The FDA cleared an investigational new drug application for KP1237, a CD38-targeting antibody-recruiting molecule, in combination with autologous natural killer cells for the treatment of patients with multiple myeloma who previously underwent hematopoietic stem cell transplantation.
KP1237 (Kleo Pharmaceuticals) is an investigational, bispecific antibody-recruiting molecule with two distinct binding domains connected by a tunable linker domain.
One of the agent’s domains binds to CD38 expressed on the surface of cancer cells. Its other binding domain attaches to antibodies in the disease microenvironment, creating a bridge that enables the patient’s antibodies to coat and kill the tumor cell via the body’s antibody-mediated immune mechanisms, according to the manufacturer.
The FDA clearance means Kleo can initiate a phase 1 clinical trial to evaluate the safety and tolerability of KP1237 in combination with infusion of the patient’s natural killer cells. The single-arm study will enroll 25 to 30 patients. Exploratory endpoints will evaluate the minimal residual disease (MRD) conversion rate at 90 to 100 days after HSCT, because MRD negativity may be a predictor of long-term remission for patients with multiple myeloma.
“We are excited to have clearance to initiate a clinical trial in the United States that addresses a significant unmet medical need in newly diagnosed, post-transplant multiple myeloma,” Doug Manion, MD, CEO of Kleo, said in a company-issued press release. “Approximately 30,000 individuals are diagnosed with multiple myeloma in the United States each year, with at least one-third of those patients undergoing autologous stem cell transplants.”
Anti-CD38 therapies kill natural killer cells. However, this phase 1 trial will employ KP1237 as a “cell homing molecule” that targets a patient’s activated natural killer cells toward cancer cells that express CD38 on their surface, according to Kleo’s press release.
Trial enrollment will begin in the first half of this year, with topline date expected in the second half of 2021.