Tocilizumab for KSHV-Associated Multicentric Castleman Disease

BACKGROUND:

• Kaposi sarcoma herpesvirus-associated multicentric Castleman disease (KSHVMCD) is a rare lymphoproliferative disorder that develops predominantly in human immunodeficiency deficiency virus (HIV) infected patients. Patients often have symptoms from interleukin-6 (IL-6), KSHV encoded viral IL-6 (vIL-6), and other cytokines
• Goals of therapy include rapid resolution symptoms and elimination of reservoirs of KSHV-infected plasmablasts.
• Tocilizumab is a humanized anti-IL-6 receptor (gp80) antibody with activity against MCD unrelated to KSHV (KSHV-negative MCD). While tocilizumab does not directly affect vIL-6 signaling or other KSHV driven pathologic processes, IL-6 overproduction plays a major role in symptoms in KSHV-MCD, and blocking IL-6 may be sufficient to treat this disorder by blocking autocrine and paracrine stimulation. Combination with zidovudine (AZT) and valganciclovir (VGC), agents that target KSHV replication, have virus-activated cytotoxic activity, and are active in KSHV-MCD may be useful and necessary in some patients.

OBJECTIVES:

• Primary objective: Estimate clinical benefit of tocilizumab 8mg/kg every 2 weeks for up to 12 weeks in patients with symptomatic KSHV-MCD using a modified KSHVMCD Clinical Benefit Response Criteria
• Secondary objectives:
• Estimate best clinical, biochemical, radiographic, and overall responses in patients with KSHV-MCD treated for up to 12 weeks with tocilizumab 8mg/kg every 2 weeks using the prior National Cancer Institute (NCI) KSHV-MCD Response Criteria.
• In patients with inadequate response to tocilizumab monotherapy: explore preliminarily the activity of tocilizumab 8mg/kg every 2 weeks, combined with AZT 600 mg orally q6 hours and VGC 900 mg orally q12 hours on days 1-5 of a 14-day cycle
• Evaluate safety and tolerability of tocilizumab alone and combined with AZT/VGC
• Evaluate the effect of tocilizumab on the pharmacokinetics of antiretroviral agents that are Cytochrome P450 3A4 (CYP3A4) substrates in patients with symptomatic KSHV-MCD
• Evaluate progression-free and overall survival of patients treated with tocilizumab and tocilizumab/AZT/VGC
• Evaluate of effect of tocilizumab on KS

Eligibility

• Pathologically confirmed KSHV-associated MCD
• Age greater than or equal to 18
• At least one clinical symptom and at least one laboratory attributable to KSHV-MCD
• Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 2
• No life- or organ-threatening manifestations of MCD
• Patients requiring therapy for rheumatoid arthritis will be excluded
• HIV-infected patients must agree to continue or start combination antiretroviral therapy

DESIGN:

• Open label, single center pilot study. Eligible patients receive tocilizumab 8 mg/kg every 2 weeks for up to 12 weeks. In addition, patients requiring treatment intensification also receive AZT 600 mg orally q6 hours and VGC 900 mg orally q12 hours on days 1-5 of a 14-day cycle.
• Sample size 17: two stage phase II design, alpha equals beta equals 0.10, ruling out <20% KSHV-MCD Clinical Benefit Partial Response or better with tocilizumab and targeting a >50% KSHV-MCD Clinical Benefit Partial Response or better requires 10 in the first stage. 0-2 of 10 major response: stop accrual, 3+/10: accrual to 17 total.
• Responses evaluated by KSHV-MCD Clinical Benefit Response Criteria and NCI KSHV-MCD criteria under prospective evaluation.
• Safety and tolerability evaluated using current Common Terminology Criteria for Adverse Events (CTCAE).

• INCLUSION CRITERIA:
• Pathologically confirmed Kaposi sarcoma (KS)-associated herpes virus multi-centric Castleman disease (KSHV-MCD)
• Age greater than or equal to 18
• At least one clinical symptom probably or definitely attributed to KSHV-MCD
• Intermittent or persistent fever for at least 1 week (>38 degrees C)
• Fatigue (Common Terminology Criteria for Adverse Events (CTCAE) Grade 2 or greater)
• Gastrointestinal symptoms [includes nausea and anorexia] (CTCAE Grade 1 or greater)
• Respiratory symptoms [includes cough and airway hyperreactivity]

(CTCAE Grade 1 or greater)

• At least one laboratory abnormality probably or definitely attributed to KSHVMCD
• Anemia (Hgb [men] </=12.5 gm/dL, Hgb [women] </= 11 gm/dL)
• Thrombocytopenia (</=130,000/mm(3))
• Hypoalbuminemia (<3.4 g/dl)
• Elevated C-reactive protein (CRP) (CRP > 3 mg/L)] probably or definitely attributable to KSHV-MCD
• No life- or organ-threatening manifestations of MCD
• Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 2
• Human Immunodeficiency Virus (HIV)-infected patients should be receiving or willing to initiate an effective combination antiretroviral therapy (cART) regimen
• Willingness to complete tuberculosis evaluation and start prophylactic antituberculosis therapy as soon as is medically feasible if patients have a reactive tuberculin skin test and have not completed an adequate course of prevented anti-tuberculosis therapy, following American Thoracic Society/ Centers for Disease Control recommended guidelines:

http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5231a4.htm

• Ability to understand and willingness to give informed consent
• Women of child bearing potential must agree to use birth control for the duration of the study

Exclusion criteria

• Uncontrolled bacterial, mycobacterial, or fungal infection
• Uncontrolled intercurrent illness including, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements or ability to receive therapy.
• Pregnant or lactating women
• Any abnormality that would be scored as National Cancer Institute (NCI) Common Toxicity Criteria (CTC) Grade 3 toxicity that is unrelated to HIV, its treatment, or to MCD that would preclude protocol treatment. Exceptions include:
• Lymphopenia
• Direct manifestations of Kaposi sarcoma or MCD
• Direct manifestation of HIV (i.e. low cluster of differentiation 4 (CD4) count)
• Direct manifestation of HIV therapy (i.e. Hyperbilirubinemia associated with protease inhibitors)
• Asymptomatic hyperuricemia
• Hypophosphatemia
• Elevated creatine kinase (CK) attributed to exercise
• Past or present history of malignant tumors other than Kaposi sarcoma unless one of the following:
• Complete remission for greater than or equal to 1 year from completion of therapy
• Completely resected basal cell carcinoma
• In situ squamous cell carcinoma of the cervix or anus
• Patients with concurrent Kaposi sarcoma requiring immediate cytotoxic chemotherapy
• History of tocilizumab therapy within prior three months
• History of rituximab or bevacizumab therapy within three months
• History of greater than or equal to 2 allergic reaction or any grade anaphylactic reaction during prior administration of tocilizumab