome [2 (3.8%)]. During the study, no mortality occurred as a consequence of treatment.

Conclusions

Apatinib combined with etoposide capsules exhibits efficacy and has an acceptable safety profile. It could be used as a later-line treatment for ES-SCLC patients who have been heavily pretreated with standard therapies. Further exploration of apatinib combined with etoposide capsules in phase III trials is warranted.

Systematic review of first-line chemotherapy for chemo-naïve extensive-stage small-cell lung cancer: network meta-analysis

BACKGROUND

Our goal was to organize the data from randomized controlled trials that evaluated first-line chemotherapy for chemo-naïve extensive disease small-cell lung cancer (ED-SCLC).

METHODS

The protocol following PRISMA methodology was submitted as PROSPERO 154049. We included individually randomized trials comparing two or more chemotherapy regimens as the first-line treatment for chemo-naïve ED-SCLC regardless of the age, sex, performance status, co-morbidities, and organ functions written in the English language since 2000. Molecular targeted agents and immune checkpoint inhibitors were considered chemotherapy along with cytotoxic medications. We pooled the logarithm of hazard ratio (HR) and its standard error using the frequentist weighted least squares approach random-model network meta-analysis.

RESULTS

A total of 46 eligible trials that involved 11,987 patients were included. The primary endpoint, HR of overall survival (OS, HRos) of the selected comparisons was as follows: carboplatin+amrubicin (HRos 0.56, 95% confidence interval (CI) 0.33-0.96), carboplatin+etoposide+atezolizumab (HRos 0.70, 95% CI 0.53-0.92), and carboplatin+irinotecan (HRos 0.73, 95% CI 0.58-0.91) were compared with carboplatin+etoposide. The carboplatin+etoposide+atezolizumab regimen was compared with carboplatin+irinotecan (HRos 0.97, 95% CI 0.68-1.37) and cisplatin+irinotecan regimen (HRos 0.87, 95% CI 0.58-1.31). "Selective carboplatin or cisplatin (CBDCA/CDDP)"+etoposide+durvalumab was compared with CBDCA/CDDP+etoposide (HRos 0.73, 95% CI 0.59-0.91). Platinum+etoposide+durvalumab was compared with platinum+irinotecan (HRos 0.88, 95% CI 0.67-1.15). Cumulative meta-analysis suggested that platinum+irinotecan was associated with better OS than platinum+etoposide as of 2010 through 40 out of 46 trials in our review that used platinum+etoposide as a reference regimen.

CONCLUSION

Patients treated with carboplatin+amrubicin, carboplatin+etoposide+atezolizumab, CBDCA/CDDP+etoposide+durvalumab, and platinum+irinotecan showed better HRos than those treated with platinum+etoposide, one of the standard regimens.