Inclusion Criteria:
* Ability to provide written informed consent by subject or guardian
* Individuals \>18 years of age
* Diagnosis of an irAE clinically suspected to be IL-17 mediated
* Intent-to-treat or prior treatment with systemic steroids for irAE management
* Histology-proven primary advanced or metastatic solid organ malignancy treated with immunotherapy. Patients being treated with curative intent are not eligible to enroll.
* Subject has a negative test for tuberculosis during screening defined as either: negative purified protein derivative (PPD) (\< 5 mm of induration at 48 to 72 hours after test is placed) OR negative QuantiFERON test. Tuberculosis testing must be performed within 30 days prior to trial initiation.
* Subjects with a positive PPD and a history of Bacillus Calmette-Guérin vaccination are allowed with a negative QuantiFERON test.
* Subjects with a positive PPD test (without a history of Bacillus Calmette-Guérin vaccination) or subjects with a positive or indeterminate QuantiFERON test are allowed if they have all of the following: no symptoms of tuberculosis (defined as fever, shortness of breath, cough or night sweats), documented history of a completed course of adequate prophylaxis (per local standard of care), no known exposure to a case of active tuberculosis after most recent prophylaxis, no evidence of active tuberculosis on chest radiograph within 3 months prior to the first dose of brodalumab.
Exclusion Criteria:
* Estimated creatinine clearance \< 40 mg/min
* Active suicidal ideation or severe depression (as defined by the Diagnostic and Statistical Manual of Mental Disorders Version IV criteria (DSM-IV)) at the time of enrollment or a PHQ-9 score \> 20
* History of prior suicide attempts
* PHQ-9 score greater \>5 and \< 20 without an established mental health provider who verifies stability in their depression
* Current or prior drug or alcohol abuse within the past 6 months (as defined by the DSM IV)
* In the opinion of the investigator, the patient requires additional immunosuppressive treatment (other than corticosteroids and brodalumab)
* Known hypersensitivity or contraindication to brodalumab, corticosteroids or any components of brodalumab
* Prior treatment with brodalumab
* Pregnancy, breastfeeding, or use of a nonreliable method of contraception
* For patients assigned female at birth: lack of willingness to use highly effective methods of birth control during treatment and for at least 4 weeks after the last dose of brodalumab (except if surgically sterile or at least 2 years postmenopausal, with postmenopausal status confirmed by Follicle-Stimulating Hormone (FSH) in the postmenopausal range).
* Highly effective methods of birth control include: use of hormonal contraceptives that inhibit ovulation, hormone-releasing intrauterine devices, and copper intrauterine devices. Oral contraceptive pills must be supplemented by a barrier method.
* Patients planning to become pregnant while enrolled in the study and within 4 weeks after the last dose of brodalumab will not be permitted to enroll
* Chronic or current severe infection requiring IV therapy
* Evidence of active hepatitis B, C, or tuberculosis.
* History of latent tuberculosis infection which is incompletely treated based upon local standard of care or which was never treated
* History of or active Crohn's disease.
* Myocardial infarction, unstable angina pectoris or stroke within the past 12 months prior to the first investigational product dose
* Any concurrent medical condition or electrocardiogram (ECG) abnormality that, in the opinion of the investigator, could cause this study to be detrimental to the subject.
* Any medical condition or treatment for a condition that, in the opinion of the investigator, might interfere with participation in the study or affect the reliability of clinician assessment or patient self-report
* Other known clinically significant active medical conditions, such as:
* Severe cardiovascular disease, including advanced heart failure (American Heart Association Stage D)
* Aspartate aminotransferase (AST) and or alanine aminotransferase (ALT) greater than 2 times the upper limit of normal or greater than 3 times the upper limit of normal in patients with liver metastases measured on at least two separate occasions
* Direct bilirubin greater than or equal to 1.5 mg/dL in patients with or without liver metastases
* Bone marrow insufficiency unrelated to the irAE (according to investigator judgment) with White Blood Cell (WBC) \<2000/mm3, absolute neutrophil count \<1500/ mm3, thrombocytopenia (platelet count) \<50,000/mm3, hemoglobin \< 8.0 g/dL
* Plan to proceed with further curative intent treatment for cancer at the time of enrollment despite the presence of irAE
* Participation in another therapeutic clinical trial and receipt of investigational drugs within 4 weeks before the screening visit
* Previous diagnosis of an autoimmune disease or administration of immunosuppressants in a time frame that would impede interpretation of brodalumab administration
* Planned use of immunosuppressive agents other than steroids (including infliximab, vedolizumab, tocilizumab etc.) or administration of such agents within 28 days of trial initiation
* Administration of live-virus vaccines within 4 weeks before the first dose of brodalumab