Risk of HBV Reactivation in Patients With Resolved HBV Infection Receiving Anti-CD19 Chimeric Antigen Receptor T Cell Therapy Without Antiviral Prophylaxis

What is the benefit of prophylaxis to prevent HBV reactivation in HBsAg-negative anti-HBc-positive patients? Meta-analysis and decision curve analysis

BACKGROUND AND AIMS

Patients with overt or occult hepatitis B virus (HBV) infection receiving immunosuppressive treatments have a wide risk of HBV reactivation (HBVr). We performed meta-analysis with decision curve analyses (DCA) to estimate the risk of HBVr in HBsAg-negative anti-HBc-positive patients naïve to nucleos(t)ide analogues (NAs) receiving immunosuppressive treatments.

APPROACH AND RESULTS

Studies were identified through literature search until October 2022. Pooled estimates were obtained using random-effects model. Subgroup analyses were performed according to underlying disease and immunosuppressive treatments. DCA was used to identify the threshold probability associated with the net benefit of antiviral prophylaxis in HBsAg-negative anti-HBc-positive patients. We selected 68 studies (40 retrospective and 28 prospective), including 8034 patients with HBsAg negative anti-HBc positive. HBVr was 4% (95% CI 3%-6%) in HBsAg-negative anti-HBc-positive patients, with a significantly high heterogeneity (I2 69%; p < .01). The number-needed-to-treat (NNT) by DCA ranged from 8 to 24 for chemotherapy plus rituximab, from 12 to 24 for targeted therapies in cancer patients and from 13 to 39 for immune-mediated diseases. Net benefit was small for monoclonal antibodies.

CONCLUSIONS

Our DCA in HBsAg-negative anti-HBc-positive patients provided evidence that NA prophylaxis is strongly recommended in patients treated with chemotherapy combined with rituximab and could be appropriate in patients with cancer treated with targeted therapies and in patients with immune-mediated diseases. Finally, in patients with cancer treated with monoclonal antibodies or with chemotherapy without rituximab, the net benefit is even lower.

Prevention and management of hepatitis B virus reactivation in patients with hematological malignancies in the targeted therapy era

Hepatitis due to hepatitis B virus (HBV) reactivation can be serious and potentially fatal, but is preventable. HBV reactivation is most commonly reported in patients receiving chemotherapy, especially rituximab-containing therapy for hematological malignancies and those receiving stem cell transplantation. Patients with inactive and even resolved HBV infection still have persistence of HBV genomes in the liver. The expression of these silent genomes is controlled by the immune system. Suppression or ablation of immune cells, most importantly B cells, may lead to reactivation of seemingly resolved HBV infection. Thus, all patients with hematological malignancies receiving anticancer therapy should be screened for active or resolved HBV infection by blood tests for hepatitis B surface antigen (HBsAg) and antibody to hepatitis B core antigen. Patients found to be positive for HBsAg should be given prophylactic antiviral therapy. For patients with resolved HBV infection, there are two approaches. The first is pre-emptive therapy guided by serial HBV DNA monitoring, and treatment with antiviral therapy as soon as HBV DNA becomes detectable. The second approach is prophylactic antiviral therapy, particularly for patients receiving high-risk therapy, especially anti-CD20 monoclonal antibody or hematopoietic stem cell transplantation. Entecavir and tenofovir are the preferred antiviral choices. Many new effective therapies for hematological malignancies have been introduced in the past decade, for example, chimeric antigen receptor (CAR)-T cell therapy, novel monoclonal antibodies, bispecific antibody drug conjugates, and small molecule inhibitors, which may be associated with HBV reactivation. Although there is limited evidence to guide the optimal preventive measures, we recommend antiviral prophylaxis in HBsAg-positive patients receiving novel treatments, including Bruton's tyrosine kinase inhibitors, B-cell lymphoma 2 inhibitors, and CAR-T cell therapy. Further studies are needed to determine the risk of HBV reactivation with these agents and the best prophylactic strategy.

2022 Chinese expert consensus and guidelines on clinical management of toxicity in anti-CD19 chimeric antigen receptor T-cell therapy for B-cell non-Hodgkin lymphoma

Adoptive cellular immunotherapy with chimeric antigen receptor (CAR) T cells has emerged as a novel modality for treating relapsed and/or refractory B-cell non-Hodgkin lymphoma (B-NHL). With increasing approval of CAR T-cell products and advances in CAR T cell therapy, CAR T cells are expected to be used in a growing number of cases. However, CAR T-cell-associated toxicities can be severe or even fatal, thus compromising the survival benefit from this therapy. Standardizing and studying the clinical management of these toxicities are imperative. In contrast to other hematological malignancies, such as acute lymphoblastic leukemia and multiple myeloma, anti-CD19 CAR T-cell-associated toxicities in B-NHL have several distinctive features, most notably local cytokine-release syndrome (CRS). However, previously published guidelines have provided few specific recommendations for the grading and management of toxicities associated with CAR T-cell treatment for B-NHL. Consequently, we developed this consensus for the prevention, recognition, and management of these toxicities, on the basis of published literature regarding the management of anti-CD19 CAR T-cell-associated toxicities and the clinical experience of multiple Chinese institutions. This consensus refines a grading system and classification of CRS in B-NHL and corresponding measures for CRS management, and delineates comprehensive principles and exploratory recommendations for managing anti-CD19 CAR T-cell-associated toxicities in addition to CRS.

Antiviral therapy use and related outcomes in patients with cancer and viral infections: results from SWOG S1204

PURPOSE

Information is limited about adherence to practice guidelines in patients with hepatitis B virus (HBV), hepatitis C virus (HCV), or HIV infection receiving anticancer treatment.

METHODS

Newly diagnosed adult cancer patients were enrolled in a multicenter, prospective cohort study (SWOG S1204) during 2013-2017 to evaluate the prevalence of HBV, HCV, or HIV in patients initiating anticancer treatment. At 6 months, records of virus-positive patients were reviewed for antiviral therapy use; anticancer treatment dose reduction; and HBV reactivation (elevated viral load). Categorical variables were compared using chi-square or Fisher's exact test.

RESULTS

Of 3055 enrolled patients with viral testing, 230 had chronic or past HBV, HCV, or HIV with 6-month follow-up data (chronic HBV, 15 patients; past HBV, 158; HCV, 49; HIV, 30). Twenty percent (3/15) of chronic HBV and 11% (17/158) of past HBV patients were co-infected with HCV and/or HIV. Rates of antiviral therapy use by 6 months were as follows: chronic HBV, 85% (11/13); past HBV receiving anti-B cell therapy, 60% (3/5); past HBV receiving systemic anticancer therapy without anti-B cell therapy, 8% (8/105); HCV, 6% (2/35); and HIV, 90% (19/21). Among patients with available data, anticancer treatment dose was reduced in 1 of 145 patients with past HBV and 1 of 42 with HCV. HBV reactivation occurred in 1 of 15 patients with chronic HBV; this patient was not receiving antiviral therapy.

CONCLUSION

Many patients with cancer and viral infections either do not receive guideline-recommended antiviral treatment or receive antiviral treatment that is not recommended in guidelines. Further education is needed to improve adherence to guidelines.

Hepatitis B virus reactivation associated with new classes of immunosuppressants and immunomodulators: A systematic review, meta-analysis, and expert opinion

HBV reactivation (HBVr) can be prevented by nucleos(t)ide analogues (NAs). We conducted a systematic review and meta-analysis on the risk of HBVr associated with new classes of immunosuppressive and immunomodulatory therapies and developed guidance on NA prophylaxis. An expert panel reviewed the data and categorised the risk of HBVr associated with each class of drugs into low (<1%), intermediate (1-10%), and high (>10%). Our search uncovered 59 studies, including 3,424 HBsAg+ and 5,799 HBsAg-/anti-HBc+ patients, which met our eligibility criteria. Based on medium-high quality evidence, immune checkpoint inhibitors, tyrosine kinase inhibitors, cytokine inhibitors, chimeric antigen receptor T-cell immunotherapies, and corticosteroids were associated with high HBVr risk in HBsAg+ patients; cytokine inhibitors, chimeric antigen receptor T-cell immunotherapies, and corticosteroids with intermediate risk in HBsAg-/anti-HBc+ patients; and anti-tumour necrosis factor agents and immune checkpoint inhibitors with low risk in HBsAg-/anti-HBc+ patients. Provisional recommendations are provided for drugs with low quality evidence. NA prophylaxis is recommended when using drugs associated with a high HBVr risk, while monitoring with on-demand NAs is recommended for low-risk drugs - either approach may be appropriate for intermediate-risk drugs. Consensus on definitions and methods of reporting HBVr, along with inclusion of HBsAg+, and HBsAg-/anti-HBc+ patients in clinical trials, will be key to gathering reliable data on the risk of HBVr associated with immunosuppressive or immunomodulatory therapies.

Phase I CAR-T Clinical Trials Review

BACKGROUND/AIM

Chimeric antigen receptor (CAR) T cells with tumor specificity are being increasingly investigated. Phase I trials are the first step of testing for safety of novel CAR-T therapy to determine the maximum tolerated dose (MTD). Several dose escalation methods have been developed over time including rule-based, model-based, and model-assisted designs. The goal of this project is to overview the phase I designs used in current CAR-T trials.

MATERIALS AND METHODS

We searched PubMed for peer-reviewed literature published between January 1, 2015 and December 31, 2021. The search was limited to human studies in the English language using the keywords "CAR-T phase I", "clinical trials", and "full text".

RESULTS

One hundred nine papers with at least partial phase I components were included for analysis. 31.2% of the trials used the traditional 3+3 or a variation of said design, and 60.6% did not mention the dose escalation design. The majority of the manuscripts (59.6%) did not report cohort size while 19.3% did not specify the timing of evaluation. Although most of the studies were registered with CT.gov, only 33.9% had any results submitted or posted to CT.gov These trends persisted even in manuscripts published in journals with high impact factors.

CONCLUSION

Standardizing the publication criteria and providing basic elements of phase I clinical trials are critical to ensure high quality of manuscripts. With the quick development and high costs of CAR-T cell therapy, adoption of advanced designs such as model-based and model-assisted should increase to improve efficiency of clinical trials.

Risk of infection in patients with hematological malignancies receiving CAR T-cell therapy: systematic review and meta-analysis

BACKGROUND

Chimeric antigen receptor (CAR) T-cell therapy has emerged as a promising treatment option for relapsed or refractory B-cell malignancies and multiple myeloma. Underlying and treatment-related variables may contribute to the development of infectious complications.

RESEARCH DESIGN AND METHODS

We conducted a systematic review and meta-analysis on the incidence of overall and severe (grade ≥3) infection in patients with hematological malignancies receiving CAR T-cells. Secondary outcomes included the specific rates of bacterial, viral and invasive fungal infection (IFI), and infection-related mortality. PubMed, Embase and Web of Science databases were searched from inception to 27 May 2022. Sensitivity analysis were performed according to the type of malignancy and study design (randomized clinical trials [RCTs] or observational studies).

RESULTS

Forty-five studies (34 RCTs) comprising 3,591 patients were included. The pooled incidence rates of overall and severe infection were 33.8% (I² = 96.31%) and 16.2% (I² = 74.41%). The respiratory tract was the most common site of infection. Most events were bacterial or viral, whereas the occurrence of IFI was rare. The pooled attributable mortality was 1.8% (I² = 43.44%).

CONCLUSIONS

Infection is a frequent adverse event in patients receiving CAR T-cell therapy. Further research should address specific risk factors in this population.

Risk of HBV reactivation in relapsed or refractory diffuse large B-cell lymphoma patients receiving Bruton tyrosine kinase inhibitors therapy

Background

Bruton tyrosine kinase inhibitors (BTKis) interrupt B-cell receptor signaling and thereby could potentially reactivate hepatitis B virus (HBV). However, data about the risk for HBV reactivation (HBVr) of BTKis in relapsed or refractory diffuse large B-cell lymphoma (R/R DLBCL) patients are sparse.

Methods

A total of 55 R/R DLBCL patients receiving BTKis therapy in the Tongji Hospital of Tongji University were enrolled. Patient clinical characteristics, treatment outcomes and details of HBVr were collected and analyzed, aiming to demonstrate the risk of HBVr in R/R DLBCL patients post BTKis therapy and the efficacy of BTKis in HBV-associated R/R DLBCL patients.

Results

Of 55 R/R DLBCL patients treated with ibrutinib (N=38) and zanubrutinib (N=17), 4 were with chronic HBV infection (HBsAg positive), 26 with resolved HBV infection (HBsAg negative and HBcAb positive) and 25 without HBV infection (HBsAg negative and HBcAb negative). In resolved HBV infection group, 2 patients developed HBVr after the use of ibrutinib and zanubrutinib respectively. Neither of them developed HBV-related hepatitis. Our finding showed that the incidence of HBVr in resolved HBV infection group was 7.69% (95% CI, 0.9-25.1%). In this study, Overall response rate (ORR) was 70.9%. 1-year overall survival (OS) rate was 80.0%. Median progression-free survival (PFS) was 4 months (95% CI, 3-5 months). In addition, HBV infection was not associated with response rates or survival among R/R DLBCL patients post BTKis treatments.

Conclusion

Our study suggested that HBV infection do not affect the efficacy of BTKis’ treatment. However, R/R DLBCL patients with resolved HBV infection are at a moderate risk of developing HBVr throughout BTKis treatment. Patients should be screened for HBVr during BTKis therapy.

CAR-T Cell Therapy in Hematological Malignancies: Current Opportunities and Challenges

Chimeric antigen receptor T (CAR-T) cell therapy represents a major breakthrough in cancer treatment, and it has achieved unprecedented success in hematological malignancies, especially in relapsed/refractory (R/R) B cell malignancies. At present, CD19 and BCMA are the most common targets in CAR-T cell therapy, and numerous novel therapeutic targets are being explored. However, the adverse events related to CAR-T cell therapy might be serious or even life-threatening, such as cytokine release syndrome (CRS), CAR-T-cell-related encephalopathy syndrome (CRES), infections, cytopenia, and CRS-related coagulopathy. In addition, due to antigen escape, the limited CAR-T cell persistence, and immunosuppressive tumor microenvironment, a considerable proportion of patients relapse after CAR-T cell therapy. Thus, in this review, we focus on the progress and challenges of CAR-T cell therapy in hematological malignancies, such as attractive therapeutic targets, CAR-T related toxicities, and resistance to CAR-T cell therapy, and provide some practical recommendations.

[Drugs and hepatitis B virus reactivation]

Drugs may induce hepatitis B virus (HBV) reactivation (HBV-R). Here we have reviewed the definition and harm of HBV-R, the risk drugs and their underlying mechanism, the influence factors, as well as the early intervention measures. It is shown that multiple drugs, including chemotherapy drugs, immunotherapy drugs, directly acting antivirals, cell therapy, etc., can induce HBV-R by affecting host immunity or directly activating HBV transcription factors. HBV-R could cause severe liver damage, even interruption of treatment of original diseases, affecting the prognosis of patients. Through precisely identifying risk drugs, monitoring the influence factors, and prescribing preventive anti-HBV regimen if necessary, the incidence of HBV-R can be significantly reduced. It is also suggested that clinical physicians should not only pay attention to the early identification and intervention of HBV-R, but also further study the mechanism of HBV-R in depth, especially the underlying mechanism between host, HBV and risk factors. This will help to promote the discovery of more valuable markers for risk prediction and targets for early intervention, and to further reduce the risk of HBV-R and improve the prognosis of patients.