Citations

Myasthenia gravis is a disease of the neuromuscular junction (NMJ) associated with autoimmune destruction of the motor end‐plate. Inhibitors of acetylcholine (ACh) esterase are commonly used to mitigate symptoms by increasing ACh availability at the NMJ. Brain‐derived neurotrophic factor (BDNF) improves neuromuscular transmission in the rat diaphragm muscle (DIAm) by maintaining ACh release with repeated activation. We hypothesized that BDNF will mitigate the deficit of neuromuscular transmission in a passive transfer model of myasthenia gravis. Female Lewis rats were injected with vehicle, McAb1 (that does not induce myasthenia), and a myasthenogenic McAb3 antibody. Neuromuscular transmission failure (NMTF) was determined in DIAm‐phrenic nerve preparations by comparing the isometric force evoked by phrenic nerve stimulation and that evoked by superimposed direct muscle stimulation. After 2 min of repetitive stimulation, neuromuscular transmission was significantly impaired in myasthenic animals (NMTF: 80%) compared to vehicle and McAb1 animals (NMTF: ~60%). Exogenous BDNF treatment significantly improved neuromuscular transmission in all groups and NMTF in McAb3‐treated rats was no longer different from control or McAb1‐treated animals. We conclude that BDNF improves neuromuscular transmission in adult myasthenic rats. Supported by a Career Development Award from Mayo Clinic.

Neuregulin (NRG) is important for expression of acetylcholine (ACh) receptors during development of the neuromuscular junction (NMJ). NRG treatment significantly increases ACh‐induced currents in hippocampal neurons, but it is not known if NRG exerts a similar effect at NMJs. Diaphragm muscle (DIAm)‐phrenic nerve preparations from 7‐ and 14‐day old rats were used to determine the effects of NRG (heregulin β177–244) on neuromuscular transmission and DIAm contractile properties. Neuromuscular transmission failure (NMTF) was assessed by the difference in force elicited by repetitive phrenic nerve stimulation (0.2 ms pulses in 40 Hz, 330 ms trains) and superimposed, intermittent direct DIAm stimulation (1 ms pulses in 40 Hz, 330 ms trains applied every 15 seconds). NMTF was higher in 7‐day old compared to 14‐day old rats (76% vs. 65%; p<0.05). Exogenous NRG treatment significantly improved neuromuscular transmission in 7‐day old rats (NMTF: 52%; p<0.05), but not in 14‐day old rats (65%). Isometric DIAm contractile properties were not affected by NRG treatment in either age group. These results indicate that NRG has important synaptic effects during early postnatal development of the DIAm. Whether NRG effects on neuromuscular transmission result from acute changes in AChR expression or alternative mechanisms remains to be explored. Supported by NIH grant AR51173 and a Career Development Award from Mayo Clinic.

Abstract Background and Aims Bowel urgency and abdominal pain are impactful, yet under-appreciated ulcerative colitis symptoms and not commonly assessed in clinical trials. We evaluated how these symptoms may improve with upadacitinib treatment and correlate with clinical and health-related quality of life [HRQOL] outcomes in the phase 2b U-ACHIEVE study. Methods Patients aged 18–75 years, with moderately to severely active ulcerative colitis, were randomised to receive placebo or upadacitinib (7.5, 15, 30, or 45 mg once daily [QD]). Bowel urgency and abdominal pain were evaluated at baseline and Weeks 2, 4, 6, and 8. Week 8 correlations were evaluated between bowel urgency/abdominal pain with clinical [Mayo subscores and high-sensitivity C-reactive protein and faecal calprotectin measurements] and HRQOL outcomes [Inflammatory Bowel Disease Questionnaire and 36-Item Short Form Health Survey scores]. Results A greater proportion of patients [n = 250] reported no bowel urgency and less abdominal pain with upadacitinib treatment compared with placebo, with improvements observed as early as 2 weeks. At Week 8, patients receiving the 45-mg QD dose had the greatest improvements versus placebo, with 46% reporting no bowel urgency [vs 9%; p ≤ 0.001] and 38% reporting no abdominal pain [vs 13%; p = 0.015]. At Week 8, moderate correlations were found between bowel urgency or abdominal pain and most clinical and HRQOL outcomes. Conclusions Induction treatment with upadacitinib demonstrated significant reductions in bowel urgency and abdominal pain compared with placebo. These symptoms also correlate to clinical and HRQOL outcomes, supporting their use to monitor disease severity and other treatment outcomes.

8023 Background: MGTA-145 (GroβT), a CXCR2 agonist, has shown promising activity for HSC mobilization with plerixafor in pre-clinical models and healthy volunteers. Methods: This phase 2 single center study evaluates HSC mobilization with MGTA-145 + plerixafor and same day apheresis in patients with multiple myeloma. Patients received plerixafor 0.24 mg/kg (0.16 mg/kg if renal dysfunction) SQ, followed 2 hours later by MGTA-145 (0.03 mg/kg) IV over 3-10 minutes and apheresis within 30 minutes. Mobilization was repeated for a second day if day 1 yield was < 6 x 106 CD34+ cells/kg. This interim analysis reports on mobilization in 10 patients (of 25 planned), including safety cohort of first 6 patients completing transplant. Primary endpoint is collection of 2 x 106 CD34+ cells/kg. Results: Median age was 63 years (range: 46-68), 50% were female, 22% had ISS stage 3 & 50% had high-risk FISH. Induction therapy was VRD in 7 and daratumumab + VRD in 3 patients; median induction duration: 4 months (3-6) & median lenalidomide exposure: 6 cycles (4-6), with > VGPR in 70%. Median total stem cell yield (CD34+ cells/kg x 106) was 7.1 (3-16.2), day 1 yield was 5.4 (1.1-16.2) & yield per apheresis session was 4 (1.1-16.2). 100% of patients met the primary endpoint of collecting sufficient HSCs in < 2 days of mobilization + apheresis to proceed to transplant (2 x 106 CD34+ cells/kg). Secondary endpoints of 4 and 6 x 106 CD34+ cells/kg in < 2 days were met in 90% & 80% patients. 30% patients underwent 1 apheresis, while 70% underwent 2 sessions. MGTA-145 was well tolerated. At least 1 adverse event (AE) was seen in 90% of patients, 20% had grade 2 AEs (anemia, hypokalemia) and 20% had grade 3 AEs (worsening of baseline grade 3 anemia; hypocalcemia); all resolved. Acute & transient bone pain was seen in 40% of patients (back-2, hip-1, sternum-1), all grade 1, all on day 1, & resolved without intervention after 6 minutes (3-10). All 6 patients in the safety cohort have completed transplant with melphalan 200 mg/m2. Median of 4.1 (3.4-5.6) x 106 CD34+ cells/kg were infused. All patients have engrafted timely (DiPersio Blood 2009); median time to neutrophil engraftment: 12 days (11-13) & platelet engraftment: 17 days (16-19). Apheresis graft analysis is available in these 6 patients. Grafts with MGTA-145+plerixafor showed high enrichment for CD90+CD45RA- among CD34+ cells, a CD34 subset of long term engrafting HSCs (median: 31% of CD34+ cells, 27-52), higher than seen with G-CSF (6%, Goncalves TCT 2021). 67% of grafts were minimal residual disease negative with next generation flow cytometry. Conclusions: This is the first study to evaluate the novel regimen of MGTA-145 + plerixafor for same day stem cell mobilization & collection in myeloma/hematologic malignancies, with 100% efficacy in interim analysis and the first to demonstrate successful engraftment in patients with cells collected with this GCSF free regimen. Clinical trial information: NCT04552743.

e18862 Background: Hematopoietic cell transplantation (HCT) is a medically complicated, expensive and resource intensive medical technology. High health care costs are usually associated with high Out-of-Pocket (OOP) costs. In this population-based study, using deidentified administrative claims data from OptumLabs Data Warehouse, we describe total and patient level costs for one-year pre and post HCT and describe the characteristics of those with top 25% cost. Methods: Patients who had undergone an autologous or allogeneic HCT in 2015 to 2019 and had continuous health plan coverage for one year prior and post the index date-the date of the first claim for HCT, were included. We examined total costs, patient paid (OOP) and plan paid costs for one year before and after HCT. We also examined inpatient, outpatient, and pharmacy costs for the one year before and after the HCT. Logistic regression models examined factors including age, gender, race/ ethnicity, Charlson comorbidity index, geographic region and costs in the year prior to HCT (baseline costs) for their association with high total costs and high OOP costs (top 25%). Results: A total of 3,346 patients (2,344 commercial plan (CPE) and 1,002 under Medicare Advantage plan (MAPE) enrollees) were included in the study. Median one year post HCT costs for CPE was $ 612,517 (IQR 413,348- 960,456) and for MAPE was $ 521,000 (IQR 347,388-736,685). Median one year post HCT OOP costs were $ 5,407 (IQR 1,584 -10,000) in CPE and $7,199 (IQR 3,485 -16,396) in MAPE group. 625 subjects in the CPE and 253 subjects in MAPE group had overall costs in the top 25%. Median baseline costs were $482,107 vs. $846,943 in the low vs. high cost group in CPE and $278,656 vs. $343,633 in MAPE. There was a low correlation between OOP costs and overall costs (r = 0.17 for CPE and 0.15 for MAPE; p < 0.05). Younger age (OR for age 0.98; p < 0.001) and higher baseline costs (OR1.89; p < 0.001) predicted top 25% total costs post HCT in the CPE group. Not being African American (OR for African American 0.5; p = 0.02) and higher baseline costs (OR 1.07; p < 0.001) predicted top 25% total costs post HCT in MAPE group. Age (OR 0.97; p < 0.001), not being African American (OR 0.5; p = 0.001) and high baseline costs (OR 1.44; p < 0.001) also predicted higher OOP costs in the CPE group. The only factor that was associated with lower likelihood of OOP costs in top 25% in MAPE group was being Hispanic (OR 0.6; p = 0.004). Conclusions: HCT is an expensive treatment modality. High costs prior to HCT are associated with high post HCT costs both for patients on commercial and Medicare Advantage plan. The magnitude of correlation between patient level and total costs was low, likely due to differences in benefit plan. A careful assessment of benefits and costs of HCT is needed for providing high-value care and allow optimum allocation of the finite resources while minimizing patient level financial burden.

3568 Background: Diets inducing an elevated insulin response have been associated with increased recurrence and mortality in patients with non-metastatic colorectal cancer, but it remains unknown if postprandial hyperinsulinemia also affects progression and mortality in mCRC patients. The goal of this study was to assess the influence of dietary insulin load (DIL) and dietary insulin index (DII) on survival of mCRC patients. Methods: This was a prospective cohort study of 1,177 patients with previously untreated mCRC enrolled in a phase III trial of systemic chemotherapy plus biologics who reported dietary intake within one month after chemotherapy initiation. DIL was calculated as a function of food insulin index and the energy content of individual foods reported on a food frequency questionnaire. DII was calculated by dividing DIL by total energy intake. The primary endpoint was overall survival (OS). Secondary endpoints were progression-free survival (PFS) and treatment-related adverse events (TRAEs). The primary statistical test was a test for trend, which was performed using the median value for each quintile of dietary insulin score as a continuous variable. Cox proportional hazards regression was used to adjust for potential confounders including assigned treatment arm, known prognostic factors, comorbidities, body mass index, and physical activity. Results: Higher DIL was significantly associated with worse OS (ptrend = 0.04); patients in the highest quintile survived 34.1 months, compared to 27.7 months in the lowest quintile (Cox hazard ratio [HR] 1.22, 95% confidence interval [CI] 0.99 - 1.51). Higher DII was non-significantly associated with worse OS (HR 1.18, 95% CI 0.94 - 1.48, ptrend = 0.09). There was no significant association between dietary insulin scores and PFS. The influence of dietary insulin scores on survival did not differ significantly by various molecular markers involved in the insulin signaling pathway, including C-peptide, adiponectin, IGF-1, IGFBP-3, and IGFBP-7. Higher dietary insulin scores were significantly associated with greater risk of any TRAE. Those with a DIL greater than the median had a 75.4% rate of any TRAE, compared to 70.8% in those with a DIL less than or equal to the median (HR 1.19, 95% CI 1.03 - 1.38, p=0.02); the most significant associations were with neutropenia (HR 1.30, 95% CI 1.05 - 1.61, p=0.01) and diarrhea (HR 1.43, 95% CI 1.00 - 2.06, p=0.05). Conclusions: Higher DIL was significantly associated with worse OS, and both higher DIL and DII were significantly associated with increased TRAEs, in patients with previously untreated mCRC. These findings may inform future dietary recommendations for patients with mCRC. Further investigation into the molecular mechanisms underlying these associations is warranted. Clinical trial information: NCT00265850.

2051 Background: GSK-3β, a serine/threonine kinase, is a key regulator of metabolism and glycogen biosynthesis. GSK-3β aberrant overexpression promotes tumor progression and chemotherapy resistance through NF-κB and p53-mediated apoptotic pathways. GSK-3β inhibition impacts immunomodulation through downregulation of checkpoints, such as PD-L1 and LAG-3, and increasing NK and T-cell mediated killing of tumor cells. 9-ING-41 is a small-molecule potent selective GSK-3β inhibitor with preclinical antitumor activity against several tumor types. In chemoresistant PDX models of glioblastoma (GBM), 9-ING-41 enhanced the antitumor effect of CCNU and CPT-11. Methods: In the first-in-human study (NCT03678883), patients (pts) with refractory malignancies received 9-ING-41 monotherapy (n = 65) or in combination with one of 8 cytotoxic regimens after prior treatment with the same chemotherapy (n = 162). We report the subset of pts with recurrent gliomas treated with 9-ING-41 monotherapy IV twice a week in 21-day cycles at different dose levels (3.3, 5, 9.3, 15mg/kg), or in combination with lomustine 30 mg/m² orally once weekly in 84-day cycles. Primary objective was safety and tolerability. Results: An RP2D of 15mg/kg IV was confirmed across all 9 regimens, no accentuation of chemotherapy-related toxicity noted. Of 18 glioma patients enrolled, 13 were GBM, 2 anaplastic astrocytomas, 1 diffuse astrocytoma, and 1 anaplastic oligodendroglioma. Four patients received single agent 9-ING-41, 14 treated concurrently with lomustine. Demographics: 6 female, 12 male; median age 52 (30-69) years; median ECOG was 1 (0-2). All received first-line radiation and temozolomide (18/18), prior therapies for recurrences included nitrosoureas (15/18), bevacizumab (8/18), TTFields (6/18), immune checkpoint inhibitor (4/18). Median recurrences 3 (1-6). Genomic alterations from available NGS reports included: IDH WT (11), IDH mutation (3), MGMT promoter unmethylated (11), MGMT promoter methylated (1), 1p19q co-deletion (10), EGFR amplification (6), EGFR v3 mutation (3), TERT promoter mutation (6), PTEN loss (3), NF1 rearrangement (2), ATRX loss (2), TP53 mutated (4), CDKN2A deletion (2), RB1 loss (1), PALB-2 mutation (10). No SAEs or grade 3/4 AEs attributed to 9-ING-41 were noted; AEs included G1/2 transient vision changes (9/18, 50%), infusion reactions (4/18, 22%). Side effects from lomustine included: G3/4 thrombocytopenia (3/14, 21%), and G1/2 fatigue (4/14, 28%). Best overall response: 1 minimal response (-43%) after 2 cycles of 9-ING-41 and lomustine. Median days on therapy was 55 (4-305), 4/18 (22%) were stable for 20 weeks or longer. Conclusions: These results show 9-ING-41 alone or in combination is safe and warrants further study in glioma patients. Clinical trial information: NCT03678883.

2016 Background: Among the primary aims of new therapies for glioblastoma (GBM) are the reduction of morbidity and restoration or preservation of quality of life (QoL). Selinexor (SEL) is a first-in class, oral, selective inhibitor of nuclear export which blocks exportin 1 (XPO1), forcing the nuclear retention and reactivation of tumor suppressor proteins, ultimately causing cell death in cancer cells. SEL is approved for the treatment of previously treated multiple myeloma and DLBCL. XPORT-GBM-029 (NCT04421378) is a phase 1 dose finding study followed by an open-label randomized phase 2, 3-arm trial to evaluate SEL in combination with standard therapies for newly diagnosed and recurrent GBM: Arm A (ndGBM, uMGMT) – radiation +/- SEL; Arm B (ndGBM, mMGMT) – radiation and temozolomide +/- SEL; Arm C (rGBM) – lomustine +/- SEL at first relapse. We look to identify sensitive, reliable, and clinically meaningful digital assessments of the functional status of ndGBM and rGBM patients via a patient-centric approach. Methods: XPORT-GBM-029 incorporates standard clinical and imaging evaluations of GBM progression with novel digital tools that objectively measure motor and cognitive function. The study is conducted at 50 sites globally with the aim of enrolling 350 patients with newly diagnosed and recurrent GBM. Following discussions with KOLs and patient advocacy partners at EndbrainCancer, we surveyed GBM patients and their caregivers to identify disease manifestations critical to patients’ QoL. The survey revealed four key areas impacting patients’ QoL that can be affected by GBM therapies and can be objectively monitored: cognitive function, lateralization, fatigue, and sleep. In this trial we use objective measurements to evaluate SEL’s effects on GBM patients’ QoL. Patients wear inertial sensors to measure their activity and sleep and complete a cognitive battery at baseline and before each MRI. Results: Associations between objective digital measures of activity, gait, fatigue, sleep, and cognition will be examined with respect to clinical assessments including physical examinations, modified Response Assessment in Neuro-Oncology (mRANO), Neurologic Assessment in Neuro-Oncology (NANO), Karnofsky Performance Score (KPS) and Patient Reported Outcome (PRO) QoL questionnaires. Descriptive summary statistics and plots are employed in exploratory data analysis, and other advanced data mining methods may also be considered. Conclusions: XPORT-GBM-029 trial is probably the first large, prospective, longitudinal study in GBM patients employing digital markers and may provide useful information regarding the utility of wearable and mobile devices for measuring functional outcomes in clinical trials. Clinical trial information: NCT04421378.

2014 Background: The cyclin D-CDK4/6-Rb pathway is activated in most glioblastomas. Abemaciclib is a potent CDK4/6 inhibitor with good brain penetration approved for HR+/HER2- breast cancer. In order to efficiently evaluate the potential impact of abemaciclib on overall survival (OS) in newly diagnosed glioblastoma and to simultaneously develop information regarding potential genomic biomarker associations, abemaciclib was included as an arm on the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. INSIGhT is a phase II platform trial using response adaptive randomization and deep genomic profiling to more efficiently test experimental agents in MGMT unmethylated glioblastoma and potentially accelerate identification of novel therapies for phase III testing. Initial randomization was equal between abemaciclib, control, and two other experimental arms but subsequent randomization was adapted based on efficacy as determined by progression-free survival (PFS). Ineffective arms were discontinued and new arms added by protocol amendment. We report preliminary results for the abemaciclib arm which has completed accrual. Methods: Patients with newly diagnosed MGMT-unmethylated glioblastoma were randomized to receive either radiotherapy with concomitant and adjuvant temozolomide at standard doses or standard radiochemotherapy followed by adjuvant abemaciclib (150-200 mg orally BID). Treatment continued until progression or development of unacceptable toxicities. The primary endpoint was OS which was assessed using the log-rank test estimated via the Kaplan Meier method using a type I error of 5%. The hazard ratio (HR) was estimated using a cox proportional hazards model. Association between abemaciclib efficacy and cyclin D-CDK4/6-Rb pathway genomic alterations was also investigated. Results: There were 142 patients (69 control; 73 treated with abemaciclib). Abemaciclib was generally well-tolerated with no new toxicity signals identified. PFS was significantly longer (HR 0.67; p = 0.03, logrank test) with abemaciclib (median 6.54 months) compared to the control arm (median 5.88 months). For patients with activation of the CDK4 pathway the PFS HR was 0.64 (p-value = 0.04). However, there was no significant improvement in overall survival (HR 0.9; p-value > 0.05) between abemaciclib (median 15.5) compared to the control arm (median 15.5). Conclusions: Abemaciclib was well-tolerated and prolonged PFS but there is no evidence of an overall survival improvement compared to standard radiochemotherapy. Clinical trial information: NCT02977780.

2006 Background: Adaptive randomization adjusts enrollment rates based upon early trial results, which can allow for decreased enrollment for therapies less likely to meet the primary endpoint of a trial. CC-115, a CNS-penetrant, oral inhibitor of mammalian target of rapamycin kinase (mTOR) and deoxyribonucleic acid-dependent protein kinase (DNA-PK), was evaluated in the Individualized Screening Trial of Innovative Glioblastoma Therapy (INSIGhT) trial. As CC-115 was discontinued due to concerns about toxicity and unfavorable risk-to-benefit ratio, we sought to investigate the impact of adaptive randomization in its testing. Methods: In INSIGhT, adults with newly diagnosed MGMT-unmethylated glioblastoma and available genomic data are adaptively randomized to an experimental arm or the control arm of standard radiotherapy with concurrent and adjuvant temozolomide. Patients randomized to CC-115 received it (10mg po BID) with radiotherapy and as adjuvant monotherapy, and a safety lead-in 3+3 design was used for this arm. By simulating the INSIGhT trial with standard uniform randomization, we estimated the reduction of enrollment rate and sample size of the CC-115 arm that was attributable to adaptive randomization. Results: Twelve patients were randomized to CC-115; 58% (n = 7) patients had possible treatment-related CTCAE grade > 3 toxicity. Compared to the control arm, there was no significant difference in progression-free survival (PFS, HR 0.66, 95% CI 0.32-1.36, p = 0.3) or overall survival (OS, HR 0.93, 95% CI 0.43-2.03, p = 0.8). Based on early PFS results, randomization probability to CC-115 decreased from 25% to 16%. At the time of the CC-115 arm closure, 14% of enrolled INSIGhT patients had been randomized to this arm. Compared to average expected enrollment by standard randomization, the use of adaptive randomization decreased the number of patients randomized to CC-115 by 50% (12 patients vs. 18 patients [95% CI 11-25 patients]). Conclusions: The INSIGhT trial, designed with adaptive randomization, facilitated more efficient testing of CC-115 and decreased the number of patients allocated to the CC-115 arm relative to a standard randomization design. Clinical trial information: NCT02977780.