A Study to Investigate Efficacy, Safety, Tolerability, and Pharmacokinetics of JZP441 Compared With Placebo in Participants With Narcolepsy Type 1

Participants are eligible to be included in the study only if all of the following criteria apply: 1. Is 18 to 64 years of age inclusive at the time of signing the informed consent. 2. Has a physician diagnosis of NT1 according to ICSD-3-TR criteria 3. Has an average sleep latency of less than 15 minutes, as documented by the mean of the first 4 trials of the Baseline MWT, as determined by central assessment. 4. Has a minimum body weight of 50 kg for men and 45 kg for women and a BMI within the range 18.0 to 35.0 kg/m\^2 (inclusive). 5. Participant agrees to the following based on sex assigned at birth. 1. Male participants are eligible to participate if they agree to the following during the study intervention period and for at least 90 days after the last dose of study intervention: * Refrain from donating sperm * Use contraception /barrier as specified in the protocol 2. Female participants are eligible to participate if she is not pregnant or breastfeeding, and one of the following conditions applies: * Is a woman of non-childbearing potential (WONCBP) OR * Is a WOCBP and using a contraceptive method that is highly effective during the study intervention period and until completion of the Safety Follow-up Period. * Male partners of WOCBP are required to use barrier protection, (eg, condoms) during the study intervention period and over the 90-day period after the last dose of study intervention. • A WOCBP must have a negati…