Pasithea Therapeutics (NASDAQ: KTTA) has announced updated safety, tolerability, and preliminary efficacy data from its ongoing Phase 1 dose-escalation study of PAS-004 monotherapy in a heavily pre-treated population of patients with MAPK pathway-driven advanced solid tumors harboring RAS, NF1 or RAF mutations, including patients who have failed prior BRAF/MEK inhibitor treatment.
The data, reflecting durable clinical benefit, including prolonged stable disease in four patients, as well as long-term tolerability and flat pharmacokinetics, are being presented today at the ESMO Congress 2026, taking place October 23-27, 2026, in Madrid, Spain.
In a statement, Dr. Kartik Krishnan, chief medical officer of Pasithea, commented, “The prolonged stable disease that we’re seeing in some patients across this heavily pre-treated population is highly encouraging, particularly in patients with BRAF V600E-mutant tumors who previously progressed on BRAFi monotherapy and/or BRAFi/MEKi combination therapy. The literature reports a median progression-free survival of approximately five months for combination BRAFi/MEKi rechallenge in this setting, and some patients in the BRAF-mutant subgroup are exceeding that benchmark with our MEKi monotherapy.”
Dr. Krishnan added, “What makes this data especially encouraging is that we’re seeing these signals of durable clinical benefit alongside a long-term tolerability profile that continues to hold up. No patient has discontinued treatment at any dose level due to treatment-related adverse events, and we continue to observe low rates of vomiting and other GI toxicity, low rates of rash, even in patients taking PAS-004 continuously for long periods of time. A tolerability profile like this is exactly what you want to see for the long-term treatment of chronic diseases including neurofibromatosis type 1.”
