Е. А. Филиппова

Ovarian cancer (OvCa) develops asymptomatically until it reaches the advanced stages with metastasis, chemoresistance, and poor prognosis. Our review focuses on the analysis of regulatory long non-coding RNAs (lncRNAs) competing with protein-coding mRNAs for binding to miRNAs according to the model of competitive endogenous RNA (ceRNA) in OvCa. Analysis of publications showed that most lncRNAs acting as ceRNAs participate in OvCa progression: migration, invasion, epithelial-mesenchymal transition (EMT), and metastasis. More than 30 lncRNAs turned out to be predictors of survival and/or response to therapy in patients with OvCa. For a number of oncogenic (CCAT1, HOTAIR, NEAT1, and TUG1 among others) and some suppressive lncRNAs, several lncRNA/miRNA/mRNA axes were identified, which revealed various functions for each of them. Our review also considers examples of alternative mechanisms of actions for lncRNAs besides being ceRNAs, including binding directly to mRNA or protein, and some of them (DANCR, GAS5, MALAT1, and UCA1 among others) act by both mechanisms depending on the target protein. A systematic analysis based on the data from literature and Panther or KEGG (Kyoto Encyclopedia of Genes and Genomes) databases showed that a significant part of lncRNAs affects the key pathways involved in OvCa metastasis, EMT, and chemoresistance.

PURPOSE Telisotuzumab vedotin (Teliso-V) is a c-Met–directed antibody-drug conjugate with a monomethyl auristatin E cytotoxic payload. The phase II LUMINOSITY trial (ClinicalTrials.gov identifier: NCT03539536 ) aimed to identify the optimal c-Met protein–overexpressing non–small cell lung cancer (NSCLC) population for treatment with Teliso-V (stage I) and expand the selected group for efficacy evaluation (stage II). Stage II enrolled patients with nonsquamous epidermal growth factor receptor ( EGFR )-wildtype NSCLC. METHODS Eligible patients had locally advanced/metastatic c-Met protein–overexpressing NSCLC and ≤2 previous lines of therapy (including ≤1 line of systemic chemotherapy). c-Met protein overexpression in nonsquamous EGFR -wildtype NSCLC was defined as ≥25% tumor cells with 3+ staining (high [≥50% 3+]; intermediate [≥25%–<50%]). Teliso-V was administered at 1.9 mg/kg once every 2 weeks. The primary end point was overall response rate (ORR) by independent central review. RESULTS In total, 172 patients with nonsquamous EGFR -wildtype NSCLC received Teliso-V in stages I and II. ORR was 28.6% (95% CI, 21.7 to 36.2; c-Met high, 34.6% [95% CI, 24.2 to 46.2]; c-Met intermediate, 22.9% [95% CI, 14.4 to 33.4]). The median duration of response was 8.3 months (95% CI, 5.6 to 11.3; c-Met high, 9.0 [95% CI, 4.2 to 13.0]; c-Met intermediate: 7.2 [95% CI, 5.3 to 11.5]). The median overall survival was 14.5 months (95% CI, 9.9 to 16.6; c-Met high, 14.6 [95% CI, 9.2 to 25.6]; c-Met intermediate, 14.2 [95% CI, 9.6 to 16.6]). The median progression-free survival was 5.7 months (95% CI, 4.6 to 6.9; c-Met high, 5.5 [95% CI, 4.1 to 8.3]; c-Met intermediate: 6.0 [95% CI, 4.5 to 8.1]). Most common any-grade treatment-related adverse events (AEs) were peripheral sensory neuropathy (30%), peripheral edema (16%), and fatigue (14%); the most common grade ≥3 AE was peripheral sensory neuropathy (7%). CONCLUSION Teliso-V was associated with durable responses in c-Met protein–overexpressing nonsquamous EGFR -wildtype NSCLC, especially in those with high c-Met. AEs were generally manageable.

Long noncoding RNAs (lncRNAs) have been identified as contributors to the development and progression of cancer through various functions and mechanisms. LncRNA GAS5 is downregulated in multiple cancers and acts as a tumor suppressor in breast cancer. GAS5 interacts with various proteins (e.g., E2F1, EZH2, and YAP), DNA (e.g., the insulin receptor promoter), and various microRNAs (miRNAs). In breast cancer, GAS5 binds with miR-21, miR-222, miR-221-3p, miR-196a-5p, and miR-378a-5p that indicates the presence of several elements for miRNA binding (MREs) in GAS5. Mediated by the listed miRNAs, GAS5 is involved in the upregulation of a number of mRNAs of suppressor proteins such as PTEN, PDCD4, DKK2, FOXO1, and SUFU. Furthermore, the aberrant promoter methylation is involved in the regulation of GAS5 gene expression in triple-negative breast cancer and some other carcinomas. GAS5 can stimulate apoptosis in breast cancer via diverse pathways, including cell death receptors and mitochondrial signaling pathways. GAS5 is also a key player in the regulation of some crucial signal pathways in breast cancer, such as PI3K/AKT/mTOR, Wnt/β-catenin, and NF-κB signaling. Through epigenetic and other mechanisms, GAS5 can increase sensitivity to multiple drugs and improve prognosis. GAS5 is thus a promising target in the treatment of breast cancer patients.

9016 Background: Teliso-V is an antibody-drug conjugate composed of a c-Met antibody (ABT-700) and a microtubule inhibitor (monomethyl auristatin E). The phase 2 M14-239 trial (LUMINOSITY, NCT03539536) aims to identify the c-Met OE NSCLC populations best suited to Teliso-V (Stage 1) and expand selected groups for further evaluation of efficacy (Stage 2). In Stage 1, pts were enrolled into cohorts defined by histopathology (non-squamous [NSQ] or squamous [SQ]) and EGFR mutation status (mutant or wild type [WT]); NSQ cohorts were further divided in groups on the basis of c-Met expression (high or intermediate). Updated data from the fourth interim analysis (IA4) are presented. Methods: Pts had locally advanced/metastatic NSCLC, ≤2 prior lines of systemic therapy, ≤1 line of chemotherapy, and tumors that were c-Met OE by central immunohistochemistry (IHC; Ventana; Tucson, AZ). c-Met OE was defined for the NSQ cohort as ≥25% 3+ by IHC (high, ≥50% 3+; intermediate, 25 to <50% 3+) and for the SQ cohort as ≥75% 1+ by IHC. The planned enrollment was up to approximately 150 pts in Stage 1 and 160 pts in Stage 2. Teliso-V was dosed at 1.9 mg/kg IV Q2W. The primary endpoint is objective response rate (ORR) by independent central review. Secondary endpoints include duration of response (DOR). Results: As of data cutoff (27 May 2021), 136 pts were treated with Teliso-V; 122 were evaluable for ORR. ORR was 36.5% in the NSQ EGFR WT cohort (52.2% in c-Met high group and 24.1% in c-Met intermediate group), but was modest in the NSQ EGFR mutant and SQ cohorts. Efficacy data in groups/cohorts are in the Table. The most common any-grade adverse events (AEs) were peripheral sensory neuropathy (25.0%), nausea (22.1%), and hypoalbuminemia (20.6%). Grade 5 AEs considered possibly related to Teliso-V occurred in 2 pts (sudden death and pneumonitis in 1 pt each in the SQ cohort). Conclusions: Teliso-V demonstrated a promising ORR in pts with previously treated c-Met OE NSQ EGFR WT NSCLC; this cohort is currently expanding in Stage 2. ORR was modest in the cohorts of pts with c-Met OE NSQ EGFR mutant NSCLC and with c-Met OE SQ NSCLC; both cohorts have now met the protocol-specified stopping criteria and are no longer enrolling. The safety profile observed was consistent with IA3. Clinical trial information: NCT03539536. [Table: see text]