MAP Kinase Inhibition Promotes T Cell and Anti-tumor Activity in Combination with PD-L1 Checkpoint Blockade.

Targeted inhibition of mitogen-activated protein kinase (MAPK) kinase (MEK) can induce regression of tumors bearing activating mutations in the Ras pathway but rarely leads to tumor eradication. Although combining MEK inhibition with T-cell-directed immunotherapy might lead to more durable efficacy, T cell responses are themselves at least partially dependent on MEK activity. We show here that MEK inhibition did profoundly block naive CD8(+) T cell priming in tumor-bearing mice, but actually increased the number of effector-phenotype antigen-specific CD8(+) T cells within the tumor. MEK inhibition protected tumor-infiltrating CD8(+) T cells from death driven by chronic TCR stimulation while sparing cytotoxic activity. Combining MEK inhibition with anti-programmed death-ligand 1 (PD-L1) resulted in synergistic and durable tumor regression even where either agent alone was only modestly effective. Thus, despite the central importance of the MAP kinase pathway in some aspects of T cell function, MEK-targeted agents can be compatible with T-cell-dependent immunotherapy.

Structure-based optimization of hydroxylactam as potent, cell-active inhibitors of lactate dehydrogenase.

Structure-based design was utilized to optimize 6,6-diaryl substituted dihydropyrone and hydroxylactam to obtain inhibitors of lactate dehydrogenase (LDH) with low nanomolar biochemical and single-digit micromolar cellular potencies. Surprisingly the replacement of a phenyl with a pyridyl moiety in the chemical structure revealed a new binding mode for the inhibitors with subtle conformational change of the LDHA active site. This led to the identification of a potent, cell-active hydroxylactam inhibitor exhibiting an in vivo pharmacokinetic profile suitable for mouse tumor xenograft study.

Intravenous ondansetron reduced nausea but not pruritus following intrathecal morphine in children: Interim results of a randomized, double-blinded, placebo-control trial.

STUDY OBJECTIVE: This study's purpose was to determine if ondansetron can prevent pruritus after administration of intrathecal morphine in children, as has been demonstrated in adults. DESIGN: A double-blinded, randomized placebo-controlled trial. SETTING: Operating room and first 24 h postoperative inpatient stay at an academic children's hospital. PATIENTS: Forty-six children aged 3-17 years, who received 4-5 mcg/kg intrathecal morphine for urological or orthopedic procedures were included. INTERVENTIONS: Children were randomized to receive intravenous ondansetron (treatment) or saline placebo (placebo), prior to intrathecal morphine administration, and q6H for 24 h thereafter. Intraoperative anti-emetics and postoperative rescue treatments for pruritus and nausea were standardized. MEASUREMENTS: Patients were interviewed q6H for scored pruritus, nausea, and pain, using standardized scales. MAIN RESULTS: The trial was terminated for futility after interim analysis. Forty-six children were recruited and 45 completed data collection. No significant difference was found between both groups for incidence of pruritus (requiring treatment) [relative risk (RR) 0.9, 95% CI: 0.7, 1.2], during the first postoperative 24 h. Notably, the incidence of pruritus was 84% overall, much higher than rates in previously published studies. Intravenous ondansetron significantly reduced the incidence of nausea, compared with the placebo group [RR 0.5, 95% CI: 0.3, 0.9]. CONCLUSIONS: This study found no evidence for intravenous ondansetron as an effective preventative for pruritus following intrathecal morphine in children. However, this RCT did find that the rate of pruritus following intrathecal morphine administration may be significantly higher than previously thought. Nausea and vomiting (a secondary outcome) were reduced significantly in the treatment group. The negative findings of this study reinforce the potential dangers of extrapolating the drug effects seen in adults onto pediatric patients.

Metabolic plasticity underpins innate and acquired resistance to LDHA inhibition.

Metabolic reprogramming in tumors represents a potential therapeutic target. Herein we used shRNA depletion and a novel lactate dehydrogenase (LDHA) inhibitor, GNE-140, to probe the role of LDHA in tumor growth in vitro and in vivo. In MIA PaCa-2 human pancreatic cells, LDHA inhibition rapidly affected global metabolism, although cell death only occurred after 2 d of continuous LDHA inhibition. Pancreatic cell lines that utilize oxidative phosphorylation (OXPHOS) rather than glycolysis were inherently resistant to GNE-140, but could be resensitized to GNE-140 with the OXPHOS inhibitor phenformin. Acquired resistance to GNE-140 was driven by activation of the AMPK-mTOR-S6K signaling pathway, which led to increased OXPHOS, and inhibitors targeting this pathway could prevent resistance. Thus, combining an LDHA inhibitor with compounds targeting the mitochondrial or AMPK-S6K signaling axis may not only broaden the clinical utility of LDHA inhibitors beyond glycolytically dependent tumors but also reduce the emergence of resistance to LDHA inhibition.

Metabolite profiling stratifies pancreatic ductal adenocarcinomas into subtypes with distinct sensitivities to metabolic inhibitors.

Although targeting cancer metabolism is a promising therapeutic strategy, clinical success will depend on an accurate diagnostic identification of tumor subtypes with specific metabolic requirements. Through broad metabolite profiling, we successfully identified three highly distinct metabolic subtypes in pancreatic ductal adenocarcinoma (PDAC). One subtype was defined by reduced proliferative capacity, whereas the other two subtypes (glycolytic and lipogenic) showed distinct metabolite levels associated with glycolysis, lipogenesis, and redox pathways, confirmed at the transcriptional level. The glycolytic and lipogenic subtypes showed striking differences in glucose and glutamine utilization, as well as mitochondrial function, and corresponded to differences in cell sensitivity to inhibitors of glycolysis, glutamine metabolism, lipid synthesis, and redox balance. In PDAC clinical samples, the lipogenic subtype associated with the epithelial (classical) subtype, whereas the glycolytic subtype strongly associated with the mesenchymal (QM-PDA) subtype, suggesting functional relevance in disease progression. Pharmacogenomic screening of an additional ∼ 200 non-PDAC cell lines validated the association between mesenchymal status and metabolic drug response in other tumor indications. Our findings highlight the utility of broad metabolite profiling to predict sensitivity of tumors to a variety of metabolic inhibitors.

A retrospective comparison of intrathecal morphine and epidural hydromorphone for analgesia following posterior spinal fusion in adolescents with idiopathic scoliosis.

BACKGROUND: Posterior spinal fusion to correct idiopathic scoliosis is associated with severe postoperative pain. Intrathecal morphine is commonly used for analgesia after adolescent posterior spinal fusion; however, anticipating and managing the increase in pain scores after resolution of analgesic effect of intrathecal morphine analgesia is challenging. In 2014, we developed a clinical protocol detailing both the administration of intrathecal morphine intraoperatively and the transition to routine, scheduled oral analgesics at 18 h postoperatively. The goal of our study was to examine the efficacy of our intrathecal morphine protocol vs epidural hydromorphone for postoperative analgesia after posterior spinal fusion. METHODS: Following IRB approval, we retrospectively identified developmentally intact children of ages 10-20 years in our electronic database with a diagnosis of idiopathic scoliosis who had undergone elective posterior spinal fusion surgery from June 2014 to April 2015. For the intrathecal morphine group, intrathecal morphine was administered in a dose of 12 µg·kg-1 (max 1000 µg) prior to incision. Postoperatively, all children in the intrathecal morphine group had an order to receive oral oxycodone (0.1 mg·kg-1 , max 5 mg) starting at 18 h postintrathecal morphine injection. For the epidural hydromorphone group, catheters were placed by the surgeon and bolused with 5 µg·kg-1 hydromorphone (max 200 µg) and 1 µg·kg-1 fentanyl (max 50 µg), followed by a continuous infusion of 40-60 µg·h-1 , and patient-controlled bolus doses of 5 µg with a lockout interval of 30 min. All patients in both groups had postoperative orders for acetaminophen, diazepam, and ketorolac. RESULTS: During the study time period, 20 patients received intrathecal morphine and were successfully matched with 20 patients who received epidural hydromorphone. All patients in the intrathecal morphine group were transitioned to oral analgesics on the first postoperative day, without need for intravenous opioids after discharge from the postanesthesia care unit. Compared to the epidural hydromorphone group, the intrathecal morphine group reported lower pain scores in the postanesthesia care unit (difference in means -4.26 [95% CI -6.56, -1.96], P = 0.001) and first 8 h after surgery (difference in means -1.88 [95% CI -3.84, 0.082, P = 0.060) and higher pain scores on the 2nd postoperative day (difference in means 1.60 [95% CI 0.10, 3.10], P = 0.037). The documented time to ambulation and time of Foley catheter removal were statistically earlier in the intrathecal morphine group, and the hospital length of stay was significantly shorter (3.0 ± 0.5 days vs 3.5 ± 0.7 days; P = 0.03). Adverse events did not significantly differ between the groups. CONCLUSION: The efficacy of intraoperative intrathecal morphine for postoperative analgesia in the posterior spinal fusion patient population has been shown previously; however, the pain and analgesic trajectory, including transition to other analgesics, has not previously been studied. Our findings suggest that for many patients, use of intrathecal morphine in addition to routine administration of nonopioid medications facilitates direct transition to oral analgesics in the early postoperative period and earlier routine ambulation and discharge of posterior spinal fusion patients.

Narcotic-only Epidural Infusion for Posterior Spinal Fusion Patients: A Single-Center, Retrospective Review.

BACKGROUND: Adequate and safe postoperative analgesia for patients with idiopathic scoliosis undergoing posterior spinal fusion (PSF) remains challenging and controversial. A past adverse event in this patient population triggered a change of our institution's practice from epidurals containing bupivacaine and has resulted in use of epidurals containing solely narcotic (hydromorphone) for postoperative analgesia. This retrospective review looks at our experiences with hydromorphone patient-controlled epidural analgesia for postoperative analgesia in this patient population. METHODS: Electronic medical records of all children with a diagnosis of idiopathic scoliosis who underwent PSF surgery at our institution during the period of January 2011 to October 2011 were reviewed from the time they entered the PACU through the first 72 hours following PACU discharge. Specifically, the charts were reviewed for pain scores, sedation scores, narcotic use, use of adjuvant medications, antiemetics, antipruritics, hours to first ambulation, hours to first oral intake, respiratory rate, SpO2 values, need for any respiratory interventions, length of stay, and any adverse events. RESULTS: Fifty-six patients were enrolled. Three patients had their epidurals removed within the first 24 hours (5.4% failure rate). Highest mean pain scores ranged from 5.6±2.3 to 5.8±2.2 with median pain scores ranging from 4 to 6. There were no respiratory or neurological adverse events. Ambulation occurred on either postoperative day 1 or 2. The incidence of vomiting in this study was 34% in the first 24 hours post-PACU discharge and during this period, 61% of patients received ondansetron, for either nausea or pruritus. The mean length of stay for our patients was 3.95 days, with a median of 4 days. CONCLUSIONS: This retrospective review suggests that hydromorphone epidurals used for pain control in postoperative PSF patients are a reasonable alternative to IV-PCA, in terms of analgesia, side-effect profile, and length of stay. LEVEL OF EVIDENCE: Level III-retrospective study.

Comparing Peak Burn Injury Times and Characteristics in Australia and New Zealand.

Burns are a leading cause of morbidity and mortality worldwide. Understanding when and how burns occur, as well as the differences between countries, would aid prevention efforts. A review of burn injuries occurring between July 2009 and June 2021 was undertaken using data from the Burns Registry of Australia and New Zealand. Peak injury times were identified on a country-by-country basis. Variations in demographic and injury event profiles between countries were compared using descriptive statistics. There were 26,925 admissions recorded across the two countries (23,323 for Australia; 3602 for New Zealand). The greatest number of injuries occurred between 6 PM to 7 PM in Australia (1871, 8.0%) and between 5 PM to 6 PM in New Zealand (280, 7.8%). In both countries, scalds accounted for the greatest proportion of injuries during peak times (988, 45.8%), but a greater proportion of young children (under three years) sustained burns during New Zealand's peak times. The number of burn injuries associated with the preparation and/or consumption of food offers an opportunity for a targeted prevention program that may yield benefits across the two countries. Age- and mechanism-related differences in the profile of burn-injured patients need to be considered when developing and implementing such a program.

RTK-Dependent Inducible Degradation of Mutant PI3Kα Drives GDC-0077 (Inavolisib) Efficacy.

PIK3CA is one of the most frequently mutated oncogenes; the p110a protein it encodes plays a central role in tumor cell proliferation. Small-molecule inhibitors targeting the PI3K p110a catalytic subunit have entered clinical trials, with early-phase GDC-0077 studies showing antitumor activity and a manageable safety profile in patients with PIK3CA-mutant breast cancer. However, preclinical studies have shown that PI3K pathway inhibition releases negative feedback and activates receptor tyrosine kinase signaling, reengaging the pathway and attenuating drug activity. Here we discover that GDC-0077 and taselisib more potently inhibit mutant PI3K pathway signaling and cell viability through unique HER2-dependent mutant p110a degradation. Both are more effective than other PI3K inhibitors at maintaining prolonged pathway suppression. This study establishes a new strategy for identifying inhibitors that specifically target mutant tumors by selective degradation of the mutant oncoprotein and provide a strong rationale for pursuing PI3Kα degraders in patients with HER2-positive breast cancer. SIGNIFICANCE: The PI3K inhibitors GDC-0077 and taselisib have a unique mechanism of action; both inhibitors lead to degradation of mutant p110a protein. The inhibitors that have the ability to trigger specific degradation of mutant p110a without significant change in wild-type p110a protein may result in improved therapeutic index in PIK3CA-mutant tumors.See related commentary by Vanhaesebroeck et al., p. 20.This article is highlighted in the In This Issue feature, p. 1.

Gabapentin and intrathecal morphine combination therapy results in decreased oral narcotic use and more consistent pain scores after posterior spinal fusion for adolescent idiopathic scoliosis.

BACKGROUND: Gabapentin and intravenous patient-controlled analgesia (PCA) can reduce postoperative pain scores, postoperative opioid use, and time to completing physical therapy compared to PCA alone after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS). Gabapentin combined with intrathecal morphine has not been studied. The primary purpose of this retrospective study was to evaluate whether perioperative gabapentin and intrathecal morphine provide more effective pain control than intrathecal morphine alone after PSF for AIS. METHODS: Patients aged 11 to 18 years who underwent PSF for AIS were identified. Patients who received intrathecal morphine only (ITM group) were matched by age and sex to patients who received intrathecal morphine and perioperative gabapentin (ITM+GABA group). The ITM+GABA group received gabapentin preoperatively and for up to 2 days postoperatively. Both groups received oxycodone and the same non-narcotic adjuvant medications. RESULTS: Our final study group consisted of 50 patients (25 ITM, 25 ITM+GABA). The ITM+GABA group had significantly lower mean total oxycodone consumption during the hospitalization (0.798 vs 1.036 mg/kg, P<0.015). While the ITM group had a lower mean pain score between midnight and 8 am on POD 1 (2.4 vs 3.7, P=0.026), pain scores were significantly more consistent throughout the postoperative period in ITM+GABA group. The ITM+GABA group experienced less nausea/vomiting (52% vs 84%, P=0.032) and pruritus (44% vs 72%, P=0.045). Time to physical therapy discharge and length of hospital stay were similar. CONCLUSION: Addition of gabapentin resulted in reduced oral opioid consumption and more consistent postoperative pain scores after PSF for AIS. The patients who received intrathecal morphine and gabapentin also experienced a lower rate of nausea/vomiting and pruritus. TRIAL REGISTRATION: All data was collected retrospectively from chart review, with institutional IRB approval. Trial registration is not applicable.

Intrathecal Morphine and Oral Analgesics Provide Safe and Effective Pain Control After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective comparative study. OBJECTIVE: The aim of this study was to demonstrate that intrathecal morphine (ITM) and oral analgesics provide effective pain control after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS), and this protocol has a low complication rate so patients can be admitted to a general care floor. SUMMARY OF BACKGROUND DATA: Previous studies have shown that ITM combined with intravenous patient-controlled analgesia or epidural infusion (EPI) provides effective pain control after PSF for AIS. Owing to concerns for respiratory depression, ITM patients were routinely admitted to the intensive care unit (ICU) postoperatively. There are little data on ITM combined with oral analgesics. METHODS: We identified AIS patients aged 10 to 17 years who had undergone PSF. Twenty-eight patients who received ITM were matched to 28 patients who received a hydromorphone EPI. The ITM group received oral oxycodone starting at 16 hours postinjection. The EPI group received oxycodone after the epidural catheter was removed on postoperative day 2. Pain scores, adverse events, and length of stay were recorded. RESULTS: A higher number of EPI patients received fentanyl (11 vs. 3, P = 0.014) in the post-anesthesia care unit (PACU). The ITM group had lower pain scores between PACU discharge and midnight (mean 2.9 vs. 4.2, P = 0.034). Pain scores were similar during the remaining postoperative periods. All ITM patients transitioned to oxycodone without intravenous opioids. Time to ambulation (19.9 vs. 26.5 hours, P = 0.010) and Foley catheter removal (21.3 vs. 41.9 hours, P < 0.001) were earlier in the ITM patients. Length of hospital stay was shorter in the ITM group (3.1 vs. 3.5 days, P = 0.043). Adverse events occurred at similar rates in both groups. CONCLUSION: ITM and oral analgesics provide safe and effective pain control after PSF for AIS. Routine postoperative admission to the ICU is not necessary. LEVEL OF EVIDENCE: 3.

Pan-Cancer Metabolic Signature Predicts Co-Dependency on Glutaminase and De Novo Glutathione Synthesis Linked to a High-Mesenchymal Cell State.

The enzyme glutaminase (GLS1) is currently in clinical trials for oncology, yet there are no clear diagnostic criteria to identify responders. The evaluation of 25 basal breast lines expressing GLS1, predominantly through its splice isoform GAC, demonstrated that only GLS1-dependent basal B lines required it for maintaining de novo glutathione synthesis in addition to mitochondrial bioenergetics. Drug sensitivity profiling of 407 tumor lines with GLS1 and gamma-glutamylcysteine synthetase (GCS) inhibitors revealed a high degree of co-dependency on both enzymes across indications, suggesting that redox balance is a key function of GLS1 in tumors. To leverage these findings, we derived a pan-cancer metabolic signature predictive of GLS1/GCS co-dependency and validated it in vivo using four lung patient-derived xenograft models, revealing the additional requirement for expression of GAC above a threshold (log2RPKM + 1 ≥ 4.5, where RPKM is reads per kilobase per million mapped reads). Analysis of the pan-TCGA dataset with our signature identified multiple indications, including mesenchymal tumors, as putative responders to GLS1 inhibitors.

Tumour and host cell PD-L1 is required to mediate suppression of anti-tumour immunity in mice.

Expression of PD-L1, the ligand for T-cell inhibitory receptor PD-1, is one key immunosuppressive mechanism by which cancer avoids eradication by the immune system. Therapeutic use of blocking antibodies to PD-L1 or its receptor PD-1 has produced unparalleled, durable clinical responses, with highest likelihood of response seen in patients whose tumour or immune cells express PD-L1 before therapy. The significance of PD-L1 expression in each cell type has emerged as a central and controversial unknown in the clinical development of immunotherapeutics. Using genetic deletion in preclinical mouse models, here we show that PD-L1 from disparate cellular sources, including tumour cells, myeloid or other immune cells can similarly modulate the degree of cytotoxic T-cell function and activity in the tumour microenvironment. PD-L1 expression in both the host and tumour compartment contribute to immune suppression in a non-redundant fashion, suggesting that both sources could be predictive of sensitivity to therapeutic agents targeting the PD-L1/PD-1 axis.

Bcl-2/Bcl-xL inhibition increases the efficacy of MEK inhibition alone and in combination with PI3 kinase inhibition in lung and pancreatic tumor models.

Although mitogen-activated protein (MAP)-extracellular signal-regulated kinase (ERK) kinase (MEK) inhibition is predicted to cause cell death by stabilization of the proapoptotic BH3-only protein BIM, the induction of apoptosis is often modest. To determine if addition of a Bcl-2 family inhibitor could increase the efficacy of a MEK inhibitor, we evaluated a panel of 53 non-small cell lung cancer and pancreatic cancer cell lines with the combination of navitoclax (ABT-263), a Bcl-2/Bcl-xL (BCL2/BCL2L1) antagonist, and a novel MAP kinase (MEK) inhibitor, G-963. The combination is synergistic in the majority of lines, with an enrichment of cell lines harboring KRAS mutations in the high synergy group. Cells exposed to G-963 arrest in G1 and a small fraction undergo apoptosis. The addition of navitoclax to G-963 does not alter the kinetics of cell-cycle arrest, but greatly increases the percentage of cells that undergo apoptosis. The G-963/navitoclax combination was more effective than either single agent in the KRAS mutant H2122 xenograft model; BIM stabilization and PARP cleavage were observed in tumors, consistent with the mechanism of action observed in cell culture. Addition of the phosphatidylinositol 3-kinase (PI3K, PIK3CA) inhibitor GDC-0941 to this treatment combination increases cell killing compared with double- or single-agent treatment. Taken together, these data suggest the efficacy of agents that target the MAPK and PI3K pathways can be improved by combination with a Bcl-2 family inhibitor.

Targeting activated Akt with GDC-0068, a novel selective Akt inhibitor that is efficacious in multiple tumor models.

PURPOSE: We describe the preclinical pharmacology and antitumor activity of GDC-0068, a novel highly selective ATP-competitive pan-Akt inhibitor currently in clinical trials for the treatment of human cancers. EXPERIMENTAL DESIGN: The effect of GDC-0068 on Akt signaling was characterized using specific biomarkers of the Akt pathway, and response to GDC-0068 was evaluated in human cancer cell lines and xenograft models with various genetic backgrounds, either as a single agent or in combination with chemotherapeutic agents. RESULTS: GDC-0068 blocked Akt signaling both in cultured human cancer cell lines and in tumor xenograft models as evidenced by dose-dependent decrease in phosphorylation of downstream targets. Inhibition of Akt activity by GDC-0068 resulted in blockade of cell-cycle progression and reduced viability of cancer cell lines. Markers of Akt activation, including high-basal phospho-Akt levels, PTEN loss, and PIK3CA kinase domain mutations, correlate with sensitivity to GDC-0068. Isogenic PTEN knockout also sensitized MCF10A cells to GDC-0068. In multiple tumor xenograft models, oral administration of GDC-0068 resulted in antitumor activity ranging from tumor growth delay to regression. Consistent with the role of Akt in a survival pathway, GDC-0068 also enhanced antitumor activity of classic chemotherapeutic agents. CONCLUSIONS: GDC-0068 is a highly selective, orally bioavailable Akt kinase inhibitor that shows pharmacodynamic inhibition of Akt signaling and robust antitumor activity in human cancer cells in vitro and in vivo. Our preclinical data provide a strong mechanistic rationale to evaluate GDC-0068 in cancers with activated Akt signaling.