Positive data for the Phase 1 trial of PharmaMar’s plitidepsin combined with bortezomib and dexamethasone for the treatment of relapsed and/or refractory multiple myeloma will be presented at the 52nd Congress of the American Society of the Clinical Oncology (ASCO) June 3-7 in Chicago.
Dr. María Victoria Mateos, M.D., of the Hematological Department of the University Hospital of Salamanca, Spain, the principal investigator of the study, will present the results in an oral session on June 3.
The 20-patient trial aimed to evaluate the optimal dose and the efficacy and safety of the triple combination administered every four weeks. The results demonstrated that the treatment led to a 56 percent overall response rate. This included partial responses in 33 percent of the patients and a noteworthy partial remission in one triple refractory patient.
The data also demonstrated a median progression free survival (PFS) of 8.3 months, with 90 percent of the patients exhibiting a duratioin of response of six months or more, and clinical benefit in 72 percent of the patients. There were no toxicity issues, and the full dose of plitidepsin and bortezomib when used as monotherapy was established as the recommended dose for the triple combination.
Ten of the 20 patients are still being treated. All patients taking part in the trial had relapsed after being previously treated with an average of 3.5 treatment regimens. Of the total cohort, 45 percent had received a hematopoietic stem cell transplant. Of the 18 patients eligible for efficacy assessment, 83 percent had been previously treated with bortezomib and lenalidomide. One of these patients was refractory to bortezomib and seven patients were refractory to treatment with lenalidomide.
According to a press release, during the presentation Mateos and colleagues will clarify that despite progress in the treatment of multiple myeloma with proteasome inhibitors, monoclonal antibodies, and immunomodulatory drugs, the disease is still incurable, urging the scientific and medical community to develop safe and adequate active compounds with novel mechanisms of action.
Plitidepsin is an anticancer compound of marine origin, initially obtained from the ascidian Aplidium albicans. It specifically binds to the eEF1A2 elongation factor and targets the non-canonical role of this protein, leading to tumor cell death via apoptosis (programmed death).