Molecular Templates, Inc. announced that, following discussion with its co-development partner Takeda, MTEM will assume full rights to TAK-169 including taking control of clinical development from Takeda. In addition, MTEM announced the decision to discontinue development of MT-3724, MTEM’s only first-generation ETB. MTEM will focus on the clinical development of next-generation ETBs MT-5111, TAK-169, and MT-6402, as well as advancing next-generation preclinical ETB candidates against targets including CTLA-4, CD20, SLAMF-7 and CD45. Takeda has communicated that its decision to turn over full rights of TAK-169, a second-generation ETB targeting CD38, was the result of Takeda’s ongoing portfolio prioritization. MTEM believes that TAK-169 is a potent molecule with a novel mechanism of action in multiple myeloma. It has demonstrated a favorable safety and efficacy profile in vivo models and potency against daratumumab refractory patient samples. TAK-169 is in an ongoing Phase 1 study with dose escalation planned through six dose cohorts, in which the first patient was dosed in February 2020. To date, Takeda has enrolled and treated four subjects in the Phase 1 study. There have been no life-threatening toxicities, and no signs of capillary leak syndrome (CLS). The maximum tolerated dose (MTD) has not been reached, patient screening continues, and dose escalation is ongoing. One dose limiting toxicity (grade 2 myocarditis) was assessed in one subject. A mild elevation in Troponin I was noted in this subject after the third dose of TAK-169. No EKG or echocardiographic abnormalities and no clinical symptoms were noted. A stable elevation in high-sensitivity troponin was seen although no comparison to baseline was available as baseline levels were not required per protocol at the time. An independent radiologist and cardiologist reviewed the imaging in the case and concluded that there was weak to intermediate evidence of myocarditis. The subject had multiple pre-existing cardiac risk factors. No other cardiac adverse events were observed in any other subject. Pharmacokinetic and pharmacodynamic data of this first cohort have been in-line with predicted outcomes. MTEM looks forward to accelerating the full enrollment and completion of this safety and dose-finding study. MTEM’s manufacturing of TAK-169 has been qualified by Takeda and MTEM has sufficient TAK-169 drug supply to continue the Phase 1 study as planned. MTEM’s assumption of the full rights to TAK-169 is expected to result in cost savings in 2021 and MTEM’s guidance of cash runway into 2H23 is unchanged. Upon transfer of the full TAK-169 rights to MTEM, per the terms of the collaboration agreement, MTEM will owe Takeda low-single digit royalties on future net sales of TAK-169. MTEM anticipates that the transition of TAK-169 development from Takeda to MTEM will be conducted over the next 90 days. There are no changes to the trials or plans for any other ETB product candidates, including MT-5111, TAK-169, and MT-6402, all of which utilize a next-generation ETB scaffold that has been designed to reduce or eliminate the propensity for innate immunity, including CLS. Furthermore, all MTEM ETBs other than MT-3724 are designed and manufactured to create a more homogeneous product that avoids the production of multiple species including protein aggregate species.