This Phase 1 randomized, placebo-controlled, double-blind study will evaluate the PK/PD relationship of single doses of QRL-101 in 12 ALS participants. The study will also assess safety and tolerability in participants receiving either QRL-101 or placebo.

This is a randomized, placebo-controlled, double-blind, single-dose, single-site, Phase 1 study to explore the pharmacokinetics (PK) and pharmacodynamics (PD) of single doses of QRL-101 in participants with ALS. In addition, the safety and tolerability of QRL-101 will be evaluated. Single doses of QRL-101 or placebo will be administered as an oral liquid to approximately 12 participants with ALS. The study will explore the PK, PD, and PK/PD relationship among three dose levels of QRL-101 and placebo. The randomization will be 1:1:1:1 for the four study groups and will be conducted in 3 blocks (cohorts) of 4, where participants will be randomized 3:1 (QRL-101:placebo) for increasing dose levels of QRL-101.

INCLUSION CRITERIA

1. Age 18 to 80 years of age inclusive at the time of signing the informed consent.
2. Diagnosis of ALS, by either Gold Coast Criteria or El Escorial Criteria (possible, probable laboratory supported, probable, or definite)
3. Clinical chemistry laboratory values within acceptable range for the population, as per investigator judgment.
4. Body mass index of 18 to 32 kg/m2 (inclusive).
5. Willing and able to practice effective contraception.

EXCLUSION CRITERIA

1. Currently enrolled in any other clinical trial involving a study drug, off-label drug or device use, or any other type of medical research judged not scientifically or medically compatible with this study.
2. History or presence of medical illness including, but not limited to, any cardiovascular, hepatic, respiratory, hematological, endocrine, psychiatric, or neurological disease, convulsions, or any clinically significant laboratory abnormality that, in the judgment of the investigator, indicate a medical problem that would preclude study participation.
3. Off-label use of drugs or devices that are being used or investigated as disease-modifying therapies in ALS
4. Participated in another clinical study within 30 days, or 5 half-lives of the previous investigational product, whichever is greater, prior to the planned randomization date.
5. Taking any prescription or nonprescription medicines that are cytochrome P450 3A4 inducers, inhibitors, or substrates within 30 days or 5 half-lives, whichever is greater, prior to the planned randomization date