Faculty Bibliography

Background Nearly all colorectal and most pancreatic and lung cancers express carcinoembryonic antigen (CEA). However, due to its expression in normal gut epithelial cells, CEAtargeted therapies have resulted in on-target, off-tumor toxicity. To overcome this, we have developed TmodTM, a logicgated T-cell therapy platform. Tmod constructs are composed of an activating CAR or T-cell receptor that targets a tumor antigen and an inhibitory receptor recognizing an antigen expressed on normal healthy tissues, but not on tumor cells due to loss of heterozygosity (LOH).1,2 A2B530 is a CEAdirected Tmod construct utilizing an LIR-1-based inhibitory receptor (blocker) targeting human leukocyte antigen A*02 (HLA-A*02). Methods To generate CEA Tmod, T cells from HLA-A*02(+) donors were transduced with a single lentivirus to express i) the CAR, ii) the blocker, and iii) an shRNA targeting b2M. Cytotoxicity was measured by culturing CEA(+) target cell line pairs (A*02[-] and A*02[+]), expressing either GFP or RFP, with engineered T cells and quantifying live target cells over time. In vivo activity was examined using NSG mice subcutaneously implanted with normal (CEA[+]A*02[+]) and tumor cells (CEA[+]A*02[-]), in the right and left flanks. Mice were treated intravenously with CEA Tmod cells or control T cells. Results Control CEA CAR T cells killed CEA(+) target cell lines in vitro irrespective of HLA-A*02 expression. In contrast, CEA Tmod cells selectively killed tumor cells (CEA[+]A*02[-]) while sparing normal cells (CEA[+]A*02[+]). In mixed target cell cultures, CEA Tmod cells killed only the A*02(-) target cells, whereas the CEA CAR T cells killed both the A*02(- ) and A*02(+) cell lines. Further, CEA Tmod cells exhibited bidirectional control between the activated and blocked states. While mice treated with control CEA CAR T cells experienced a reduction in volume and bioluminescence of both normal and tumor grafts, CEA Tmod cells specifically cleared A*02(-) tumors in mice (table 1). Finally, although expansion of Tmod cells in peripheral blood trended lower than CAR and TCR controls, anti-tumor activity was comparable in these groups. Conclusions A2B530 is an autologous CEA Tmod cell product that exploits common LOH at the HLA locus in cancer cells, enabling these engineered T cells to discriminate between normal and tumor cells. BASECAMP-1 (NCT04981119), an observational study identifying patients with somatic HLA LOH, is recruiting. Eligible patients with metastatic colorectal, pancreatic, or non-small cell lung cancer will be apheresed for a future A2B530 EVEREST-1 interventional study

Type 2 diabetes mellitus (T2DM) is associated with advanced glycation end product (AGE) enrichment and considered a risk factor for intervertebral disc (IVD) degeneration. We hypothesized that systemic AGE inhibition, achieved using pyridoxamine (PM), attenuates IVD degeneration in T2DM rats. To induce IVD degeneration, lumbar disc injury or sham surgery was performed on Zucker Diabetic Sprague Dawley (ZDSD) or control Sprague Dawley (SD) rats. Post-surgery, IVD-injured ZDSD rats received daily PM dissolved in drinking water or water only. The resulting groups were SD uninjured, SD injured, ZDSD uninjured, ZDSD injured, and ZDSD injured + PM. Levels of blood glycation and disc degeneration were investigated. At week 8 post-surgery, glycated serum protein (GSP) levels were increased in ZDSDs compared to SDs. PM treatment attenuated this increase. Micro-MRI analysis demonstrated IVD dehydration in injured versus uninjured SDs and ZDSDs. In the ZDSD injured + PM group, IVD dehydration was diminished compared to ZDSD injured. AGE levels were decreased and aggrecan levels increased in ZDSD injured + PM versus ZDSD injured rats. Histological and immunohistochemical analyses further supported the beneficial effect of PM. In summary, PM attenuated GSP levels and IVD degeneration processes in ZDSD rats, demonstrating its potential to attenuate IVD degeneration in addition to managing glycemia in T2DM.

CASE:Stiff-person syndrome (SPS) presents with progressive muscle rigidity, postural instability, and periodic debilitating spasms. Reports of axial hyperextension exist, but kyphotic deformities have not been described. We surgically treated a patient with debilitating SPS and severe cervicothoracic hyperkyphosis with posterior spinal fusion and instrumentation. At 1-year follow-up, the patient displayed better upright gait and forward gaze, 18° cervical lordosis, and improved patient-reported outcome scores. CONCLUSION:SPS can lead to extreme spinal deformity and disease, including hyperkyphosis of the cervicothoracic spine, and can successfully be managed with a multidisciplinary team and a posterior-only correction with spinal instrumentation and fusion.

STUDY DESIGN/UNASSIGNED:Post hoc comparison using single-site data from 4 multicenter randomized controlled trials. OBJECTIVES/UNASSIGNED:Discogenic back pain is associated with significant morbidity and medical cost. Several terminated, unreported randomized controlled trials have studied the effect of intradiscal biologic injections. Here we report single-center outcomes from these trials to determine if there is clinical improvement associated with these intradiscal injections. METHODS/UNASSIGNED:Post hoc comparison was performed using single-site data from 4 similar multi-center randomized controlled trials. All trials evaluated an injectable therapy (growth factor, fibrin sealant, or stem cells) for symptomatic lumbar disc disease with near-identical inclusion and exclusion criteria. Demographics and patient reported outcomes were analyzed across treatment arms postinjection. RESULTS/UNASSIGNED:< .01). There was no significant difference in VAS scores between the saline and investigational groups at 12 months. Similarly, there was significant improvement in patient-reported disability scores in both the investigational and saline groups at all time points. There were no significant differences in disability score improvement between the saline and investigational treatment groups at 12 months postinjection. CONCLUSIONS/UNASSIGNED:A single-center analysis of 4 randomized controlled studies demonstrated no difference in outcomes between therapeutic intradiscal agents (growth factor, fibrin sealant, or stem cells) and control saline groups. In all groups, patient reported pain and disability scores decreased significantly. Future studies are needed to evaluate the therapeutic benefit of any intradiscal injections.

INTRODUCTION:Synthetic bone grafts are often used to achieve a well-consolidated fusion mass in spinal fusion procedures. These bone grafts function as scaffolds, and ideally support cell function and facilitate protein binding. OBJECTIVE:The aim was to characterize an electrospun, synthetic bone void filler (Reb) for its bone morphogenetic protein (BMP)-2 release properties and support of human mesenchymal stem cell (hMSC) function in vitro, and its efficacy in promoting BMP-2-/bone marrow aspirate-(BMA)-mediated posterolateral spinal fusion (PLF) in vivo. METHODS:BMP-2 release kinetics from Reb versus standard absorbable collagen sponge (ACS) was determined. hMSC adhesion and proliferation on Reb was tested using cell counting, fluorescence microscopy and MTS. Cell osteogenic differentiation was quantified via cellular alkaline phosphatase (ALP) activity. For in vivo analysis, 18 Lewis rats were treated during PLF surgery with the following groups: (I) Reb + BMA, (II) Reb + BMA + BMP-2 and (III) BMA. A safe, minimally effective dose of BMP-2 was used. Fusion consolidation was followed for 3 months using radiography and micro-CT. After sacrifice, fusion rate and biomechanical stiffness was determined using manual palpation, biomechanical tests and histology. RESULTS:In vitro, BMP-2 release kinetics were similar between Reb versus ACS. MSC proliferation and differentiation were increased in the presence of Reb. At 3 months post-surgery, fusion rates were 29% (group I), 100% (group II), and 0% (group III). Biomechanical stiffness was higher in group II versus I. Micro-CT showed an increased bone volume and connectivity density in group II. Trabecular thickness was increased in group I versus II. H&E staining showed newly formed bone in group II only. CONCLUSIONS:Reb possesses a high protein binding affinity and promotes hMSC function. Combination with BMA and minimal dose BMP-2 allowed for 100% bone fusion in vivo. This data suggests that a minimally effective dose of BMP-2 can be used when combined with Reb.

Introduction/UNASSIGNED:Intervertebral disc (IVD) degeneration is often associated with low back pain and radiating leg pain. The purpose of this study is to develop a reproducible and standardized preclinical model of painful lumbar IVD degeneration by evaluation of structural and behavioral changes in response to IVD injury with increasing needle sizes. This model can be used to develop new therapies for IVD degeneration. Methods/UNASSIGNED:Forty-five female Sprague Dawley rats underwent anterior lumbar disc needle puncture at levels L4-5 and L5-6 under fluoroscopic guidance. Animals were randomly assigned to four different experimental groups: needle sizes of 18 Gauge (G), 21G, 23G, and sham control. To monitor the progression of IVD degeneration and pain, the following methods were employed: μMRI, qRT-PCR, histology, and biobehavioral analysis. Results/UNASSIGNED:T1- and T2-weighted μMRI analysis showed a correlation between the degree of IVD degeneration and needle diameter, with the most severe degeneration in the 18G group. mRNA expression of markers for IVD degeneration markers were dysregulated in the 18G and 21G groups, while pro-nociceptive markers were increased in the 18G group only. Hematoxylin and Eosin (H&E) and Alcian Blue/Picrosirius Red staining confirmed the most pronounced IVD degeneration in the 18G group. Randall-Selitto and von Frey tests showed increased hindpaw sensitivity in the 18G group. Conclusion/UNASSIGNED:Our findings demonstrate that anterior disc injury with an 18G needle creates severe IVD degeneration and mechanical hypersensitivity, while the 21G needle results in moderate degeneration with no increased pain sensitivity. Therefore, needle sizes should be selected depending on the desired phenotype for the pre-clinical model.

Study Design/UNASSIGNED:Review article. Objective/UNASSIGNED:A review of the literature on current strategies utilized in intervertebral regeneration and repair efforts. Methods/UNASSIGNED:A review of the literature and analysis of the data to provide an updated review on current concepts of intervertebral disc repair and regeneration efforts. Results/UNASSIGNED:Multiple regenerative strategies for intervertebral disc regeneration are being employed to reduce pain and improve quality of life. Current promising strategies include molecular therapy, gene therapy, cell-based therapy, and augmentation with biomaterials. Multiple clinical trials studying biologic, cell-based, and scaffold-based injectable therapies are currently being investigated. Conclusion/UNASSIGNED:Low back pain due to intervertebral disc disease represents a significant health and societal burden. Current promising strategies include molecular therapy, gene therapy, cell-based therapy, and augmentation with biomaterials. To date, there are no Food and Drug Administration-approved intradiscal therapies for discogenic back pain, and there are no large randomized trials that have shown clinically significant improvement with any investigational regenerative treatment. Multiple clinical trials studying biologic, cell-based, or scaffold-based injectable therapies are being currently investigated.

Ankle malunions with a shortened fibula and syndesmosis widening can pose challenges to the patient and treating physician. Indications for revision-operative intervention include persistent pain and disability. Shortened fibula malunions can be addressed using a lengthening fibular osteotomy and revision fixation. Chronic syndesmotic injuries can be addressed with syndesmotic debridement, open reduction, and suture button fixation. In this video, we present our surgical technique and rationale for the management of a shortened fibular malunion with persistent syndesmotic widening.

BACKGROUND:Geriatric femoral neck fractures are associated with substantial morbidity and medical cost. We evaluated the incidence and management trends of femoral neck fractures in recent years in the U.S. METHODS:Patient data from 2003 through 2013 were obtained from the Nationwide Inpatient Sample database. Femoral neck fractures in patients ≥65 years old were identified and grouped using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes for internal fixation, hemiarthroplasty, or total hip arthroplasty (THA). The nationwide incidence of femoral neck fractures was calculated and presented as an age-adjusted population rate. Univariable methods were used for trend analysis and comparisons between groups. Logistic regression modeling was used to analyze complications. RESULTS:From 2003 to 2013, we identified 808,940 femoral neck fractures in patients ≥65 years old. The national age-adjusted incidence of femoral neck fractures decreased from 242 per 100,000 U.S. adults in 2003 to 146 in 2013. The proportion of fractures managed operatively with THA increased over time (5.9% in 2003 versus 7.4% in 2013; p < 0.001). Concurrently, the use of hemiarthroplasty declined (65.1% versus 63.6%; p < 0.001). In 2013, the median age of the patients treated with THA was significantly younger (77.3 years) compared with that in the hemiarthroplasty and internal fixation groups (83.2 and 82.0 years). The THA group had significantly higher median initial hospital costs ($17,097) compared with the hemiarthroplasty and internal fixation groups ($14,776 and $10,462). CONCLUSIONS:In the last decade, the total number and population rate of femoral neck fractures in the elderly declined significantly. There was a modest but significant increase in the utilization of THA. CLINICAL RELEVANCE/CONCLUSIONS:This report identifies the changing trends in clinical practice in the treatment of geriatric femoral neck fractures in the U.S. Treating physicians should be aware of these trends, which include a decreasing national incidence of geriatric femoral neck fractures as well as an increase in the use of THA.

STUDY DESIGN/METHODS:Review of the literature. OBJECTIVE:Surgery and cement augmentation procedures are effective palliative treatment of symptomatic spinal metastases. Our objective is to systematically review the literature to describe the survival, prognostic factors, and clinical outcomes of surgery and cement augmentation procedures for breast cancer metastases to the spine. METHODS:We performed a literature review using PubMed to identify articles that reported outcomes and/or prognostic factors of the breast cancer patient population with spinal metastases treated with any surgical technique since 1990. RESULTS:The median postoperative survival for metastatic breast cancer was 21.7 months (8.2 to 36 months), the mean rate of any pain improvement was 92.9% (76 to 100%), the mean rate of neurologic improvement was 63.8% (53 to 100%), the mean rate of neurologic decline was 4.1% (0 to 8%), and the local tumor control rate was 92.6% (89 to 100%). Kyphoplasty studies reported a high rate of pain control in selected patients. Negative prognostic variables included hormonal (estrogen and progesterone) and human epidermal growth factor receptor 2 (HER2) receptor refractory tumor status, high degree of axillary lymph node involvement, and short disease-free interval (DFI). All other clinical or prognostic parameters were of low or insufficient strength. CONCLUSION/CONCLUSIONS:With respect to clinical outcomes, surgery consistently yielded neurologic improvements in patients presenting with a deficit with a minimal risk of worsening; however, negative prognostic factors associated with shorter survival following surgery include estrogen receptor/progesterone receptor negativity, HER2 negativity, and a short DFI.