Case Report: Post-CAR-T Infusion HBV Reactivation in Two Lymphoma Patients Despite Entecavir Preventive Therapy

Chimeric antigen receptor-T-cell therapies going viral: latent and incidental viral infections

PURPOSE OF REVIEW

Infections are the leading cause of non-relapse mortality following chimeric antigen receptor (CAR)-T-cell therapy, with viral infections being frequent both in the early and late phases post-infusion. We review the epidemiology of viral infections and discuss critical approaches to prevention and management strategies in this setting.

RECENT FINDINGS

Herpesviruses dominate the early period. herpes simplex virus and varicella zoster virus infections are rare due to widespread antiviral prophylaxis, but cytomegalovirus (CMV) reactivation is increasingly observed, particularly in high-risk groups including B cell maturation antigen (BCMA)-CAR-T-cell therapy recipients and patients receiving corticosteroids. While CMV end-organ disease is rare, CMV is associated with increased mortality, emphasizing the need to evaluate the broader impact of CMV on long-term hematological, infection, and survival outcomes. Human herpesvirus-6 (HHV-6) has also emerged as a concern, with its diagnosis complicated by overlapping symptoms with neurotoxicity, underscoring the importance of considering viral encephalitis in differential diagnoses. Respiratory viruses are the most common late infections with a higher incidence after BCMA CAR-T-cell therapy. Vaccination remains a critical preventive measure against respiratory viruses but may be less immunogenic following CAR-T-cell therapy. The optimal timing, type of vaccine, and dosing schedule require further investigation.

SUMMARY

A better understanding of viral epidemiology and preventive trials are needed to improve infection prevention practices and outcomes following CAR-T-cell therapies.

Post-Chimeric Antigen Receptor T-Cell Therapy Hepatitis B Virus Reactivation After 23 Months of Entecavir Prophylaxis

Hepatitis B virus (HBV) reactivation can occur in immunosuppressed patients. Specifically, HBV reactivation after chimeric antigen receptor T-cell (CAR T-cell) therapy is a known complication with few case reports and specific treatment guidelines. Our patient experienced HBV reactivation 27 months after CAR T-cell therapy even with 23 months of entecavir prophylaxis. This unique case highlights the need for further investigation into the risk of HBV reactivation after CAR T-cell therapy and the proper HBV prophylaxis during and after CAR T-cell therapy.

Preventing viral relapse with prophylactic tenofovir in hepatitis B carriers receiving chemotherapy: a phase IV randomized study in Taiwan

BACKGROUND AND AIMS

This study aimed to compare the efficacy of shorter vs. longer tenofovir disoproxil fumarate (TDF) prophylaxis in preventing hepatitis B virus (HBV) relapse in cancer patients with chronic hepatitis B (CHB) undergoing chemotherapy.

METHODS

This phase IV, prospective randomized trial enrolled cancer patients with CHB from 2014 to 2019 in Taiwan. Included patients were randomized to receive either 24- (Arm A) or 48-week (Arm B) post-chemotherapy TDF and compared for cumulative incidence of virological and clinical relapse. Logistic regressions were conducted to determine the factors associated with HBV relapse.

RESULTS

One hundred patients were randomized, and 41 patients in Arm A and 46 in Arm B completed the TDF treatment. No significant difference was found in cumulative incidence of virological relapse (Arm A: 94.4%, Arm B: 93.1%, p = 0.110) or clinical relapse among patients with baseline HBV DNA > 2000 IU/mL (Arm A: 38.9%, Arm B: 26.7%, p = 0.420) between the two arms. High baseline HBV DNA ≥ 10,000 IU/mL (OR = 51.22) and HBsAg ≥ 1000 IU/mL (OR = 8.64) were independently associated with an increased virological relapse. Alanine aminotransferase (ALT), serum phosphorus, vitamin D, and estimated glomerular filtration rate (eGFR) remained stable throughout the study.

CONCLUSIONS

The 24-week preventative TDF has comparable efficacy to the 48-week treatment in virologic and clinical relapse. High baseline HBsAg or HBV DNA is associated with a higher risk of HBV relapse. These findings imply a 24-week duration of TDF treatment with a close monitor for patients with a high baseline viral load. Hepatitis B virus infection is a prominent cause of liver cancer and chronic liver disease and affected millions of people worldwide. When HBV-infected people are exposed to immunosuppressive medication or chemotherapy for cancer, the chance of HBV reactivation rises considerably. This trial showed 24-week tenofovir disoproxil fumarate (TDF) may be sufficient for preventing HBV relapse in cancer patients receiving chemotherapy.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02081469.

Low incidence of hepatitis B virus reactivation in patients with hematological malignancies receiving novel anticancer drugs: A report from a high epidemic area and literature review

BACKGROUND

More and more novel anticancer drugs have been approved for patients with hematological malignancies in recent years, but HBV reactivation (HBV-R) data in this population is very scarce. This study aimed to evaluated HBV-R risk in patients with hematological malignancies receiving novel anticancer drugs.

METHODS

HBV markers and serum HBV DNA levels of patients with hematological malignancies receiving novel anticancer drugs in a tertiary cancer hospital were retrospectively collected. HBV-R risk in the whole cohort and subgroups was described. The relevant literature was reviewed to make a pooled analysis.

RESULTS

Of 845 patients receiving novel anticancer drugs, 258 (30.5%) were considered at risk for HBV-R. The median duration of exposure to novel drugs was 5.6 (0.1-67.6) months. The incidence of HBV-R was 2.1% in patients with past HBV infection without prophylactic antiviral treatment (PAT) and 1.2% in all patients at risk of HBV-R. In a pooled analysis of 11 studies with 464 patients, the incidence of HBV-R was 2.4% (95% CI: 1.3-4.2) in all at-risk patients receiving novel anticancer drugs and 0.6% (95% CI: 0.03-3.5) in patients with anticancer drugs plus PAT. The incidence of death due to HBV-R was 0.4% (95% CI: 0.1-1.6) in all at-risk patients and 18.2% (95% CI: 3.2-47.7) in patients with HBV-R.

CONCLUSION

Most episodes of HBV-R are preventable, and most cases with HBV-R are manageable. We recommend that novel anticancer drugs should not be intentionally avoided when treating cancer patients with HBV infection.