is a highly selective, reversible inhibitor of the 26S proteasome.
This drug is thought to inhibit many proteins (known as proteasomes)
that cancer cells need to survive and multiply. It has been shown
to have anti-tumor activity in B cell malignancies.
Bortezomib is "indicated" (recommended) for single-agent
use in the treatment of patients with multiple myeloma who have
received at least two prior therapies and are progressing on their
most recent therapy. Clinical investigations have been completed
or are under way to evaluate the safety and efficacy of bortezomib
alone or in combination with chemotherapy in multiple myeloma,
both at relapse and presentation, as well as in other cancer types.
Bortezomib (VELCADE®, formerly PS-341) was approved for the
treatment of patients with relapsed or refractory multiple myeloma
in May 2003 by the US Food and Drug Administration and in April
2004 by the Committee for Proprietary Medicinal Products of the
European Union. In December 2006 the FDA approved Bortezomib for
treatment of mantle cell lymphoma.
Bortezomib binds to the proteasome and does so "reversibly"
(this is a chemical term that means that the bortezomib molecule
can come free under different micro-cellular chemical conditions.)
Normal healthy (non-cancer) cells are not as prone to damage from
this binding after the Bortezomib comes off, as cancer cells are.
Malignant cells suffer a breakdown even after inhibition of the
proteasome for a short time.
Research has found that lymphoma
patients who had become resistant to standard treatment respond
well to a combination of bortezomib and obatoclax.
Other boron compounds are of interest in both prevention of cancer (chemoprevention) and treatment of cancer (chemotherapy, or at least "targeted therapy")