A Study of JNJ-77242113 for the Treatment of Participants With Generalized Pustular Psoriasis or Erythrodermic Psoriasis

77242113PSO3005: 77242113PSO3005 Ph III Trial Local Study (N=20) {EP/GPP}

The purpose of this study is to evaluate how effective JNJ-77242113 is in participants with generalized pustular psoriasis (GPP) or erythrodermic psoriasis (EP).

Inclusion Criteria:

• The study participant has a diagnosis of generalized pustular psoriasis (GPP) or erythrodermic psoriasis (EP) at screening. For GPP, a diagnosis must be classified based on the criteria for diagnosis of GPP by the Japanese Dermatological Association (JDA); for EP, has a history of plaque-type psoriasis. In addition, has an involved body surface area (BSA) of lesion greater than or equal to (>=) 80 percent (%) at baseline
• Candidate for phototherapy or systemic treatment for psoriasis (either naive or history of previous treatment)
• A female participant of childbearing potential must have a negative highly sensitive serum pregnancy test (beta-human chorionic gonadotropin [beta-hCG]) at screening and have a negative urine pregnancy test at Week 0 prior to administration of study intervention
• A male participant must agree not to plan to father a child while enrolled in this study or within 90 days after the last dose of study intervention
• A male participant must agree not to donate sperm for the purpose of reproduction during the study and for a minimum of 90 days after receiving the last dose of study intervention

Exclusion Criteria:

• The study participant has a total score of JDA severity index for GPP >=14 at baseline if participants have a diagnosis of GPP
• The study participant has a differential diagnosis of the erythroderma (for example, erythroderma caused by lymphoma or drug eruption) other than EP
• The study participant has a history of or current diagnosis or signs or symptoms of severe, progressive, or uncontrolled liver, renal; cardiac, vascular, pulmonary, gastrointestinal, endocrine, neurologic, hematologic, rheumatologic, psychiatric, or metabolic disturbances
• The study participant has a history of amyloidosis
• Known allergies, hypersensitivity, or intolerance to JNJ-77242113 or its excipients
• The study participant who doesn't meet the criteria of prior/current concomitant therapy and/or history/conditions of infections