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Currently, there is no established guidance on how to process and evaluate resected lung cancer specimens after neoadjuvant therapy in the setting of clinical trials and clinical practice. There is also a lack of precise definitions on the degree of pathologic response, including major pathologic response or complete pathologic response. For other cancers such as osteosarcoma and colorectal, breast, and

Tumor cells trends to express high level of pyruvate kinase M2 (PKM2). The inhibition of PKM2 activity is needed for antioxidant response by diverting glucose flux into the pentose phosphate pathway and thus generating sufficient reducing potential. Here we report that PKM2 is succinylated at lysine 498 (K498) and succinylation increases its activity. SIRT5 binds to, desuccinylates and inhibits PKM2 activity. Increased level of reactive oxygen species (ROS) decreases both the succinylation and activity of PKM2 by increasing its binding to SIRT5. Substitution of endogenous PKM2 with a succinylation mimetic mutant K498E decreases cellular NADPH production and inhibits cell proliferation and tumor growth. Moreover, inhibition of SIRT5 suppresses tumor cell proliferation through desuccinylation of PKM2 K498. These results reveal a new mechanism of PKM2 modification, a new function of SIRT5 in response to oxidative stress which stimulates cell proliferation and tumor growth, and also a potential target for clinical cancer research.

9501 Background: NIVO + IPI was shown to improve overall survival (OS) and durability of response vs chemo in 1L advanced NSCLC in CheckMate 227 Part 1, regardless of PD-L1 expression. We hypothesized that a limited course of chemo combined with NIVO + IPI could provide rapid disease control while building on the durable OS benefit seen with dual PD-1 and CTLA-4 inhibition. CheckMate 9LA (NCT03215706) is a phase 3 randomized study evaluating NIVO + IPI + 2 cycles chemo vs chemo in 1L stage IV/recurrent NSCLC. Methods: Adults with tx-naive, histologically confirmed stage IV/recurrent NSCLC, ECOG performance status 0–1, and no known sensitizing EGFR/ALK alterations were randomized 1:1 to NIVO 360 mg Q3W + IPI 1 mg/kg Q6W + chemo (2 cycles) (n = 361) or chemo (4 cycles) alone (n = 358), stratified by PD-L1 (< 1% vs ≥ 1%), sex, and histology (squamous vs non-squamous). Chemo was based on histology. Pts with non-squamous NSCLC in the chemo-only arm could receive optional pemetrexed maintenance. Pts were treated with immunotherapy until disease progression, unacceptable toxicity, or for 2 y. The primary endpoint was OS; the interim analysis using Lan–DeMets alpha spending function with O’Brien–Fleming boundary was planned at ~80% information fraction (ie, after observing ~322 total events). Secondary endpoints included progression-free survival (PFS) and objective response rate (ORR) by blinded independent central review, and efficacy by PD-L1 subgroups. Exploratory endpoints included safety/tolerability. Results: Baseline characteristics were balanced across arms. At a preplanned interim analysis (minimum follow-up 8.1 mo), OS was significantly prolonged with NIVO + IPI + chemo vs chemo (HR 0.69, 96.71% CI: 0.55–0.87; P = 0.0006); statistically significant improvements in PFS and ORR were seen. With longer follow-up (minimum 12.7 mo), NIVO + IPI + chemo vs chemo continued to provide longer OS; median 15.6 vs 10.9 mo (HR 0.66, 95% CI: 0.55–0.80); 1-y OS rates were 63 vs 47%. Clinical benefit was consistent across all efficacy measures in key subgroups including by PD-L1 and histology. Grade 3–4 tx-related adverse events were reported in 47 vs 38% of pts in the NIVO + IPI + chemo vs chemo arms, respectively. Conclusions: CheckMate 9LA met its primary endpoint: a statistically significant improvement in OS was observed with NIVO + NSCLC-optimized IPI + a limited course of chemo vs chemo (4 cycles) in 1L advanced NSCLC. No new safety signals were reported. Clinical trial information: NCT03215706 .

8503 Background: CheckMate 816 (NCT02998528) is a randomized phase 3 study of neoadjuvant NIVO + chemo vs chemo in resectable NSCLC. The study met its first primary endpoint, demonstrating significantly improved pathological complete response (pCR) with neoadjuvant NIVO + chemo. Here we report key surgical outcomes from the study. Methods: Adults with stage IB (≥ 4 cm)–IIIA (per AJCC 7th ed) resectable NSCLC, ECOG PS ≤ 1, and no known EGFR/ ALK alterations were randomized to NIVO 360 mg + platinum-doublet chemo Q3W or chemo Q3W for 3 cycles (n = 179 each). Definitive surgery was to be performed within 6 weeks of treatment. Primary endpoints are pCR (defined as 0% viable tumor cells in lung and lymph nodes) and event-free survival; both are evaluated by blinded independent review. Feasibility of surgery and surgery-related adverse events (AEs) are exploratory endpoints. Results: Baseline characteristics were comparable between arms; 64% of patients (pts) were stage IIIA. Definitive surgery rates were 83% with NIVO + chemo (n = 149) vs 75% with chemo (n = 135). Reasons for cancelled surgery were disease progression (12 and 17 pts, respectively), AEs (2 pts/arm), or other scenarios (14 and 19 pts, respectively; including pt refusal, unresectability, poor lung function). Minimally invasive surgery rates were 30% and 22%, and conversion from minimally invasive to open surgery rates were 11% and 16% for NIVO + chemo and chemo, respectively. Lobectomy was performed in 77% vs 61% of pts, and pneumonectomy in 17% and 25% for NIVO + chemo vs chemo, respectively. AEs were responsible for delays of surgery in 6 pts in the NIVO + chemo arm and 9 pts in the chemo arm. An R0 resection was achieved in 83% vs 78% of pts and median residual viable tumor (RVT) cells in the primary tumor bed were 10% vs 74% for NIVO + chemo vs chemo. There was no increase in median (Q1, Q3) duration of surgery and length of hospitalization between NIVO + chemo vs chemo (184 [130, 252] vs 217 [150, 283] min; and 10.0 [7, 14] vs 10.0 [7, 14] days, respectively). Any-grade and grade 3–4 surgery-related AEs were reported in 41% vs 47% and 11% vs 15% of the NIVO + chemo vs chemo arms, respectively. Grade 5 surgery-related AEs were reported in 2 vs 0 pts in the NIVO + chemo vs chemo arms; 0 vs 3 pts died due to treatment-related AEs, respectively. Conclusions: In CheckMate 816, neoadjuvant NIVO + chemo did not impede the feasibility and timing of surgery, nor the extent or completeness of resection vs chemo alone; treatment was tolerable and did not increase surgical complications. NIVO + chemo led to increased depth of pathological response. The surgical outcome data from CheckMate 816 along with significant improvement in pCR support NIVO + chemo as a potential neoadjuvant option for patients with stage IB to IIIA resectable NSCLC. Clinical trial information: NCT02998528.

The advent of fluorescence-based quantitative real-time PCR (qPCR) has revolutionized the quantification of gene expression analysis in many fields, including life sciences, agriculture, forensic science, molecular diagnostics, and medicine. While SYBR Green-based qPCR is the most commonly-used platform due to its inexpensive nature and robust chemistry, quantifying the expression of genes with low abundance or RNA samples extracted from highly restricted or limited sources can be challenging because the detection sensitivity of SYBR Green-based qPCR is limited. Here, we develop a novel and effective touchdown qPCR (TqPCR) protocol by incorporating a 4-cycle touchdown stage prior to the quantification amplification stage. Using the same cDNA templates, we find that TqPCR can reduce the average Cq values for Gapdh, Rps13, and Hprt1 reference genes by 4.45, 5.47, and 4.94 cycles, respectively, when compared with conventional qPCR; the overall average Cq value reduction for the three reference genes together is 4.95. We further find that TqPCR can improve PCR amplification efficiency and thus increase detection sensitivity. When the quantification of Wnt3A-induced target gene expression in mesenchymal stem cells is analyzed, we find that, while both conventional qPCR and TqPCR can detect the up-regulation of the relatively abundant target Axin2, only TqPCR can detect the up-regulation of the lowly-expressed targets Oct4 and Gbx2. Finally, we demonstrate that the MRQ2 and MRQ3 primer pairs derived from mouse reference gene Tbp can be used to validate the RNA/cDNA integrity of qPCR samples. Taken together, our results strongly suggest that TqPCR may increase detection sensitivity and PCR amplification efficiency. Overall, TqPCR should be advantageous over conventional qPCR in expression quantification, especially when the transcripts of interest are lowly expressed, and/or the availability of total RNA is highly restricted or limited.

Ovarian cancer is the most lethal gynecologic malignancy with an overall cure rate of merely 30%. Most patients experience recurrence within 12–24 months of cure and die of progressively chemotherapy-resistant disease. Thus, more effective anti-ovarian cancer therapies are needed. Here, we investigate the possibility of repurposing antibiotic monensin as an anti-ovarian cancer agent. We demonstrate that monensin effectively inhibits cell proliferation, migration and cell cycle progression, and induces apoptosis of human ovarian cancer cells. Monensin suppresses multiple cancer-related pathways including Elk1/SRF, AP1, NFκB and STAT, and reduces EGFR expression in ovarian cancer cells. Monensin acts synergistically with EGFR inhibitors and oxaliplatin to inhibit cell proliferation and induce apoptosis of ovarian cancer cells. Xenograft studies confirm that monensin effectively inhibits tumor growth by suppressing cell proliferation through targeting EGFR signaling. Our results suggest monensin may be repurposed as an anti-ovarian cancer agent although further preclinical and clinical studies are needed.