Factors associated with refractoriness or early progression after idecabtagene vicleucel in patients with relapsed/ refractory multiple myeloma: US Myeloma Immunotherapy Consortium real world experience

While response rates and survival outcomes have been very promising for idecabtagene vicleucel (ide-cel), a proportion of patients do not respond or relapse early after this B-cell maturation antigen (BCMA) targeted chimeric antigen receptor (CAR) T-cell therapy. Understanding the characteristics of these patients is important for patient selection and development of novel strategies to improve outcomes. We evaluated factors associated with early progression (progression or death due to myeloma ≤3 months after CAR T-cell infusion) in patients treated with standard of care ide-cel at 11 US academic centers. Among 211 patients that received ide-cel, 43 patients had a progressive event ≤3 months of infusion. Patients with a history of extramedullary disease, prior BCMA targeted therapy, elevated ferritin at lymphodepletion, use of bridging therapy, Hispanic ethnicity, plasma cell leukemia and t(4;14) were more likely to progress ≤3 months of infusion (P<0.05). Of these risk factors for early progression identified in univariate analyses, history of extramedullary disease, prior BCMA targeted therapy, elevated ferritin at lymphodepletion, plasma cell leukemia, and t(4;14) were associated with worse progression-free survival (PFS) in multivariable analysis. Presence of three or more of these factors had a significant negative impact on PFS (P<0.001; median PFS for ≥3 factors, 3.2 months vs. 0 factors, 14.1 months). This study helps identify patients at high risk of early progression after CAR T-cell therapy who may benefit from specific interventions pre and post CAR T-cell therpy to improve outcomes.

Applying the EHA/EBMT grading for ICAHT after CAR-T: comparative incidence and association with infections and mortality

ABSTRACT

Cytopenias represent the most common side effect of CAR T-cell therapy (CAR-T) and can predispose for severe infectious complications. Current grading systems, such as the Common Terminology Criteria for Adverse Events (CTCAE), neither reflect the unique quality of post-CAR-T neutrophil recovery, nor do they reflect the inherent risk of infections due to protracted neutropenia. For this reason, a novel EHA/EBMT consensus grading was recently developed for Immune Effector Cell-Associated HematoToxicity (ICAHT). In this multicenter, observational study, we applied the grading system to a large real-world cohort of 549 patients treated with BCMA- or CD19-directed CAR-T for refractory B-cell malignancies (112 multiple myeloma [MM], 334 large B-cell lymphoma [LBCL], 103 mantle cell lymphoma [MCL]) and examined the clinical sequelae of severe (≥3°) ICAHT. The ICAHT grading was strongly associated with the cumulative duration of severe neutropenia (r = 0.92, P < .0001), the presence of multilineage cytopenias, and the use of platelet and red blood cell transfusions. We noted an increased rate of severe ICAHT in patients with MCL vs those with LBCL and MM (28% vs 23% vs 15%). Severe ICAHT was associated with a higher rate of severe infections (49% vs 13%, P < .0001), increased nonrelapse mortality (14% vs 4%, P < .0001), and inferior survival outcomes (1-year progression-free survival: 35% vs 51%, 1-year overall survival: 52% vs 73%, both P < .0001). Importantly, the ICAHT grading demonstrated superior capacity to predict severe infections compared with the CTCAE grading (c-index 0.73 vs 0.55, P < .0001 vs nonsignificant). Taken together, these data highlight the clinical relevance of the novel grading system and support the reporting of ICAHT severity in clinical trials evaluating CAR-T therapies.

Idecabtagene vicleucel chimeric antigen receptor T-cell therapy for relapsed/refractory multiple myeloma with renal impairment

We evaluated patients with relapsed multiple myeloma with renal impairment (RI) treated with standard of care idecabtagene vicleucel (ide-cel), as outcomes with chimeric antigen receptor (CAR) T-cell therapy are unknown in this population. RI was defined as creatinine clearance (CrCl) <50 mL/min. CrCl of <30 mL/min or dialysis dependence were defined as severe RI. The study cohort included 214 patients, 28 (13%) patients with RI, including 11 patients severe RI (dialysis, N=1). Patients with RI were older, more likely to be female and had higher likelihood of having Revised International Staging System stage 3 disease. Rates and severity of cytokine release syndrome (89% vs. 84%, grade ≥3: 7% vs. 2%) and immune effector cell-associated neurotoxicity syndrome (23% vs. 20%) were similar in patients with and without RI, respectively. Patients with RI had higher incidence of short-term grade ≥3 cytopenias, although cytopenias were similar by 3 months following CAR T-cell therapy. Renal function did not worsen after CAR T-cell therapy in patients with RI. Response rates (93% vs. 82%) and survival outcomes (median progression-free survival: 9 vs. 8 months; P=0.26) were comparable in patients with and without RI, respectively. Treatment with ide-cel is feasible in patients with RI, with a comparable safety and efficacy profile as patients without RI, with notable exception of higher short-term high-grade cytopenias.

Simple Score of Albumin and CRP Predicts High-Grade Toxicity in Patients with Multiple Myeloma Receiving CAR-T Therapy

Administration of chimeric-antigen receptor T-cell (CAR-T) therapy is complex and associated with unique toxicities. Identifying patients at risk for inferior outcomes is important for individualized management. The Glasgow-prognostic score (GPS) is a simple score shown to be highly prognostic of outcomes in the setting of traditional chemotherapy or checkpoint inhibitor administration. We sought to evaluate the value of the GPS to predict outcomes of patients with relapse refractory multiple myeloma (RRMM) receiving anti-BCMA CAR-T therapy. We included all patients treated with commercial CAR-T therapy for RRMM between 5/1/2021 and 2/1/2023 at the Moffitt Cancer Center. The GPS (CRP >1 mg/dL, 1 point; albumin <3.5, 1 point) was calculated for all patients at lymphodepletion (day -6) and patients were grouped as high-risk GPS (score = 2) or low-risk GPS (0 or 1). The primary endpoint was overall survival (OS) at day 100. A total of 139 pts were included, with a median follow-up of 6.7 months (95% CI, 6.2 to 8.9 months). Pts were treated with either idecabtagene vicleucel (83%) or ciltacabtagene autoleucel (17%). In total, 14% were classified with high-risk GPS, with significantly increased risk for grade 3 cytokine release syndrome (P = .003) and ICANS of any grade (P < .001). Patients in the high-risk GPS group had significantly lower day-100 OS (68.4% versus 97.3%, P < .001), OS at 6 months (56% versus 91.8% P = .0019) and PFS at 6 months (38.3% versus 72.3%, P = .03). The association of GPS with day-100 OS remained significant in a multivariable model. In conclusion, the GPS identifies a group of high-risk patients with RRMM receiving CAR-T therapy who experience increased rates of immune-mediated toxicity and are at higher risk for early mortality.

Racial and ethnic differences in clinical outcomes among patients with multiple myeloma treated with CAR T-cell therapy

ABSTRACT

Idecabtagene vicleucel (ide-cel) was the first chimeric antigen receptor T-cell therapy to gain US Food and Drug Administration approval for patients with relapsed/refractory multiple myeloma (RRMM). The clinical outcomes of standard of care (SOC) ide-cel in racially and ethnically diverse populations have been understudied. This study pooled data from 207 patients with RRMM (28% patients of racial and ethnic minority groups) treated with SOC ide-cel across 11 institutions to examine racial and ethnic differences in the incidence of toxicities and adverse events, response to ide-cel, and survival. This study included 22 (11%) Hispanic, 36 (17%) non-Hispanic Black, and 149 (72%) non-Hispanic White patients with RRMM. Compared with Hispanic and non-Hispanic White patients, non-Hispanic Black patients had higher median levels of C-reactive protein (1.0, 0.8, and 3.5 mg/dL, respectively; P = .02) and baseline ferritin (362.0 vs 307.0 vs 680.5, respectively; P = .08) and were more likely to develop cytokine release syndrome (77%, 85%, and 97%, respectively; P = .04). Although best overall response rate was lower among Hispanic patients (59%) than among non-Hispanic Black (86%) and White patients (86%; P = .01), there were no racial and ethnic differences in progression-free or overall survival. We provide, to our knowledge, the first and largest investigation of clinical outcomes of SOC ide-cel by race and ethnicity. Despite differences in safety and response to ide-cel, our findings encourage the use of ide-cel in all patients with RRMM. These findings should be confirmed in larger samples of diverse patients with RRMM, with longer follow-up time.

The Impact of Outpatient versus Inpatient Administration of CAR-T Therapies on Clinical, Economic, and Humanistic Outcomes in Patients with Hematological Cancer: A Systematic Literature Review

Although chimeric antigen receptor (CAR)-T cell therapies are typically administered in the inpatient setting, outpatient administration is rapidly expanding. However, there is limited summarized evidence comparing outcomes between outpatient and inpatient administration. This systematic literature review aims to compare the safety, efficacy, quality of life (QoL), costs, and healthcare resource utilization (HCRU) outcomes in patients with hematological cancer who are administered CAR-T therapy in an outpatient versus an inpatient setting. Publications (2016 or later) that reported the outcomes of interest in patients treated with a CAR-T therapy in both outpatient and inpatient settings, or only the outpatient setting, were reviewed. In total, 38 publications based on 21 studies were included. Safety findings suggested the comparable frequency of adverse events in the two settings. Eleven studies that reported data in both settings showed comparable response rates (80-82% in outpatient and 72-80% in inpatient). Improvements in the QoL were observed in both settings while costs associated with CAR-T therapy were lower in the outpatient setting. Although unplanned hospitalizations were higher in the outpatient cohort, overall HCRU was lower. Outpatient administration of CAR-T therapy appears to have comparable outcomes in safety, efficacy, and QoL to inpatient administration while reducing the economic burden.

Impact of weight and creatinine adjustments on the accuracy of Cockcroft-gault equation in hematopoietic cell transplant patients

BACKGROUND

Hematopoietic cell transplant (HCT) patients undergo pre- transplant renal function evaluation to confirm transplant eligibility and tailor pharmacotherapy. There is limited evidence regarding the most accurate method of estimating creatinine clearance (CrCl) within this patient population and no studies exist that evaluate the weight utilized within the Cockcroft-Gault (CG) equation in HCT patients. This study evaluates different weight and serum creatinine (SCr) adjustments utilized within the CG equation estimating for renal clearance in patients undergoing HCT.

OBJECTIVE

This is a retrospective, single center analysis of adult HCT patients who underwent pre-transplant evaluation with a measured CrCl using a 24-h urine creatinine collection. The primary outcome was to evaluate the correlation of various weights used in estimation of CrCl compared to measured CrCl. Key secondary outcomes include evaluation of the impact of various weights on estimated CrCl in subpopulations, evaluation of adjusting SCr to pre-determined limits, and determination of an appropriate obesity threshold to utilize body weight adjustments.

RESULTS

Seven-hundred and forty-two patients were included in the study. In the primary analysis, CG utilizing adjusted body weight (ADjBW0.4 ) had a greater correlation (r = .812) to measured CrCl when compared to total or ideal body weight (r = .801 and r = .790 respectively). The threshold of 120% of ideal body weight (IBW) produced less bias and greater accuracy in comparison to the threshold of 140% IBW. In patients 60 years or older, rounding low SCr values up .8 or 1 mg/dL resulted in decreased correlation and a greater mean difference in comparison to not rounding SCr.

CONCLUSION

In HCT patients who are overweight or obese, ADjBW .4 is the most accurate weight for the CG equation. In HCT patients who have a total body weight < 120% IBW, total body weight is the most accurate weight to utilize. Rounding up low SCr to .8 or 1 mg/dL does not improve the accuracy or led to less bias of the CG equation.

Patient-Reported Outcomes among Multiple Myeloma Patients Treated with Standard of Care Idecabtagene Vicleucel

Idecabtagene vicleucel (ide-cel) was the first FDA-approved chimeric antigen receptor T-cell therapy for relapsed/refractory multiple myeloma (RRMM) patients. This was the first study to evaluate patient-reported outcomes (PROs) among RRMM patients receiving ide-cel in standard of care (SOC). We prospectively assessed health-related quality of life (HRQOL) and symptoms from pre-infusion (baseline) through day (D)90 post-infusion. Baseline PRO associations with patient characteristics, mean PRO changes, and time to stable change were evaluated with t-tests, linear mixed-effects models, and Kaplan-Meier analyses, respectively. Within-person change scores and minimally important difference thresholds determined clinical and meaningful significance. Participants (n = 42) were a median of 66 years old (range: 43-81). At baseline, extramedullary disease was associated with worse physical well-being (p = 0.008), global pain (p < 0.001), performance status (p = 0.002), and overall symptom burden (p < 0.001). Fatigue (p < 0.001) and functional well-being (p = 0.003) worsened by D7 before returning to baseline levels. Overall HRQOL (p = 0.008) and physical well-being (p < 0.001) improved by D60. Most participants reported PRO improvement (10-57%) or maintenance (23-69%) by D90. The median time it took to stabile deterioration in functional well-being was 14 days. The median time it took to stabile improvement in physical and emotional well-being was 60 days. Overall, RRMM patients reported improvements or maintenance of HRQOL and symptom burden after SOC ide-cel.

Experience of Autologous Stem Cell Transplant in Multiple Myeloma: The Patient and Caregiver Perspective

A qualitative study of the experiences of patients who received autologous stem cell transplant (ASCT) for the treatment of multiple myeloma (MM) was conducted to better understand their MM disease journey, including first symptoms, diagnosis, ASCT, and recovery. Sixteen participants, including 12 patients with MM and 4 caregivers of patients with MM, were interviewed in focus group meetings. Pain, weakness, and bone pain were common first symptoms among patients. The MM diagnosis was often made by a hematologist or oncologist. Patients were referred to a specialized oncologist after diagnosis, who was the primary driver in making ASCT treatment decisions. Eight patients received their ASCT in the inpatient setting, with some having lengthy hospital stays; 4 received their ASCT in an outpatient setting with 3 eventually being hospitalized. The focus groups identified that patients and caregivers perceived various unmet needs and impacts on quality of life throughout their transplant journey. Educational resources and innovative therapies are needed to reduce the disease burden of MM and enhance the quality of life for both patients and their caregivers.

Cardiac events after standard of care idecabtagene vicleucel for relapsed and refractory multiple myeloma

Idecabtagene vicleucel (ide-cel) is a type of B-cell maturation antigen (BCMA)-targeting chimeric antigen receptor T-cell (CAR-T) approved for the treatment of relapsed and refractory multiple myeloma (RRMM). Currently, the incidence of cardiac events associated with ide-cel remains unclear. This was a retrospective single-center observational study of patients treated with ide-cel for RRMM. We included all consecutive patients who received standard-of-care ide-cel treatment at least 1-month follow-up. Baseline clinical risk factors, safety profile, and responses were examined based on the development of a cardiac event. A total of 78 patients were treated with ide-cel, and 11 patients (14.1%) developed cardiac events: heart failure (5.1%), atrial fibrillation (10.3%), nonsustained ventricular tachycardia (3.8%), and cardiovascular death (1.3%). Only 11 of the 78 patients had repeat echocardiogram. Baseline risk factors associated with the development of cardiac events included being female sex and having poor performance status, λ light-chain disease, and advanced Revised International Staging System stage. Baseline cardiac characteristics were not associated with cardiac events. During index hospitalization after CAR-T, higher-grade (≥grade 2) cytokine release syndrome (CRS) and immune cell-associated neurologic syndrome were associated with cardiac events. In multivariable analyses, the hazard ratio for the association of the presence of cardiac events with overall survival (OS) was 2.66 and progression-free survival (PFS) was 1.98. Ide-cel CAR-T for RRMM was associated with similar cardiac events as other types of CAR-T. Worse baseline performance status and higher-grade CRS and neurotoxicity were associated with cardiac events after BCMA-directed CAR-T-cell therapy. Our results suggest that the presence of cardiac events may confer worse PFS or OS; although because of the small sample size, the power to detect an association was limited.

Real-world experience of patients with multiple myeloma receiving ide-cel after a prior BCMA-targeted therapy

Most patients with multiple myeloma experience disease relapse after treatment with a B-cell maturation antigen-targeted therapy (BCMA-TT), and data describing outcomes for patients treated with sequential BCMA-TT are limited. We analyzed clinical outcomes for patients infused with standard-of-care idecabtagene vicleucel, an anti-BCMA chimeric antigen receptor (CAR) T-cell therapy, at 11 US medical centers. A total of 50 patients with prior BCMA-TT exposure (38 antibody-drug conjugate, 7 bispecific, 5 CAR T) and 153 patients with no prior BCMA-TT were infused with ide-cel, with a median follow-up duration of 4.5 and 6.0 months, respectively. Safety outcomes between cohorts were comparable. The prior BCMA-TT cohort had a lower overall response rate (74% versus 88%; p = 0.021), median duration of response (7.4 versus 9.6 months; p = 0.03), and median progression-free survival (3.2 months versus 9.0 months; p = 0.0002) compared to the cohort without prior BCMA-TT. All five patients who received a prior anti-BCMA CAR T responded to ide-cel, and survival outcomes were best for this subgroup. In conclusion, treatment with ide-cel yielded meaningful clinical responses in real-world patients exposed to a prior BCMA-TT, though response rates and durability were suboptimal compared to those not treated with a prior BCMA-TT.

The CAR-HEMATOTOX score as a prognostic model of toxicity and response in patients receiving BCMA-directed CAR-T for relapsed/refractory multiple myeloma

BACKGROUND

BCMA-directed CAR T-cell therapy (CAR-T) has altered the treatment landscape of relapsed/refractory (r/r) multiple myeloma, but is hampered by unique side effects that can lengthen hospital stays and increase morbidity. Hematological toxicity (e.g. profound and prolonged cytopenias) represents the most common grade ≥ 3 toxicity and can predispose for severe infectious complications. Here, we examined the utility of the CAR-HEMATOTOX (HT) score to predict toxicity and survival outcomes in patients receiving standard-of-care idecabtagene vicleucel and ciltacabtagene autoleucel.

METHODS

Data were retrospectively collected from 113 r/r multiple myeloma patients treated between April 2021 and July 2022 across six international CAR-T centers. The HT score-composed of factors related to hematopoietic reserve and baseline inflammatory state-was determined prior to lymphodepleting chemotherapy.

RESULTS

At lymphodepletion, 63 patients were HT^low (score 0-1) and 50 patients were HT^high (score ≥ 2). Compared to their HT^low counterparts, HT^high patients displayed prolonged severe neutropenia (median 9 vs. 3 days, p < 0.001), an increased severe infection rate (40% vs. 5%, p < 0.001), and more severe ICANS (grade ≥ 3: 16% vs. 0%, p < 0.001). One-year non-relapse mortality was higher in the HT^high group (13% vs. 2%, p = 0.019) and was predominantly attributable to fatal infections. Response rates according to IMWG criteria were higher in HT^low patients (≥ VGPR: 70% vs. 44%, p = 0.01). Conversely, HT^high patients exhibited inferior progression-free (median 5 vs. 15 months, p < 0.001) and overall survival (median 10.5 months vs. not reached, p < 0.001).

CONCLUSIONS

These data highlight the prognostic utility of the CAR-HEMATOTOX score for both toxicity and treatment response in multiple myeloma patients receiving BCMA-directed CAR-T. The score may guide toxicity management (e.g. anti-infective prophylaxis, early G-CSF, stem cell boost) and help to identify suitable CAR-T candidates.

Idecabtagene Vicleucel for Relapsed/Refractory Multiple Myeloma: Real-World Experience From the Myeloma CAR T Consortium

PURPOSE

Idecabtagene vicleucel (ide-cel) is an autologous B-cell maturation antigen-directed chimeric antigen receptor T-cell therapy approved for relapsed/refractory multiple myeloma (RRMM) on the basis of the phase II pivotal KarMMa trial, which demonstrated best overall and ≥ complete response rates of 73% and 33%, respectively. We report clinical outcomes with standard-of-care (SOC) ide-cel under the commercial Food and Drug Administration label.

METHODS

Data were retrospectively collected from patients with RRMM who underwent leukapheresis as of February 28, 2022, at 11 US institutions with intent to receive SOC ide-cel. Toxicities were graded per American Society for Transplantation and Cellular Therapy guidelines and managed according to each institution's policies. Responses were graded on the basis of the International Myeloma Working Group response criteria.

RESULTS

One hundred fifty-nine of 196 leukapheresed patients received ide-cel by data cutoff. One hundred twenty (75%) infused patients would have been ineligible for participation in the KarMMa clinical trial because of comorbidities at the time of leukapheresis. Any grade and grade ≥ 3 cytokine release syndrome and neurotoxicity occurred in 82/3% and 18/6%, respectively. Best overall and ≥ complete response rates were 84% and 42%, respectively. At a median follow-up of 6.1 months from chimeric antigen receptor T infusion, the median progression-free survival was 8.5 months (95% CI, 6.5 to not reached) and the median overall survival was 12.5 months (95% CI, 11.3 to not reached). Patients with previous exposure to B-cell maturation antigen-targeted therapy, high-risk cytogenetics, Eastern Cooperative Oncology Group performance status ≥ 2 at lymphodepletion, and younger age had inferior progression-free survival on multivariable analysis.

CONCLUSION

The safety and efficacy of ide-cel in patients with RRMM in the SOC setting were comparable with those in the phase II pivotal KarMMa trial despite most patients (75%) not meeting trial eligibility criteria.

Efficacy and safety of selinexor-based regimens for relapsed/refractory multiple myeloma: a systematic review of literature

With the incorporation of novel agents in earlier lines of therapy, an increasing number of multiple myeloma patients are refractory to traditional classes of drugs. Selinexor in combination with dexamethasone has emerged as a viable option for heavily pretreated triple-class relapsed and refractory multiple myeloma (RRMM). In this systematic review, we analyzed available literature on the role of selinexor in RRMM. The Boston trial demonstrated that selinexor when combined with dexamethasone and bortezomib is associated with a better depth and duration of response without excessive toxicity, compared with bortezomib and dexamethasone alone. Similarly, selinexor in combination with carfilzomib and dexamethasone was found to have a durable response and tolerable safety profile in both carfilzomib-naive and carfilzomib refractory RRMM patients. Selinexor in combination with IMiDs (lenalidomide and pomalidomide) as well as CD38 monoclonal antibodies (daratumumab) also have promising results. Selinexor combination therapy is both safe and effective for patients with pretreated RRMM.

Idecabtagene vicleucel (Ide-cel) chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory multiple myeloma (RRMM): Real-world experience

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Background: Ide-cel, a BCMA directed CAR T-cell therapy, was FDA approved 3/26/2021 for the treatment of RRMM after 4 prior lines of therapy. We evaluated the real-world outcomes of patients treated with standard of care ide-cel under the commercial FDA label. Methods: Ten US academic centers contributed data to this effort independent of the manufacturer. As of 1/10/2022, 138 patients were leukapheresed with overall manufacturing failure in 6 (4%). 108 patients were infused ≥ 30 days prior to data-cut off and constitute the study population for this retrospective analysis. Results: Table describes the study population compared to the pivotal KarMMa-1 trial (Munshi et al, NEJM 2021). Patients in our study were less likely to have ECOG PS of 0/1 (77%) and more likely to be penta-refractory (41%). 67% of patients would not have met eligibility criteria for KarMMa. Common reasons for ineligibility (> 1 reason in 22% patients) were co-morbidities (28%), cytopenias (22%), prior therapy with alloSCT/CAR-T/other BCMA therapy (19%), CNS myeloma/non-measurable disease/plasma cell leukemia (13%), and fitness (12%). 81% of patients received bridging therapy. Toxicity was comparable to that seen in KarMMa-1. Cytokine release syndrome (CRS) was seen in 82% (> grade 3: 4%) and immune effector cell-associated neurotoxicity syndrome (ICANS) in 15% (> grade 3: 5%) of patients, respectively. Tocilizumab and steroids were used in 72% and 25% of patients, respectively. Infections were seen in 34% of patients. Day 30 response was evaluable in 104 patients. Response rates were: ≥ partial response, 83%; ≥ very good partial response, 64%; and ≥ complete response (CR), 34%. 11% of patients have died by data cut-off, 7 due to disease progression and 5 due to other causes (1 grade 5 CRS, 1 hemophagocytic lymphohistiocytosis, 1 progressive neurological weakness, 2 COVID-19). Conclusions: This multicenter retrospective study delineates the real-world outcomes of ide-cel CAR T-cell therapy for RRMM. Despite more patients being penta-refractory and less fit compared to the pivotal KarMMa trial, safety and 30-day responses in the real-world setting (overall response rate: 83%, CR: 34%) are comparable to the clinical trial population. Follow-up is ongoing and updated data will be presented. [Table: see text]

Longitudinal Collection of Patient-Reported Outcomes and Activity Data during CAR-T Therapy: Feasibility, Acceptability, and Data Visualization

Background: Clinicians must closely monitor patients for toxicities after chimeric antigen receptor T-cell therapy (CAR-T). Patient-reported outcomes (PROs) (e.g., toxicities, quality of life) and activity data (e.g., steps, sleep) may complement clinicians’ observations. This study tested the feasibility and acceptability of collecting PROs and activity data from patients with hematologic malignancies during CAR-T and explored preliminary data patterns. Methods: Participants wore a Fitbit tracker and completed PROs at several timepoints through 90-days post-infusion. Feasibility was assessed with a priori benchmarks for recruitment (≥50%), retention (≥70%), PRO completion (≥70%), and days wearing the Fitbit (≥50%). Acceptability was assessed with participant satisfaction (a priori benchmark > 2 on a 0−4 scale). Results: Participants (N = 12) were M = 66 years old (SD = 7). Rates of recruitment (68%), retention (83%), PRO completion (85%), and days wearing the Fitbit (85%) indicated feasibility. Satisfaction with completing the PROs (M = 3.2, SD = 0.5) and wearing the Fitbit (M = 2.9, SD = 0.5) indicated acceptability. Preliminary data patterns suggested that participants with better treatment response (vs. progressive disease) had a higher toxicity burden. Conclusions: Longitudinal PRO and activity data collection was feasible and acceptable. Data collected on a larger scale may be used to specify risk prediction models to identify predictors of severe CAR-T-related toxicities and inform early interventions.

Toxicities associated with adoptive cellular therapies

Chimeric antigen receptor (CAR) T cell therapy is an effective strategy for the treatment of relapsed/refractory hematologic malignancies leading to the Food and Drug Administration (FDA) approval of five CAR T cell products. Despite encouraging efficacy, the widespread utilization of CAR T cell therapy is limited by unique immune mediated toxicities, primarily cytokine release syndrome (CRS) and neurologic toxicity. Data regarding late effects and long-term toxicities of CAR T cell therapy is evolving and includes prolonged cytopenias, hypogammaglobulinemia, infections and secondary malignancies. In this review, we will describe the clinical presentation, diagnosis, mechanisms and management of short- and long-term toxicities of CAR T cell therapy.

Clinical presentation and outcome of patients with AL amyloidosis requiring salvage therapy

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Background: The diagnosis and upfront management of immunoglobulin light chain (AL) amyloidosis have greatly improved in recent years. However, little is known about the presentation, treatment, and outcome of these patients at first relapse/progression (R/P). Methods: All patients with AL amyloidosis who received salvage therapy for first R/P disease at Moffitt Cancer Center between 2008 and 2020 were included in this retrospective review. Definitions of hematologic and organ R/P were based on 2012 consensus. Overall survival was measured from the time of salvage to last follow up/death. Survival was assessed by Kaplan-Meier with log-rank comparison. Results: Sixty-nine patients were included. The median age at diagnosis was 62 years and 61% were male. Upfront therapy included high dose melphalan with autologous transplant in 36% and bortezomib in 52%. At salvage, 19% had disease refractory to upfront therapy and 40% had not achieved an organ response. The median time from upfront to salvage therapy was 22 months. Salvage regimens included proteasome inhibitors, daratumumab and immunomodulatory drugs in 55%, 13% and 22%, respectively. At least a very good partial response and organ response were achieved in 35% (22/62) and 39% (21/54) with measurable disease. The median overall survival was 60 months. Based on salvage indication, patients were classified into hematologic (n = 29) and organ R/P (n = 40), and the latter showed more frequent lambda-light chain disease (59% vs. 83%, p = 0.028) and low difference of involved-uninvolved free light chain at diagnosis (< 50 mg/L, 8% vs. 44%, p = 0.002). Negative prognostic markers for survival included bone marrow plasma cells ≥20% at diagnosis (median 17 months vs. not reached; p < 0.001) and organ, particularly cardiac R/P (median, 31 months vs. not reached; p = 0.003). Salvage ( p = 0.48) or prior regimens ( p = 0.11) did not impact post-salvage survival. Conclusions: Our study highlights the unmet need of salvage in R/P AL amyloidosis in a real-world setting, given the low rate of deep responses regardless of current salvage options. Patients with bone marrow plasma cells ≥20% at diagnosis and organ R/P at salvage had inferior survival, supporting use of intensive upfront regimens for the former and adjustment of therapy if deep response is not achieved.[Table: see text]

ELN 2017 Genetic Risk Stratification Predicts Survival of Acute Myeloid Leukemia Patients Receiving Allogeneic Hematopoietic Stem Cell Transplantation

European LeukemiaNet (ELN) 2017 risk stratification by genetics is prognostic of outcomes in patients with acute myeloid leukemia (AML). However, the prognostic impact of the 2017 ELN genetic risk stratification after allogeneic hematopoietic cell transplantation (alloHCT) is not well established. We examined the effect of 2017 ELN genetic risk stratification on alloHCT outcomes of AML. We included 500 adult (≥18 years) AML patients in first (n = 370) or second (n = 130) complete remission receiving alloHCT from 2005 to 2016. Patients were classified into favorable (12%), intermediate (57%), and adverse (32%) 2017 ELN risk groups. The Cox proportional hazard model was used to conduct the multivariable analyses of leukemia-free survival (LFS) and overall survival (OS). Relapse and nonrelapse mortality were analyzed by the Fine-Gray regression model. OS at 2 years was 72% in the favorable versus 60% in the intermediate versus 45% in the adverse risk groups (P < .001). In multivariable analyses, the 2017 ELN classifier was an independent predictor of OS after alloHCT with significantly higher overall mortality in the intermediate (hazard ratio [HR] = 1.68, 95% confidence interval [CI], 1.06-2.68; P = .03) and adverse (HR = 2.50, 95% CI, 1.54-4.06; P < .001) risk groups compared to the favorable risk group. Similarly, LFS was worse in the intermediate (HR = 1.63, 95%, CI 1.06-2.53; P = .03) and adverse (HR 2.23, 95% CI, 1.41-3.54; P < .001) risk groups while relapse was higher in the adverse risk group (HR = 2.36, 95% CI, 1.28-4.35; P = .006) as compared to the favorable risk group. These data highlight the prognostic impact of the 2017 ELN genetic risk stratification on the survival of AML patients after alloHCT. Patients in the adverse risk group had the highest risk of relapse and worst survival. Thus the 2017 ELN prognostic system can help identify AML patients who may benefit from clinical trials offering relapse mitigation strategies to improve transplant outcomes.

Will adding alkylating agent to bortezomib improve survival of newly diagnosed AL amyloidosis patients?

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Background: The combination of bortezomib (Bort) and alkylating agent (AA) is a frequently used first-line therapy for AL amyloidosis. Kastritis et al. compared melphalan and dexamethasone with or without bortezomib as primary therapy and demonstrated increased hematologic response rate with the bortezomib and melphalan combination. However, the role of AA is unclear. This study aimed to evaluate if adding AA to Bort improved patient outcomes in AL amyloidosis. Methods: We retrospectively reviewed clinical data on 209 patients with systemic AL Amyloidosis at Moffitt Cancer Center between 2008 and 2020. We excluded patients with localized amyloidosis or amyloid other than AL. Patients were divided into two groups based on upfront therapy: A) Bort and B) Bort + AA. All patients also received dexamethasone. The staging was per Mayo 2012. Organ involvement, response, and progression were defined based on the 2005 criteria. Overall survival (OS) was defined as the time from initial diagnosis until death or last contact. Time to next therapy (TTNT) was calculated in patients with the documented hematologic response from the time of initiation of therapy to time of the next therapy/last follow up/death. Results: Of 209 patients, 36% (n=76) received Bort+AA; 30% (n=62) received Bort. No significant difference in clinical characteristics was seen in both groups except for age (which was higher for arm A: median 65 and 62 years, respectively, p=0.043) (table). In addition, Bort+AA became more commonly used as a frontline therapy after 1/1/2014 (p=0.001). Group A and B had similar median OS (69.9 months [95% CI. 44.7-95.2] and 64.4 mo [95% CI 40.5-88.3] respectively, p=0.60). 86% of patients in group B achieved a hematologic response as compared to 74% of patients in group A (p=0.15). Similarly, 47% of patients in group B achieved an organ response as compared to 34% of patients in group A (p=0.22). TTNT was higher in group A than group B (16.9 mo [95% CI, 0-41.5] and 7.8 mo [95% CI, 3.5-12.0], respectively, p=0.08). Conclusions: While Bort+AA is a commonly used regimen for amyloidosis, the addition of AA to Bort did not result in superior OS, TTNT compared to Bort alone in this retrospective study. This finding should be confirmed in prospective studies. Baseline Characteristics. [Table: see text]

Impact of doxycycline on outcomes in AL amyloidosis

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Background: It has been shown in mouse models doxycycline(Doxy) interferes with amyloid fibril formation. Retrospective data suggests the addition of Doxy to standard chemotherapy(chemo) reduces mortality in cardiac amyloidosis. We examined the relationship between Doxy use, treatment, and OS in a cohort of AL Amyloidosis(AL) within an academic center. Methods: AL pts between 2008 and 2020 at Moffitt Cancer Center. For this study we included patients with AL, with all types of organ involvement. We excluded pts with non-AL Amyloidosis and pts with localized amyloidosis were excluded. Data on organ involved, organ response, date of death, treatment were obtained for each pt. OS was defined as time from AL diagnosis to date of death. Univariate comparisons were performed to identify differences in treatment and other prognostic variables between Doxy groups, where appropriate (Table). Results: 209 pts that met inclusion criteria, 13 pts(6%) had cardiac involvement with AL. Of those 13 pts, only 3 pts(23%) received Doxy in addition to standard of care chemo. For this study, we included all types of AL for total 209 pts. Of the 209 pts, 9.5% received Doxy in addition to standard of care chemo and 90.5% pts did not receive Doxy and had chemo alone. Pts who received Doxy had more proteinuria (suggesting more significant renal involvement) but other characteristics were not statistically different including cardiac biomarkers (table). A numerically higher rate of organ response (67% versus 43%) was noted in patients who received Doxy but this didn’t reach statistical significance. Further the OS was numerically higher for Doxy treated pts however again this didn’t meet statistical significance. Conclusions: We noted higher organ responses and overall survival in Doxy treated pts, we could not identify statistical differences in outcomes possibly because of the sample size. Nevertheless, further follow up is warranted and Doxy may be associated with improved outcomes in AL. [Table: see text]

Influence of an n-3 long-chain polyunsaturated fatty acid-enriched diet on experimentally induced synovitis in horses

Dietary n-3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation has previously been shown to modify joint-related inflammation in several species, although information in the horse is lacking. We investigated whether dietary supplementation with n-3 LCPUFA would modify experimentally induced synovitis in horses. Twelve, skeletally mature, non-pregnant mares were randomly assigned to either a control diet (CONT) or an n-3 long-chain fatty acid-enriched treatment diet (N3FA) containing 40 g/day of n-3 LCPUFA for 91 days. Blood samples taken on days 0, 30, 60 and 90, and synovial fluid collected on days 0 and 90 were processed for lipid composition. On day 91, joint inflammation was stimulated using an intra-articular (IA) injection of 100 ng of recombinant equine IL-1beta (reIL-1β). Synovial fluid samples taken at post-injection hours (PIH) 0, 4, 8 and 24 were analysed for prostaglandin E2 (PGE2 ), matrix metalloproteinase (MMP) activity and routine cytology. Synovium and articular cartilage samples collected at PIH 8 were analysed for gene expression of MMP 1 and MMP 13, interleukin-1beta (IL-1β), cyclooxygenase 2 (COX-2), tumour necrosis factor-alpha and the aggrecanases, a disintegrin and metalloprotease with thrombospondin motifs (ADAMTS)-4 and ADAMTS-5. A 90-day feeding period of n-3 LCPUFA increased serum phospholipid and synovial fluid lipid compositions of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) compared to CONT horses. The reIL-1β injection caused an inflammatory response; however, there was no effect of dietary treatment on synovial fluid PGE2 content and MMP activity. Synovial tissue collected from N3FA horses exhibited lower expression of ADAMTS-4 compared to CONT horses. Despite the presence of EPA and DHA in the synovial fluid of N3FA horses, dietary n-3 LCPUFA supplementation did not modify synovial fluid biomarkers compared to CONT horses; however, the lower ADAMTS-4 mRNA expression in N3FA synovium warrants further investigation of n-3 LCPUFA as a joint therapy.

Effects of two different dietary sources of long chain omega-3, highly unsaturated fatty acids on incorporation into the plasma, red blood cell, and skeletal muscle in horses

The objective of this study was to examine the effects of different sources of dietary omega-3 (n-3) fatty acid supplementation on plasma, red blood cell, and skeletal muscle fatty acid compositions in horses. Twenty-one mares were blocked by age, BW, and BCS and assigned to 1 of 3 dietary treatments with 7 mares per treatment. Dietary treatments were: 1) control or no fatty acid supplement (CON), 2) 38 g of n-3 long chain, highly unsaturated fatty acid (LCHUFA) supplement/d provided by algae and fish oil (MARINE) containing alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and docosapentaenoic acid (DPA), and 3) 38 g of n-3 LCHUFA supplement/d provided by a flaxseed meal (FLAX) containing ALA. Each supplement was added to a basal diet consisting of hay and barley and was fed for 90 d. Blood samples and muscle middle gluteal biopsies were taken at d 0, 30, 60 and 90 of supplementation. Plasma, red blood cell and skeletal muscle fatty acid profiles were determined via gas chromatography. Plasma linoleic acid (LA) and ALA were at least 10 and 60% less (P < 0.01), respectively, in the MARINE compared with the FLAX and CON groups. Plasma EPA and DHA were only detected in the MARINE group, and EPA increased 40% (P < 0.001) from d 30 to 60, and DHA 19% (P < 0.01) from d 30 to 90. Red blood cell LA and ALA were not different among treatments. Red blood cell EPA and DHA were only detected in the MARINE group, where EPA increased 38% (P < 0.01) from d 30 to 60, and DHA increased 56% (P < 0.001) between d 30 and 90. Skeletal muscle LA was at least 17% less (P < 0.001) in the MARINE group compared with the other treatments. Skeletal muscle ALA was 15% less (P = 0.03) in the MARINE group compared with FLAX and CON groups. Skeletal muscle EPA was at least 25% greater (P < 0.001) in MARINE group compared with other treatments and increased (P < 0.001) by 71% from d 30 to 60. Skeletal muscle DHA was at least 57% greater (P < 0.001) in the MARINE group compared with other groups and increased (P < 0.001) by 40% between d 30 and 90. As far as the authors are aware, this is the first study to demonstrate that dietary fatty acid supplementation will affect muscle fatty acid composition in horses. Incorporation of n-3 LCHUFA into blood and muscle depends directly on dietary supply of specific fatty acids.

In vitro effects of folate derivatives on valproate-induced neural tube defects in mouse and rat embryos

The anticonvulsant drug valproic acid (VPA), produces neural tube defects in mouse and rat embryos treated in vivo or in vitro. The mechanism for the drug's embryotoxic effect is unknown, but 5-formyltetrahydrofolate has been reported to decrease the incidence of VPA-induced neural tube defects in mice treated in vivo. In the present study we have examined the ability of 5-formyltetrahydrofolate, tetrahydrofolate, 5-methyltetrahydrofolate and folic acid to protect against VPA-induced neural tube defects in CD-1 mouse or CD rat embryos grown in a whole embryo culture system. Mouse embryos with 2-5 somite pairs were cultured for 48 hr beginning on gestation day 8; presomite stage rat embryos were cultured beginning on gestation day 9 (for both species gestation day 0 was taken as the day a vaginal sperm plug was found). VPA at 1.2 mm (rats) or 1.8 mm (mice) produced a high incidence of open neural tubes. None of the folate derivatives in concentrations up to 100 mug/ml was able to decrease the incidence of VPA-induced defects in either species. These data suggest that folate is not involved in the mechanism of VPA-induced neural tube defects.

Changes in gait associated with acute stage II posterior tibial tendon dysfunction

The purpose of this study was to examine differences in gait mechanics between patients with acute stage II PTTD and healthy volunteers. Hindfoot and midfoot kinematics, plantar foot pressures and electromyographic (EMG) activity of the posterior tibialis, gastrocnemius, anterior tibialis and the peroneals were measured in five patients with acute stage II PTTD. Kinematics and kinetics were compared to a database of 20 healthy volunteers. EMG and plantar pressure data were obtained from five healthy volunteers. Hindfoot moments and powers were also calculated. The center of pressure excursion index (CPEI) was calculated from the plantar pressures. Significant differences were observed between the two groups, which confirmed clinical observations. Limited hindfoot eversion and increased midfoot external rotation occurred during the first and third rockers. The EMG data suggested that tendon dysfunction in the posterior tibialis is associated with compensatory activity, not only in its antagonists (the peroneals), but also in the anterior tibialis and the gastrocnemius. These data suggest that non-operative treatment of patients with PTTD should consider minimizing the activity of the posterior tibialis as well as the peroneals, the anterior tibialis and the gastrocnemius.

Minimal effects from developmental exposure to St. John's wort (Hypericum perforatum) in Sprague-Dawley rats

Increasing widespread use of St. John's Wort (SJW, Hypericum perforatum) has led to concerns about its use in pregnant women. Behavioral and physiological alterations resulting from developmental treatment were investigated in Sprague-Dawley rats exposed to diets containing 0, 180, 900, 1800 or 4500ppm SJW beginning on gestational day 3 and ending at offspring weaning on postnatal day (PND) 21. These dietary doses span 1-25 times the recommended human dose. Post-weaning behavioral assessments of male and female offspring included: open field activity, acoustic startle, performance of complex and Morris water mazes, and activity in an elevated plus-maze. There were no SJW effects on maternal weight gain or duration of gestation; offspring body weights were similar to controls from PND 2 through PND 56 after which, some treated groups weighed significantly less than the controls. There were no SJW-related behavioral alterations on any measure. Whole and regional brain weights of offspring at adulthood indicated no significant effects of SJW. These results indicate that there are few neurobehavioral alterations resulting from developmental SJW treatment in rats.

Comparison of in vitro BBMEC permeability and in vivo CNS uptake by microdialysis sampling

The studies presented in this report were designed to assess the correlation of the bovine brain microvessel endothelial cell (BBMEC) apparent permeability coefficient (P(app)) and in vivo BBB penetration using microdialysis sampling. A mathematical model was developed to describe the relationship of brain extracellular fluid (ECF) concentration to free drug in plasma. The compounds studied have a broad range of physico-chemical characteristics and have widely varying in vitro and in vivo permeability across the blood-brain barrier (BBB). BBMEC permeability coefficients vary in magnitude from a low of 0.9 x 10(-5) cm/s to a high value of 7.5 x 10(-5) cm/s. Corresponding in vivo measurements of BBB permeability are represented by clearance (CL(in)) into the brain ECF and range from a low of 0.023 microl/min/g to a high of 12.9 microl/min/g. While it is apparent that in vitro data from the BBMEC model can be predictive of the in vivo permeability of a compound across the BBB, there are numerous factors both prior to and following entry into the brain which impact the ultimate uptake of a compound. Even in the presence of high BBB permeability, factors such as high plasma protein binding, active efflux across the BBB, and metabolism within the CNS can greatly limit the ultimate concentrations achieved. In addition, concentrations in the intracellular space may not be the same as concentrations in the extracellular space. While these data show that the BBMEC permeability is predictive of the in vivo BBB permeability, the complexity of the living system makes prediction of brain concentrations difficult, based solely on the in vitro measurement.

Isolation and characterization of a folate receptor mRNA-binding trans-factor from human placenta. Evidence favoring identity with heterogeneous nuclear ribonucleoprotein E1

The interaction of an 18-base cis-element in the 5'-untranslated region of human folate receptor (FR)-alpha mRNA with a cytosolic trans-factor protein is critical for the translation of FR (Sun, X.-L., and Antony, A. C. (1996) J. Biol. Chem. 271, 25539-25547). This trans-factor was isolated to apparent homogeneity as a 43- and 38-kDa doublet from human placenta using poly(U)-Sepharose, followed by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis and electro-elution as major purification steps. Amino acid microsequencing of two cyanogen bromide-generated peptide fragments of the 43-kDa trans-factor revealed complete identity with 43-kDa heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1). Purified specific rabbit anti-hnRNP E1 peptide antibodies (generated against a synthetic oligopeptide that was not represented in microsequenced peptides of the trans-factor) also recognized the purified trans-factor on Western blots. Conversely, the 18-base FR RNA cis-element also bound hnRNP E1 protein on Northwestern blots. Moreover, a 19-base RNA cis-element in the 3'-untranslated region of 15-lipoxygenase mRNA that is known to bind hnRNP E1 also interacted with placental 43-kDa trans-factor. In addition, several murine tissues containing a hnRNP E1-related protein (also known as alphaCP-1) readily interacted with the 18-base FR RNA cis-element. Finally, anti-hnRNP E1 antibodies specifically inhibited translation of FR in vitro in a dose-dependent manner, and the antibody effect could be reversed in a dose-dependent manner by either purified trans-factor or hnRNP E1. Collectively, the data favor identity of the FR mRNA-binding trans-factor and hnRNP E1, confirm its critical role in the translation of FR, and highlight yet another role of multifunctional hnRNP E1 in eukaryotic mRNA regulation.

An overview of rodent toxicities: liver and kidney effects of fumonisins and Fusarium moniliforme

Fumonisins are produced by Fusarium moniliforme F. verticillioides) and other Fusarium that grow on corn worldwide. They cause fatal toxicoses of horses and swine. Their effects in humans are unclear, but epidemiologic evidence suggests that consumption of fumonisin-contaminated corn contributes to human esophageal cancer in southern Africa and China. Much has been learned from rodent studies about fumonisin B1(FB1), the most common homologue. FB1 is poorly absorbed and rapidly eliminated in feces. Minor amounts are retained in liver and kidneys. Unlike other mycotoxins, fumonisins cause the same liver cancer promotion and subchronic (studies (3/4) 90 days) liver and kidney effects as (italic)F. moniliforme. FB 1 induces apoptosis of hepatocytes and of proximal tubule epithelial cells. More advanced lesions in both organs are characterized by simultaneous cell loss (apoptosis and necrosis) and proliferation (mitosis). Microscopic and other findings suggest that an imbalance between cell loss and replacement develops, a condition favorable for carcinogenesis. On the molecular level, fumonisins inhibit ceramide synthase, and disrupt sphingolipid metabolism and, theoretically, sphingolipid-mediated regulatory processes that influence apoptosis and mitosis. Liver sphingolipid effects and toxicity are correlated, and ceramide synthase inhibition occurs in liver and kidney at doses below their respective no-observed-effect levels. FB1 does not cross the placenta and is not teratogenic in vivoin rats, mice, or rabbits, but is embryotoxic at high, maternally toxic doses. These data have contributed to preliminary risk evaluation and to protocol development for carcinogenicity and chronic toxicity studies of FB1 in rats and mice.

Lack of embryotoxicity of homocysteine thiolactone in mouse embryos in vitro

Recent work from humans and chick embryos has suggested that homocysteine may play a role in producing neural tube defects (NTDs). In an effort to determine if homocysteine is able to produce NTDs in mammalian embryos, mouse embryos were explanted on GD 8 and cultured for 44 h. When either homocysteine or homocysteine thiolactone was added to the culture medium, treated embryos developed as well as controls and had closed neural tubes. Homocysteine thiolactone was also microinjected into the amniotic sac of mouse embryos. Again, development proceeded normally with no significant increase in the number of embryos with open neural tubes at the end of the culture period. HPLC analysis of embryonic thiols 24 h after microinjection revealed a significant increase in embryonic cystathionine levels. These data suggest that homocysteine does not produce NTDs in mouse embryos cultured in vitro and that early organogenesis-stage embryos are able to metabolize homocysteine.

Antisense modulation of 5,10-methylenetetrahydrofolate reductase expression produces neural tube defects in mouse embryos

The role of folate metabolism in producing neural tube defects (NTDs) in humans is unknown. In the current study, antisense oligodeoxyribonucleotide technology was utilized to disrupt normal expression of the gene for 5,10-methylenetetrahydrofolate reductase (MTHFR) in organogenesis-stage mouse embryos. Two different antisense probes were microinjected into the amniotic sac of gestation day (GD) 8 mouse embryos with PBS or scrambled sense oligodeoxyribonucleotides injected into control embryos. Concentration-dependent increases in the frequencies of embryos with NTDs were observed for both antisense sequences. The level of mRNA for MTHFR was decreased in embryos treated with the higher concentration of one antisense sequence, indicating that the sequence is able to decrease gene expression. 5-methyltetrahydrofolate, the product of the MTHFR reaction, was able to decrease the incidence of antisense-induced NTDs, but co-injection with L-methionine did not. These results suggest that reduced expression of MTHFR may play a role in producing NTDs.

Evaluation of the BBMEC model for screening the CNS permeability of drugs

Combinatorial synthesis and high-throughput pharmacology screening have greatly increased compound throughput in modern drug-discovery programs. For CNS drugs, it is also important to determine permeability to the blood--brain barrier. Yet, given the increased pace of discovery, it difficult to conduct this screen in a timely fashion. In this presentation, we describe several improvements to an existing CNS permeability screen, the bovine brain microvessel endothelial cell (BBMEC) model. By implementation of these incremental process improvements, we have achieved a robust, facile screen for determination of CNS permeability of multiple compounds.

Dose-response of retinoic acid induced stress protein synthesis and teratogenesis in mice

Stress proteins are synthesized in response to a variety of stressors, including several teratogenic agents. However, their role, if any, in the teratogenic process is unknown. We have previously demonstrated that all-trans-retinoic acid administered to pregnant CD-1 mice on gestational day 11 or 13 produced limb defects and cleft palate near term in a dose-responsive manner. This chemical also induced the synthesis of several nuclear stress proteins in embryonic tissues within several hours of dosing. The stress proteins were only observed in tissues that eventually became malformed and not in tissues that appeared normal at term. In the current work, we examined the stress response in embryonic target tissues after several different doses of retinoic acid. The nuclear stress proteins were synthesized in a dose-related manner and at a lower retinoic acid dose than doses producing malformations in the corresponding tissue at birth. Each individual stress protein and the total stress protein response were highly correlated, across dose, with the respective malformations observed at term.

Hypothesis: folate-responsive neural tube defects and neurocristopathies

BACKGROUND

What accounts for the wide spectrum of folate-responsive dysmorphogeneses? Both embryonic and fetal cells are entirely dependent on maternal folate to support their requirement for precisely timed proliferative bursts during gestation. Folate receptors (FRs) mediate transport into cells and are central to transplacental maternal-to-fetal folate transport. FRs are also critical for neural tube and neural crest development because recent murine "knock-out" and "knock-down" of FRs results in a high percentage of folate-responsive neural tube defects (NTDs) and neurocristopathies.

HYPOTHESIS

Central to our hypothesis is the fact that folate deficiency is accompanied by a reduction in the proliferative capacity of highly mitotic neural tube or neural crest cells. Therefore, depending on when in pregnancy various cohorts of highly proliferative cells are deprived of folate, and the origin of the affected cells will determine the type of developmental dysmorphogenesis. Thus, selective folate deficiency in early pregnancy of only highly proliferative neural tube or neural crest cells predisposes to NTDs or gross dysmorphogenesis, respectively. Folate deficiency that compromises placental development will predispose to small-for-date babies due to an overall nutrient deficiency, and the development of folate insufficiency later in pregnancy could predispose to more subtle midline birth defects involving atresia of neural crest cell-derived structures. Finally, a congenital folate transport defect would only be corrected by suprapharmacological doses of folate, which ensures passive diffusion.

CONCLUSION

This hypothesis can explain the results of several earlier and more recent clinical trials on folate supplementation in pregnancy, but it also raises the possibility that there may be several as yet undiscovered neurocristopathies that are folate responsive. Teratology 62:42-50, 2000. Published 2000 Wiley-Liss, Inc.

Food and Drug Administration proposed testing guidelines for developmental toxicity studies. Revision Committee. FDA Guidelines for Developmental Toxicity and Reproduction, Food and Drug Administration

The Food and Drug Administration (FDA) is the agency responsible for ensuring that the direct food additives and color additives used in food in the United States are safe for all consumers. In 1982, in an effort to provide guidance concerning appropriate tests, the FDA issued Toxicological Principles for the Safety Assessment of Direct Food Additives and Color Additives Used in Food, commonly known as the Redbook. The Redbook included detailed guidelines for testing the effects of direct and indirect food and color additives on mothers and their developing fetuses. Based on refinements in safety assessment and risk evaluation as well as expansion of knowledge concerning the metabolism and pharmacokinetics of food and color additives, the need to revise and update the 1982 document became apparent. In 1993, Redbook II in draft form was made available for public comment. Since then, test end points and developmental landmarks have been refined. The latest proposed guidelines for developmental toxicity studies are provided here.

Food and Drug Administration proposed testing guidelines for reproduction studies. Revision Committee. FDA Guidelines for Developmental Toxicity and Reproduction, Food and Drug Administration

In the United States, the Food and Drug Administration (FDA) is the agency responsible for ensuring that the direct food additives and color additives used in food are safe for all consumers. In order to determine the safety of these additives for consumption, appropriate information and results from a series of tests must be made available to the agency. In 1982, in an effort to provide guidance to the food industry concerning the appropriate tests for the determination of safety, the FDA issued the Toxicological Principles for the Safety Assessment of Direct Food Additives and Color Additives Used in Foods, commonly referred to as the Redbook. In 1993, based on the expansion of technology and the use of food additives, as well as the refinement of the scientific criteria for establishing safety, the FDA updated its guidelines and issued the draft Redbook II. Since Redbook II was issued, additional refinements have been made in the procedures for the multigeneration reproduction study and for the assessment of effects on male reproduction. The latest proposed guidelines for multigeneration studies are provided here.