Trial Outcomes & Findings for A Study of TAK-853 in Adult Participants With Folate Receptor Alpha-Positive Advanced Ovarian Cancer And Other Solid Tumors (NCT NCT06390995)

Participants took part in the study at 15 investigative sites in Japan from 20 May 2024.

A total of 28 participants were enrolled across two parts of the study. Three participants were enrolled in Phase 1, and twenty-five participants were enrolled in Phase 2. The study is currently ongoing. Results in this summary are reported based on the primary completion date (16 April 2025) of the study.

A Study of TAK-853 in Adult Participants With Folate Receptor Alpha-Positive Advanced Ovarian Cancer And Other Solid Tumors

DLT was evaluated according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) V5.0 and defined as any of following events: 1. If re-treatment was not initiated within 14 days due to adverse event (AE) related to protocol treatment; 2. Grade 4 neutropenia for more than 7 days; 3. Grade 3 or 4 neutropenia with single temperature reading \>= 38.3-degree Celsius (°C) or sustained temperature reading of greater than (\>) 38°C for \>1 hour; 4. Platelet counts decreased of Grade 3 requiring platelet transfusion or blood platelet decreased of Grade 4; 5. Grade 3 or higher non-hematologic toxicity that was considered clinically significant, except following cases, AEs related to underlying disease, Alopecia, Grade 3 fatigue, Lymphopenia unless accompanied by clinically significant infection, isolated and asymptomatic Grade 3 abnormalities in biochemistry laboratory values that last for less than and equal to (\<=) 7 days including electrolyte abnormalities.

An AE means any untoward medical occurrence in a participant administered a pharmaceutical product; the untoward medical occurrence does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product whether or not it is related to the medicinal product. This includes any newly occurring event, or a previous condition that has increased in severity or frequency since the administration of study drug.

The severity grade was evaluated as per the NCI CTCAE Version 5.0, where Grade 1 scales as Mild (asymptomatic or mild symptoms; clinical or diagnostic observations only; intervention not indicated); Grade 2 scales as Moderate (minimal, local or noninvasive intervention indicated; limiting age-appropriate instrumental Activities of Daily Living \[ADL\]); Grade 3 was severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living (ADL), Grade 4 was life-threatening consequences; urgent intervention indicated, and Grade 5 was death related to AE. TEAEs were AEs with an onset date on or after the first dose of study drug, and within 30 days of the last dose of study drug or prior to the start of a new anti-cancer treatment, whichever occurs first.

A serious TEAE is any untoward medical occurrence or effect that at any dose: resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in persistent or significant disability/incapacity, was a congenital abnormality/birth defect, and was an important medical event.

TEAEs were defined as AEs with an onset date on or after the first dose of study drug, and within 30 days of the last dose of study drug or prior to the start of a new anti-cancer treatment, whichever occurred first. Number of participants with TEAEs leading to study drug discontinuation were reported.

TEAEs were defined as AEs with an onset date on or after the first dose of study drug, and within 30 days of the last dose of study drug or prior to the start of a new anti-cancer treatment, whichever occurred first. Number of participants with TEAEs leading to infusion interruption were reported.

TEAEs were defined as AEs with an onset date on or after the first dose of study drug, and within 30 days of the last dose of study drug or prior to the start of a new anti-cancer treatment, whichever occurred first. Number of participants with TEAEs leading to dose delayed were reported.

TEAEs were defined as AEs with an onset date on or after the first dose of study drug, and within 30 days of the last dose of study drug or prior to the start of a new anti-cancer treatment, whichever occurred first. Number of participants with TEAEs leading to dose reduction were reported.

AECIs (serious or nonserious) were those TEAEs which were of scientific and medical concern specific to the TAK-853. AECIs for TAK-853 included: 1. Ocular TEAEs, 2. Pneumonitis TEAEs, 3. Peripheral neuropathy TEAEs and 4. Infusion related TEAEs.

ORR was defined as the percentage of participants who achieved a confirmed Partial Response (PR) or confirmed Complete Response (CR) during the study using RECIST 1.1. Complete response (CR): Disappearance of all target lesions. All pathological lymph nodes (whether target or non-target) must have reduction in short axis to \< 10 millimeters (mm). Partial response (PR): At least a 30% decrease in the sum of diameters (SoD of target lesions, taking as reference the baseline SoD).

Pharmacokinetic (PK) parameters were calculated using standard non-compartmental methods. Cmax of TAK-853 and TAb were reported at cycle 1 and cycle 3.

PK parameters were calculated using standard non-compartmental methods. Cmax of DM4 and S-methyl DM4 were reported at cycle 1 and cycle 3.

PK parameters were calculated using standard non-compartmental methods. AUClast and AUCinf of TAK-853 and TAb were reported at cycle 1 and cycle 3.

PK parameters were calculated using standard non-compartmental methods. AUClast and AUCinf of DM4 and S-methyl DM4 were reported at cycle 1 and cycle 3.

PK parameters were calculated using standard non-compartmental methods. t1/2 of TAK-853, TAb, DM4 and S-methyl DM4 were reported at cycle 1 and cycle 3.

PK parameters were calculated using standard non-compartmental methods. CL of TAK-853 and TAb were reported at cycle 1 and cycle 3.

PK parameters were calculated using standard non-compartmental methods. CL/F of DM4 and S-methyl DM4 were reported at cycle 1 and cycle 3.

PK parameters were calculated using standard non-compartmental methods. Vss of TAK-853, TAb and VZ/F of DM4 and S-methyl DM4 were reported at cycle 1 and cycle 3.

Blood samples were collected to measure the presence of TAK-853 antibodies (ADA). Seronegative was defined as a participant with negative ADA at baseline and negative ADA at post-treatment. Treatment-emergent ADA was defined as a participant with negative ADA at baseline and positive ADA at post-treatment. Treatment-unaffected ADA was defined as a participant with positive ADA at baseline and post-dose titer increase that was less than or equal to 4-fold compared to baseline. Treatment-enhanced ADA was defined as a participant with positive ADA at baseline and post-dose titer increase that was greater than 4-fold compared to baseline.

DOR was defined as the time from the first observation of CR/PR (whichever is first recorded) to the first date at which progressive disease is objectively documented per RECIST 1.1, or death due to any cause, whichever occurs first. DOR was estimated using the Kaplan-Meier method.

Plasma concentrations of TAK-853 and TAb were reported at cycle 1 and cycle 3.

Plasma concentrations of DM4 and S-methyl DM4 were reported at cycle 1 and cycle 3.