Array BioPharma Inc., a biopharmaceutical company developing targeted-small molecule drugs to treat patients suffering from cancer, announced the interim results from an ongoing ARRY-520 clinical trial in multiple myeloma (MM) at the 2013 Congress of the European Hematology Association in Stockholm, Sweden. ARRY-520 inhibits kinesin spindle protein (KSP) with high selectivity and is used to treat MM. KSP is involved in the establishment of a functional bipolar mitotic spindle during cell division and considered to be an attractive target for cancer chemotherapy with reduced side effects.
In the phase-1 study of ARRY-520 combined with Kyprolis® (crfilzomib) in patients with relapsed or refractory MM, it was shown that the early signals of activity of a disease control rate was 82% and a clinical benefit rate was 53%. In addition, this combination did not show any unexpected hematologic toxicity and a manageable side effect profile.
“To date, the combination of ARRY-520 with Kyprolis has been well tolerated. Reversible neutropenia is the most common adverse event and does not appear to be additive relative to the observed events for either drug alone,” said Jatin J. Shah, M.D., Assistant Professor, Lymphoma/Myeloma, Division of Cancer Medicine, The University of Texas, MD Anderson Cancer Center. “While this is an ongoing study, and we await mature data, there have been promising signs of activity in a heavily pretreated population, which includes several patients previously exposed to ARRY-520 or carfilzomib.” Carfilzomib is an analog of epoxomicin, the FDA-approved drug to inhibit tumor growth in 20 July 2012.
In this Congress at Stockholm, the data on a potential patient selection marker associated with the clinical activity of ARRY-520 in relapsed and refractory MM patients was also presented. Alpha 1-acid glycoprotein (AAG) appeared to act as the marker in these multiple studies, and the patients with low level of AGG had longer free survival time (time to next treatment of death). In the ongoing phase-2 ARRY-520 clinical study, the survival time of patients with low level of AAG was reported to be markedly longer than those with high level of AAG, which were 20.2 months and 4.5 months respectively. These results may enable more precise targeting of patient populations who will benefit from ARRY-520.
Array BioPharma Inc. is now conducting three clinical trials of ARRY-520. Array expects to begin clinical trials of MEK162 in NRAS-mutant melanoma, in BRAF-mutant melanoma and in low-grade serous ovarian cancer with Novartis, and of selumetinib in thyroid cancer and in non-small cell lung cancer with AstraZeneca in 2013.