TLR8 Agonist VTX-2337 and Cyclophosphamide in Treating Patients With Metastatic, Persistent, Recurrent, or Progressive Solid Tumors

Inclusion Criteria:

Histologically or cytologically confirmed metastatic solid tumor, including but not limited to pancreatic adenocarcinoma, breast cancer, melanoma, renal cell carcinoma (RCC), colorectal adenocarcinoma, non-small cell lung cancer, and others approved by the principal investigator
Persistent, recurrent or progressive disease following at least one prior line of systemic therapy and there is no available therapy likely to improve survival
Measurable disease with >= 1 target lesion
White blood cells (WBC) >= 4200/mm^3
Absolute neutrophil count (ANC) >= 1400/mm^3
Platelets (PLT) >= 100,000/mm^3
Lymphocytes >= 700/mm^3
Hemoglobin >= 10 g/dL
Total bilirubin =< 1.5 X upper limit of normal (ULN) unless history of Gilbert's syndrome documented prior to first-line treatment of cancer and other liver function tests are within normal limits
Prothrombin time (PT)/international normalized ratio (INR) and partial thromboplastin time (PTT) =< 1.2 x ULN unless on anticoagulation medication with stable dosing for at least one month; in addition, patient must be able to stop taking medication for up to a week in order to have percutaneous biopsies of tumor tissue performed
Aspartate transaminase (AST) and alanine aminotransferase (ALT) =< 1.5 x ULN (=< 5 x ULN for patients with liver involvement)
Creatinine =< ULN or a calculated creatinine clearance of >= 45 ml/min if creatinine is greater than the ULN
Alkaline phosphatase =< 3 x ULN (=< 5 x ULN if liver or bone involvement)
Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 or 1
Willing and able to provide informed written consent
Willing and able to return to enrolling institution for follow-up (during the Active Monitoring Phase of the study); Note: During the Active Monitoring Phase of a study (i.e., active treatment and observation), participants must be willing and able to return to the consenting institution for follow-up
Estimated life expectancy >= 84 days (3 months)
Willing and able to provide samples for correlative research purposes
If female of child-bearing potential, have a negative pregnancy test =< 14 days prior to registration
If fertile male or female of child-bearing potential, agree to consistently use a highly effective method of birth control (including birth control pills, barrier device, or intrauterine device) from the time of consent through 4 months following the last dose of study drug

Exclusion Criteria:

Is pregnant, breastfeeding, or planning a pregnancy
Known standard therapy for the patient's disease that is potentially curative
Treatment with any systemic anticancer treatment or an investigational agent within 4 weeks and any radiation within 2 weeks of registration
Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit subject safety or compliance with study requirements
Active autoimmune disease, defined as any autoimmune condition currently requiring therapy (e.g., systemic lupus erythematosus, multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis)
History of other invasive malignancy, with the exception of non-melanoma skin cancer and well-excised cervical carcinoma in situ, =< 3 years prior to enrollment unless assessed by the principal investigator as unlikely to compromise subject safety or to interfere with the study's objectives
Treatment with oral or parenteral corticosteroids dosed greater than 40 mg hydrocortisone daily or its equivalent (e.g., prednisone 10 mg, prednisolone 8 mg, or decadron 3 mg) =< 2 weeks of treatment initiation; or a clinical requirement for ongoing systemic immunosuppressive therapy
History of central nervous system (CNS) metastases unless previously treated and stable for > 8 weeks prior to study initiation
Immunocompromised patients and patients known to be human immunodeficiency virus (HIV) positive
Hypersensitivity to pegfilgrastim or Escherichia (E.) coli derived proteins