Seattle Genetics Commences Dosing in Early-Stage Multiple Myeloma Trial

Seattle Genetics, Inc. dosed its first patient with an early-stage treatment for patients with relapsed or refractory multiple myeloma (MM).

The Bothell, Wash.-based company announced the initial dosing of its investigational medicine SGN-CD48A, an antibody-drug conjugate that has the potential to be used as a monotherapy treatment. The experimental SGN-CD48A targets the CD48 protein, which is highly expressed on multiple myeloma cells. Seattle Genetics said SGN-CD48A uses the company’s latest ADC technology advancement, a PEGylated glucuronide linker that improves stability, reduces off-target uptake, and enables conjugation of more molecules of the microtubule-disrupting cytotoxic agent monomethyl auristatin E (MMAE) per antibody. During preclinical studies, Seattle Genetics said SGN-CD48A has “demonstrated promising antitumor activity.”

The Phase I study will be used to evaluate the safety and tolerability, as well as maximum-tolerated dose, of SGN-CD48A in patients with relapsed or refractory multiple myeloma. The trial will include 75 patients with relapsed or refractory MM and SGN-CD48A will be administered every three weeks. Key secondary objectives include assessing the antitumor activity and identifying the recommended single-agent dose and schedule, the company said. The company is eying a 2020 date for completion of the trial, according to ClinicalTrials.gov.

There are more than 118,000 people living with, or in remission from, multiple myeloma in the United States. Approximately 30,280 Americans are diagnosed with multiple myeloma each year and 12,590 patient deaths are reported on an annual basis, according to the American Cancer Society. Multiple myeloma is managed with sequential lines of treatment, but those tend to yield shorter durations of disease control. With each relapse some patients receive more than four lines of treatment over the course of their disease, Seattle Genetics said in its announcement.

Robert Lechleider, head of clinical development at Seattle Genetics, said multiple myeloma, the second most common blood cancer in the United States, “remains an incurable disease despite recent medical advances.”

“Patients are in need of new targeted treatment options that increase durable remissions. SGN-CD48A uses our latest ADC technology, and the initiation of this phase 1 trial in relapsed or refractory multiple myeloma highlights our continued leadership in ADCs as we address this challenging disease,” Lechleider said in a statement.

Analysts predict the multiple myeloma market will grow exponentially by 2024. In 2015 the space was valued at about $7.5 billion, but in the next six years, the market is estimated to grow by an additional $30 billion, according to Grand View Research. Celgene’s blockbuster drug Revlimid is one of the biggest drugs in the space, bringing in about $2 billion in annual revenue for the company.