A histone deacetylase inhibitor — that is, a medicine that blocks certain enzymes in the body and interferes with the growth of tumor cells — Romidepsin is used to treat certain types of cancer.

It is approved by the U.S. Food and Drug Administration (FDA) as a treatment for several types of lymphomas, specifically cutaneous T-cell lymphoma (CTCL) and peripheral T-cell lymphoma (PTCL). The therapy is marketed under the brand name Istodax by Celgene, now part of Bristol-Myers Squibb.

Romidepsin also is used off-label to treat myeloma.

How does romidepsin work?

Romidepsin is a small molecule that acts as an inhibitor of histone deacetylase (HDAC) enzymes. DNA in cells is not “free-floating” but is coiled around histones — proteins that stabilize and protect the DNA while also controlling how accessible it is for genes to be made into proteins. Normally, HDACs act to “turn off” or “turn down” gene expression by modifying histones. For example, by making the histones bind more tightly to DNA, they can restrict the availability of the DNA to enzymes.

HDAC inhibitors work by blocking the activity of HDAC enzymes, meaning that gene expression stays turned on. This strategy can be used to turn on tumor suppressor genes that control cell division and cause cancer cell death.

Romidepsin in clinical trials for myeloma

A Phase 2 clinical trial (NCT00066638) tested the effectiveness of romidepsin in treating people with relapsed or refractory multiple myeloma (RRMM). Participants received romidepsin by intravenous infusion over four hours on days 1, 8, and 15, every 28 days. A total of 13 patients received between one and seven cycles of therapy.

The trial’s results were published in the journal Cancer. None of the patients achieved an objective, or measurable response, though several participants showed improvements in bone pain and hypercalcemia, or high levels of calcium in the blood. The researchers concluded that romidepsin administered alone is unlikely to be associated with a response rate of 30% or higher in people with RRMM.

A Phase 1/2  trial (NCT01755975) is currently underway to evaluate the efficacy of a combination of romidepsin and Revlimid (lenalidomide), another cancer treatment, in patients with RRMM. Participants will receive romidepsin by intravenous infusion on days 1, 8, and 15 of each 28-day cycle. In addition, they will be treated with oral Revlimid on days 1 through to 21 of each 28-day cycle. The primary outcome measure is to determine the maximum tolerated dose, as well as the safety and toxicity of the two therapies in combination. The trial is expected to conclude in December 2020.

Other information

Romidepsin can cause side effects, including stomach cramps, bone pain, nausea, dizziness, vomiting, and headache.


Last updated: Feb. 6, 2020


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