Phase I study of sapanisertib (CB-228/TAK-228/MLN0128) in combination with ziv-aflibercept in patients with advanced solid tumors.

BACKGROUND: Sapanisertib is a potent ATP-competitive, dual inhibitor of mTORC1/2. Ziv-aflibercept is a recombinant fusion protein comprising human VEGF receptor extracellular domains fused to human immunoglobulin G1. HIF-1α inhibition in combination with anti-angiogenic therapy is a promising anti-tumor strategy. This Phase 1 dose-escalation/expansion study assessed safety/ tolerability of sapanisertib in combination with ziv-aflibercept in advanced solid tumors. METHODS: Fifty-five patients with heavily pre-treated advanced metastatic solid tumors resistant or refractory to standard treatment received treatment on a range of dose levels. RESULTS: Fifty-five patients were enrolled and treated across a range of dose levels. Forty were female (73%), median age was 62 (range: 21-79), and ECOG PS was 0 (9, 16%) or 1 (46, 84%). Most common tumor types included ovarian (8), colorectal (8), sarcoma (8), breast (3), cervical (4), and endometrial (4). Median number of prior lines of therapy was 4 (range 2-11). Sapanisertib 4 mg orally 3 days on and 4 days off plus 3 mg/kg ziv-aflibercept IV every 2 weeks on a 28-day cycle was defined as the maximum tolerated dose. Most frequent treatment-related grade ≥2 adverse events included hypertension, fatigue, anorexia, hypertriglyceridemia, diarrhea, nausea, mucositis, and serum lipase increase. There were no grade 5 events. In patients with evaluable disease (n = 50), 37 patients (74%) achieved stable disease (SD) as best response, two patients (4%) achieved a confirmed partial response (PR); disease control rate (DCR) (CR + SD + PR) was 78%. CONCLUSION: The combination of sapanisertib and ziv-aflibercept was generally tolerable and demonstrated anti-tumor activity in heavily pre-treated patients with advanced malignancies.

Phase I Study of mTORC1/2 Inhibitor Sapanisertib (CB-228/TAK-228) in Combination with Metformin in Patients with mTOR/AKT/PI3K Pathway Alterations and Advanced Solid Malignancies.

BACKGROUND: Sapanisertib (CB-228/TAK-228) is a potent, selective ATP-competitive, dual inhibitor of mTORC1/2. Metformin is thought to inhibit the mTOR pathway through upstream activation of 5'-AMP-activated protein kinase (AMPK) suggesting combination therapy may enhance antitumor activity of sapanisertib. We report preliminary safety, tolerability, and efficacy from the dose-escalation study of sapanisertib in combination with metformin in patients with advanced solid tumors. METHODS: Patients with advanced metastatic solid tumors resistant or refractory to standard treatment, with and without mTOR/AKT/PI3K pathway alterations, received sapanisertib 3 or 4 mg daily together with metformin once to three times daily (500-1,500 mg). All patients underwent 14-day titration period for metformin in cycle 1. Tumor measurements were performed following cycle 2 and subsequently every 8 weeks. RESULTS: A total of 30 patients were enrolled across four cohorts (3 mg/500 mg; 3 mg/1,000 mg, 4 mg/1,000 mg; 4 mg/1,500 mg). 19 were female (63%), median age was 57 (range: 30-77), all were Eastern Cooperative Oncology Group performance status 1. Tumor types included sarcoma (6), breast (4), ovarian (4), head and neck (3), colorectal (2), lung (2), renal cell (2), endometrial (2), gastroesophageal junction (1), prostate (1), stomach (1), urachus (1), and cervical cancer (1). Median number of prior lines of therapy was 4. Most common genomic alterations included PIK3CA (27%), PTEN (17%), AKT1/2 (10%), mTOR (10%). Of 30 patients evaluable for response, 4 patients achieved partial response (PR); 15 patients achieved stable disease (SD) as best response. Disease control rate (PR+SD) was 63%. Of the responders in PR, 3 of 4 patients had documented PTEN mutations (3/5 patients enrolled with PTEN mutations had PR); 2 of 4 of patients in PR had comutations (patient with leiomyosarcoma had both PTEN and TSC; patient with breast cancer had both PTEN and STK11); 1 of 4 patients in PR had AKT and mTOR mutation; tumor types included leiomyosarcoma (n = 2), breast (n = 1), and endometrial cancer (n = 1). Most common treatment-emergent adverse events included nausea, anorexia, diarrhea, and rash. Grade (G) 3-5 treatment-related adverse events included hyperglycemia (4/30; 13%), fatigue (2/30; 7%), hypertriglyceridemia (1/30; 3%), rash (2/20; 7%), diarrhea (2/30; 7%), creatinine increase (1/30; 3%), acidosis (1/30; 3%). No dose-limiting toxicities (DLT) were reported in the 3 mg/500 mg cohort. One of 6 patient had DLT in the 3 mg/1,000 mg cohort (G3 diarrhea) and 2 of 11 patients had DLTs in the 4 mg/1,500 mg cohort (G3 fatigue, G3 rash). 4 mg/1,000 mg was defined as the MTD. CONCLUSIONS: The safety profile of mTORC1/2 inhibitor sapanisertib in combination with metformin was generally tolerable, with antitumor activity observed in patients with advanced malignancies harboring PTEN mutations and AKT/mTOR pathway alterations. SIGNIFICANCE: Sapanisertib (CB-228/TAK-228) is a potent, selective ATP-competitive, next-generation dual inhibitor of mTORC1/2. Metformin is thought to inhibit the mTOR pathway through upstream activation of AMPK suggesting combination therapy may enhance antitumor activity of sapanisertib. This dose-escalation study of sapanisertib and metformin in advanced solid tumors and mTOR/AKT/PI3K pathway alterations, demonstrates safety, tolerability, and early clinical activity in advanced malignancies harboring PTEN mutations and AKT/mTOR pathway alterations.Clinical trial information: NCT03017833.

HRAS Mutations Define a Distinct Subgroup in Head and Neck Squamous Cell Carcinoma.

PURPOSE: In head and neck squamous cell carcinoma (HNSCC), HRAS mutation is a new actionable oncogene driver. We aimed to evaluate HRAS mutational variants, comutation profile, and survival outcomes of this molecularly defined population. METHODS: We leveraged four deidentified patient data sets with HRAS-mutant HNSCC, MD Anderson Cancer Center, Kura Oncology, Inc trial, Foundation Medicine, and American Association for Cancer Research GENIE v.12. Patient demographic information and clinical courses were extracted, when available, in addition to HRAS mutation type and co-occurring mutations. Survival outcomes were analyzed (Kaplan-Meier method). RESULTS: Two hundred forty-nine patients with HRAS-mutant HNSCC were identified from the four data sets. Median age ranged from 55 to 65 years, with a higher frequency in male patients (64%); the majority of HRAS-mutant HNSCC occurred in human papillomavirus-negative HNSCC. HRAS mutation patterns were similar across data sets; G12S was the most common (29%). Treatment responses to tipifarnib were not codon-specific. Compared with wild-type, significantly co-occurring mutations with HRAS were Casp8 (Fisher's exact test, P < .00013), TERT (P < .0085), and NOTCH1 (P < .00013). Analysis of clinical courses from the MD Anderson Cancer Center and Kura Oncology, Inc data sets demonstrated poor clinical outcomes with a high rate of recurrence following primary definitive treatment (50%-67% relapse < 6 months) and short disease-free survival (4.0 months; 95% CI, 1.0 to 36.0) and overall survival (OS; 15.0 months; 95% CI, 6.0 to 52.0). Use of tipifarnib in this data set demonstrated improved OS (25.5 months; 95% CI, 18.0 to 48.0). CONCLUSION: Oncogenic mutations in HRAS occur in 3%-4% of HNSCC, with G12S being the most frequent. Without targeted therapy, patients with HRAS-mutant HNSCC had poor clinic outcomes; observable trend toward improvement in OS has been noted in cohorts receiving treatments such as tipifarnib. The comutation pattern of HRAS-mutant in HNSCC is distinct, which may provide insight to future therapeutic combination strategies.

Antibody-drug conjugates in lung cancer: dawn of a new era?

Antibody-drug conjugates (ADCs) are one of fastest growing classes of oncology drugs in modern drug development. By harnessing the powers of both cytotoxic chemotherapy and targeted therapy, ADCs are unique in offering the potential to deliver highly potent cytotoxic agents to cancer cells which express a pre-defined cell surface target. In lung cancer, the treatment paradigm has shifted dramatically in recent years, and now ADCs are now joining the list as potential options for lung cancer patients. Since 2020, the first ADC for NSCLC patients has been FDA-approved (trastuzumab deruxtecan) and two ADCs have been granted FDA Breakthrough Therapy Designation, currently under evaluation (patritumab deruxtecan, telisotuzumab vedotin). Furthermore, several early-phase trials are assessing various novel ADCs, either as monotherapy or in combinations with advanced lung cancer, and more selective and potent ADCs are expected to become therapeutic options in clinic soon. In this review, we discuss the structure and mechanism of action of ADCs, including insights from pre-clinical work; we summarize the ADCs' recent progress in lung cancer, describe toxicity profiles of ADCs, and explore strategies designed to enhance ADC potency and overcome resistance. In addition, we discuss novel ADC strategies of interest in lung cancer, including non-cytotoxic payloads, such as immunomodulatory and anti-apoptotic agents.

Worth the paper they are printed on? Findings from an independent evaluation of the understandability of patient information leaflets for antiseizure medications.

OBJECTIVE: The Patient Information Leaflet (PIL) is an authoritative document that all people with epilepsy in the EU receive when prescribed antiseizure medication (ASM). We undertook the first independent, comprehensive assessment to determine how understandable they are. Regulators state that when patients are asked comprehension questions about them, ≥80% should answer correctly. Also, recommended is that PILs have a maximum reading requirement of US grade 8. METHODS: Study 1: We obtained 140 current ASM PILs written in English. "Readability" was assessed using four tests, with and without adjustment for influence of familiar, polysyllabic words. A total of 179 online materials on epilepsy were also assessed. Study 2: Two PILs from Study 1 were randomly selected (Pregabalin Focus; Inovelon) and shown to 35 people from the UK epilepsy population. Their comprehension was assessed. Study 3: To understand whether the student population provides an accessible alternative population for future examination of ASM PILs, Study 3 was completed, using the same methods as Study 2, except that participants were 262 UK university students. RESULTS: Study 1: No PIL had a reading level of grade 8. Median was grade 11. Adjusting for context, the PILs were still at grade 10.5. PILs for branded ASMs were most readable. PILs were no more readable than (unregulated) online materials. Study 2: Users struggled to comprehend the PILs' key messages. The eight questions asked about pregabalin were typically answered correctly by 54%. For Inovelon, it was 62%. Study 3: Most student participants comprehended the PILs' key messages. The questions about Inovelon were answered correctly by 90%; for pregabalin it was 86%. SIGNIFICANCE: This is the first independent and comprehensive examination of ASM PILs. It found that PILs being used fail to meet recommendations and regulatory requirements and risk not being understandable to a substantial proportion of users. In finding that people from the epilepsy population differ markedly in comprehension of PILs compared to students, this study highlights the importance of completing user testing with the target population.

Targeting un-MET needs in advanced non-small cell lung cancer.

Lung cancer classification has been radically transformed in recent years as genomic profiling has identified multiple novel therapeutic targets including MET exon 14 (METex14) alterations and MET amplification. Utilizing targeted therapies in patients with molecularly-defined NSCLC leads to remarkable objective response rates and improved progression-free survival. However, acquired resistance is inevitable. Several recent phase II trials have confirmed that METex14 NSCLC can be treated effectively with MET kinase inhibitors, such as crizotinib, capmatinib, tepotinib, and savolitinib. However, response rates for many MET TKIs are modest relative to the activity of targeted therapy in other oncogene-driven lung cancers, where ORRs are more consistently greater than 60%. In spite of significant gains in the field of MET inhibition in NSCLC, challenges remain: the landscape of resistance mechanisms to MET TKIs is not yet well characterized, and there may be intrinsic and acquired resistance mechanisms that require further characterization to enable increased MET TKI activity. In this review, we overview MET pathway dysregulation in lung cancer, methods of detection in the clinic, recent clinical trial data, and discuss current mechanisms of TKI resistance, exploring emerging strategies to overcome resistance.

Clinical Development of AKT Inhibitors and Associated Predictive Biomarkers to Guide Patient Treatment in Cancer Medicine.

The serine/threonine kinase AKT is a critical effector of the phosphoinositide 3-kinase (PI3K) signaling cascade and has a pivotal role in cell growth, proliferation, survival, and metabolism. AKT is one of the most commonly activated pathways in human cancer and dysregulation of AKT-dependent pathways is associated with the development and maintenance of a range of solid tumors. There are multiple small-molecule inhibitors targeting different components of the PI3K/AKT pathway currently at various stages of clinical development, in addition to new combination strategies aiming to boost the therapeutic efficacy of these drugs. Correlative and translational studies have been undertaken in the context of clinical trials investigating AKT inhibitors, however the identification of predictive biomarkers of response and resistance to AKT inhibition remains an unmet need. In this review, we discuss the biological function and activation of AKT, discuss its contribution to tumor development and progression, and review the efficacy and toxicity data from clinical trials, including both AKT inhibitor monotherapy and combination strategies with other agents. We also discuss the promise and challenges associated with the development of AKT inhibitors and associated predictive biomarkers of response and resistance.

Landscape and Clonal Dominance of Co-occurring Genomic Alterations in Non-Small-Cell Lung Cancer Harboring MET Exon 14 Skipping.

MET exon 14 skipping alterations (METex14) comprise a diverse set of actionable oncogene drivers in non-small-cell lung cancer (NSCLC). Recent studies have established the efficacy of tyrosine kinase inhibitors for this patient population. The landscape of co-occurring genetic alterations in METex14 NSCLC and their potential impact to therapeutic sensitivities has not yet been fully described. MATERIALS AND METHODS: METex14 NSCLC cases were collected from three cohorts: the VISION trial, and data sets from Guardant360 and GenePlus. Clinicopathologic characteristics and METex14 mutation sites were analyzed and compared across data sets. Co-occurring genetic alterations and the clonality relationships to METex14 were evaluated. RESULTS: Of 40,824 NSCLCs, 692 METex14 cases (1.7%) were identified, including 332 in Guardant360, 188 in VISION, and 172 in GenePlus. The demographics and mutation type and/or sites were similar in the Asian versus Western cohorts. MET amplification, which were found to be associated with sensitivity to MET kinase inhibitors, co-occurs in 7.6%-13.8% of cases, whereas kinase domain secondary mutation of MET co-occurs in 5%-6%. When co-occurring with METex14, EGFR mutations were often identified as the dominant clone (78%, 7 of 9), whereas when co-occurring, METex14 (39%, 7 of 18) and KRAS (44%, 8 of 18) had similar rates of clonal dominance. PIK3CA and PTEN mutations were almost always subclones (89%, 16 of 18) to METex14. Moreover, RET-CCDC6 fusion and EGFR mutation were detected following crizotinib treatment in two patients, suggesting novel mechanisms of resistance. CONCLUSION: METex14 mutations frequently co-occur with other potential driver oncogenes with differing patterns of clonal dominance observed among the drivers. This cellular context can provide insights into whether METex14 is acting as a primary oncogenic driver or resistance mechanism and help guide treatment choices.

Emergence of mTOR mutation as an acquired resistance mechanism to AKT inhibition, and subsequent response to mTORC1/2 inhibition.

Acquired resistance to molecular targeted therapy is a significant challenge of the precision medicine era. The ability to understand these mechanisms of resistance may improve patient selection and allow for the development of rationally designed next-line or combination treatment strategies and improved patient outcomes. AKT is a critical effector of the phosphoinositide 3-kinase signaling cascade, one of the most commonly activated pathways in human cancer. Deregulation of signaling pathways, such as RAF/MEK/ERK are previously described mechanisms of resistance to AKT/PI3K inhibitors. Mutations in the mTOR gene, however, are exceedingly rare. We present a case of acquired mTOR resistance, following targeted AKT inhibition, and subsequent response to mTOR1/2 inhibitor in a patient with metastatic endometrial cancer, the first documented response to ATP-competitive mTOR inhibition in this setting. This case supports mTOR mutation as a mechanism of resistance, and underscores the importance of tumor molecular profiling, exemplifying precision medicine in action.

Taking Aim at the Undruggable.

The term "undruggable" is used to describe a protein that is not pharmacologically capable of being targeted; recently, however, substantial efforts have been made to turn these proteins into "druggable" targets. Thus, "difficult to drug" or "yet to be drugged" are perhaps more appropriate terms. In cancer, a number of elusive targets fall into this category, including transcription factors such as STAT3, TP53, and MYC. Pharmacologically targeting these intractable proteins is now a key challenge of modern drug development, requiring innovation and the development of new technologies. In this article, we discuss some of the recent technologic and pharmacologic advances that have underpinned the erosion of the concept of undruggability. We describe recent successes in drugging the undruggable RAS (KRAS G12C and HRAS), and discuss the advances that have led to the validation of further targets previously believed to be undruggable, such as HIF-2α, BCL-2, MDM2, and MLL. Finally, we look to the future and describe important advances that are likely to have a major impact on targeting undruggable targets, such as the advent of proteolysis-targeting chimeras and protein-protein modulators, which are leading to considerable excitement surrounding the development of cancer targets.

The role of Schlafen 11 (SLFN11) as a predictive biomarker for targeting the DNA damage response.

The therapeutic landscape of drugs targeting the DNA damage response (DDR) is rapidly expanding; however, an urgent unmet need remains for validated predictive biomarkers of response. SLFN11 has emerged as a promising predictor of sensitivity to DNA-damaging chemotherapies, and recently, been associated with sensitivity to PARP inhibition. We discuss its use as a predictive biomarker of response for targeting the DDR.

Transformation to neuroendocrine carcinoma as a resistance mechanism to lorlatinib.

OBJECTIVES: Small cell transformation is a well-recognized mechanism of resistance to EGFR-TKI therapy in EGFR-mutant NSCLC, yet it remains a poorly-described phenomenon in ALK-rearranged NSCLC. MATERIAL AND METHODS: Chart and literature review. RESULTS: We report a case of a patient with ALK-rearranged lung cancer progressing on three-lines of ALK-targeted therapies, with development of acquired resistance to lorlatinib, with both transformation to a neuroendocrine carcinoma, and acquisition of ALK 1196 M. CONCLUSIONS: Given the inevitable development of resistance in ALK + NSCLC, if feasible, re-biopsy on progression should be standard over liquid biopsy. Neuroendocrine carcinoma transformation remains an important mechanism of acquired resistance to lorlatinib.

Where youth matters-clinicopathologic characteristics and emerging trends in treatment and outcomes in young Irish women with breast cancer.

BACKGROUND: Young women with breast cancer (YWBC) represent 7-12% of breast cancer diagnoses and ostensibly have more biologically aggressive subtypes with higher relapse and mortality rates. We studied the clinical and pathological characteristics in YWBC and examined how outcomes and treatment have evolved. METHODS: YWBC were identified from pathology databases at two tertiary centers. Patients were divided into two cohorts: those diagnosed from 2000 to 2005 (C1) and from 2006 to 2015 (C2). Data were retrieved from clinical, radiology, and histology databases. Statistical analysis was performed using R® (V3.2.0). RESULTS: We identified 345 patients. Median age was 36 years (23-39 years). Mastectomy was performed in 232 patients (67.2%) and axillary lymph node clearance (ALNC) in 207 patients (60% [C1 82.7 vs. C2: 49.4%, p < 0.001]). One hundred-seventy patients (49%) were ER + HER2-, 88 (25.5%) were HER2+, and 58 (16.8%) were triple negative. Eighty patients (23.2%) received neoadjuvant therapy. Pathological complete response rates were statistically similar between C1 and C2 [C1 1 (0.9%) vs C2 16 (6.8%) p = 0.1]. Distant relapse occurred in 59 (19%) patients. There was a higher relapse rate (RR) in C1 [27 (32.1%) vs. 32 (15.7%), p < 0.002). HER2+ and ER+ HER2- patients in C1 had higher RRs than C2. Median overall survival in patients with metastatic disease was 29 months (range 2-119 months). CONCLUSION: Locally advanced disease was more prevalent in YWBC. Mastectomy and ALNC rates were high and most received multimodal treatment. The extent of axillary surgery declined over time. Outcomes were unchanged in triple negative patients. These remain a priority for research.

Detection of circulating tumour cell clusters in human glioblastoma.

Human glioblastoma (GBM) is a highly aggressive, invasive and hypervascularised malignant brain cancer. Individual circulating tumour cells (CTCs) are sporadically found in GBM patients, yet it is unclear whether multicellular CTC clusters are generated in this disease and whether they can bypass the physical hurdle of the blood-brain barrier.  Here, we assessed CTC presence and composition at multiple time points in 13 patients with progressing GBM during an open-label phase 1/2a study with the microtubule inhibitor BAL101553. We observe CTC clusters ranging from 2 to 23 cells and present at multiple sampling time points in a GBM patient with pleomorphism and extensive necrosis, throughout disease progression. Exome sequencing of GBM CTC clusters highlights variants in 58 cancer-associated genes including ATM, PMS2, POLE, APC, XPO1, TFRC, JAK2, ERBB4 and ALK. Together, our findings represent the first evidence of the presence of CTC clusters in GBM.

CNS cancer immunity cycle and strategies to target this for glioblastoma.

Immunotherapeutics have revolutionized the management of solid malignancies over the last few years. Nevertheless, despite relative successes of checkpoint inhibitors in numerous solid tumour types, success in tumours of the central nervous system (CNS) has been lacking. There are several possible reasons for the relative lack of success of immunotherapeutics in this setting, including the immune microenvironment of glioblastoma, lymphocyte tracking through the blood-brain barrier (BBB) into the central nervous system and impairment of drug delivery into the CNS through the BBB. This review utilizes the cancer-immunity cycle as a conceptual framework through which the specific challenges associated with the development of immunotherapeutics for CNS malignancies can be viewed.

Safety, efficacy and survival of patients with primary malignant brain tumours (PMBT) in phase I (Ph1) trials: the 12-year Royal Marsden experience.

BACKGROUND: Primary malignant brain tumours (PMBT) constitute less than 2% of all malignancies and carry a dismal prognosis. Treatment options at relapse are limited. First-in-human solid tumour studies have historically excluded patients with PMBT due to the poor prognosis, concomitant drug interactions and concerns regarding toxicities. METHODS: Retrospective data were collected on clinical and tumour characteristics of patients referred for consideration of Ph1 trials in the Royal Marsden Hospital between June 2004 and August 2016. Survival analyses were performed using the Kaplan-Meier method, Cox proportional hazards model. Chi squared test was used to measure bivariate associations between categorical variables. RESULTS: 100pts with advanced PMBT were referred. At initial consultation, patients had a median ECOG PS 1, median age 48 years (range 18-70); 69% were men, 76% had glioblastoma; 68% were on AEDs, 63% required steroid therapy; median number of prior treatments was two. Median OS for patients treated on a Ph1 trials was 9.3 months (95% CI 5.9-12.9) versus 5.3 months (95% CI 4.1-6.1) for patients that did not proceed with a Ph1 trial, p = 0.0094. Steroid use, poor PS, neutrophil-to-lymphocyte ratio and treatment on a Ph1 trial were shown to independently influence OS. CONCLUSIONS: We report a survival benefit for patients with PMBT treated on Ph1 trials. Toxicity and efficacy outcomes were comparable to the general Ph1 population. In the absence of an internationally recognized standard second line treatment for patients with recurrent PMBT, more Ph1 trials should allow enrolment of patients with refractory PMBT and Ph1 trial participation should be considered at an earlier stage.

Development of Molecularly Targeted Agents and Immunotherapies in Glioblastoma: A Personalized Approach.

Over the past decade, precision cancer medicine has driven major advances in the management of advanced solid tumours with the identification and targeting of putative driver aberrations transforming the clinical outcomes across multiple cancer types. Despite pivotal advances in the characterization of genomic landscape of glioblastoma, targeted agents have shown minimal efficacy in clinical trials to date, and patient survival remains poor. Immunotherapy strategies similarly have had limited success. Multiple deficiencies still exist in our knowledge of this complex disease, and further research is urgently required to overcome these critical issues. This review traces the path undertaken by the different therapeutics assessed in glioblastoma and the impact of precision medicine in this disease. We highlight challenges for precision medicine in glioblastoma, focusing on the issues of tumour heterogeneity, pharmacokinetic-pharmacodynamic optimization and outline the modern hypothesis-testing strategies being undertaken to address these key challenges.