Advanced MalignanciesPhase 1/2NCT04181788

Sasanlimab (PF-06801591, PD-1 Inhibitor) in Participants With Advanced Malignancies

A Phase 1/2 study testing PF-06801591 in people with Advanced Malignancies and Non-small-cell Lung Cancer, run by Pfizer at 49 sites in 6 countries.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record

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Trial summary

This is a Phase 1b/2 protocol to evaluate pharmacokinetics, safety, efficacy, and pharmacodynamics of PF-06801591, a programmed death-1(PD-1) antagonist monoclonal antibody (mAb) in participants with advanced malignancies. Read more about this study

Who is it for?: Ages 18 years and older
Conditions the study is for: Advanced Malignancies, Non-small-cell Lung Cancer
What is being tested?: PF-06801591
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 155 participants
Where: 49 sitesin 6 countries
Study dates: 18 Mar 2020to 13 May 2026
Phase: Phase 1/2
Are there results?: Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

Ages 18 years and older
All sexes
No healthy volunteers
Adult, Older adult

Who may be able to join

Age ≥18 years (≥ 20 years in Japan; ≥ 19 years in South Korea)
Easter Cooperative Oncology Group (ECOG) performance status 0 or 1
Adequate bone marrow function, renal and liver functions Phase 1b
Histological or Cytological diagnosis of advanced solid tumor with clinical evidence of response to anti-PD-1 or PD-L1 agent
Participant must have received at least 1 prior line of therapy for recurrent or metastatic disease, and must have progressed/relapsed, be refractory, or intolerant to standard therapy approved for the specific tumor type Phase 2
Participants must have a documented diagnosis of stage III where participants are not candidates for surgical resection or definitive chemoradiation, or stage IV NSCLC

Show all 11Show fewer

EGFR mutation, BRAF mutation, and ALK or ROS1 translocation/rearrangement are not permitted
Participants whose tumor is known to be PD-L1 positive (Tumor Proportion Score [TPS] ≥1%) or unknown are eligible
Up to 1 line of prior therapy in advanced or metastatic disease settings allowed
Participant should not have received prior treatment with anti PD-1/PD-L1 drugs
At least one measurable lesion as defined by RECIST version 1.1

Who cannot join

Participants with known symptomatic brain metastases requiring steroids
Participants with Interstitial Lung Disease history or complication
Q-T interval corrected for heart rate QTc > 450 msec for male participants or QTc > 470 msec for female participants or QTc > 480 msec in participants with right bundle branch block.
Hypertension that cannot be controlled by medications (eg, systolic > 150 mmHg and diastolic > 90 mmHg) despite optimal medical therapy.
Known or suspected hypersensitivity to active ingredient or excipients of the study drug.
History of Grade ≥3 immune mediated AE (including AST/ ALT elevations that where considered drug related and cytokine release syndrome [CRS]) that was considered related to prior immune modulatory therapy (eg, immune checkpoint inhibitors, co-stimulatory agents, etc.) and required immunosuppressive therapy (For Phase 1b only).
Vaccination with live attenuated vaccines within 4 weeks prior to randomization is prohibited; however inactivated vaccines are permitted.

Trial locations and contacts

49 sites in 6 countries.

Country

City, postcode or hospital

49 sites in 6 countries

Russia20 sites

Evimed Llc
Chelyabinsk, 454048
Chelyabinsk Regional Clinical Centre of Oncology and Nuclear Medicine
Chelyabinsk, 454087
Ars Medika Center, LLC
Kaliningrad, 236006
GBUZ Regional Clinical Hospital of Kaliningrad region
Kaliningrad, 236016
Enlimed Llc
Kopeysk, 456620
Orenburg Regional Clinical Oncological Dispensary
Orenburg, 460021
Russian Scientific Center For Radiology and Surgical Technologies
Pesochny, 197758
Private Medical Institution "Euromedservice"
Pushkin, Sankt-Peterburg, 196603
Klinika UZI 4D, LLC
Pyatigorsk, Stavropol Kray, 357502
Russian Research Centre for Radiology and Surgical Technologies
Saint Petersburg, Pesochny, 197758
LLC Medical Center "Magnit"
Saint Petersburg, 190005
Llc "Mss"
Saint Petersburg, 191025
North-West Medical Center
Saint Petersburg, 191119
Road clinical clinic of JSC "RZD"
Saint Petersburg, 192007
NS HI "Road Clinical Hospital of JSC "Russian Railways""
Saint Petersburg, 195271
Private Healthcare Institution "Clinical Hospital "RZD-Medicine" of St. Petersburg
Saint Petersburg, 195271
LLC "Diagnostic center "Energo"
Saint Petersburg, 196247
Medical University REAVIZ
Samara, 443001
Medical University REAVIZ
Samara, 443011
State budgetary institution of healthcare of Yaroslavl region "Clinical oncology hospital"
Yaroslavl, Yaroslavl Oblast, 150054

Other trials in Russia

Ukraine18 sites

Communal Non-profit Enterprise City Clinical Hospital #4 of Dnipro City Council
Dnipro, 49102
LLC "AR DI PI Ukraine"
Dnipro, 49102
Llc "Mdc Expert"
Dnipro, 49102
Municipal Non-profit Enterprise "SubCarpathian Clinical Oncological Centre of Ivano-Frankivsk RC"
Ivano-Frankivsk, 76018
Asklepion Medical Center
Khodosovka, Kyivska Oblast, 08173
Private Enterprise of Private Manufacturing Company "Acinus", Medical and Diagnostic Center
Kropyvnytskyi, 25006
Medical centre "Verum" Limited Liability Company
Kyiv, 03039
Vita Сom LLC
Kyiv, 03141
The State Institution "Romodanov Neurosurgery Institute,
Kyiv, 04050
Llc Medical Centre
Odesa, 65006
Municipal Non-profit Enterprise Odesa Regional Clinical Hospital of Odesa Regional Council
Odesa, 65025
Llc Lidermed
Odesa, 65062
Limited Liability Company "MedX-ray International Group"
Pliuty Village, Kyiv Oblast
"Medeya Sumy" LLC
Sumy, Sumska Oblast, 40021
Municipal Non Profit enterprise of Sumy Regional Council "Sumy Regional Clinical Oncology Center"
Sumy, 40022
Llc Medical Center Diamed
Uzhhorod, 88000
MNPE Central City Clinical Hospital of Uzhhorod City Council
Uzhhorod, 88000
Мunicipal non-profit enterprise "Zhytomyr Regional Oncology Dispensary" of Zhytomyr Regional Council
Zhytomyr, 10002

Other trials in Ukraine

China4 sites

Beijing Cancer hospital
Beijing, Beijing Municipality, 100142
Chongqing Cancer Hospital
Chongqing, Chongqing Municipality, 400030
Nanjing Drum Tower Hospital
Nanjing, Jiangsu, 210008
Huashan Hospital Affiliated to Fudan University
Shanghai, Shanghai Municipality, 201107

Other trials in China

South Korea4 sites

Gachon University Gil Medical Center
Incheon, 21656
Seoul National University Bundang Hospital
Seongnam-si, Gyeonggi-do, 13620
Severance Hospital, Yonsei Univ. Health System
Seoul, 03722
Asan Medical Center
Seoul, 05505

Other trials in South Korea

Taiwan2 sites

Kaohsiung Medical University Chung-Ho Memorial Hospital
Kaohsiung City, 807
Taipei Veterans General Hospital
Taipei, 11217

Other trials in Taiwan

Japan1 site

National Cancer Center Hospital
Chuo-ku, Tokyo, 104-0045

Other trials in Japan

About this study

Official title: A PHASE 1B/2 OPEN-LABEL STUDY TO EVALUATE PHARMACOKINETICS, SAFETY, EFFICACY, AND PHARMACODYNAMICS OF PF-06801591 (PD-1 INHIBITOR) IN PARTICIPANTS WITH ADVANCED MALIGNANCIES

This study consists of 2 parts:

Phase 1b part (dose escalation and dose expansion) in patients with advanced malignancies in Asia and a global Phase 2 part in non small cell lung cancer (NSCLC) patients.

Conditions: Advanced Malignancies, Non-small-cell Lung Cancer
Being tested: PF-06801591
Keywords: Advanced solid tumors, NSCLC
Medical subject headings: Carcinoma, Non-Small-Cell Lung

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

PF-06801591Drug
A monoclonal antibody (mAb) that blocks the interaction between PD-1 and PDL1/ PD-L2.

Study groups in NCT04181788
Study group	Role	What they receive
Arm A1 (Phase 1b)	Experimental	Not described Receives: Drug: PF-06801591
Arm B1 (Phase 1b)	Experimental	Not described Receives: Drug: PF-06801591
Arm A2 (Phase 2)	Experimental	Not described Receives: Drug: PF-06801591
Arm B2 (Phase 2)	Experimental	Not described Receives: Drug: PF-06801591

What is being measured

The primary outcome is the main question the study is designed to answer.

Phase 1b: Number of Participants With Dose-Limiting Toxicities (DLT)
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with first line (1L) and second line (2L) non-small cell lung cancer (NSCLC) (Phase 2).
For the Phase 1b, any of the following AEs occurring during the DLT observation period (the first cycle of treatment) which were attributable to the investigational product were classified as DLTs: Grade 5 AE not clearly due to the underlying disease or extraneous causes; Hematologic toxicity; Non-Hematologic Toxicity; Delay of ≥ 3 weeks in receiving the next scheduled administration due to persisting treatment-related toxicities.
Measured: Phase 1b: at the end of cycle 1 (28 days) for the PF-06801591 300 mg SC Q4W arms, and (42 days) for the PF-06801591 600 mg SC Q6W arms
Phase 2: AUCτ of PF-06801591 at Steady State
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
AUCτ is area under the plasma concentration-time profile from time zero to the next dose (at steady state, starting at Week 12). (τ = X days, where X = 28 days for Q4W regimen and 42 days for Q6W regimen)
Measured: Phase 2: Cycle 4 Day 1, 8, 15, 22 and Cycle 5 Day 1 for the PF-06801591 300 mg SC Q4W arm, and Cycle 3 Day 1, 8, 15, 29 and Cycle 4 Day 1 for the PF-06801591 600 mg SC Q6W arm
Phase 2: Ctrough of PF-06801591 at Steady State, at Week 12
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
Steady state Ctrough is pre-dose concentration following multiple dosing at steady state (Week 12)
Measured: Phase 2: Cycle 4 Day 1 for the PF-06801591 300 mg SC Q4W arm, and Cycle 3 Day 1 for the PF-06801591 600 mg SC Q6W arm

Secondary outcomes (9)

Number of Participants With Treatment-Emergent Adverse Events
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship.
Measured: Phase 1b/2: On-treatment period is defined as the time from the first dose of study treatment through minimum (30 days + last dose of study treatment, start day of new anti-cancer drug therapy - 1 day).
Number of Participants With Laboratory Abnormalities
Laboratory results were classified according to the NCI-CTCAE criteria version 5.0. Grade 1: asymptomatic or mild symptoms, clinical or diagnostic observations only, intervention not indicated; Grade 2: moderate, minimal, local or noninvasive intervention indicated, limiting age-appropriate instrumental activities of daily life (ADL); Grade 3: severe or medically significant but not immediately life-threatening, hospitalization or prolongation of existing hospitalization indicated, disabling, limiting self-care (ADL); Grade 4: life-threatening consequence, urgent intervention indicated; Grade 5: death related to AE. Number of participants with Grade 1 to Grade 4 laboratory abnormalities were reported.
Measured: Phase 1b/2: On-treatment period is defined as the time from the first dose of study treatment through minimum (30 days + last dose of study treatment, start day of new anti-cancer drug therapy - 1 day).
Pharmacokinetic Parameters: AUCτ After First Dose
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
AUCτ is area under the plasma concentration-time profile from time zero to the next dose (after single dose). (τ = X days, where X = 28 days for Q4W regimen and 42 days for Q6W regimen)
Measured: Phase 1b/2: For the PF-06801591 300 mg SC Q4W arms, Cycle 1 Day 1, 8, 15, 22, Cycle 2 Day 1; for the PF-06801591 600 mg SC Q6W arms, Cycle 1 Day 1, 8, 15, 29, Cycle 2 Day 1
Pharmacokinetic Parameters: Ctrough After First Dose
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
Ctrough is pre-dose concentration after single dose (first dose).
Measured: Phase 1b/2: Cycle 2 Day 1 for all Arms
Pharmacokinetic Parameters: Ctrough at Steady State
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
Steady state Ctrough is pre-dose concentration following multiple dosing at steady state (Week 12)
Measured: Phase 1b/2: For the PF-06801591 300 mg SC Q4W arms, Day 1 of Cycle 4; for the PF-06801591 600 mg SC Q6W arms, Day 1 of Cycle 3
Number of Participants With Treatment-Induced Anti-Drug Antibody (ADA) /Neutralizing Antibodies (NAb)
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
Treatment-induced ADA = Baseline ADA titer was missing or negative and participant had ≥1 post-treatment positive ADA titer (ADA titer greater than or equal to 99 with assay cut-point of 1.09).
Treatment-induced NAb = Baseline NAb titer was missing or negative or ADA-negative and participant had ≥1 post-treatment positive NAb titer.
Measured: Phase 1b/2: Day 1 of Cycle 1, 2, 3, 4, 6, 8, 10 and end of treatment (EOT) for the PF-06801591 300 mg SC Q4W arms; Day 1 of Cycle 1, 2, 3, 4, 5, 7 and EOT for the PF-06801591 600 mg SC Q6W arms
Number of Participants With Objective Response (OR)
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
OR was defined as confirmed best overall response (BOR) of complete response (CR) or partial response (PR) according to RECIST v1.1.
Complete Response (CR): Complete disappearance of all target lesions with the exception of nodal disease. All target nodes must decrease to normal size (short axis <10 mm). All target lesions must be assessed.
Partial Response (PR): Greater than or equal to 30% decrease under baseline of the sum of diameters of all target measurable lesions. All target lesions must be assessed.
Measured: Phase 1b/2: Up to 30 months
Time to Response (TTR)
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
TTR was defined for participants with confirmed objective response (CR or PR) as the time from the 'start date' to the date of first documentation of objective tumor response which is subsequently confirmed.
Measured: Phase 1b/2: Up to 30 months
Number of Participants With Objective Response (Complete Response + Partial Response) Reported by Baseline Programmed Death-Ligand 1 (PD-L1) Status (High, Low, and Unknown)
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2).
OR was defined as confirmed BOR of CR or PR according to RECIST v1.1. CR: Complete disappearance of all target lesions with the exception of nodal disease. All target nodes must decrease to normal size (short axis <10 mm). All target lesions must be assessed.
PR: Greater than or equal to 30% decrease under baseline of the sum of diameters of all target measurable lesions. All target lesions must be assessed.
PD-L1 expression was defined as the number of PD-L1 positive cells and/or qualitative assessment of PD-L1 staining on tumor and inflammatory cells in regions of interest that are defined by tumor cell morphology.
Measured: Phase 1b/2: Baseline up to 30 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

18 Mar 202013 May 2026

First posted29 Nov 2019
Study start18 Mar 2020
Primary completion3 Mar 2022
Study completion13 May 2026

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Publications (1)Papers the sponsor has linked to this study.
Other trials for Advanced MalignanciesStudies of the same condition, open and under way.
More trials run by PfizerThe sponsor's other registered studies.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design

Study type: Interventional
Phase: Phase 1/2
Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Enrolment: 155 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04181788
Sponsor's protocol ID: B8011007
Status last verified: May 2026
First submitted: 14 Nov 2019
Last updated: 15 Jun 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: Yes
FDA-regulated device: No
Individual data sharing: Yes: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.

Publications

Penkov K, Bondarenko I, Saenko DV, Kulyaba Y, Guo J, Gong Y, Yamamoto N, Hotko YS, Boyko V, Fadeeva NV, Ursol GM, Ahn HK, Kislov NV, Shen CI, Davis C, Kowalski K, Michelon E, Pavlov D, Hirohashi T, Cho BC. Pharmacokinetics, safety, and efficacy of an alternative dosing regimen of sasanlimab in participants with advanced NSCLC and other malignancies. Ther Adv Med Oncol. 2024 Sep 11;16:17588359241274592. doi: 10.1177/17588359241274592. eCollection 2024.
PubMed 39281971

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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Study at a glance

From the registry record, last updated by the sponsor on 15 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A PHASE 1B/2 OPEN-LABEL STUDY TO EVALUATE PHARMACOKINETICS, SAFETY, EFFICACY, AND PHARMACODYNAMICS OF PF-06801591 (PD-1 INHIBITOR) IN PARTICIPANTS WITH ADVANCED MALIGNANCIES
ClinicalTrials.gov ID: NCT04181788
Acronym / sponsor ID: B8011007
Conditions: Advanced Malignancies, Non-small-cell Lung Cancer
Keywords: Advanced solid tumors, NSCLC
Phase: Phase 1/2
Study type: Interventional
Recruitment status: Completed
Enrolment: 155 participants (actual)
Lead sponsor: PfizerIndustry (pharma, biotech, devices)
Study start: 18 Mar 2020 (actual)
Primary completion: 3 Mar 2022 (actual)
Study completion: 13 May 2026 (actual)
First posted: 29 Nov 2019 (actual)
Results: Posted 8 May 2023

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

This study consists of 2 parts:

Phase 1b part (dose escalation and dose expansion) in patients with advanced malignancies in Asia and a global Phase 2 part in non small cell lung cancer (NSCLC) patients.

Study design

Primary purpose: Treatment
Allocation: Randomised
Intervention model: Parallel groups
Masking: None (open label)
Number of arms: 4

Arm	Type	Receives
Arm A1 (Phase 1b)	Experimental	Drug: PF-06801591
Arm B1 (Phase 1b)	Experimental	Drug: PF-06801591
Arm A2 (Phase 2)	Experimental	Drug: PF-06801591
Arm B2 (Phase 2)	Experimental	Drug: PF-06801591

Who may qualify

Ages: 18 years and older
Sex: All
Healthy volunteers: Not accepted
Age groups: Adult, Older adult

Key inclusion criteria (11 listed)

Age ≥18 years (≥ 20 years in Japan; ≥ 19 years in South Korea)
Easter Cooperative Oncology Group (ECOG) performance status 0 or 1
Adequate bone marrow function, renal and liver functions Phase 1b
Histological or Cytological diagnosis of advanced solid tumor with clinical evidence of response to anti-PD-1 or PD-L1 agent
Participant must have received at least 1 prior line of therapy for recurrent or metastatic disease, and must have progressed/relapsed, be refractory, or intolerant to standard therapy approved for the specific tumor type Phase 2

Key exclusion criteria (7 listed)

Participants with known symptomatic brain metastases requiring steroids
Participants with Interstitial Lung Disease history or complication
Q-T interval corrected for heart rate QTc > 450 msec for male participants or QTc > 470 msec for female participants or QTc > 480 msec in participants with right bundle branch block.
Hypertension that cannot be controlled by medications (eg, systolic > 150 mmHg and diastolic > 90 mmHg) despite optimal medical therapy.
Known or suspected hypersensitivity to active ingredient or excipients of the study drug.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Intervention	Type	Arms
PF-06801591A monoclonal antibody (mAb) that blocks the interaction between PD-1 and PDL1/ PD-L2.	Drug	Arm A1 (Phase 1b), Arm A2 (Phase 2), Arm B1 (Phase 1b), Arm B2 (Phase 2)

Primary outcome

Phase 1b: Number of Participants With Dose-Limiting Toxicities (DLT)
Time frame: Phase 1b: at the end of cycle 1 (28 days) for the PF-06801591 300 mg SC Q4W arms, and (42 days) for the PF-06801591 600 mg SC Q6W arms
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with first line (1L) and second line (2L) non-small cell lung cancer (NSCLC) (Phase 2). For the Phase 1b, any of the following AEs occurring during the DLT observation period (the first cycle of treatment) which were attributable to the investigational product were classified as DLTs: Grade 5 AE not clearly due to the underlying disease or extraneous causes; Hematologic toxicity; Non-Hematologic Toxicity; Delay of ≥ 3 weeks in receiving the next scheduled administration due to persisting treatment-related toxicities.
Phase 2: AUCτ of PF-06801591 at Steady State
Time frame: Phase 2: Cycle 4 Day 1, 8, 15, 22 and Cycle 5 Day 1 for the PF-06801591 300 mg SC Q4W arm, and Cycle 3 Day 1, 8, 15, 29 and Cycle 4 Day 1 for the PF-06801591 600 mg SC Q6W arm
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2). AUCτ is area under the plasma concentration-time profile from time zero to the next dose (at steady state, starting at Week 12). (τ = X days, where X = 28 days for Q4W regimen and 42 days for Q6W regimen)
Phase 2: Ctrough of PF-06801591 at Steady State, at Week 12
Time frame: Phase 2: Cycle 4 Day 1 for the PF-06801591 300 mg SC Q4W arm, and Cycle 3 Day 1 for the PF-06801591 600 mg SC Q6W arm
This study included Asian participants with advanced solid tumors (Phase 1b) and global participants with 1L and 2L NSCLC (Phase 2). Steady state Ctrough is pre-dose concentration following multiple dosing at steady state (Week 12)

9 secondary outcomes

Number of Participants With Treatment-Emergent Adverse Events
Time frame: Phase 1b/2: On-treatment period is defined as the time from the first dose of study treatment through minimum (30 days + last dose of study treatment, start day of new anti-cancer drug therapy - 1 day).
Number of Participants With Laboratory Abnormalities
Time frame: Phase 1b/2: On-treatment period is defined as the time from the first dose of study treatment through minimum (30 days + last dose of study treatment, start day of new anti-cancer drug therapy - 1 day).
Pharmacokinetic Parameters: AUCτ After First Dose
Time frame: Phase 1b/2: For the PF-06801591 300 mg SC Q4W arms, Cycle 1 Day 1, 8, 15, 22, Cycle 2 Day 1; for the PF-06801591 600 mg SC Q6W arms, Cycle 1 Day 1, 8, 15, 29, Cycle 2 Day 1
Pharmacokinetic Parameters: Ctrough After First Dose
Time frame: Phase 1b/2: Cycle 2 Day 1 for all Arms
Pharmacokinetic Parameters: Ctrough at Steady State
Time frame: Phase 1b/2: For the PF-06801591 300 mg SC Q4W arms, Day 1 of Cycle 4; for the PF-06801591 600 mg SC Q6W arms, Day 1 of Cycle 3
Number of Participants With Treatment-Induced Anti-Drug Antibody (ADA) /Neutralizing Antibodies (NAb)
Time frame: Phase 1b/2: Day 1 of Cycle 1, 2, 3, 4, 6, 8, 10 and end of treatment (EOT) for the PF-06801591 300 mg SC Q4W arms; Day 1 of Cycle 1, 2, 3, 4, 5, 7 and EOT for the PF-06801591 600 mg SC Q6W arms
Number of Participants With Objective Response (OR)
Time frame: Phase 1b/2: Up to 30 months
Time to Response (TTR)
Time frame: Phase 1b/2: Up to 30 months
Number of Participants With Objective Response (Complete Response + Partial Response) Reported by Baseline Programmed Death-Ligand 1 (PD-L1) Status (High, Low, and Unknown)
Time frame: Phase 1b/2: Baseline up to 30 months

Results and safety

Results posted to the registry on 8 May 2023, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Phase 1b Escalation 300 mg SC Q4W	4	0
Phase 1b Expansion 300 mg SC Q4W	12	0
Phase 1b Escalation 600 mg SC Q6W	6	0
Phase 1b Expansion 600 mg SC Q6W	12	0
Phase 2 300 mg SC Q4W	41	0
Phase 2 600 mg SC Q6W	80	0

Primary outcome: Phase 1b: Number of Participants With Dose-Limiting Toxicities (DLT)

Time frame: Phase 1b: at the end of cycle 1 (28 days) for the PF-06801591 300 mg SC Q4W arms, and (42 days) for the PF-06801591 600 mg SC Q6W arms. Count of participants. Unit: Participants

Measure	Phase 1b Escalation 300 mg SC Q4W n = 3	Phase 1b Expansion 300 mg SC Q4W n = 11	Phase 1b Escalation 600 mg SC Q6W n = 6	Phase 1b Expansion 600 mg SC Q6W n = 12
Value	0	0	0	0

Population analysed: DLT-evaluable analysis set included all participants who received at least 1 dose of study treatment in the Phase 1b and either experienced DLT during the DLT-evaluation period or completed the DLT-evaluation period without DLT.

Primary outcome: Phase 2: AUCτ of PF-06801591 at Steady State

Time frame: Phase 2: Cycle 4 Day 1, 8, 15, 22 and Cycle 5 Day 1 for the PF-06801591 300 mg SC Q4W arm, and Cycle 3 Day 1, 8, 15, 29 and Cycle 4 Day 1 for the PF-06801591 600 mg SC Q6W arm. Geometric mean (Geometric Coefficient of Variation). Unit: microgram*hour per milliliter (μg*hr/mL)

Measure	Phase 2 300 mg SC Q4W n = 23	Phase 2 600 mg SC Q6W n = 49
Value	20800 (54)	48090 (47)

Phase 2 300 mg SC Q4W vs Phase 2 600 mg SC Q6W: Ratio of experimental vs control: 231.20 (90% CI 190.09 to 281.21)

Population analysed: Phase 2: The PK concentration analysis set was a subset of the safety analysis set and included participants who had at least 1 reportable concentration measurement. Safety analysis set included all enrolled participants who received at least 1 dose of study drug. Here "Number of participants analyzed" signifies participants who had data available for this outcome measure.

Primary outcome: Phase 2: Ctrough of PF-06801591 at Steady State, at Week 12

Time frame: Phase 2: Cycle 4 Day 1 for the PF-06801591 300 mg SC Q4W arm, and Cycle 3 Day 1 for the PF-06801591 600 mg SC Q6W arm. Geometric mean (Geometric Coefficient of Variation). Unit: microgram per milliliter (μg/mL)

Measure	Phase 2 300 mg SC Q4W n = 24	Phase 2 600 mg SC Q6W n = 55
Value	21.48 (60)	23.95 (74)

Phase 2 300 mg SC Q4W vs Phase 2 600 mg SC Q6W: Ratio of experimental vs control: 111.48 (90% CI 86.31 to 143.99)

9 secondary outcomes are reported in the full results.

Adverse events

Time frame: Phase 1b/2: On-treatment period (defined as the time from the first dose of study treatment through minimum [30 days + last dose of study treatment, start day of new anti-cancer drug therapy - 1 day] for the treatment-emergent adverse events (TEAEs); Baseline up to 30 months for all-causality mortality.. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Phase 1b Escalation 300 mg SC Q4W	1 of 4 (25%)	4 of 4 (100%)	0 of 4
Phase 1b Expansion 300 mg SC Q4W	2 of 12 (16.7%)	11 of 12 (91.7%)	0 of 12
Phase 1b Escalation 600 mg SC Q6W	0 of 6 (0%)	6 of 6 (100%)	1 of 6
Phase 1b Expansion 600 mg SC Q6W	0 of 12 (0%)	12 of 12 (100%)	2 of 12
Phase 2 300 mg SC Q4W	16 of 41 (39%)	40 of 41 (97.6%)	16 of 41
Phase 2 600 mg SC Q6W	13 of 80 (16.3%)	58 of 80 (72.5%)	31 of 80

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 15 Jun 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
Derived from this study: PubMed 39281971Penkov K, Bondarenko I, Saenko DV, Kulyaba Y, Guo J, Gong Y, Yamamoto N, Hotko YS, Boyko V, Fadeeva NV, Ursol GM, Ahn HK, Kislov NV, Shen CI, Davis C, Kowalski K, Michelon E, Pavlov D, Hirohashi T, Cho BC. Pharmacokinetics, safety, and efficacy of an alternative dosing regimen of sasanlimab in participants with advanced NSCLC and other malignancies. Ther Adv Med Oncol. 2024 Sep 11;16:17588359241274592. doi: 10.1177/17588359241274592. eCollection 2024.
To obtain contact information for a study center near you, click here.Link provided by the sponsor.
Individual participant dataSharing planned: Yes. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Pfizer CT.gov Call Center study director

Pfizer

49 sites in 6 countries: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing PF-06801591 in people with Advanced Malignancies and Non-small-cell Lung Cancer, run by Pfizer at 49 sites in 6 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 11 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 49 sites in Russia, Ukraine, China, South Korea, Taiwan and 1 more country. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this combined phase mean?

Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 8 May 2023). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Phase 1b: Number of Participants With Dose-Limiting Toxicities (DLT) (time frame: Phase 1b: at the end of cycle 1 (28 days) for the PF-06801591 300 mg SC Q4W arms, and (42 days) for the PF-06801591 600 mg SC Q6W arms). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT04181788, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Jun 2026.