Background/Objectives: A stem cell therapy for type 1 diabetes (T1D) is experimentally available but only to those few humans in whom the use of systemic immunosuppression can be justified. For others with T1D, a means to deliver the islets needs to be perfected. We have previously bioengineered a removable device for this purpose and now wish to test the effect of adding extracellular matrix (ECM) derived from decellularised human pancreas to it. Methods: The complete device consists of encapsulated pluripotent stem cell differentiated islets seeded into tubular scaffolds of polycaprolactone made by melt electrospin writing and to which ECM was added. The seeded device was implanted either subcutaneously (SC) or intraperitoneally (IP) into streptozotocin diabetic immunodeficient mice. The outcome over the next few months was compared with that achieved in diabetic mice implanted IP with encapsulated islets alone. Results: The device seeded with encapsulated islets but not containing ECM functioned less well than encapsulated islets implanted alone, with lower human C-peptide production. However, when ECM was added to the seeded device and whether implanted SC or IP, islets functioned as efficiently as those implanted without use of a scaffold. Conclusions: These data provide optimism for the use of seeded scaffolds in diabetic humans in whom a single scaffold seeded with multiple encapsulated islets can more readily be removed if needed for safety reasons than can multiple encapsulated islets not seeded into a scaffold.

Background: Implantation of insulin-secreting cells has been trialed as a treatment for Type 1 diabetes mellitus; however, the host immunogenic response limits their effectiveness. Methodology: The authors developed a core-shell nanostructure of upconversion nanoparticle-mesoporous silica for controlled local delivery of an immunomodulatory agent, MCC950, using near-infrared light and validated it in in vitro models of fibrosis. Results: The individual components of the nanosystem did not affect the proliferation of insulin-secreting cells, unlike fibroblast proliferation (p < 0.01). The nanosystem is effective at releasing MCC950 and preventing fibroblast differentiation (p < 0.01), inflammation (IL-6 expression; p < 0.05) and monocyte adhesion (p < 0.01). Conclusion: This MCC950-loaded nanomedicine system could be used in the future together with insulin-secreting cell implants to increase their longevity as a curative treatment for Type 1 diabetes mellitus.

Drug-delivery vehicles have garnered immense interest in recent years due to unparalleled progress made in material science and nanomedicine. However, the development of stimuli-responsive devices with controllable drug-release systems (DRSs) is still in its nascent stage. In this paper, we designed a two-way controlled drug-release system that can be promoted and prolonged, using the external stimulation of near-infrared light (NIR) and protein coating. A hierarchical nanostructure was fabricated using upconversion nanoparticles (UCNPs)—mesoporous silica as the core-shell structure with protein lysozyme coating. The mesoporous silica shell provides abundant pores for the loading of drug molecules and a specific type of photosensitive molecules. The morphology and the physical properties of the nanostructures were thoroughly characterized. The results exhibited the uniform core-shell nanostructures of ~four UCNPs encapsulated in one mesoporous silica nanoparticle. The core-shell nanoparticles were in the spherical shape with an average size of 200 nm, average surface area of 446.54 m2/g, and pore size of 4.6 nm. Using doxorubicin (DOX), a chemotherapy agent as the drug model, we demonstrated that a novel DRS with capacity of smart modulation to promote or inhibit the drug release under NIR light and protein coating, respectively. Further, we demonstrated the therapeutic effect of the designed DRSs using breast cancer cells. The reported novel controlled DRS with dual functionality could have a promising potential for chemotherapy treatment of solid cancers.

The current most pragmatic therapy for type 1 diabetes (T1D) is the administration of insulin through a pump, with continuous monitoring of glucose levels. Replacing the pancreatic beta cells that were destroyed by an autoimmune process will achieve more physiological control of blood glucose levels. However, this treatment is only available to patients with hypoglycaemic unawareness if the benefit outweighs the risk due to the restricted supply of donor pancreatic islets and the requirement that recipients take toxic anti-rejection medicines. Pluripotent stem cell derived beta cells are now a reality, thanks to progress in developmental biology over the past decade. It takes 4 weeks in a laboratory to differentiate beta cells from pluripotent stem cells. The administration of these cells in the clinic requires a bioengineered device that can immunoisolate the beta cells and avoid their rejection by the recipient. The first human trial with beta cell precursors in such a device commenced in 2014 in California, USA, showing safety but not efficacy because of the host reaction to the implant. In the USA, Europe and Australia, different devices have progressed to phase 1b/2a clinical trials. It is reasonable to believe that with such forces in play and the continuing involvement of large pharmaceutical companies, a practical solution to the administration of pluripotent stem cell derived beta cells is near at hand.

A 78-year-old man was referred to clinic due to a 5-year history of weight loss, lethargy, and pathology showing hyponatremia. In the year prior, he had a hospital admission for symptomatic hyponatremia. MRI brain during that admission showed a 1-2 mm pituitary lesion of unknown significance. Testing during this presentation revealed hypocortisolism with ACTH deficiency. Progress MRI brain revealed the presence of a Rathke's Cleft Cyst (RC). Medical management with glucocorticoids resulted in symptomatic and biochemical parameter improvement. To our knowledge this is the first reported case of isolated ACTH deficiency in the setting of a RC.

Immunoprotection and oxygen supply are vital in implementing a cell therapy for type 1 diabetes (T1D). Without these features, the transplanted islet cell clusters will be rejected by the host immune system, and necrosis will occur due to hypoxia. The use of anti-rejection drugs can help protect the transplanted cells from the immune system; yet, they also may have severe side effects. Cell delivery systems (CDS) have been developed for islet transplantation to avoid using immunosuppressants. CDS provide physical barriers to reduce the immune response and chemical coatings to reduce host fibrotic reaction. In some CDS, there is architecture to support vascularization, which enhances oxygen exchange. In this review, we discuss the current clinical and preclinical studies using CDS without immunosuppression as a cell therapy for T1D. We find that though CDS have been demonstrated for their ability to support immunoisolation of the grafted cells, their functionality has not been fully optimized. Current advanced methods in clinical trials demonstrate the systems are partly functional, physically complicated to implement or inefficient. However, modifications are being made to overcome these issues.

Type 1 diabetes (T1D) is a chronic, lifelong metabolic disease. It is characterised by the autoimmune-mediated loss of insulin-producing pancreatic β cells in the islets of Langerhans (β-islets), resulting in disrupted glucose homeostasis. Administration of exogenous insulin is the most common management method for T1D, but this requires lifelong reliance on insulin injections and invasive blood glucose monitoring. Replacement therapies with beta cells are being developed as an advanced curative treatment for T1D. Unfortunately, this approach is limited by the lack of donated pancreatic tissue, the difficulties in beta cell isolation and viability maintenance, the longevity of the transplanted cells in vivo, and consequently high costs. Emerging approaches to address these limitations are under intensive investigations, including the production of insulin-producing beta cells from various stem cells, and the development of bioengineered devices including nanotechnologies for improving islet transplantation efficacy without the need for recipients taking toxic anti-rejection drugs. These emerging approaches present promising prospects, while the challenges with the new techniques need to be tackled for ultimately clinical treatment of T1D. This review discussed the benefits and limitations of the cell-based therapies for beta cell replacement as potential curative treatment for T1D, and the applications of bioengineered devices including nanotechnology to overcome the challenges associated with beta cell transplantation.

Replacement of pancreatic beta-cells is one of the most promising treatment options for treatment of type 1 diabetes (T1D), even though, toxic immunosuppressive drugs are required. In this study, we aim to deliver allogeneic beta-cell therapies without antirejection drugs using a bioengineered hybrid device that contains microencapsulated beta-cells inside 3D polycaprolactone (PCL) scaffolds printed using melt electrospin writing (MEW). Mouse beta-cell (MIN6) pseudoislets and QS mouse islets are encapsulated in alginate microcapsules, without affecting viability and insulin secretion. Microencapsulated MIN6 cells are then seeded within 3D MEW scaffolds, and these hybrid devices implanted subcutaneously in streptozotocin-treated diabetic NOD/SCID and BALB/c mice. Similar to NOD/SCID mice, blood glucose levels (BGL) are lowered from 30.1 to 4.8 mM in 25-41 days in BALB/c. In contrast, microencapsulated islets placed in prevascularized MEW scaffold 3 weeks after implantation in BALB/c mice normalize BGL (<12 mM) more rapidly, lasting for 60-105 days. The lowering of glucose levels is confirmed by an intraperitoneal glucose tolerance test. Vascularity within the implanted grafts is demonstrated and quantified by 3D-doppler ultrasound, with a linear increase over 4 weeks (r = 0.65). Examination of the device at 5 weeks shows inflammatory infiltrates of neutrophils, macrophages, and B-lymphocytes on the MEW scaffolds, but not on microcapsules, which have infrequent profibrotic walling. In conclusion, we demonstrate the fabrication of an implantable and retrievable hybrid device for vascularization and enhancing the survival of encapsulated islets implanted subcutaneously in an allotransplantation setting without immunosuppression. This study provides proof-of-concept for the application of such devices for human use, but, will require modifications to allow translation to people with T1D. Impact statement The retrievable 3D printed PCL scaffold we have produced promotes vascularization when implanted subcutaneously and allows seeded microencapsulated insulin-producing cells to normalize blood glucose of diabetic mice for at least 2 months, without the need for antirejection drugs to be administered. The scaffold is scalable for possible human use, but will require modification to ensure that normalization of blood glucose levels can be maintained long term.

BackgroundSystemic lupus erythematosus (SLE), a severe multiorgan autoimmune disease, involves dysfunction of multiple immune system components. In preclinical studies, KZR-616, a first-in-class small molecule selective inhibitor of the immunoproteasome, demonstrated pleiotropic immunomodulatory functions encompassing both innate and adaptive immune pathways1,2. In the recently completed MISSION Phase 1b trial in SLE patients (pts), KZR-616 exhibited encouraging safety, tolerability, and clinical improvements3. Preliminary biomarker analysis of the first two cohorts was previously reported4. Here, we present complete biomarker results from all cohorts in this study.Objectives1) To characterize biomarker changes (gene expression, circulating protein levels and immune cell phenotypes) following KZR-616 treatment. 2) To evaluate correlations between biomarker changes and treatment response to KZR-616.MethodsThe open-label Phase 1b MISSION Trial (NCT 03393013) was a 25-week trial of KZR- 616 administered subcutaneously once weekly at doses ranging from 30-75 mg for 13 weeks (W) with a 12 W follow-up. Forty-seven SLE pts with and without nephritis were enrolled with 35 completing all 25 W of study. Clinical response definitions at W13 or later were defined as either a >4 reduction of SLEDAI-2K or >50% drop in swollen joint counts (SJC) (baseline SJC>2). Biomarker samples included whole blood in RNA tubes (31 pts), cryopreserved PBMCs (15 pts), plasma (35 pts) and urine (2 pts). Whole blood RNA sequencing was performed using Illumina TruSeq. Differential expression was modelled using DESeq2. Fast pre-ranked gene set enrichment analysis (GSEA) was performed with gene sets derived from published literature. Cryopreserved PBMCs were analysed by flow cytometry to profile immune cell subtypes. Plasma protein was measured by Meso Scale Discovery (MSD) kits. Healthy volunteer (HV, N=12) samples were used to establish potential disease-related biomarker changes in patients at baseline (BL).ResultsMany gene modules were found to be altered at BL in SLE pts, relative to HV, including those representing interferon (IFN) response and B/plasma cells and changes were consistent with our prior report4. Comparisons of SLEDAI-2K responders (R) versus non-responders (NR) revealed enrichment of 193 gene modules (57 down and 136 up-regulated, padj,<0.1) at BL and 190 modules (105 down and 85 up) 4 weeks after treatment (W17). Expression of a 4-gene IFN module was enriched in SLEDAI-2K R vs NR at BL; expression of this module trended downward at W17 in R, whereas it increased over time in NR at W 5. Reduced numbers of circulating class-switched memory B cells and IgG-producing plasma cells were observed at W17 and/or W25. Plasma levels of BAFF were consistently increased at W5 but returned to BL levels by W17. Plasma levels of CD169/ SIGLEC-1, a monocyte activation marker, were higher at BL in SJC R vs. NR and were reduced after treatment in both groups. Two pts with active proliferative nephritis were enrolled into this study and both showed a reduction in levels of urine CD163 (uCD163), while plasma levels of this marker were stable.ConclusionOur integrative analysis indicates that KZR-616 elicits a potent effect on multiple immune pathways in SLE patients. Potential new biomarkers (gene, gene module, circulating protein) that may be useful for prediction of patient response were identified. Future biomarker studies in placebo-controlled trials may further our understanding of KZR-616 mechanism of action, patient selection and prediction of patient responses.References[1]Kirk, C.J. et al., Cells 2022, 11(1):9[2]Muchamuel T, Arthritis Rheumatol. 2019; 71 (suppl 10).[3]Furie R et al., Annals of the Rheumatic Diseases 2021;80:595-596,[4]Fan R, et al., Arthritis Rheumatol. 2019; 71 (suppl 10).AcknowledgementsKezar Life Sciences acknowledges the support of site investigators and patient participants in the MISSION study.Disclosure of InterestsAndrea Fan Shareholder of: Kezar, Employee of: Kezar, Brian Tuch Consultant of: Kezar, Tony Muchamuel Shareholder of: Kezar, Employee of: Kezar, Janet Anderl Shareholder of: Kezar, Employee of: Kezar, Richard Leff Consultant of: Kezar, Noreen Henig Shareholder of: Kezar, Employee of: Kezar, Christopher Kirk Shareholder of: Kezar, Employee of: Kezar

INTRODUCTION:Delirium is one of the most common conditions diagnosed in hospitalised older people and is associated with numerous adverse outcomes, yet there are no proven pharmacological treatments. Recent research has identified cerebral glucose hypometabolism as a pathophysiological mechanism offering a therapeutic target in delirium. Insulin, delivered via the intranasal route, acts directly on the central nervous system and has been shown to enhance cerebral metabolism and improve cognition in patients with mild cognitive impairment and dementia. This trial will determine whether intranasal insulin can reduce the duration of delirium in older hospitalised patients.METHODS AND ANALYSIS:This is a prospective randomised, placebo-controlled, double-blind study with 6 months follow-up. One hundred patients aged 65 years or older presenting to hospital with delirium admitted under geriatric medicine will be recruited. Participants will be randomised to intranasal insulin detemir or placebo administered twice daily until delirium resolves, defined as Confusion Assessment Method (CAM) negative for 2 days, or discharge from hospital. The primary outcome measure will be duration of delirium using the CAM. Secondary outcome measures will include length of hospital stay, severity of delirium, adherence to treatment, hospital complications, new admission to nursing home, mortality, use of antipsychotic medications during hospital stay and cognitive and physical function at 6 months postdischarge.ETHICS AND DISSEMINATION:This trial has been approved by the South Eastern Sydney Human Research and Ethics Committee. Dissemination plans include submission to a peer-reviewed journal for publication and presentation at scientific conferences.TRIAL REGISTRATION NUMBER:ACTRN12618000318280.

Pericapsular fibrotic overgrowth (PFO) is associated with poor survival of encapsulated islets. A strategy to overcome PFO and improve islet function is co-encapsulation with mesenchymal stromal cells (MSC), which have both immunomodulatory and regenerative properties. MSC co-encapsulation did not alter islet viability and significantly improved islet metabolic function. Preconditioning MSC with a pro-inflammatory cytokine cocktail prior to transplantation enhanced their immunosuppressive potential by inducing nitric oxide and by increasing the secretion of immunomodulatory cytokines. MSC co-encapsulation significantly reduced PFO and improved islet graft survival in syngeneic, allogeneic, and xenogeneic transplantation setting with a better outcome seen with preconditioned MSC. Peritoneal lavage demonstrated higher levels of immunomodulatory cytokines such as IL-4, IL-6, IL-10, and IL-13 in the MSC co-encapsulated groups compared to encapsulated islets alone. In summary, preconditioning MSC enhanced their immunosuppressive potential and MSC co-encapsulation improved islet survival by modulating the immune response and reducing PFO.

Background and Objective: New and more efficient methods of gene editing have intensified the ethical and legal issues associated with editing germlines. Yet no research has separated the impact of hereditary concern on public attitudes from moral concern. This research compares the impact these two concerns have on public attitudes across five applications including, the prevention of human disease, human and animal research, animals for the use of human food and the enhancement of human appearance. Methods: A sample of 1004 Australians responded to either a telephone (n = 501; randomly selected) or online survey (n = 503; sourced by Qualtrics). Both samples were representative in terms of States and Territories as well as gender (51% female), though the online sample was younger (M = 40.64, SD = 16.98; Range = 18-87) than the telephone sample (M = 54.79, SD = 18.13; Range = 18-96). A 5 (application) by 3 (type of cell) within groups design was utilized, where all respondents reported their level of approval with scientists editing genes across the 15 different contexts. Multilevel modeling was used to examine the impact of moral (embryo vs. germ) and hereditary (germ vs. somatic) concern on attitudes across all applications. Results: Australians were comfortable with editing human and animal embryos, but only for research purposes and to enhance human health. The effect of moral concern was stronger than hereditary concern, existing in all applications except for the use of animals for human purposes. Hereditary concern was only found to influence attitudes in two applications: improving human health and human research. Moral concern was found to be accentuated amongst, women, more religious individuals and those identifying as Australian, while hereditary concern was strongest amongst non-Australians, those with stronger trust in scientists, and more religious respondents. Conclusion: Moral and hereditary concerns are distinct, and require different approaches to public education, engagement and possibly regulation. Further research needs to explore hereditary concern in relation to non-human applications, and the reasons underlying cultural and gender differences.

Type 1 diabetes, characterized by autoimmune destruction of pancreatic beta cells, affects 41 million people worldwide. Beta cell replacement therapies have immense potential as a treatment option because pancreatic progenitors derived from human pluripotent stem cells can provide a near limitless supply of transplantable tissue. The key limitation of this approach is the need for lifelong use of immunosuppressive drugs that have undesirable side effects. Microencapsulation is an option for providing protection for transplanted cells from mechanical stress and immune attack. Traditionally, pluripotent cells are differentiated on a 2D matrix before being transferred into an immunoisolation device. Here, we describe a method of differentiating pluripotent stem cells into pancreatic progenitors while the cells are encapsulated in alginate microspheres. This method provides several advantages including the need for fewer steps compared to the traditional approach, protection against mechanical/physical damage during differentiation in bioreactors, and immune-protection of cells once transplanted into the host.

Background: Neurotrophic tyrosine receptor kinases (NTRK1-3) are a gene family encoding kinases involved in development and maturation of the central and peripheral nervous system. In cancer, fusion of one of these genes with various upstream partners leads to aberrant protein expression and unchecked proliferation. Identification of tumors driven by TRK fusions is clinically relevant because they can be targeted by highly selective small molecule inhibitors. Pan-TRK immunohistochemical (IHC) staining for aberrant expression of TRK proteins may be an important approach to identify tumors with TRK fusions when followed by confirmation.

Internal Medicine JournalVolume 48, Issue 2 p. 221-222 Letter to the Editor Benefit of routine testicular examination: hypogonadism in a person with 47XYY Eman Negm, Eman Negm Specialist Medical Centre, Sydney, New South Wales, AustraliaSearch for more papers by this authorBernard E. Tuch, Bernard E. Tuch orcid.org/0000-0003-1472-0394 Specialist Medical Centre, Sydney, New South Wales, Australia School of Medical Sciences, Discipline of Physiology, University of Sydney, Sydney, New South Wales, AustraliaSearch for more papers by this author Eman Negm, Eman Negm Specialist Medical Centre, Sydney, New South Wales, AustraliaSearch for more papers by this authorBernard E. Tuch, Bernard E. Tuch orcid.org/0000-0003-1472-0394 Specialist Medical Centre, Sydney, New South Wales, Australia School of Medical Sciences, Discipline of Physiology, University of Sydney, Sydney, New South Wales, AustraliaSearch for more papers by this author First published: 07 February 2018 https://doi.org/10.1111/imj.13696Citations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume48, Issue2February 2018Pages 221-222 RelatedInformation

Technology is now available which facilitates gene editing and has recently been applied internationally to embryos in the laboratory. A 2002 law in Australia prohibits making heritable changes in embryos, regardless of whether the treated embryo is discarded thereafter. We sought to begin to understand public opinion in Australia about this matter, using a questionnaire given to the audience attending a Q and A panel of experts. We found majority support for allowing heritable changes for health purposes. If this is confirmed in a larger survey of the population, we suggest the existing law should be reviewed.

RET kinase gene fusions are actionable drivers that occur in ∼2% of non-small cell lung cancers (NSCLC). However, the clinical activity of multikinase inhibitors (MKIs) with anti-RET activity in RET fusion+ NSCLC patients has been limited. LOXO-292 is a highly selective RET inhibitor, with preclinical activity against diverse RET fusions, potential acquired resistance mutations, and against brain metastases. LIBRETTO-001 is a multicenter global phase 1/2 study (26 sites, 9 countries) enrolling patients w/ advanced solid tumors (NCT03157128) including RET fusion+ NSCLC. Patients are dosed orally in 28-day cycles with dose escalation following a 3+3 design. The primary endpoint is MTD/recommended dose determination. Secondary endpoints include safety, overall response rate (ORR, RECIST 1.1) and duration of response (DoR). Initial data were presented at the ASCO 2018 Annual Meeting. As of 02-April 18, 82 solid tumor patients (including 38 RET fusion+ NSCLC) were treated at 8 doses (20 mg QD-240 mg BID). The MTD was not reached. AEs (≥10% of patients) were fatigue (20%), diarrhea (16%), constipation (15%), dry mouth (12%), nausea (12%), and dyspnea (11%); most were grade 1-2. 2 TEAEs ≥ grade 3 were attributed to LOXO-292 (Gr3 tumor lysis syndrome, Gr3 increased ALT). Of the 38 RET fusion+ NSCLC pts, 30 had at least 1 post-baseline assessment or discontinued LOXO-292 prior to such assessment. 26 of 30 patients (87%) had >20% radiographic tumor reduction (range: -21 to -72%). The ORR was 77% (23/30, 3 responses pending confirmation) with a confirmed ORR of 74% (20/27, excluding 3 patients with unconfirmed responses). The response rate was similar regardless of prior MKI treatment (12/15 MKI-naïve, 11/15 MKI pretreated). Responses occurred independent of upstream fusion partner when known (13/16 KIF5B vs 9/11 other) and included patients w/ baseline brain metastases. Most patients remained on treatment (33/38), including all responders. The median DoR was not reached (longest response was the first responder: >10+ months). Rapid plasma clearance of RET variants was observed, with complete clearance by day 15 in 10 of 17 (59%) NSCLC patients with assessable baseline and day 15 ctDNA. LOXO-292 was well-tolerated and had marked antitumor activity in RET-fusion+ NSCLC patients, including those w/ resistance to prior MKIs and brain metastases. Phase 2 cohorts are now open globally (160 mg BID). Updated safety and efficacy data as of 19 Jul 2018 will be presented.

Human islet transplantation, as currently carried out by portal vein infusion in the liver, can provide good glycaemic control in diabetic patients and can significantly reduce the need to inject exogenous insulin. Perhaps the main challenge in islet transplantation is the need for life long immunosuppression which is highly undesirable due to side effects resulting in poor quality of life. Unquestionably, there has been significant progress in clinical islet transplantation, but many challenges are yet to be overcome. This calls for novel approaches to make islet based therapies more practical, sustainable and economical. By preventing adverse immune reaction and creating an environment that would reduce death of the grafted cells islet transplantation strategies can be vastly improved. Here we discuss various bioengineering approaches that are currently in development to achieve desirable outcome in islet transplantation within a clinical setting.

RET fusions are validated therapeutic targets in human lung cancers. However, the clinical activity of multikinase inhibitors (MKIs) with anti-RET activity is limited by a narrow therapeutic index from off-target effects and poor pharmacokinetics (PK). Moreover, MKIs have limited RET inhibition in the central nervous system (CNS), and patients often experience disease progression in the brain. LOXO-292 is a potent and highly selective RET inhibitor, with >100-fold selectivity versus important off-targets, and anti-tumor activity in the brain and periphery in RET-dependent tumor models in vivo. Two RET fusion-positive lung cancer patients were treated with LOXO-292: a patient with CCDC6-RET-rearranged lung cancer with acquired resistance to RXDX-105; and a patient with KIF5B-RET-rearranged lung cancer with progressive disease in the brain while on alectinib treated under a single patient protocol with real-time, PK- guided intra-patient dose titration. The first patient was enrolled on cohort 1 of the Phase 1 trial (20 mg daily) and was the first lung cancer patient to receive LOXO-292. She achieved a rapid, confirmed partial response (PR) by RECIST 1.1, with a 44% reduction in target lesion size. The second patient, the first to receive LOXO-292 in the setting of brain metastases, achieved a PR with escalating doses of LOXO-292 (20-60-100 mg twice daily) that included target lesion responses in both the lungs and brain (Fig 1), and resolution of cancer-related CNS symptoms. Early clinical experience with LOXO-292 has already established drug exposures that are consistent with significant RET inhibition in vitro and RET-dependent tumor regression in vivo. Importantly, LOXO-292 has been well-tolerated, with the majority of treatment-emergent adverse events reported as Grade 1-2, and none attributed to LOXO-292. LOXO-292 has demonstrated proof-of-concept tolerability, significant exposure, and efficacy in two patients with MKI-resistant, RET-dependent cancers, including a patient with progressive brain metastases after alectinib.