Trial results for the Phase 1 study (NCT02720068) investigating favezelimab as monotherapy and in combination with pembrolizumab for advanced solid tumors were posted on ClinicalTrials.gov on 2025-05-30. The study reported only 1 dose-limiting toxicity (DLT) across all evaluated monotherapy and combination arms, indicating a favorable safety profile.
Background
The study, titled "Study of Favezelimab (MK-4280) as Monotherapy and in Combination With Pembrolizumab (MK-3475) With or Without Chemotherapy or Lenvatinib (MK-7902) AND Favezelimab/Pembrolizumab (MK-4280A) as Monotherapy in Adults With Advanced Solid Tumors (MK-4280-001)," aimed to assess the safety and pharmacokinetics of favezelimab as monotherapy and in combination with pembrolizumab in adults with metastatic solid tumors for which there is no available therapy which may convey clinical benefit.
Trial design
The Phase 1 study (NCT02720068) was a safety and pharmacokinetics trial that enrolled 481 participants with advanced solid tumors. The study investigated favezelimab as monotherapy and in combination with pembrolizumab, and also included other interventions such as oxaliplatin, irinotecan, and leucovorin (calcium folinate). Part A of the study involved a dose escalation design for favezelimab as monotherapy across various doses (7 mg, 21 mg, 70 mg, 210 mg, 700 mg) and in combination with pembrolizumab 200 mg (with favezelimab doses of 7 mg, 21 mg, 70 mg, 210 mg, 700 mg). Part B focused on dose confirmation to estimate the recommended Phase 2 dose (RP2D) based on dose-limiting toxicities.
Key results
The primary safety outcome measured was the "Number of Participants Who Experienced a Dose-Limiting Toxicity (DLT)". The results for various treatment arms were as follows:
- In Part A, favezelimab monotherapy at doses of 7 mg, 21 mg, 70 mg, 210 mg, and 700 mg each reported 0 participants who experienced a DLT.
- In Part A, favezelimab in combination with pembrolizumab 200 mg, across favezelimab doses of 7 mg, 21 mg, 70 mg, 210 mg, and 700 mg, each reported 0 participants who experienced a DLT.
- In Part B, favezelimab 800 mg monotherapy (Arm 1) reported 0 participants who experienced a DLT.
- In Part B, favezelimab 200 mg + pembrolizumab 200 mg (Arm 2A) reported 1 participant who experienced a DLT.
What this means
The results from this Phase 1 study suggest a favorable safety profile for favezelimab as monotherapy and in combination with pembrolizumab in adults with advanced solid tumors. The observation of only 1 dose-limiting toxicity across numerous dose levels and combination arms is a key finding for a first-in-human trial, supporting the potential for these regimens to proceed to further clinical development for efficacy evaluation. These safety data are critical for establishing recommended Phase 2 doses.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT02720068, titled "Study of Favezelimab (MK-4280) as Monotherapy and in Combination With Pembrolizumab (MK-3475) With or Without Chemotherapy or Lenvatinib (MK-7902) AND Favezelimab/Pembrolizumab (MK-4280A) as Monotherapy in Adults With Advanced Solid Tumors (MK-4280-001)," were posted on 2025-05-30 on clinicaltrials.gov.