CABATEN is a multicohort phase II study of cabozantinib plus atezolizumab in advanced and
progressive tumors from endocrine system.
The main hypothesis is that the administration of cabozantinib plus atezolizumab will improve
the probability of expected objective response rate in advanced and refractory tumors of the
The primary objective is to assess the efficacy of cabozantinib plus atezolizumab combination
by means of radiological objective response rate (ORR) evaluated following RECIST v1.1
criteria in advanced endocrine tumors. Secondary objectives include:
- To evaluate the safety profile of cabozantinib and atezolizumab combination, according
to NCI-CTCAE V5.0.
- Duration of response (DoR) as per RECIST V1.1.
- Progression-free survival (PFS): median PFS as per RECIST V1.1.
- Overall Survival (OS): median OS as per RECIST V1.1.
- Tumor biomarkers: translational sub-study (optional).
All the subjects will be treated with the combination until disease progression, unacceptable
toxicity, or patient consent withdrawal (whichever occurs first):
- Cabozantinib 40 mg or 20 mg tablets, oral administration once daily continuously.
- Atezolizumab 1200 mg administered intravenously (IV) every three weeks (cycle).
Endocrine tumors from different origins (thyroid, lung, pancreas and digestive tract, adrenal
gland and paraganglia) are characterized by being remarkably vascular and expressing several
growth factors including vascular endothelial growth factor (VEGF), platelet-derived growth
factor (PDGF), insulin-like growth factor 1 (IGF-1), basic fibroblast growth factor (BFGF),
and transforming growth factor (TGF)-α and -β. The (over) expression of some of these factors
has been linked to poor prognosis. Cabozaninib, a VEGF inhibitor, in combination with
atezolizumab, an inhibitor of PD-L1, may be active in endocrine tumors by overcoming the
resistance to prior antiangiogenic drugs.
The trial will include patients with advanced and refractory tumors of endocrine system and
patients would be allocated to six different cohorts according to the following tumor types:
Cohort 1: Well-differentiated neuroendocrine tumors of the lung and thymus (grades 1 and 2)
after progression to somatostatin analogs, targeted agents, PRRT, and/or chemotherapy.
Cohort 2: Anaplastic thyroid cancer in first-line or after progression to chemotherapy or
Cohort 3: Adrenocortical carcinoma after progression to chemotherapy and/or mitotane.
Cohort 4: Pheochromocytoma and paraganglioma after progression to peptide receptor
radionuclide therapy (PRRT) if indicated, prior chemotherapy and biological therapy, such as
somatostatin analogs, are allowed.
Cohort 5: Well-differentiated neuroendocrine tumors of digestive system after progression to
somatostatin analogs, targeted agents, PRRT, and/or chemotherapy.
Cohort 6: Grade 3 neuroendocrine neoplasm of any origin, excluding small cell lung cancer,
after progression to chemotherapy or targeted agents/PRRT.
1. Male or female subjects ≥ 18 years old.
2. Willingness to participate in the study by signing informed consent form (ICF)
approved by the trial Central Ethic Committee (CEIm).
3. Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1.
4. Measurable disease per RECIST 1.1 as determined by the investigator.
5. Patients with an histopathologically confirmed disease (as per local pathology
report), meeting one of the following (according to WHO 2010 classification):
1. Cohort 1: Well-differentiated neuroendocrine tumours of the lung and thymus (WHO
grade 1 and 2, typical and atypical carcinoids) after progression to somatostatin
analogs, targeted agents, PRRT, and/or chemotherapy.
2. Cohort 2: Anaplastic thyroid cancer in first-line or after progression to
chemotherapy or investigational drugs. Primary tumour can be resected or not but
risk of aerodigestive compression or bleeding should be ruled out.
3. Cohort 3: Adrenocortical carcinoma after progression to chemotherapy and/or
4. Cohort 4: Pheochromocytoma and paraganglioma after progression to peptide
receptor radionuclide therapy (PRRT) if indicated. Prior chemotherapy and
biological therapy, such as somatostatin analogs, are allowed.
5. Cohort 5: Well-differentiated neuroendocrine tumours of digestive system (WHO
grade 1 and 2) after progression to somatostatin analogs, targeted agents, PRRT,
6. Cohort 6: Grade 3 neuroendocrine neoplasm (WHO grade 3, including neuroendocrine
(NET) and neuroendocrine carcinomas (NEC) G3) of any origin, excluding small cell
lung cancer, after progression to chemotherapy or targeted agents/PRRT.
6. Recovery from toxicity related to any prior treatments to ≤ Grade 1, unless the
adverse events (AEs) are clinically non-significant and/or stable on supportive
7. Ability to swallow tablets.
8. Adequate normal organ and marrow function as defined below:
1. Haemoglobin ≥ 9.0 g/dL.
2. Absolute neutrophil count (ANC) > 1500 per mm.
3. Platelet count ≥ 100,000 per mm.
4. Serum bilirubin ≤ 1.5x institutional upper limit of normal (ULN) unless liver
metastases are present, in which case it must be ≤ 2X ULN. This will not apply to
patients with confirmed Gilbert's syndrome (persistent or recurrent
hyperbilirubinemia that is predominantly unconjugated in the absence of
haemolysis or hepatic pathology); however, they will be allowed only in
consultation with their physician.
5. Aspartate Transaminase (AST) (SGOT)/Alanine aminotransferase (ALT) (SGPT) ≤ 2.5x
institutional upper limit of normal unless liver metastases are present, in which
case it must be ≤ 3x ULN.
6. Measured creatinine clearance (CL) > 40 mL/min or Calculated creatinine CL > 40
mL/min by the Cockcroft-Gault formula (Cockcroft and Gault 1976) or by 24-hour
urine collection for the determination of creatinine clearance.
9. Female subjects of childbearing potential (not surgically sterile or at least 2 years
postmenopausal) must provide a negative urine pregnancy test at Screening, and use a
medically accepted double barrier method of contraception (i.e condom with spermicide
+ IUD or cervical caps). In addition, they must agree to continue the use of this
double barrier method for the duration of the study and for 4 months after
participation in the study.
10. Males should agree to abstain from sexual intercourse with a female partner or agree
to use a double barrier method of contraception (i.e.condom with spermicide, in
addition to having their female partner use some contraceptive measures such as,
intrauterine device (IUD) or cervical caps), for the duration of the study and for 4
months after participation in the study.
11. Willingness and ability of patients to comply with the protocol for the duration of
the study including undergoing treatment as well as availability for scheduled visits
and examinations including follow up.
1. Prior treatment with cabozantinib or any immune checkpoint inhibitor therapy (e.g,
CTLA4, PD-1, or PD-L1 targeting agent).
2. Receipt of any type of small molecule kinase inhibitor (including investigational
kinase inhibitor) within 2 weeks or 5 half-lives of the agent, whichever is longer.
Patients should have been out of mitotane for at least 4 weeks.
3. Receipt of any type of anticancer antibody (including investigational antibody) or
systemic chemotherapy within 2 weeks before starting treatment.
4. Current or prior use of immunosuppressive medication within 2 weeks before the first
dose of cabozantinib and atezolizumab, with the exceptions of intranasal and inhaled
corticosteroids or systemic corticosteroids at physiological doses, which are not to
exceed 10 mg/day of prednisone, or an equivalent corticosteroid.
5. Active or prior documented autoimmune disease within the past 2 years. Note: Subjects
with vitiligo, Grave's disease, or psoriasis not requiring systemic treatment (within
the past 2 years) are not excluded.
6. Active or prior documented inflammatory bowel disease (e.g., Crohn's disease and
7. History of allogeneic organ transplant.
8. Subjects having a diagnosis of immunodeficiency or are receiving systemic steroid
therapy or any other form of immunosuppressive therapy within 28 days prior to the
first dose of trial treatment.
9. Receipt of radiation therapy for bone metastasis within 2 weeks or any other radiation
therapy within 4 weeks before inclusion. Subjects with clinically relevant ongoing
complications from prior radiation therapy that have not completely resolved are not
eligible (e.g, radiation esophagitis or other inflammation of the viscera).
10. Known brain metastases or cranial epidural disease unless adequately treated with
radiotherapy and/or surgery (including radiosurgery) and stable for at least 4 weeks
before inclusion. Eligible subjects must be neurologically asymptomatic and without
corticosteroid treatment at the time of study treatment.
11. Concomitant anticoagulation with oral anticoagulants (e.g, warfarin, direct thrombin
and factor Xa inhibitors) or platelet inhibitors (e.g, clopidogrel), except for the
following allowed anticoagulants:
- Low-dose aspirin for cardioprotection (per local applicable guidelines) and
low-dose low molecular weight heparins (LMWH).
- Anticoagulation with therapeutic doses of LMWH in subjects without known brain
metastases and who are on a stable dose of LMWH for at least 6 weeks before
inclusion and who have had no clinically significant hemorrhagic complications
from the anticoagulation regimen or the tumour.
12. The subject has uncontrolled, significant intercurrent or recent illness including,
but not limited to, the following conditions:
a. Cardiovascular disorders: i. Class 3 or 4 congestive heart failure as defined by
the New York Heart Association, unstable angina pectoris, and serious cardiac
ii. Uncontrolled hypertension defined as sustained blood press > 150 mm hg systolic or
> 100 mm hg diastolic despite optimal antihypertensive treatment.
iii. Stroke, including transient ischemic attack (TIA), myocardial infarction, other
ischemic event, or thromboembolic event, e.g, deep venous thrombosis (DVT) and
pulmonary embolism) within 6 months before inclusion. Subjects with a more recent
diagnosis of DVT are allowed if stable, asymptomatic, and treated with LMWH for at
least 6 weeks before study treatment.
b. Gastrointestinal disorders (e.g, malabsorption syndrome or gastric outlet
obstruction) including those associated with a high risk of perforation or fistula
formulation: i. Tumours invading the GI tract, active peptic ulcer disease,
inflammatory bowel disease, ulcerative colitis, diverticulitis, cholecystitis,
symptomatic cholangitis or appendicitis, acute pancreatitis or acute obstruction of
the pancreatic or biliary duct, or gastric outlet obstruction. ii. Abdominal fistula,
GI perforation, bowel obstruction, or intra-abdominal abscess within 6 months before
inclusion. Note: complete healing of an intra-abdominal abscess must be confirmed
prior to start of the treatment.
c. Clinically significant hematemesis or hemoptysis of > 0.5 teaspoon (> 2.5 ml) of
red blood or history of other significant bleeding within 3 months before treatment.
d. Cavitating pulmonary lesion(s) or known endobronchial disease manifestation. e.
Lesions invading major pulmonary blood vessels. f. Other clinically significant
disorders such as: i. Active infection requiring systemic treatment, infection with
human immunodeficiency virus or acquired immunodeficiency syndrome-related illness, or
chronic hepatitis B or C infection.
ii. Serious non-healing wound/ulcer/bone fracture. iii. Moderate to severe hepatic
impairment (child-pugh B or C). iv. Requirement for hemodialysis or peritoneal
dialysis. v. Uncontrolled diabetes mellitus. vi. History of solid organ
13. Major surgery (e.g, GI surgery and removal or biopsy of brain metastasis) within 8
weeks before inclusion. Complete wound healing from major surgery must have occurred 4
weeks before study treatment and from minor surgery (e.g, simple excision, tooth
extraction) at least 10 days before study treatment. Subjects with clinically relevant
ongoing complications from prior surgery are not eligible.
14. Corrected QT interval calculated by the Fridericia formula (QTcf) > 500 ms within 28
days before study treatment.
Note: if a single ECG shows a QTCf with an absolute value > 500 ms, two additional
ECGs at intervals of approximately 3 min must be performed within 30 min after the
initial ECG, and the average of these 3 consecutive results for qtcf will be used to
15. Pregnant or lactating females.
16. Inability to swallow tablets.
17. Previously identified allergy or hypersensitivity to components of the study treatment
18. Diagnosis of another malignancy within 3 years before study treatment, except for
superficial skin cancers, or localized, low grade tumors deemed cured and not treated
with systemic therapy.