Efficacy and Safety of Rovalpituzumab Tesirine Compared With Topotecan as Second-Line Therapy in DLL3-High SCLC: Results From the Phase 3 TAHOE Study

INTRODUCTION

DLL3, an atypical Notch ligand, is expressed in SCLC tumors but is not detectable in normal adult tissues. Rovalpituzumab tesirine (Rova-T) is an antibody-drug conjugate containing a DLL3-targeting antibody tethered to a cytotoxic agent pyrrolobenzodiazepine by means of a protease-cleavable linker. The efficacy and safety of Rova-T compared with topotecan as second-line therapy in patients with SCLC expressing high levels of DLL3 (DLL3-high) was evaluated.

METHODS

The TAHOE study was an open-label, two-to-one randomized, phase 3 study comparing Rova-T with topotecan as second-line therapy in DLL3-high advanced or metastatic SCLC. Rova-T (0.3 mg/kg) was administered intravenously on day 1 of a 42-day cycle for two cycles, with two additional cycles available to patients who met protocol-defined criteria for continued dosing. Topotecan (1.5 mg/m2) was administered intravenously on days 1 to 5 of a 21-day cycle. The primary end point was overall survival (OS).

RESULTS

Patients randomized to Rova-T (n = 296) and topotecan (n = 148) were included in the efficacy analyses. The median age was 64 years, and 77% had the extensive disease at initial diagnosis. The median OS (95% confidence interval) was 6.3 months (5.6-7.3) in the Rova-T arm and 8.6 months (7.7-10.1) in the topotecan arm (hazard ratio, 1.46 [95% confidence interval: 1.17-1.82]). An independent data monitoring committee recommended that enrollment be discontinued because of the shorter OS observed with Rova-T compared with topotecan. Safety profiles for both drugs were consistent with previous reports.

CONCLUSIONS

Compared with topotecan, which is the current standard second-line chemotherapy, Rova-T exhibited an inferior OS and higher rates of serosal effusions, photosensitivity reaction, and peripheral edema in patients with SCLC. A considerable unmet therapeutic need remains in this population.

Potential prognostic value of delta-like protein 3 in small cell lung cancer: a meta-analysis

BACKGROUND

Current researches have revealed that delta-like protein 3 (DLL3) may be related with prognosis in patients with small cell lung cancer (SCLC). However, this finding remains controversial in small cell lung cancer. This meta-analysis was systematically performed to evaluate the prognostic value of DLL3 in SCLC.

METHODS

The PubMed, EMBASE and Web of Science databases were retrieved to collect the eligible references. Through Stata 15.0 software, we pooled hazard ratios (HR) with 95% confidence intervals (CI) by using random or fixed-effects models to evaluate the association between DLL3 and SCLC survival results.

RESULTS

A total of 6 inter-related studies including 645 patients were qualified. After we removed 1 study, the remaining 5 studies including 601 patients were pooled to testify that high expression of DLL3 was an inferior prognostic for patients with SCLC in Asian populations (HR = 1.37, 95% CI = 1.05, 1.69; I² = 0.0%, p = 0.000). The pooled results showed that DLL3 might be higher expression in advanced metastasis SCLC in Asian populations (RR = 0.84, 95% CI = 0.71, 0.99; I² = 44.7%, p = 0.039). But the expression of DLL3 was not correlated with sex (RR = 1.33, 95% CI = 0.98, 1.80; I² = 0.0%, p = 0.064), smoking history (RR = 1.01, 95% CI = 0.58, 1.75; I² = 72.1%, p = 0.967) and tumour stage (RR = 0.68, 95% CI = 0.44, 1.05; I² = 66.6%, p = 0.081).

CONCLUSIONS

Our meta-analysis confirms that in Asian populations, high expression of DLL3 was a potential poor prognostic biomarker for SCLC and DLL3 highly expressed in advanced stage SCLC in Asian populations.

NOTCH2/NOTCH3/DLL3/MAML1/ADAM17 signaling network is associated with ovarian cancer

Notch signaling is well-known for its role in regulating cell self-renewal and differentiation. Within the cancer research field, it has been identified that dysregulated Notch signaling is involved directly with various types of cancer. Although Notch signaling is generally considered as oncogenic, it sometimes acts as a tumor suppressor, highlighting the complexity of the role of Notch in cancer. A number of studies have associated Notch signaling components with ovarian cancer, but the underlying molecular mechanisms are not well-elucidated. In the present study, the roles of main components of Notch signaling in ovarian cancer were systematically analyzed through large data portals, including Prediction of Clinical Outcomes from Genomic Profiles, Gene Expression across Normal and Tumor tissue, CSIOVDB, Broad Institute Cancer Cell Line Encyclopedia and cBioPortal. Upregulated expression of proteins in the Notch signaling pathway components in ovarian cancer was identified to be generally associated with poor overall and disease-free survival time, and more advanced cancer stages. In addition, Notch components were enriched in ovarian cancer tissues and cell lines. These results led to a proposed neurogenic locus notch homolog protein (NOTCH)2/NOTCH3/Delta-like protein 3/Mastermind-like protein 1/a disintegrin and metalloproteinase domain-containing protein 17 network. Anticancer drugs, developed to target this network, may have high specificity in treating Notch-associated ovarian cancer.