Inclusion
Dose Escalation and Dose Expansion (Backfill) Cohorts (BHV-1530 monotherapy):
Participants with urothelial cancer of the urinary tract: (including renal pelvis, ureters, urinary bladder, and urethra), non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) of the oral cavity, hypopharynx, oropharynx, nasopharynx, larynx and sinonasal tract.
Tumors originating from the salivary glands, or unknown primary sites are not eligible.
Other advanced or metastatic solid tumors with a documented activating FGFR3 alteration (mutation or fusion).
Dose Escalation and Dose Expansion (Backfill) Cohorts (BHV-1530 in combination with cemiplimab):
Participants with urothelial cancer of the urinary tract: (including renal pelvis, ureters, urinary bladder, and urethra), non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC) of the oral cavity, hypopharynx, oropharynx, nasopharynx, larynx and sinonasal tract.
Tumors originating from the salivary glands, or unknown primary sites are not eligible.
Other advanced or metastatic solid tumors with a documented activating FGFR3 alteration (mutation or fusion).
Bilirubin ≤ 1.5 × upper limit of normal (ULN). Participants with known Gilbert's syndrome who have total bilirubin level ≤3×ULN may be enrolled.
AST, ALT, and alkaline phosphatase ≤ 2.5 × ULN (if liver metastases are present, then ≤ 5 × ULN is allowed) 9. Acceptable renal function:
Blood transfusion or growth factor support is not allowed within 7 days prior to blood samples that will be used to establish eligibility
Absolute neutrophil count greater than or equal to 1500/mm3. Participants with known Duffy null phenotype who have absolute neutrophil count ≥ 1,200/mm3 may be enrolled
Platelet count greater than or equal to 100,000 mm3
Hemoglobin greater than or equal to 9 g/dL
Activated partial thromboplastin time (aPTT) ≤1.5×ULN. Study participants on therapeutic doses of anticoagulation medication must have INR and/or aPTT ≤ the upper limit of the therapeutic range for intended use 11. A negative urine or serum pregnancy test (if a woman of childbearing potential); 12. Women of childbearing potential and men must agree to use adequate contraception prior to study entry, for the duration of study participation and for 7 months (for women) or 4 months (for men) after the last dose of study drug.
Exclusion
New York Heart Association Class III or IV heart failure
Myocardial infarction, unstable angina, or stroke ≤ 6 months prior to C1D1
Newly diagnosed thromboembolic events that require therapeutic intervention over the last 4 months prior to C1D1 (participants with stable control of lower limb deep venous thrombosis over at least 1 months are allowed, and participants with incidental, asymptomatic pulmonary embolism and clinically stable for at least 1 month prior to C1D1 are allowed)
Severe aortic stenosis
Uncontrolled arrhythmia
Symptomatic pericardial effusion
Congenital long QT syndrome
A mean of Fredericia's formula-QT corrected interval (QTcF) prolongation to \>470 msec based on a triplicate 12-lead ECG
Uncontrolled hypertension (systolic blood pressure ≥180 mmHg and/or diastolic blood pressure ≥110 mmHg) or diabetes (hemoglobin A1C ≥9.0%)
Left ventricular ejection fraction (LVEF) \<45% determined by echocardiogram or multiple gated acquisition scan (MUGA) 3. Active, uncontrolled bacterial, viral, or fungal infections, requiring systemic therapy 4. Primary central nervous system (CNS) tumors, current or previously treated leptomeningeal disease or known active brain metastases.
Participants with hepatitis B (hepatitis B virus surface antigen \[HbsAg\] positive), or hepatitis C (hepatitis C virus \[HCV\] antibody positive, confirmed by HCV ribonucleic acid). Participants with HCV with undetectable virus after treatment are eligible. Participants with a prior history of hepatitis B virus are eligible if quantitative polymerase change reaction for hepatitis B virus DNA is negative
Participants with human immunodeficiency virus (HIV) infection with acquired immune deficiency syndrome (AIDS) defining illness are not eligible for enrollment; however, participants who have had HIV infection and who have a cluster of differentiation 4 (CD4) + T cell count \>350 cells/μL and no history of an AIDS-defining illness are eligible for entry 10. Has an active second malignancy. Note: participants with a history of malignancy that have been completely treated, with no evidence of active cancer for 3 years prior to enrollment, or participants with tumors cured with radiotherapy or surgery with low risk of recurrence (e.g., non melanoma skin cancer, histologically confirmed complete excision of carcinoma in situ) are allowed 11. Participants who in the opinion of the Investigator will not be able to adhere to the schedule of assessments and/or may have difficulties complying with the treatment regimen or are unwilling or unable to comply with procedures required in this protocol 12. Known sensitivity to BHV-1530 or any of the excipients in BHV-1530; 13. History of (noninfectious) clinically significant interstitial lung disease (ILD)/pneumonitis that required steroids, active clinically significant ILD/pneumonitis, or suspected clinically significant ILD/pneumonitis that cannot be ruled out by imaging at screening. 14. Requires supplemental oxygen for daily activities 15. Treatment with a live, attenuated vaccine within 4 weeks prior to initiation of study treatment