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
A Study to Assess the Safety and Effects of ABBV-1758 Following Subcutaneous or Intravenous Injections in Participants With Alzheimer's Disease
AbbVie
- Location
- Irvine, CA + 10 other US sites
- Eligibility basics
- Ages 50–90
- RecruitingPhase 1
A Study to Assess Adverse Events and How Oral ABBV-932 Moves Through the Body When Given With Oral Itraconazole in Adult Participants With Bipolar Disorder
AbbVie
- Location
- Los Alamitos, CA
- Eligibility basics
- Ages 18–65
- RecruitingPhase 1/Phase 2
A Safety, Tolerability, and Preliminary Efficacy of Low-intensity Focused Ultrasound Neuromodulation in Patients With Drug-resistant Epilepsy
NaviFUS Corporation
- Location
- Palo Alto, CA + 2 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1
Dose Escalation Study With Bispecific Antibodies in Adult Participants With Lupus Nephritis
Regeneron Pharmaceuticals
- Location
- San Francisco, CA + 2 other US sites
- Eligibility basics
- Ages 18–60
- RecruitingPhase 1
A Gene Transfer Therapy Study to Evaluate the Safety of and Expression From Delandistrogene Moxeparvovec (SRP-9001) in Participants With Duchenne Muscular Dystrophy (DMD) - Non-Ambulatory Cohort
Sarepta Therapeutics, Inc.
- Location
- La Jolla, CA + 10 other US sites
- Eligibility basics
- Ages 2+ · Men only
- RecruitingPhase 1/Phase 2
CNP-103 in Adolescent and Adult Subjects Ages 12-35 With Recently Diagnosed (Within 6 Months) Stage 3 Type 1 Diabetes (T1D)
COUR Pharmaceutical Development Company, Inc.
- Location
- Newport Beach, CA + 44 other US sites
- Eligibility basics
- Ages 12–35
- RecruitingPhase 1/Phase 2
A Study to Investigate the Safety, Tolerability, and Efficacy of AZD0120 in Adults With Refractory SLE
AstraZeneca
- Location
- San Francisco, CA + 8 other US sites
- Eligibility basics
- Ages 18–70
- RecruitingPhase 1
A Study to Investigate the Safety and Preliminary Efficacy of ALLO-329, an Allogeneic CAR T-cell Therapy, in Adults With Autoimmune Disease
Allogene Therapeutics
- Location
- Loma Linda, CA + 15 other US sites
- Eligibility basics
- Ages 18–74
- RecruitingPhase 1
A Study to Assess the Safety and Clinical Activity of Azer-cel in Participants With B-cell Mediated Autoimmune Disorders
TG Therapeutics, Inc.
- Location
- La Jolla, CA + 7 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1/Phase 2
Study of Intrathecal ELP-02 for Charcot-Marie-Tooth Disease Type 4J (CMT4J)
Elpida Therapeutics SPC
- Location
- Palo Alto, CA
- Eligibility basics
- Ages 3–20
- RecruitingPhase 1
A Research Study Investigating How a New Medicine NNC0113-5840 Works in People With Overweight or Obesity
Novo Nordisk A/S
- Location
- Glendale, CA + 1 other US site
- Eligibility basics
- Ages 18–55
- RecruitingPhase 1
A Study to Evaluate Sequential Administration of Injections of AGN-151586 Followed by BOTOX in Adult Participants for Treatment of Glabellar Lines
AbbVie
- Location
- Newport Beach, CA + 7 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1/Phase 2
Study Assessing CLENPIQ as Bowel Preparation for Pediatric Colonoscopy
Ferring Pharmaceuticals
- Location
- San Diego, CA + 3 other US sites
- Eligibility basics
- Ages 1–8
- RecruitingPhase 1
A Study of the Safety and Tolerability of ASP7317 in Senior Adults Who Are Losing Their Clear, Sharp Central Vision Due to Geographic Atrophy Secondary to Dry Age-related Macular Degeneration
Astellas Institute for Regenerative Medicine
- Location
- Los Angeles, CA + 12 other US sites
- Eligibility basics
- Ages 50+
- RecruitingPhase 1
Safety and Feasibility Study of the CELLSPAN Esophageal Implant (CEI) in Patients Requiring Short Segment Esophageal Replacement
Harvard Apparatus Regenerative Technology, Inc.
- Location
- Los Angeles, CA + 2 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1
A Study to Find Out How Nusinersen is Processed in the Body When Given Through the ThecaFlex DRx™ System in Adult and Pediatric Participants With Spinal Muscular Atrophy (PIERRE-PK)
Biogen
- Location
- Orange, CA + 11 other US sites
- Eligibility basics
- Ages 3+
- RecruitingPhase 1/Phase 2
Dose Escalation Study of EG110A, Administered by Intradetrusor Injections to Adults With Neurogenic Detrusor Overactivity-related Incontinence Following Spinal Cord Injury Who Regularly Perform Clean Intermittent…
Cyllene Therapeutics
- Location
- Downey, CA + 3 other US sites
- Eligibility basics
- Ages 18–75
- RecruitingPhase 1
OM336 in Autoimmune Cytopenias
Lakefront Biotherapeutics West LLC
- Location
- Duarte, CA + 3 other US sites
- Eligibility basics
- Ages 18–75
- RecruitingPhase 1
A Study of VERVE-102 in Patients With Familial Hypercholesterolemia or Premature Coronary Artery Disease
Verve Therapeutics, Inc.
- Location
- Pomona, CA + 9 other US sites
- Eligibility basics
- Ages 18–70
- RecruitingPhase 1
A Study to Evaluate the Safety, Tolerability, and PK of an Injectable Form of KarXT
Bristol-Myers Squibb
- Location
- Los Alamitos, CA + 7 other US sites
- Eligibility basics
- Ages 18–55
- RecruitingPhase 1
Phase 1 Study Evaluating Safety and Pharmacokinetics of ASY202 in Adults With Asthma
Aspeya, Inc.
- Location
- Anaheim, CA
- Eligibility basics
- Ages 18–55
- RecruitingPhase 1/Phase 2
FT839 in Autoimmune Diseases
Fate Therapeutics
- Location
- Fullerton, CA
- Eligibility basics
- Ages 18–70
- RecruitingPhase 1/Phase 2
Study of CTO1681 for the Prevention and Treatment of CRS in Patients Receiving CAR T-Cell Therapy
CytoAgents, Inc.
- Location
- Orange, CA + 5 other US sites
- Eligibility basics
- Ages 18+
- RecruitingPhase 1/Phase 2
ALXN2350 in Adult Participants With BAG3-Associated Dilated Cardiomyopathy
Alexion Pharmaceuticals, Inc.
- Location
- Palo Alto, CA + 6 other US sites
- Eligibility basics
- Ages 18–70
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.