Phase II study of bryostatin 1 in patients with relapsed multiple myeloma

Bryostatin 1, a macrocyclic lactone isolated from the marine bryozoan Bugul a neritina, is a protein kinase C (PKC) modulator which has shown both prec linical and clinical activity in lymphoid malignancies. We conducted a phas e II trial of bryostatin 1 administered at a dose of 120 mug/m(2) by 72-h c ontinuous infusion every 2 weeks in patients with relapsed multiple myeloma . Treatment was well tolerated with myalgias constituting the primaray toxi city. There were no responses in nine evaluable patients. The preclinical a nti-lymphoid activity is strong enough to support further exploration of br yostatin 1 in different schedules and in combination therapy for multiple m yeloma.