SARS-CoV-2 mRNA vaccination exposes progressive adaptive immune dysfunction in patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) patients have lower seroconversion rates and antibody titers following SARS-CoV-2 vaccination, but the reasons for this diminished response are poorly understood. Here, we studied humoral and cellular responses in 95 CLL patients and 30 healthy controls after two BNT162b2 or mRNA-2173 mRNA immunizations. We found that 42% of CLL vaccinees developed SARS-CoV-2-specific binding and neutralizing antibodies (NAbs), while 32% had no response. Interestingly, 26% were seropositive, but had no detectable NAbs, suggesting the maintenance of pre-existing endemic human coronavirus-specific antibodies that cross-react with the S2 domain of the SARS-CoV-2 spike. These individuals had more advanced disease. In treatment-naïve CLL patients, mRNA-2173 induced 12-fold higher NAb titers and 1.7-fold higher response rates than BNT162b2. These data reveal a graded loss of immune function, with pre-existing memory being preserved longer than the capacity to respond to new antigens, and identify mRNA-2173 as a superior vaccine for CLL patients.

SARS-CoV-2-specific circulating T follicular helper cells correlate with neutralizing antibodies and increase during early convalescence

T-cell immunity is likely to play a role in protection against SARS-CoV-2 by helping generate neutralizing antibodies. We longitudinally studied CD4 T-cell responses to the M, N, and S structural proteins of SARS-CoV-2 in 26 convalescent individuals. Within the first two months following symptom onset, a majority of individuals (81%) mounted at least one CD4 T-cell response, and 48% of individuals mounted detectable SARS-CoV-2-specific circulating T follicular helper cells (cTfh, defined as CXCR5⁺PD1⁺ CD4 T cells). SARS-CoV-2-specific cTfh responses across all three protein specificities correlated with antibody neutralization with the strongest correlation observed for S protein-specific responses. When examined over time, cTfh responses, particularly to the M protein, increased in convalescence, and robust cTfh responses with magnitudes greater than 5% were detected at the second convalescent visit, a median of 38 days post-symptom onset. CD4 T-cell responses declined but persisted at low magnitudes three months and six months after symptom onset. These data deepen our understanding of antigen-specific cTfh responses in SARS-CoV-2 infection, suggesting that in addition to S protein, M and N protein-specific cTfh may also assist in the development of neutralizing antibodies and that cTfh response formation may be delayed in SARS-CoV-2 infection.

Since December 2019, the Coronavirus Disease 2019 (COVID-19) pandemic has caused significant morbidity and mortality worldwide. Recently approved vaccines against SARS-CoV-2 are understood to protect against infection by inducing neutralizing antibodies. However, the underlying immune responses necessary for protection remain unclear. It is well established that T follicular helper cells (Tfh), a subset of CD4 T cells, are essential to the development of neutralizing antibodies and that some of these cells, called circulating T follicular helper cells (cTfh), can be studied in the blood. Not much is known about Tfh responses mounted in SARS-CoV-2 infection. Here, we studied cTfh responses to three major structural proteins in individuals recovered from COVID-19. We find that SARS-CoV-2-specific cTfh frequencies correlate with neutralizing antibody responses. We also find that cTfh responses to SARS-CoV-2 increase well into convalescence before contracting. Our results suggest that cTfh responses against proteins other than the spike protein may contribute to the development of neutralizing antibodies and that the formation of cTfh responses in SARS-CoV-2 infection may be delayed.

Predictors of Nonseroconversion after SARS-CoV-2 Infection

Not all persons recovering from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection develop SARS-CoV-2–specific antibodies. We show that nonseroconversion is associated with younger age and higher reverse transcription PCR cycle threshold values and identify SARS-CoV-2 viral loads in the nasopharynx as a major correlate of the systemic antibody response.

Intradermal delivery of a synthetic DNA vaccine protects macaques from Middle East respiratory syndrome coronavirus

Emerging coronaviruses from zoonotic reservoirs, including severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have been associated with human-to-human transmission and significant morbidity and mortality. Here, we study both intradermal and intramuscular 2-dose delivery regimens of an advanced synthetic DNA vaccine candidate encoding a full-length MERS-CoV spike (S) protein, which induced potent binding and neutralizing antibodies as well as cellular immune responses in rhesus macaques. In a MERS-CoV challenge, all immunized rhesus macaques exhibited reduced clinical symptoms, lowered viral lung load, and decreased severity of pathological signs of disease compared with controls. Intradermal vaccination was dose sparing and more effective in this model at protecting animals from disease. The data support the further study of this vaccine for preventing MERS-CoV infection and transmission, including investigation of such vaccines and simplified delivery routes against emerging coronaviruses.

Convalescent plasma-mediated resolution of COVID-19 in a patient with humoral immunodeficiency

Convalescent plasma (CP) is widely used to treat COVID-19, but without formal evidence of efficacy. Here, we report the beneficial effects of CP in a severely ill COVID-19 patient with prolonged pneumonia and advanced chronic lymphocytic leukemia (CLL), who was unable to generate an antiviral antibody response of her own. On day 33 after becoming symptomatic, the patient received CP containing high-titer (ID50 > 5,000) neutralizing antibodies (NAbs), defervesced, and improved clinically within 48 h and was discharged on day 37. Hence, when present in sufficient quantities, NAbs to SARS-CoV-2 have clinical benefit even if administered relatively late in the disease course. However, analysis of additional CP units revealed widely varying NAb titers, with many recipients exhibiting endogenous NAb responses far exceeding those of the administered units. To obtain the full therapeutic benefits of CP immunotherapy, it will thus be important to determine the neutralizing activity in both CP units and transfusion candidates.

SARS-CoV-2-specific peripheral T follicular helper cells correlate with neutralizing antibodies and increase during convalescence

T-cell immunity is likely to play a role in protection against SARS-CoV-2 by helping generate neutralizing antibodies. We longitudinally studied CD4 T-cell responses to the M, N, and S structural proteins of SARS-CoV-2 in 21 convalescent individuals. Within the first two months following symptom onset, a majority of individuals (81%) mount at least one CD4 T-cell response, and 48% of individuals mount detectable SARS-CoV-2-specific peripheral T follicular helper cells (pTfh, defined as CXCR5+PD1+ CD4 T cells). SARS-CoV-2-specific pTfh responses across all three protein specificities correlate with antibody neutralization with the strongest correlation observed for S protein-specific responses. When examined over time, pTfh responses increase in frequency and magnitude in convalescence, and robust responses with magnitudes greater than 5% were detected only at the second convalescent visit, an average of 38 days post-symptom onset. These data deepen our understanding of antigen-specific pTfh responses in SARS-CoV-2 infection, suggesting that M and N protein-specific pTfh may also assist in the development of neutralizing antibodies and that pTfh response formation may be delayed in SARS-CoV-2 infection.

Abstract B67: Synthetic DNA multi-neoantigen vaccine drives predominately MHC class I CD8+ T cell-mediated effector immunity impacting tumor challenge

T-cell recognition of cancer neoantigens is important for effective immune checkpoint blockade therapy, and there is increasing interest in developing personalized tumor neoantigen vaccines. Previous studies utilizing RNA and synthetic long peptide neoantigen vaccines in preclinical and early-phase clinical studies have shown immune responses predominantly driven by MHC class II CD4+ T cells. Although it has been established that CD4+ T cells are able to recognize tumor neoantigens, the majority of naturally occurring tumor antigen-specific killer T cells identified in patients have been of CD8+ origin, indicating that additional immunization strategies aimed to stimulate neoantigen-specific CD8+ T cells may be useful. Here, we report the first preclinical study utilizing a synthetic DNA vaccine platform to target tumor neoantigens in mice. For this study, we identified neoepitopes by sequencing syngeneic mouse tumors, and designed optimized DNA plasmids encoding long strings of neoepitopes separated by highly efficient cleavage sites preserving epitope integrity. We tested the immunogenicity of 84 independent neoepitopes encoded into optimized DNA plasmids delivered by adaptive electroporation in mice in vivo. We observed that this approach generated robust T-cell immunity against a similar proportion of epitopes compared to other vaccine platforms (20/84, 24%). Strikingly, however, the synthetic neoantigen DNA vaccine platform generated a much larger proportion of CD8+ T-cell responses compared to the prior studies. Synthetic neoantigen DNA vaccines generated 75% CD8+ only or CD4/CD8+ T-cell responses, and 25% CD4+ only T-cell responses, showing a dramatic and important CD8+ T-cell bias. Inclusion of only high-affinity MHC class I (<500nM) epitopes selected for a larger proportion of immunogenic epitopes, and for 100% CD8+ or CD8+/CD4+ T-cell epitopes. These neoantigen vaccines were able to control tumor growth therapeutically in vivo in both lung and ovarian cancer models, and T cells expanded from immunized mice were able to kill tumor cells ex vivo. Because of the potential for rapid synthesis of vaccine constructs, the capacity to deliver a large number of neoepitopes simultaneously, and the potent CD8+ stimulatory capacity, this advanced DNA vaccine platform represents a likely important new approach for cancer immunotherapy.

Citation Format: Elizabeth K. Duperret, Alfredo Perales-Puchalt, Regina Stoltz, G.H. Hiranjith, Nitin Mandloi, James Barlow, Amitabha Chaudhuri, Niranjan Y. Sardesai, David B. Weiner. Synthetic DNA multi-neoantigen vaccine drives predominately MHC class I CD8+ T cell-mediated effector immunity impacting tumor challenge [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr B67.

A Synthetic DNA, Multi-Neoantigen Vaccine Drives Predominately MHC Class I CD8+ T-cell Responses, Impacting Tumor Challenge

T-cell recognition of cancer neoantigens is important for effective immune-checkpoint blockade therapy, and an increasing interest exists in developing personalized tumor neoantigen vaccines. Previous studies utilizing RNA and long-peptide neoantigen vaccines in preclinical and early-phase clinical studies have shown immune responses predominantly driven by MHC class II CD4⁺ T cells. Here, we report on a preclinical study utilizing a DNA vaccine platform to target tumor neoantigens. We showed that optimized strings of tumor neoantigens, when delivered by potent electroporation-mediated DNA delivery, were immunogenic and generated predominantly MHC class I-restricted, CD8⁺ T-cell responses. High MHC class I affinity was associated specifically with immunogenic CD8⁺ T-cell epitopes. These DNA neoantigen vaccines induced a therapeutic antitumor response in vivo, and neoantigen-specific T cells expanded from immunized mice directly killed tumor cells ex vivo These data illustrate a unique advantage of this DNA platform to drive CD8⁺ T-cell immunity for neoantigen immunotherapy.

A Designer Cross-reactive DNA Immunotherapeutic Vaccine that Targets Multiple MAGE-A Family Members Simultaneously for Cancer Therapy

PURPOSE

Cancer/testis antigens have emerged as attractive targets for cancer immunotherapy. Clinical studies have targeted MAGE-A3, a prototype antigen that is a member of the MAGE-A family of antigens, in melanoma and lung carcinoma. However, these studies have not yet had a significant impact due to poor CD8⁺ T-cell immunogenicity, platform toxicity, or perhaps limited target antigen availability. In this study, we develop an improved MAGE-A immunogen with cross-reactivity to multiple family members.

EXPERIMENTAL DESIGN

In this study, we analyzed MAGE-A expression in The Cancer Genome Atlas and observed that many patients express multiple MAGE-A isoforms, not limited to MAGE-A3, simultaneously in diverse tumors. On the basis of this, we designed an optimized consensus MAGE-A DNA vaccine capable of cross-reacting with many MAGE-A isoforms, and tested immunogenicity and antitumor activity of this vaccine in a relevant autochthonous melanoma model.

RESULTS

Immunization of this MAGE-A vaccine by electroporation in C57Bl/6 mice generated robust IFNγ and TNFα CD8⁺ T-cell responses as well as cytotoxic CD107a/IFNγ/T-bet triple-positive responses against multiple isoforms. Furthermore, this MAGE-A DNA immunogen generated a cross-reactive immune response in 14 of 15 genetically diverse, outbred mice. We tested the antitumor activity of this MAGE-A DNA vaccine in Tyr::CreER;BRAF^Ca/+;Pten^lox/lox transgenic mice that develop melanoma upon tamoxifen induction. The MAGE-A DNA therapeutic vaccine significantly slowed tumor growth and doubled median mouse survival.

CONCLUSIONS

These results support the clinical use of consensus MAGE-A immunogens with the capacity to target multiple MAGE-A family members to prevent tumor immune escape.

Synthetic DNA-Encoded Monoclonal Antibody Delivery of Anti-CTLA-4 Antibodies Induces Tumor Shrinkage In Vivo

Antibody-based immune therapies targeting the T-cell checkpoint molecules CTLA-4 and PD-1 have affected cancer therapy. However, this immune therapy requires complex manufacturing and frequent dosing, limiting the global use of this treatment. Here, we focused on the development of a DNA-encoded monoclonal antibody (DMAb) approach for delivery of anti-CTLA-4 monoclonal antibodies in vivo With this technology, engineered and formulated DMAb plasmids encoding IgG inserts were directly injected into muscle and delivered intracellularly by electroporation, leading to in vivo expression and secretion of the encoded IgG. DMAb expression from a single dose can continue for several months without the need for repeated administration. Delivery of an optimized DMAb encoding anti-mouse CTLA-4 IgG resulted in high serum levels of the antibody as well as tumor regression in Sa1N and CT26 tumor models. DNA-delivery of the anti-human CTLA-4 antibodies ipilimumab and tremelimumab in mice achieved potent peak levels of approximately 85 and 58 μg/mL, respectively. These DMAb exhibited prolonged expression, with maintenance of serum levels at or above 15 μg/mL for over a year. Anti-human CTLA-4 DMAbs produced in vivo bound to human CTLA-4 protein expressed on stimulated human peripheral blood mononuclear cells and induced T-cell activation in a functional assay ex vivo In summary, direct in vivo expression of DMAb encoding checkpoint inhibitors serves as a novel tool for immunotherapy that could significantly improve availability and provide broader access to such therapies.Significance: DNA-encoded monoclonal antibodies represent a novel technology for delivery and expression of immune checkpoint blockade antibodies, thus expanding patient access to, and possible clinical applications of, these therapies. Cancer Res; 78(22); 6363-70. ©2018 AACR.

Neonatal Abstinence Syndrome:The Experience of Infant Massage

Babies born to women who have used opioids during pregnancy frequently develop withdrawal symptoms following birth. Although a consistently used protocol is not available to treat these infants, interventions commonly used include a pharmacological regimen and supportive care such as swaddling, frequent feedings, decreased sensory stimulation, and protection from skin breakdown (Murphy-Oikonen, Montelpare, Bertoldo, Southon, & Persichino, 2012). A qualitative study was designed to better understand how infant massage might impact these babies’ behavior and the mothers’ relationship with their babies. Themes derived from the data include empowerment, enjoyment and bonding, and calm and comfort. The themes suggest that infant massage helps alleviate withdrawal symptoms in infants while fostering a connection between mother and child.

Pharmacodynamics, safety, tolerability, and pharmacokinetics of the 0.8-mg dose of cerivastatin in patients with primary hypercholesterolemia

Cerivastatin is a third generation hydroxy-methyl-glutaryl-Co-enzyme A (HMG-CoA) reductase inhibitor proven to lower low-density lipoprotein (LDL) cholesterol 28% to 31% in patients with primary hypercholesterolemia when given at 0.3 mg/day. This study evaluates the safety, tolerability, pharmacodynamics, and pharmacokinetics of cerivastatin 0.8 mg once daily for 4 weeks. In this randomized, double-blind, placebo-controlled parallel group trial conducted at 2 study centers, 41 patients (63% women) with primary hypercholesterolemia were placed on an American Heart Association Step 1 diet for 4 weeks. Single-blind placebo was administered for the final 2 weeks, before randomization. Patients received cerivastatin 0.8 mg (n = 28) or placebo (n = 13) once each evening for 28 days. Cerivastatin at 0.8 mg daily was well tolerated. No discontinuations occurred during the study. Adverse events were mild and transient. One cerivastatin-treated patient experienced asymptomatic creatinine kinase, 8x the upper limit of normal (ULN) elevation on the last day of the study, which resolved 6 days after the completion of the study. Cerivastatin 0.8 mg daily significantly reduced LDL cholesterol compared with placebo (-44.0 +/- 2.0% vs 2.2 +/- 2.8%, p <0.0001); total cholesterol (-30.8 +/- 1.4% vs 2.6 +/- 2.1%, p <0.0001), triglycerides (-11.2 +/- 5.9% vs 15.9 +/- 8.6%, p <0.02), but did not significantly alter high-density lipoprotein (HDL) cholesterol (3.2 +/- 2.1% vs -1.2 +/- 3.1%, p = NS). The pharmacokinetics of the 0.8-mg dose revealed dose proportional elevations in the 24-hour area under the curve and maximum plasma concentration relative to 0.3- and 0.4-mg doses with no change in time to maximum concentration or the elimination half-life in plasma. The increased efficacy and lack of clinically significant laboratory abnormalities or adverse events demonstrates a need for a large long-term study to confirm the safety and efficacy of this dose of cerivastatin.

Ineffectiveness of neurokinin-1 antagonist in acute migraine: a crossover study

Lanepitant is a high-affinity, selective neurokinin-1 receptor (NK-1) and is effective in the dural inflammation model of acute migraine. Lanepitant 30, 80, and 240 mg given orally was evaluated in a double-blind, placebo-controlled crossover study to determine its effect in reducing migraine pain and severity of associated symptoms. Outpatients treated four migraine headaches of moderate or severe pain intensity with study drug according to a randomization schedule. They recorded their pain intensity and severity of migraine-associated symptoms at 30, 60, 90, and 120 min. Although 53 patients were randomly allocated to a treatment sequence, only 40 patients completed all treatments. There was no statistically significant difference in improvement in migraine pain at any time for any of the treatments. Additionally, there was no change in severity of migraine-associated symptoms associated with lanepitant therapy. No adverse events could be attributed to lanepitant. Lanepitant was ineffective orally in treating acute migraine in this trial. This may be due to poor bioavailability during a migraine attack. Alternatively, the neurogenic inflammation hypothesis may not apply to migraine.

Valsartan, a new angiotensin II antagonist for the treatment of essential hypertension: efficacy, tolerability and safety compared to an angiotensin-converting enzyme inhibitor, lisinopril

OBJECTIVE

To compare the efficacy, safety and tolerability of valsartan to an angiotensin-converting enzyme (ACE) inhibitor, lisinopril, and placebo in patients with mild-to-moderate essential hypertension.

DESIGN

A total of 734 men and women were randomised in this multicentre, double-blind, optional titration, parallel group trial. Volunteers received valsartan 80 mg (n = 364), lisinopril 10 mg (n = 187) or placebo (n = 183) daily for 4 weeks, with subsequent titration of dose depending on response to treatment (valsartan 80 mg titrated to valsartan 160 mg once daily or valsartan 80 mg twice daily, lisinopril 10 mg titrated to lisonopril 20 mg once daily). Patients were assessed at 4, 8 and 12 weeks.

MAIN OUTCOME MEASURES

The primary variable was change from baseline in mean sitting diastolic blood pressure (SDBP). Other efficacy variables included sitting systolic blood pressure (SSBP) and percentage of 'successful' responders (SDBP <90 mm Hg or > or =10 mm Hg reduction from baseline).

RESULTS

All active treatment groups were shown to demonstrate significant reductions in SDBP compared to placebo at endpoint of therapy (least mean square reduction from baseline: valsartan 80/160 mg: -5.25 mm Hg (Cl -7.17, -3.34, P< 0.001); valsartan 80/80 mg twice daily: -5.63 mm Hg (Cl -7.51, -3.75, P< 0.001); lisinopril 10/20 mg: -6.93 mm Hg, (Cl -8.81, -5.05, P< 0.001). There were no statistically significant differences between the active treatment groups at endpoint of therapy. In patients requiring titration to a higher dose (placebo n = 142, valsartan 80/80 twice daily n = 124, valsartan 80/160 n = 114, lisinopril 10/20 n = 120), there were no significant treatment differences between valsartan 160 mg given as a single daily dose or as 80 mg twice daily (P = 0.658). Both valsartan and lisinopril produced similarly high percentages of 'successful' responders at endpoint of therapy. A somewhat higher frequency of drug related cough was observed in lisinopril treated patients (8%) compared to valsartan (1.1%) or placebo (0.5%).

CONCLUSIONS

Valsartan 80 mg daily, with titration to 160 mg daily as required, provides similar antihypertensive efficacy to lisinopril 10 mg daily with titration to 20 mg daily. Valsartan provides a new antihypertensive agent with comparable efficacy to lisinopril and appears to be associated with a reduced incidence of cough.