Phase 1 · California
Phase 1 clinical trials in California
262 studies have at least one recruiting site in California. Phase 1 (and early Phase 1) trials are usually the first time a medicine is studied in people. They are typically small, closely monitored, and many are run in dedicated research units, sometimes with overnight stays.
262 recruiting studiesSource: ClinicalTrials.gov, refreshed October 26, 2026How we list studies
Studies
- RecruitingPhase 1/Phase 2
Evaluation of Intra-articular CX-011 to Treat Moderate to Severe Pain From Knee Osteoarthritis
CarthroniX, Inc.
- Location
- Los Angeles, CA
- Eligibility basics
- Ages 40–75
- RecruitingPhase 1
A Study to Investigate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of AZD4954 in Healthy Adult Participants With or Without Elevated Lipoprotein (a) (Lp[a]) Levels, and Participants With Dyslipidemia
AstraZeneca
- Location
- Glendale, CA + 5 other US sites
- Eligibility basics
- Ages 18–70
- RecruitingPhase 1/Phase 2
4D-150 in Patients With Neovascular (Wet) Age-Related Macular Degeneration
4D Molecular Therapeutics
- Location
- Oxnard, CA + 19 other US sites
- Eligibility basics
- Ages 50+
- RecruitingPhase 1/Phase 2
Study to Evaluate Safety, Efficacy and Immunogenicity of Acne mRNA Vaccine in Adults With Moderate to Severe Acne
Sanofi Pasteur, a Sanofi Company
- Location
- Cerritos, CA + 78 other US sites
- Eligibility basics
- Ages 18–45
- RecruitingPhase 1/Phase 2
AAV Gene Therapy Clinical Study in Adult Classic PKU (PHEdom)
NGGT INC.
- Location
- Orange, CA + 4 other US sites
- Eligibility basics
- Ages 18–55
- RecruitingPhase 1
A Study to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamics of DNL952 in Adult Participants With Late-Onset Pompe Disease
Denali Therapeutics Inc.
- Location
- Irvine, CA + 3 other US sites
- Eligibility basics
- Ages 18–75
- RecruitingPhase 1
A Study of Amicidin-β Topical Solution for Patients With Surgical or Traumatic Wound Infections
Macro Biologics, Inc.
- Location
- Torrance, CA + 4 other US sites
- Eligibility basics
- Ages 18–79
- RecruitingPhase 1
Phase 1 Study of C.001 in Retinal Degeneration
Cellio Therapeutics Inc
- Location
- Beverly Hills, CA
- Eligibility basics
- Ages 18+
- RecruitingPhase 1
Study to Evaluate the Safety and Efficacy of CSB-001 Ophthalmic Solution 0.1% in Subjects With Limbal Stem Cell Deficiency
Claris Biotherapeutics, Inc.
- Location
- Loma Linda, CA + 5 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1/Phase 2
A Phase 1/2 Study of NKX019 in Subjects With Immune-Mediated Diseases (Ntrust-2)
Nkarta, Inc.
- Location
- Orange, CA + 14 other US sites
- Eligibility basics
- Ages 18–75
- RecruitingPhase 1
A Study of ABBV-295 Subcutaneous Injections to Assess Adverse Events and Pharmacokinetics in Adult Participants With Obesity
AbbVie
- Location
- Anaheim, CA + 1 other US site
- Eligibility basics
- Ages 18–65
- RecruitingPhase 1/Phase 2
A Study With NVC-001 in Patients With LMNA-related Dilated Cardiomyopathy (SUNBEAM-LMNA)
Nuevocor Pte. Ltd.
- Location
- Los Angeles, CA + 2 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1/Phase 2
A Study of DB-OTO, an Adeno-Associated Virus (AAV) Based Gene Therapy, in Children/Infants, Adolescents and Adults With Hearing Loss Due to Otoferlin Mutations
Regeneron Pharmaceuticals
- Location
- Los Angeles, CA + 8 other US sites
- Eligibility basics
- Any age listed
- RecruitingPhase 1/Phase 2
Study of Aritinercept in Patients With Generalized Myasthenia Gravis
Aurinia Pharmaceuticals Inc.
- Location
- Pasadena, CA + 9 other US sites
- Eligibility basics
- Ages 18–85
- RecruitingPhase 1
Study of BHV-1300 in Graves' Disease
Biohaven Therapeutics Ltd.
- Location
- South Gate, CA + 9 other US sites
- Eligibility basics
- Ages 18–65
- RecruitingPhase 1/Phase 2
Phase 1/2 Study of MZ-1866, an AAV-9 Gene Therapy Delivered by Intracerebroventricular Injection to Participants With Pitt Hopkins Syndrome
Mahzi Therapeutics
- Location
- Oakland, CA + 2 other US sites
- Eligibility basics
- Ages 2–25
- RecruitingPhase 1/Phase 2
A Study to Assess the Safety and Efficacy of IPN10200 in Adult Participants With Upper Limb Spasticity.
Ipsen
- Location
- Downey, CA + 3 other US sites
- Eligibility basics
- Ages 18–70
- RecruitingPhase 1/Phase 2
A Phase 1/2 Study of the Safety and Efficacy of MVX-220 in Angelman Syndrome
MavriX Bio, LLC
- Location
- Los Angeles, CA + 2 other US sites
- Eligibility basics
- Ages 4–50
- RecruitingPhase 1
Phase 1b Trial of RAY121 in Immunological Diseases (RAINBOW Trial)
Chugai Pharmaceutical
- Location
- Orange, CA + 6 other US sites
- Eligibility basics
- Ages 18–85
- RecruitingPhase 1
Examination of How the Duration of Fasting and Temporary Stopping of GLP-1 Medications Affect the Amount of Food Left in the Stomach in People Using Liraglutide (Injected), Semaglutide (Taken by Mouth) or Semaglutide…
Novo Nordisk A/S
- Location
- Cypress, CA
- Eligibility basics
- Ages 18+
- RecruitingPhase 1
Assessing the Safety, Tolerability, and Efficacy of APR-2020 in Pediatric and Adolescent Subjects With RPS19 Deficient Diamond-Blackfan Anemia
Apriligen, Inc.
- Location
- Stanford, CA + 1 other US site
- Eligibility basics
- Ages 2–25
- RecruitingPhase 1
Phase 1a/b Tolerability of NTR-1011 in Healthy Adults and Adult Patients With SLE and RA
Neutrolis
- Location
- Apple Valley, CA + 6 other US sites
- Eligibility basics
- Ages 18–75
- RecruitingPhase 1
ISP-001: Sleeping Beauty Transposon-Engineered B Cells for MPS I
Immusoft of CA, Inc.
- Location
- Oakland, CA + 1 other US site
- Eligibility basics
- Ages 10+
- RecruitingPhase 1/Phase 2
Safety, Tolerability and Exploratory Efficacy of EC5026 in Parkinson's Disease (STEP Study)
EicOsis Human Health Inc.
- Location
- Sacramento, CA
- Eligibility basics
- Ages 50–80
Who these studies look for
Phase 1 studies often have narrow eligibility: specific age and weight ranges, no recent participation in another study, no nicotine, and limits on medications. Some Phase 1 studies recruit patients rather than healthy volunteers, so check each listing.
Matching a page like this one never means you qualify. Each research team decides eligibility at screening.
Questions
Are Phase 1 trials riskier?
Every study carries risk. Phase 1 studies involve less human data about the product, which is why they are closely monitored. The informed consent document explains the known risks; read it carefully and ask questions before signing.
Why do some Phase 1 studies include overnight stays?
Staying in the unit lets staff dose on a precise schedule and collect samples around the clock. Where a record mentions an inpatient stay we flag it on the listing.