The results of a small Phase 1 clinical trial demonstrate that BT-062, a new drug specifically targeting multiple myeloma cells, shows activity and is tolerable in heavily pretreated multiple myeloma patients.

Dr. Sundar Jagannath of the Mount Sinai Medical Center in New York City presented the results at the 2011 American Society of Hematology (ASH) conference in San Diego last month.

Based on the favorable safety and activity of BT-062 ^[1], a Phase 1/2 ^[2] clinical trial has been initiated and is currently recruiting patients. It will use a more frequent dosing schedule than the Phase 1 study, based on results from another clinical trial that support such dosing.

BT-062, which is being developed by the German pharmaceutical company Biotest, is a compound that combines a chemotherapeutic drug with an antibody that helps deliver the drug to myeloma and other cancer cells. When the compound enters a cancer cell, it releases the drug that ultimately kills the cell.

The Phase 1 study was designed to determine the safety and efficacy of BT-062 and to determine its maximum tolerated dose in a small number of relapsed/refractory multiple myeloma patients.

The study included 32 patients who had received a median of seven prior anti-myeloma therapies. All patients had previously failed treatment with at least one immunomodulatory agent, such as Revlimid ^[3] (lenalidomide) or thalidomide ^[4] (Thalomid), and at least one protease inhibitor, such as Velcade ^[5] (bortezomib) or carfilzomib ^[6] (Kyprolis ^[7]).

Participants received treatment with one of seven doses of BT-062, ranging from 10 mg/m² to 200 mg/m².

Of the 28 patients who were evaluated for response, 4 percent achieved a partial response, 8 percent had a minor response, and 38 percent showed stable disease.

The maximum tolerated dose was 200 mg/m², with mucositis (inflammation and ulceration of the mucous membranes lining the digestive tract) being the dose-limiting side effect.

Side effects included mucositis, hand-foot syndrome, blurred vision, and dry eyes, with the last two side effects primarily reported at very high doses.

Dr. Jagannath reported that most patients discontinued treatment due to disease progression, not side effects.

For more information, see abstract 305 ^[8] on the ASH annual meeting website.