- Arm A: CHVP + alpha2a-interferon. Patients will receive 12 courses of CHVP (cyclophosphamide 600 mg/m², adriamycin 25 mg/m², etoposide 100 mg/m² on day 1 and prednisolone 40 mg/m² for 5 days), one course every month for 6 months then one course every other month for 12 additional months associated with alpha2a-interferon 4.5 millions units sub-cutaneously three times a week for 18 months.