Head and Neck Squamous Cell CarcinomaPhase 1/2NCT04616196

Study of NKTR 255 in Combination With Cetuximab in Solid Tumors

A Phase 1/2 study testing NKTR-255 and Cetuximab in people with Head and Neck Squamous Cell Carcinoma and Colorectal Cancer, run by Nektar Therapeutics at 6 sites in United States.

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, open-label multicenter study evaluating NKTR-255 as a monotherapy and together with cetuximab in patients with head and neck squamous cell carcinoma (HNSCC) and colorectal carcinoma (CRC). Read more about this study

Who is it for?: Ages 18 years and older
Conditions the study is for: Head and Neck Squamous Cell Carcinoma, Colorectal Cancer
What is being tested?: NKTR-255 and Cetuximab
Type of treatment: Injection or infusion
Could I receive a placebo?: No, everyone receives an active treatment
How many people: 25 participants
Where: 6 sitesUnited States
Study dates: 30 Oct 2020to 30 Mar 2023
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

Histologically confirmed diagnosis of a locally advanced or metastatic HNSCC or CRC.
Life expectancy > 12 weeks as determined by the Investigator.
Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.
Measurable disease per RECIST 1.1.
HNSCC:
Progression on any first or second line platinum-based chemotherapy and/or anti-PD-1 or programmed death-ligand 1 antibody.
CRC:
Patients must have received or were intolerant to at least 2 prior cancer therapy regimens administered for metastatic disease.

Who cannot join

Use of an investigational agent or an investigational device within 28 days before administration of first dose of study drug(s)
Prior surgery or radiotherapy within 14 days of initiating study drug(s)
Evidence of clinically significant interstitial lung disease or active, noninfectious pneumonitis; active infection requiring systemic therapy within 7 days prior to dosing
Patients who have been previously treated with IL-2 or IL-15
Known Grade 3 or 4 hypersensitivity reaction to cetuximab, history of allergy to red meat or tick bites, or history of positive test results for immunoglobulin E antibodies against cetuximab
Patients who have an active, known, or suspected autoimmune disease
NOTE: Other protocol defined inclusion/exclusion criteria may apply

Trial locations and contacts

6 sites in 1 country.

City, postcode or hospital

6 sites in 1 country

United States6 sites

Mary Crowley Cancer Research
Dallas, Texas, 75230
MD Anderson Cancer Center
Houston, Texas, 77030
University of Minnesota
Minneapolis, Minnesota, 55455
START Center for Cancer Care
San Antonio, Texas, 78229
University of California, San Diego
San Diego, California, 92103
University of California, San Francisco
San Francisco, California, 94158

Other trials in United States

About this study

Official title: A Phase 1b/2, Open-label, Multicenter, Dose Escalation and Dose Expansion Study of NKTR-255 Monotherapy or in Combination With Cetuximab as a Salvage Regimen for Solid Tumors

Read the detailed description

NKTR-255 is a cytokine that is designed to regulate T and natural killer cell activation, proliferation and promote their anti-tumor effects.

In the dose escalation (Phase 1/b) phase patients with HNSCC or CRC will be treated with ascending doses of NKTR-255 in combination with cetuximab, until the maximum tolerated dose (MTD) and/or the recommended Phase 2 dose (RP2D) is reached.

Conditions: Head and Neck Squamous Cell Carcinoma, Colorectal Cancer
Being tested: NKTR-255, Cetuximab
Keywords: HNSCC, Head and Neck Squamous Cell Carcinoma, CRC, Colorectal Cancer, NKTR-255, Cetuximab, Erbitux®
Medical subject headings: Squamous Cell Carcinoma of Head and Neck, Colorectal Neoplasms

What participants receive

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

NKTR-255Drug
NKTR-255 IV every 21 days
CetuximabDrug
Also called Erbitux®
Cetuximab will be given at specified doses on specified days

Study groups in NCT04616196
Study group	Role	What they receive
Dose Escalation of NKTR-255 with Cetuximab	Experimental	Establish RP2D, of NKTR-255 with cetuximab. Receives: Drug: NKTR-255; Drug: Cetuximab

What is being measured

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

Incidence of Treatment-Emergent Adverse Events (TEAE) and Serious Adverse Events (SAE) of NKTR-255 in Combination With Cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation
Safety and tolerability of NKTR-255 in combination with cetuximab as evaluated by dose limiting toxicities, incidence of drug-related Adverse Events (AEs), SAEs, and AEs leading to discontinuation, deaths, and clinical laboratory abnormalities per CTCAE 5.0
Measured: 60 days after the last dose of study treatment, up to an average of 6 months.
The Maximum Tolerated Dose (MTD) and/or Recommended Phase 2 Dose (RP2D) of NKTR-255 in Combination With Cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation
To define the MTD and/or RP2D of NKTR-255 in combination with cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation
Measured: Up to 21 days

Timeline

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

30 Oct 202030 Mar 2023

First posted4 Nov 2020
Study start30 Oct 2020
Primary completion30 Mar 2023
Study completion30 Mar 2023

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.
Other trials for Head and Neck Squamous Cell CarcinomaStudies of the same condition, open and under way.
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: Not applicable
Intervention model: Sequential
Model description: Phase 1: Dose escalation cohorts will be sequential
Masking: None (open label)
Enrolment: 25 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT04616196
Sponsor's protocol ID: 19-255-03
Status last verified: May 2025
First submitted: 30 Oct 2020
Last updated: 8 Jun 2025
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: Yes
FDA-regulated drug: Yes
FDA-regulated device: No

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?

See locations

RecruitingPhase 1/2
Study of INBRX-106 and INBRX-106 in Combination With Pembrolizumab (Keytruda®) in Subjects With Locally Advanced or Metastatic Solid Tumors (Hexavalent OX40 Agonist)
Solid Tumor, Non-Small Cell Lung Cancer
RecruitingPhase 2
Proton Spatially Fractionated Radiotherapy or Photon Stereotactic Body Radiotherapy in Combination With Pembrolizumab Before Surgery for the Treatment of Locally Advanced and Radiation-Naive Locoregionally Recurrent Oral Cavity Cancer, OSPRI Trial
Locally Advanced Oral Cavity Squamous Cell Carcinoma, Locally Recurrent Oral Cavity Squamous Cell Carcinoma
RecruitingObservational study
Multicenter Prospective Cohort on Esophageal Endoscopic Submucosal Dissection
Superficial Esophageal Cancer, Oesophageal Adenocarcinoma
RecruitingPhase 1/2
Docetaxel and SX-682 in Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma, Salivary Gland Carcinoma, and Advanced Prostate Cancer
Head and Neck Cancer, Head and Neck Squamous Cell Carcinoma
Not yet recruiting
Tumoral Versus Luminal Microbiome in Head and Neck Squamous Cell Carcinoma
Squamous Cell Cancer of Head and Neck (SCCHN)

All Head and Neck Squamous Cell Carcinoma trials

Study at a glance

From the registry record, last updated by the sponsor on 8 Jun 2025. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: A Phase 1b/2, Open-label, Multicenter, Dose Escalation and Dose Expansion Study of NKTR-255 Monotherapy or in Combination With Cetuximab as a Salvage Regimen for Solid Tumors
ClinicalTrials.gov ID: NCT04616196
Acronym / sponsor ID: 19-255-03
Conditions: Head and Neck Squamous Cell Carcinoma, Colorectal Cancer
Keywords: HNSCC, Head and Neck Squamous Cell Carcinoma, CRC, Colorectal Cancer, NKTR-255, Cetuximab, Erbitux®
Phase: Phase 1/2
Study type: Interventional
Recruitment status: Completed
Enrolment: 25 participants (actual)
Lead sponsor: Nektar TherapeuticsIndustry (pharma, biotech, devices)
Study start: 30 Oct 2020 (actual)
Primary completion: 30 Mar 2023 (actual)
Study completion: 30 Mar 2023 (actual)
First posted: 4 Nov 2020 (actual)
Results: Posted 8 Jun 2025

Clinical summary

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

Detailed description

NKTR-255 is a cytokine that is designed to regulate T and natural killer cell activation, proliferation and promote their anti-tumor effects.

Study design

Primary purpose: Treatment
Allocation: Not applicable
Intervention model: Sequential
Masking: None (open label)
Number of arms: 1
Model description: Phase 1: Dose escalation cohorts will be sequential

Arm	Type	Receives
Dose Escalation of NKTR-255 with Cetuximab	Experimental	Drug: NKTR-255, Drug: CetuximabEstablish RP2D, of NKTR-255 with cetuximab.

Who may qualify

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

Key inclusion criteria (8 listed)

Histologically confirmed diagnosis of a locally advanced or metastatic HNSCC or CRC.
Life expectancy > 12 weeks as determined by the Investigator.
Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1.
Measurable disease per RECIST 1.1.
Progression on any first or second line platinum-based chemotherapy and/or anti-PD-1 or programmed death-ligand 1 antibody.

Key exclusion criteria (7 listed)

Use of an investigational agent or an investigational device within 28 days before administration of first dose of study drug(s)
Prior surgery or radiotherapy within 14 days of initiating study drug(s)
Evidence of clinically significant interstitial lung disease or active, noninfectious pneumonitis; active infection requiring systemic therapy within 7 days prior to dosing
Patients who have been previously treated with IL-2 or IL-15
Known Grade 3 or 4 hypersensitivity reaction to cetuximab, history of allergy to red meat or tick bites, or history of positive test results for immunoglobulin E antibodies against cetuximab

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
NKTR-255NKTR-255 IV every 21 days	Drug	Dose Escalation of NKTR-255 with Cetuximab
CetuximabAlso: Erbitux®Cetuximab will be given at specified doses on specified days	Drug	Dose Escalation of NKTR-255 with Cetuximab

Primary outcome

Incidence of Treatment-Emergent Adverse Events (TEAE) and Serious Adverse Events (SAE) of NKTR-255 in Combination With Cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation
Time frame: 60 days after the last dose of study treatment, up to an average of 6 months.
Safety and tolerability of NKTR-255 in combination with cetuximab as evaluated by dose limiting toxicities, incidence of drug-related Adverse Events (AEs), SAEs, and AEs leading to discontinuation, deaths, and clinical laboratory abnormalities per CTCAE 5.0
The Maximum Tolerated Dose (MTD) and/or Recommended Phase 2 Dose (RP2D) of NKTR-255 in Combination With Cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation
Time frame: Up to 21 days
To define the MTD and/or RP2D of NKTR-255 in combination with cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation

Results and safety

Results posted to the registry on 8 Jun 2025, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Dose Escalation of NKTR-255 Level 1 (1.5 µg/kg) With Cetuximab	8	0
Dose Escalation of NKTR-255 Level 2 (3.0 µg/kg) With Cetuximab	8	1
Dose Escalation of NKTR-255 Level 3 (4.5 µg/kg) With Cetuximab	6	0
Dose Escalation of NKTR-255 Level 4 (6.0 µg/kg) With Cetuximab	3	0

Primary outcome: Incidence of Treatment-Emergent Adverse Events (TEAE) and Serious Adverse Events (SAE) of NKTR-255 in Combination With Cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation

Time frame: 60 days after the last dose of study treatment, up to an average of 6 months.. Count of participants. Unit: Participants

Measure	Dose Escalation of NKTR-255 Level 1 (1.5 µg/kg) With Cetuximab n = 7	Dose Escalation of NKTR-255 Level 2 (3.0 µg/kg) With Cetuximab n = 7	Dose Escalation of NKTR-255 Level 3 (4.5 µg/kg) With Cetuximab n = 6	Dose Escalation of NKTR-255 Level 4 (6.0 µg/kg) With Cetuximab n = 3
Patients with dose limiting toxicities (DLTs): Infusion related reaction	0	1	0	0
Patients With at Least one TEAE	7	7	6	2
Patients With at Least one TEAE Related to NKTR-255	5	7	5	2
Patients With at Least one Serious TEAE	2	2	5	1
Patients With at Least one Serious TEAE Related to NKTR-255	0	1	0	1
Patients With at Least one TEAE Leading to Death	0	0	0	0
Patients With at Least one TEAE Related to NKTR-255 Leading to Death	0	0	0	0
Patients With at Least one TEAE Leading to NKTR-255 Discontinuation	0	2	0	0

Population analysed: DLTs were assessed using the DLT Population, which only included patients who received at least 1 dose of the combination treatment of NKTR-255 and cetuximab and who completed the DLT observation period or discontinued from the study treatment due to a DLT, where DLT window was 21 days since the first dose of NKTR-255. The other rows were assessed using the Safety Population, patients who received at least 1 dose (or partial dose) of NKTR-255.

Primary outcome: The Maximum Tolerated Dose (MTD) and/or Recommended Phase 2 Dose (RP2D) of NKTR-255 in Combination With Cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation

Time frame: Up to 21 days. Number. Unit: µg/kg

Measure	Dose Escalation of NKTR-255 Level 1 (1.5 µg/kg) With Cetuximab n = 7	Dose Escalation of NKTR-255 Level 2 (3.0 µg/kg) With Cetuximab n = 7	Dose Escalation of NKTR-255 Level 3 (4.5 µg/kg) With Cetuximab n = 6	Dose Escalation of NKTR-255 Level 4 (6.0 µg/kg) With Cetuximab n = 3
Value	NA	NA	NA	NA

Adverse events

Time frame: Through study completion, up to 6 months.. Other adverse events reported at 5% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Dose Escalation of NKTR-255 Level 1 (1.5 µg/kg) With Cetuximab	2 of 7 (28.6%)	7 of 7 (100%)	2 of 8
Dose Escalation of NKTR-255 Level 2 (3.0 µg/kg) With Cetuximab	2 of 7 (28.6%)	7 of 7 (100%)	4 of 8
Dose Escalation of NKTR-255 Level 3 (4.5 µg/kg) With Cetuximab	5 of 6 (83.3%)	6 of 6 (100%)	1 of 6
Dose Escalation of NKTR-255 Level 4 (6.0 µg/kg) With Cetuximab	1 of 3 (33.3%)	2 of 3 (66.7%)	1 of 3

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 8 Jun 2025.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

Related trials for Head and Neck Squamous Cell Carcinoma

RecruitingPhase 1/2
Study of INBRX-106 and INBRX-106 in Combination With Pembrolizumab (Keytruda®) in Subjects With Locally Advanced or Metastatic Solid Tumors (Hexavalent OX40 Agonist)
Solid Tumor, Non-Small Cell Lung Cancer
RecruitingPhase 2
Proton Spatially Fractionated Radiotherapy or Photon Stereotactic Body Radiotherapy in Combination With Pembrolizumab Before Surgery for the Treatment of Locally Advanced and Radiation-Naive Locoregionally Recurrent Oral Cavity Cancer, OSPRI Trial
Locally Advanced Oral Cavity Squamous Cell Carcinoma, Locally Recurrent Oral Cavity Squamous Cell Carcinoma
RecruitingObservational study
Multicenter Prospective Cohort on Esophageal Endoscopic Submucosal Dissection
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RecruitingPhase 1/2
Docetaxel and SX-682 in Recurrent/Metastatic Head and Neck Squamous Cell Carcinoma, Salivary Gland Carcinoma, and Advanced Prostate Cancer
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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.

Study Director study director

Nektar Therapeutics

6 sites in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

A Phase 1/2 study testing NKTR-255 and Cetuximab in people with Head and Neck Squamous Cell Carcinoma and Colorectal Cancer, run by Nektar Therapeutics at 6 sites in United States.

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 8 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 8 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 6 sites in United States. 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 Jun 2025). 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?

Incidence of Treatment-Emergent Adverse Events (TEAE) and Serious Adverse Events (SAE) of NKTR-255 in Combination With Cetuximab in R/R HNSCC or CRC for Phase 1b Dose Escalation (time frame: 60 days after the last dose of study treatment, up to an average of 6 months.). The study lists 2 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 NCT04616196.

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 8 Jun 2025.