Adoptive T-cell therapy for pediatric cytomegalovirus-associated retinitis

The Role of Corticosteroids and Immunomodulatory Therapy in the Management of Infectious Uveitis

PURPOSE

The index review aims to provide an update on the role of corticosteroids and steroid-sparing immunomodulatory therapy (IMT) in managing patients with infectious uveitis.

METHOD

Narrative literature review.

RESULTS

Corticosteroids and immunomodulatory therapy (IMT) focus on the host defense system instead of the pathogen, adjusting exaggerated inflammatory reactions to reduce potential harm to ocular tissues. Systemic or local corticosteroids are primarily selected as adjunctive medication for infectious uveitis. Concomitant corticosteroids have also been used in cases of paradoxical worsening in ocular tuberculosis and immune recovery uveitis in cytomegalovirus (CMV) retinitis. While there is no well-established evidence to support the use of IMT in infectious uveitis, it is occasionally used in clinical settings to treat persistent inflammation following resolution of infection such as cases of ocular tuberculosis and ocular syphilis where an insufficient response is observed with corticosteroids.

CONCLUSION

There is no consensus on the position of immunomodulatory therapy in the management of infectious uveitis with different etiologies. The index review provides an overview of available adjunctive corticosteroids and IMT options to assist clinicians in managing such disease entities more efficiently.

Refractory human cytomegalovirus infection without evidence of genetic resistance in the UL-54 and UL-97 genes in a pediatric hematopoietic stem cell transplant recipient: a case report

Cytomegalovirus (CMV) infection is a common complication in patients undergoing hematopoietic stem cell transplantation (HSCT). Management of refractory CMV infections, especially in developing countries, can be challenging due to the limited availability of second and third-line antiviral drugs or alternative treatments. Here, we present a case of an 8 years-old patient diagnosed with acute myeloid leukemia. Eight months post-diagnosis, the patient underwent TCR-αβ+/CD19+-depleted haploidentical HSCT. Both the donor and recipient tested positive for anti-CMV IgG and negative for IgM antibodies. Before transplantation, the patient received CMV prophylaxis in the form of intravenous ganciclovir. Post-transplantation, the patient exhibited oscillating CMV viral loads and was diagnosed with a refractory infection. Treatment with ganciclovir, foscarnet, and cidofovir was unsuccessful. Sequencing of UL-54 and UL-97 genes was performed to rule out potential resistance to first-line treatment. Ten months after the HSCT, the child died from hypovolemic shock due to gastrointestinal bleeding. This is the first case reported in Peru and Latin America of a refractory CMV infection in a pediatric HSCT recipient without evidence of clinical symptoms and CMV genetic resistance. This case demonstrates the need for alternative treatments to manage refractory CMV infections, especially in haploidentical HSCT cases where drug resistance is frequent (~15%). Furthermore, this case highlights the importance of using highly sensitive genetic tools to detect mutations associated with virus resistance in a broader range of the viral genome.

Viral-specific T cells for Cytomegalovirus retinitis following hematopoietic stem cell transplantation: A success story

Cytomegalovirus retinitis (CMVR) following hematopoietic stem cell transplantation (HCT) for a primary immunodeficiency is a rare but highly morbid condition with potential irreversible consequences despite optimal antiviral pharmacotherapy. Viral-specific T cells (VSTs) pose a promising and safe approach eradicating intractable viral disease. We describe the case of a 21-month-old male with Wiskott-Aldrich syndrome (WAS) and CMVR post HCT with sustained long-term virologic and clinical response after CMV-specific T-cell therapy. This case highlights the need to consider VST as an adjunct upfront strategy in refractory CMVR and for routine ophthalmologic screening and surveillance in high-risk patients post HCT.

Prevention and management of CMV infection in pediatric solid organ transplant recipients

Human cytomegalovirus (CMV) remains one of the most common opportunistic infections following solid organ transplantation in children. CMV causes morbidity and mortality through direct tissue-invasive disease and indirect immunomodulatory effects. In recent years, several new agents have emerged for the prevention and treatment of CMV disease in solid organ transplant recipients. However, pediatric data remain scarce, and many of the treatments are extrapolated from the adult literature. Controversies exist about the type and duration of prophylactic therapies and the optimal dosing of antiviral agents. This review provides an up-to-date overview of treatment modalities used to prevent and treat CMV disease in solid organ transplant (SOT) recipients.

Adoptive Immunotherapy for Prophylaxis and Treatment of Cytomegalovirus Infection

Cytomegalovirus (CMV), a member of the Herpesviridae family, is frequent among hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients in absence of antiviral prophylaxis, and is a major cause of morbidity and mortality in these vulnerable populations. Antivirals such ganciclovir, valganciclovir, and foscarnet are the backbone therapies, however drug toxicity and antiviral resistance may render these agents suboptimal in treatment. Newer therapies such as letermovir and maribavir have offered additional approaches for antiviral prophylaxis as well as treatment of drug resistant CMV infection, though may be limited by cost, drug intolerance, or toxicity. Adoptive immunotherapy, the transfer of viral specific T-cells (VSTs), offers a new approach in treatment of drug-resistant or refractory viral infections, with early clinical trials showing promise with respect to efficacy and safety. In this review, we will discuss some of the encouraging results and challenges of widespread adoption of VSTs in care of immunocompromised patients, with an emphasis on the clinical outcomes for treatment and prophylaxis of CMV infection among high-risk patient populations.

Immunocompromised host section: Adoptive T-cell therapy for dsDNA viruses in allogeneic hematopoietic cell transplant recipients

PURPOSE OF REVIEW

Double-stranded DNA (dsDNA) viruses remain important causes of morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT). As treatment options are limited, adoptive therapy with virus-specific T cells (VST) is promising in restoring immunity and thereby preventing and treating virus infections. Here we review current evidence and recent advances in the field of VST for dsDNA viruses in allogeneic HCT recipients.

RECENT FINDINGS

Four different protocols for VST generation are currently used in clinical trials, and various products including multivirus-specific and off-the-shelf products are under investigation for prophylaxis, preemptive therapy or treatment. Data from nearly 1400 dsDNA-VST applications in allogeneic HCT patients have been published and demonstrated its safety. Although Epstein-Barr virus, cytomegalovirus, and adenovirus-specific T-cell therapy studies have predominated over the past 25 years, additional human herpes viruses were added to multivirus-specific T cells over the last decade and clinical evidence for polyomavirus-specific VST has just recently emerged. Response rates of around 70-80% have been reported, but cautious interpretation is warranted as data are predominantly from phase 1/2 studies and clinical efficacy needs to be confirmed in phase 3 studies.

SUMMARY

Investigation on the 'ideal' composition of VST is ongoing. Several products recently entered phase 3 trials and may allow widespread clinical use in the near future.

Cytomegaloviral Retinitis in a Heart Transplant Patient: Case Report and Review of the Literature

Cytomegalovirus (CMV) poses a significant threat to solid organ transplant recipients (SOTR). The incidence of CMV disease in SOTR varies according to immunosuppressive therapy, antiviral prophylaxis, donor and recipient serologic compatibility, and the transplanted organ: 9% to 23%, 22% to 29% and 8% to 32% after heart, liver and kidney transplant, respectively. CMV retinitis (CMVR) is a rare manifestation of CMV with a high risk of blindness. Infection may vary in severity, from initially clinically silent cases to full-blown advanced changes involving the eye. The most characteristic effects are changes in the retina, which usually begin at the retina's periphery and are asymptomatic, then these changes spread toward the center as the disease progresses and impairs vision. We describe CMV vitritis and retinitis in a 74-year-old patient after heart transplantation conducted in 1992. The first symptom of the disease was low vision in the left eye. Initially no blood viremia was observed; then the CMV viral load in the blood and vitreous body of the right eye was 2454 and 26 million IU/mL.Despite the initiation of treatment (intravitreal and then intravenous ganciclovir), the inflammatory process progressed rapidly and vision in the left eye was lost, although functional visual acuity in the right eye was maintained. Systemic antiviral therapy with intravenous ganciclovir lasted 6 weeks until the eradication of CMV viremia. The patient was on prophylactic therapy with oral valganciclovir for 12 months. A clinically silent course of CMVR delays diagnosis and therapy. Therefore, it is recommended that all SOTR undergo periodic ophthalmologic control to avoid delayed diagnosis.

American Society for Transplantation and Cellular Therapy Series: #4 - Cytomegalovirus treatment and management of resistant or refractory infections after hematopoietic cell transplantation

The Practice Guidelines Committee of the American Society of Transplantation and Cellular Therapy (ASTCT) partnered with its Transpl. Infect. Dis. Special Interest Group (TID-SIG) to update its 2009 compendium-style infectious disease guidelines for hematopoietic cell transplantation (HCT). A new approach was employed with the goal of better serving clinical providers by publishing each standalone topic in the infectious diseases series as a concise format of frequently asked questions (FAQ), tables, and figures. Adult and pediatric infectious diseases and HCT content experts developed and answered FAQs. Topics were finalized with harmonized recommendations that were made by assigning an A through E strength of recommendation paired with a level of supporting evidence graded I through III. The fourth topic in the series focuses on the management and treatment of cytomegalovirus (CMV) resistant and refractory infections. The diagnosis, definitions of resistant and refractory CMV, risk factors, virological genotypes and treatment algorithms are reviewed.

Is It Feasible to Use CMV-Specific T-Cell Adoptive Transfer as Treatment Against Infection in SOT Recipients?

During the last decade, many studies have demonstrated the role of CMV specific T-cell immune response on controlling CMV replication and dissemination. In fact, it is well established that transplanted patients lacking CMV-specific T-cell immunity have an increased occurrence of CMV replication episodes and CMV-related complications. In this context, the use of adoptive transfer of CMV-specific T-cells has been widely investigated and applied to Hematopoietic Stem Cell Transplant patients and may be useful as a therapeutic alternative, to reconstitute the CMV specific T-cell response and to control CMV viremia in patients receiving a transplantation. However, only few authors have explored the use of T-cell adoptive transfer in SOT recipients. We propose a novel review in which we provide an overview of the impact of using CMV-specific T-cell adoptive transfer on the control of CMV infection in SOT recipients, the different approaches to stimulate, isolate and expand CMV-specific T-cells developed over the years and a discussion of the possible use of CMV adoptive cellular therapy in this SOT population. Given the timeliness and importance of this topic, we believe that such an analysis will provide important insights into CMV infection and its treatment/prevention.

'Off-the-shelf' allogeneic antigen-specific adoptive T-cell therapy for the treatment of multiple EBV-associated malignancies

Background

Epstein-Barr virus (EBV), an oncogenic human gammaherpesvirus, is associated with a wide range of human malignancies of epithelial and B-cell origin. Recent studies have demonstrated promising safety and clinical efficacy of allogeneic ‘off-the-shelf’ virus-specific T-cell therapies for post-transplant viral complications.

Methods

Taking a clue from these studies, we developed a highly efficient EBV-specific T-cell expansion process using a replication-deficient AdE1-LMPpoly vector that specifically targets EBV-encoded nuclear antigen 1 (EBNA1) and latent membrane proteins 1 and 2 (LMP1 and LMP2), expressed in latency II malignancies.

Results

These allogeneic EBV-specific T cells efficiently recognized human leukocyte antigen (HLA)-matched EBNA1-expressing and/or LMP1 and LMP2-expressing malignant cells and demonstrated therapeutic potential in a number of in vivo models, including EBV lymphomas that emerged spontaneously in humanized mice following EBV infection. Interestingly, we were able to override resistance to T-cell therapy in vivo using a ‘restriction-switching’ approach, through sequential infusion of two different allogeneic T-cell therapies restricted through different HLA alleles. Furthermore, we have shown that inhibition of the programmed cell death protein-1/programmed death-ligand 1 axis in combination with EBV-specific T-cell therapy significantly improved overall survival of tumor-bearing mice when compared with monotherapy.

Conclusion

These findings suggest that restriction switching by sequential infusion of allogeneic T-cell therapies that target EBV through distinct HLA alleles may improve clinical response.

Scaffold-Mediated Static Transduction of T Cells for CAR-T Cell Therapy

Chimeric antigen receptor T (CAR-T) cell therapy has produced impressive clinical responses in patients with B-cell malignancies. Critical to the success of CAR-T cell therapies is the achievement of robust gene transfer into T cells mediated by viral vectors such as gamma-retroviral vectors. However, current methodologies of retroviral gene transfer rely on spinoculation and the use of retronectin, which may limit the implementation of cost-effective CAR-T cell therapies. Herein, a low-cost, tunable, macroporous, alginate scaffold that transduces T cells with retroviral vectors under static condition is described. CAR-T cells produced by macroporous scaffold-mediated viral transduction exhibit >60% CAR expression, retain effector phenotype, expand to clinically relevant cell numbers, and eradicate CD19⁺ lymphoma in vivo. Efficient transduction is dependent on scaffold macroporosity. Taken together, the data show that macroporous alginate scaffolds serve as an attractive alternative to current transduction protocols and have high potential for clinical translation to genetically modify T cells for adoptive cellular therapy.