Prophylactic antivirals may be helpful in prevention of varicella-zoster virus reactivation in myeloma, but are they safe?

Efficacy of Intermittent, Oral Famciclovir Prophylaxis for Bortezomib-Induced Herpes Zoster in Multiple Myeloma Patients

Objective

To explore the efficacy and safety of intermittent, oral famciclovir prophylaxis for bortezomib-induced herpes zoster in multiple myeloma patients.

Method

We retrospectively analyzed the incidence of bortezomib treatment-related varicella-zoster virus reactivation in 719 newly-diagnosed multiple myeloma patients receiving intermittent oral famciclovir prophylaxis, continuous oral acyclovir prophylaxis or no prophylaxis. The definition of intermittent oral famciclovir prophylaxis was oral famciclovir at a dose of 250mg twice daily for 9 days after finishing the last dose of bortezomib therapy every cycle. Age, gender, stage per the International Staging System, type of M protein, baseline of absolute lymphocyte count, absolute neutrophil count, and absolute monocyte count were analyzed to find the potential factors that could predispose to herpes zoster infections.

Results

Varicella-zoster virus infection occurred in 96 patients (13.4%) during bortezomib treatment. The incidence of herpes zoster was significantly higher in the non-prophylaxis group compared with the prophylaxis group (22.9% vs 8.2% P<0.001), while the rate was similar between the intermittent oral famciclovir group and the continuous oral acyclovir group (8.4% vs 7.9% P=0.835). Hepatic and renal toxicity were observed in 12% and 2.8% of the patient respectively in the intermittent famciclovir group, which was similar in the continuous acyclovir group (18.1% and 4.2%). The prophylactic use of antiviral agents is a predictive factor for varicella-zoster virus reactivation.

Conclusion

Intermittent famciclovir prophylaxis is effective and safe in preventing herpes zoster development and can markedly reduce the duration of oral medicine treatment compared with continuous acyclovir prophylaxis.

Can we change the disease biology of multiple myeloma?

Despite improvements in disease management, multiple myeloma (MM) remains incurable. Conventional treatment methods are unsatisfactory, leading to a pattern of regression and remission, and ultimately failure. This pattern suggests that one of the possible strategies for improving outcomes is continuous therapy to maintain suppression of the surviving tumor cells. Optimal management of MM requires potent agents and modalities with direct tumoricidal activity, which can also provide continuous suppression of the residual tumor to prevent disease relapse. Immunomodulatory agents exert immunomodulatory and tumoricidal effects, and cause disruption of stromal cell support from the bone marrow microenvironment. Therefore continuous therapy with immunomodulatory agents may be able to provide both tumor reduction and tumor suppression, enabling physicians to consider the possibility of incorporating continuous therapy into the treatment paradigm of patients with MM.

Acyclovir prophylaxis against varicella zoster virus reactivation in multiple myeloma patients treated with bortezomib-based therapies: a retrospective analysis of 100 patients

BACKGROUND

Previous studies have indicated that, in patients with multiple myeloma (MM), bortezomib is associated with an increased incidence of herpes zoster, resulting from reactivation of latent varicella zoster virus (VZV).

OBJECTIVE

Our objective was to determine whether increased risk of VZV reactivation could be abrogated by using prophylactic acyclovir.

METHODS

We retrospectively evaluated 100 consecutive MM patients treated with bortezomib-based therapies at the Roswell Park Cancer Institute for development of herpes zoster. Frontline and relapsed/refractory patients were included, and patients received bortezomib alone or in combination with agents such as doxorubicin, melphalan, or dexamethasone. All patients received >4 weeks of acyclovir prophylaxis (400 mg twice daily), which was initiated prior to starting treatment with bortezomib and discontinued 4 weeks following bortezomib.

RESULTS

Median patient age was 62 years, 57% were male, and most (56%) had Durie-Salmon stage IIIA MM. None of the 100 MM patients receiving acyclovir prophylaxis developed herpes zoster during treatment with bortezomib, irrespective of patients receiving a wide variety of concomitant antimyeloma therapies and regardless of response to bortezomib-based therapy. One additional patient, found to be noncompliant with acyclovir therapy, experienced VZV reactivation, having received 3 cycles of bortezomib (3 weeks each cycle) in combination with cyclophosphamide and dexamethasone.

LIMITATIONS

Limitations of the study include its small size and retrospective nature.

CONCLUSIONS

The increased risk of VZV reactivation observed in previous studies of bortezomib-based therapy was completely abrogated in this series of patients who received prophylaxis with acyclovir.

Efficacy of continuous, daily, oral, ultra-low-dose 200 mg acyclovir to prevent herpes zoster events among bortezomib-treated patients: a report from retrospective study

OBJECTIVE

Herpes zoster is the most common infection in patients treated with bortezomib-containing regimens for multiple myeloma. Some clinical trials have reported on the use of acyclovir prophylaxis to decrease the incidence of herpes zoster. However, the appropriate acyclovir dose and duration of prophylaxis remain unclear. The primary objective of this study was to evaluate the efficacy of continuous oral 200 mg/day acyclovir prophylaxis and the secondary objective was to determine the risk factors for developing herpes zoster.

METHODS

We collected medical information from consecutive patients who received bortezomib with or without acyclovir prophylaxis for relapsed or refractory multiple myeloma at our hospital and retrospectively analyzed the efficacy of acyclovir prophylaxis and the parameters for predicting the risk factors for developing herpes zoster. The definition of acyclovir prophylaxis was oral continuous administration of 200 mg of once daily, without cessation, during the entire period of bortezomib treatment.

RESULTS

Six of the 33 patients in the study developed herpes zoster during bortezomib treatment. No varicella-zoster virus reactivation was observed in the 19 patients in the acyclovir prophylaxis group. The incidence of herpes zoster was significantly higher in the group that did not receive acyclovir prophylaxis (43%, 6 of 14 patients) than in the group that did (0%, 0 of 19; P = 0.003). The predictive factors for varicella-zoster virus reactivation were male sex (P = 0.035) and the use of acyclovir (P = 0.003).

CONCLUSIONS

Continuous prophylaxis by oral 200 mg/day acyclovir in multiple myeloma patients receiving bortezomib treatment is effective and sufficient in preventing herpes zoster.