Trial Outcomes & Findings for A Safety and Activity Study of SBT6050 in Combination With Other HER2-directed Therapies for HER2-positive Cancers (NCT NCT05091528)

Last Updated: 2022-08-18

Results Overview

Severity of treatment-emergent adverse events as assessed by the NCI CTCAE Version 5.0. This outcome measure applies only to participants in the dose escalation cohorts.

Recruitment status

TERMINATED

Study phase

PHASE1/PHASE2

Target enrollment

2 participants

Primary outcome timeframe

21 days

Results posted on

2022-08-18

Participant Flow

Participant milestones

Participant milestones
Measure	SBT6050 + T-DXd (6.4 mg/kg) SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles
Overall Study STARTED	1	1
Overall Study COMPLETED	0	0
Overall Study NOT COMPLETED	1	1

Reasons for withdrawal

Reasons for withdrawal
Measure	SBT6050 + T-DXd (5.4 mg/kg) SBT6050 plus trastuzumab deruxtecan SBT6050: Dose range of 0.45 to 0.6 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 5.4 mg/kg by intravenous (IV) infusion in 21-day cycles	SBT6050 + T-DXd (6.4 mg/kg) SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab + Capecitabine SBT6050 plus tucatinib, trastuzumab, and capecitabine SBT6050: Dose range of 0.45 to 0.6 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles capecitabine: 1000 mg/m2 PO BID for 14 days of each 21-day cycle	SBT6050 + Tucatinib + Trastuzumab SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles
Overall Study Study Termination by Sponsor	0	1	0	1

Baseline Characteristics

A Safety and Activity Study of SBT6050 in Combination With Other HER2-directed Therapies for HER2-positive Cancers

Baseline characteristics by cohort

PRIMARY outcome

Timeframe: 21 days

Population: Participants who were enrolled and treated with at least 1 dose of SBT6050.

Severity of treatment-emergent adverse events as assessed by the NCI CTCAE Version 5.0. This outcome measure applies only to participants in the dose escalation cohorts.

Outcome measures

Outcome measures
Measure	SBT6050 + T-DXd (6.4 mg/kg) n=1 Participants SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab n=1 Participants SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles
Proportion of Participants With Dose Limiting Toxicities	0 Participants	0 Participants

PRIMARY outcome

Timeframe: 18 weeks

Population: Participants who were enrolled and treated with at least 1 dose of SBT6050.

Severity of treatment-emergent adverse events as assessed by the NCI CTCAE Version 5.0. This outcome measure applies only to participants in the dose escalation cohorts.

Outcome measures

Outcome measures
Measure	SBT6050 + T-DXd (6.4 mg/kg) n=1 Participants SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab n=1 Participants SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles
Number of Participants With Treatment-emergent Adverse Events	1 Participants	1 Participants

PRIMARY outcome

Timeframe: 18 weeks

Population: Participants who were enrolled and treated with at least 1 dose of SBT6050.

Clinically significant treatment-emergent laboratory abnormalities as assessed by the NCI CTCAE Version 5.0. This outcome measure applies only to participants in the dose escalation cohorts.

Outcome measures

Outcome measures
Measure	SBT6050 + T-DXd (6.4 mg/kg) n=1 Participants SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab n=1 Participants SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles
Number of Participants With Laboratory Abnormalities	0 Participants	0 Participants

PRIMARY outcome

Timeframe: 0 weeks

Population: No participants were enrolled in the dose expansion cohorts; study was terminated by Sponsor.

Complete response and partial response as assessed by RECIST Version 1.1 Criteria. This outcome measure applies only to participants in the dose expansion cohorts.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 0 weeks

Population: No participants were enrolled in the dose expansion cohorts; study was terminated by Sponsor.

Severity of treatment-emergent adverse events as assessed by the NCI CTCAE Version 5.0. This outcome measure applies only to participants in the dose expansion cohorts.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 18 weeks

Population: Participants who were enrolled and treated with at least 1 dose of SBT6050.

Complete response and partial response as assessed by RECIST Version 1.1 Criteria. This outcome measure applies only to participants in the dose escalation cohorts.

Outcome measures

Outcome measures
Measure	SBT6050 + T-DXd (6.4 mg/kg) n=1 Participants SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab n=1 Participants SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles
Number of Participants With an Objective Response Rate	1 Participants	0 Participants

SECONDARY outcome

Timeframe: 0 weeks

Population: Data not captured; study was terminated by Sponsor.

The length of time from the participant's first complete response or partial response as assessed by RECIST Version 1.1 Criteria until disease progression or death. This outcome measure applies to all participants.

Outcome measures

Outcome data not reported

SECONDARY outcome

Timeframe: 0 weeks

Population: No participants were enrolled in the dose expansion cohorts; study was terminated by Sponsor.

Complete response, partial response, or durable stable disease as assessed by RECIST Version 1.1 Criteria. This outcome measure applied only to participants in the dose expansion cohorts.

Outcome measures

Outcome data not reported

Adverse Events

SBT6050 + T-DXd (6.4 mg/kg)

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

SBT6050 + Tucatinib + Trastuzumab

Serious events: 0 serious events

Other events: 1 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure	SBT6050 + T-DXd (6.4 mg/kg) n=1 participants at risk SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab n=1 participants at risk SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles
General disorders Fatigue	100.0% 1/1 • 18 weeks	0.00% 0/1 • 18 weeks
Immune system disorders Cytokine release syndrome	100.0% 1/1 • 18 weeks	0.00% 0/1 • 18 weeks
General disorders Injection site reaction	100.0% 1/1 • 18 weeks	100.0% 1/1 • 18 weeks
Metabolism and nutrition disorders Decreased appetite	100.0% 1/1 • 18 weeks	0.00% 0/1 • 18 weeks
Skin and subcutaneous tissue disorders Palmar-plantar erythrodysesthesia	100.0% 1/1 • 18 weeks	0.00% 0/1 • 18 weeks
Gastrointestinal disorders Bloating	100.0% 1/1 • 18 weeks	0.00% 0/1 • 18 weeks
Gastrointestinal disorders Constipation	0.00% 0/1 • 18 weeks	100.0% 1/1 • 18 weeks

Additional Information

Chief Scientific Officer

Silverback Therapeutics, Inc.

Phone: 206-456-2900

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Measure	SBT6050 + T-DXd (6.4 mg/kg) n=1 Participants SBT6050 plus trastuzumab deruxtecan SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles trastuzumab deruxtecan: 6.4 mg/kg by IV infusion in 21-day cycles	SBT6050 + Tucatinib + Trastuzumab n=1 Participants SBT6050 plus tucatinib and trastuzumab SBT6050: Dosed with 0.45 mg/kg by subcutaneous (SC) injection in 21-day cycles tucatinib: 300 mg by mouth (PO) twice daily (BID) trastuzumab: 8 mg/kg loading dose (first dose), then 6 mg/kg maintenance dose (subsequent doses) IV infusion in 21-day cycles	Total n=2 Participants Total of all reporting groups
Sex: Female, Male Male	1 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants
Ethnicity (NIH/OMB) Hispanic or Latino	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Ethnicity (NIH/OMB) Not Hispanic or Latino	1 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants
Ethnicity (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical <=18 years	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Age, Categorical >=65 years	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Sex: Female, Male Female	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) White	1 Participants n=5 Participants	1 Participants n=7 Participants	2 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants	0 Participants n=7 Participants	0 Participants n=5 Participants
Region of Enrollment United States	1 participants n=5 Participants	1 participants n=7 Participants	2 participants n=5 Participants
Primary Tumor Type Gastric cancer	1 Participants n=5 Participants	0 Participants n=7 Participants	1 Participants n=5 Participants
Primary Tumor Type Colorectal cancer	0 Participants n=5 Participants	1 Participants n=7 Participants	1 Participants n=5 Participants
Prior Therapy Regimens	1 Number of therapy regimens n=5 Participants	1 Number of therapy regimens n=7 Participants	2 Number of therapy regimens n=5 Participants