Phase IIa L-serine Trial for eAD (LSPI-2)


Aleksandra Stark

Status and phase

Phase 2


Alzheimer Disease


Other: Placebo Gummy
Drug: L-Serine

Study type


Funder types



Details and patient eligibility


This is a Phase IIa, randomized, double-blind, placebo controlled trial. Subjects for participation in this study will be identified by the Investigator based on their Clinical Dementia Rating score which will be completed as part of standard practice. Patients meeting the criteria for early Alzheimer's disease will be considered for study participation, with the Investigator taking the additional inclusion/exclusion criteria into consideration. Up to 40 subjects will be enrolled. Subjects participating in the study will be randomized to receive either gummies containing L-Serine or placebo gummies, with the Investigator and study staff blinded to the group assignments.

Full description

L-serine (C3H7NO3; 105.09 g/mol; synonym (S)-2-amino-3-hydroxypropanoic acid) is a naturally-occurring dietary amino acid. It is abundant in soy products, some edible seaweeds, sweet potatoes, eggs, and meat. Since some L-serine is produced by astrocytes in the brain, it is considered a non-essential amino acid. L-serine is directly involved in the biosynthesis of purines, pyrimidines, and other amino acids. Serine residues are found in most proteins and within proteins function as a site for phosphorylation.

L-serine is considered as GRAS (generally recognized as safe) by the FDA and has been approved as a normal food additive under CFR172.320. It is widely sold as a dietary supplement. A pilot study of L-serine supplementation of 14 patients with hereditary sensory neuropathy has been published, and subsequent trial is on-going ( identifier NCT01733407). The authors did not report adverse effects at doses of 400mg/kg/day, which for an average American of 75.5kg is about 30 grams, the dose which we propose to use in this study.

L-serine will be administered orally through gummies. Each gummy contains 1 g L-serine (treatment) and will be packaged in a foil packet containing 15 pieces to be taken both morning and evening for nine months. The placebo will be a gummy containing no L-serine, packaged and taken in the same manner. In order to assess tolerability in patients, we have designed a 4 week dose ramp-up. We will monitor side-effects and amino acid balances in blood samples in the early Alzheimer's Disease patients during a dose ramp-up period. If a patient cannot tolerate the full dose of gummies, they will remain in the study taking a total of 1 package of gummies split into two time periods within the day. The same ramp-up schedule and procedures will be observed for both placebo and L-serine patients. Patients will be assessed at baseline, 3 months, 6 months, and 9 months.


29 patients




No Healthy Volunteers

Inclusion criteria

  1. Diagnosis of early stage Alzheimer's disease as scored by the ClinicalDementia Rating Scale score of 0.5 -1.0 within the 6 months prior to study enrollment.
  2. Participants able to provide informed consent.
  3. Participants taking NMDA receptor antagonist medications or acetylcholinesterase inhibitor medications must be on a stable dose of these medications for at least 30 days prior to enrolling in this clinical trial.
  4. Participants able to consume study gummy chews throughout the course of the clinical trial.

Exclusion criteria

  1. Diagnosis or previous history of ischemic stroke, astrocytoma, meningioma or oligodendroma.
  2. Diagnosis or previous history of any other comorbid diagnosis of neurodegenerative disease including amyotrophic lateral sclerosis, Parkinson's disease, Lewy Body Disease, Pick's Disease, Huntington's Disease, or Progressive Supra Nuclear Palsy.
  3. Undergoing any chemotherapy or radiation therapy for any tumor or carcinoma.
  4. Diagnosis or previous history of type I or type II diabetes. Potential subjects with no history of diabetes will be referred to their PCP for a hemoglobin A1C test if they have not had one in the year prior to enrollment.
  5. Diagnosis or previous history of psychiatric illness that in the investigator's opinion would affect the subject's ability to successfully participate in the study.
  6. In the Investigator's opinion, subject would be unable to successfully participate in the study for any reason.

Trial design

Primary purpose




Interventional model

Parallel Assignment


Quadruple Blind

29 participants in 2 patient groups, including a placebo group

L-Serine Gummy Arm
Active Comparator group
L-serine will be presented in gummies containing 1g serine each. Subjects randomized into the L-serine arm will take 15 grams of L-Serine (15 gummies containing 1g of L-serine) orally twice daily for 246 days after the initial ascending dose period to confirm tolerability of the dose.
Drug: L-Serine
Placebo Gummy Arm
Placebo Comparator group
Placebo gummies containing no L-serine will be packaged in the same manner as that of the L-Serine gummy arm and be given to patients to take two times a day.
Other: Placebo Gummy

Trial documents

Trial contacts and locations



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