Merck (NYSE:MRK), known as MSD outside the United States and Canada, today announced the first presentation of preliminary data from a Phase 1 clinical trial evaluating MK-1454, an investigational STING (stimulator of interferon genes) agonist, as monotherapy and in combination with KEYTRUDA® (pembrolizumab), Merck’s anti-PD-1 therapy, in patients with advanced solid tumors or lymphomas. MK-1454 is one of more than 20 novel investigational immuno-therapeutic candidates Merck is evaluating as part of its broad oncology pipeline. The findings for MK-1454 were accepted as a late-breaking abstract and are being presented today in a poster discussion session at the ESMO 2018 Congress (Abstract #LBA15).
“Merck is advancing a broad pipeline focused on the development of novel therapies with potential to provide meaningful clinical benefit to people with advanced cancers,” said Dr. Eric H. Rubin, senior vice president, early-stage development, clinical oncology, Merck Research Laboratories. “We are encouraged by these early findings with our STING agonist, most notably the observations of several robust anti-tumor responses in patients receiving MK-1454 in combination with KEYTRUDA. Further studies are ongoing.”
Study Design and Findings for MK-1454 (Abstract #LBA15)
In this Phase 1, open-label, multi-arm, multicenter, dose-escalation clinical trial (NCT03010176), MK-1454 was administered to patients with advanced solid tumors or lymphomas by intratumoral injection every week for nine weeks for three cycles then every three weeks thereafter. Dose escalations for MK-1454 were 10-3,000 µg (MK-1454 monotherapy arm) and 90-2,000 µg (MK-1454 in combination with KEYTRUDA arm) using accelerated titration followed by modified toxicity probability interval design. KEYTRUDA was administered as an intravenous (IV) injection at a dose of 200 mg every three weeks. Patients receiving MK-1454 as monotherapy who progressed while on therapy were eligible for crossover to the MK-1454-KEYTRUDA combination arm. Study objectives included evaluation of safety, tolerability, pharmacodynamics, pharmacokinetics and tumor responses evaluated using RECIST v1.1 criteria.
Interim data presented at ESMO were based on findings from 26 patients enrolled in the MK-1454 monotherapy arm and 25 patients enrolled in the combination arm with KEYTRUDA, plus 9 patients who crossed over from monotherapy to receive the combination regimen. In the monotherapy arm, no complete or partial responses were observed (n=0/20). In the combination arm, partial responses were observed in 24 percent of patients (n=6/25) (three head and neck squamous cell carcinoma, one triple-negative breast cancer, and two anaplastic thyroid carcinoma), with median reductions of 83 percent in the size of both target-injected and non-injected tumors. At the time of analysis, all of the partial responses were ongoing and had lasted six months or longer. None of the responders had previously received a PD-1/PD-L1 inhibitor therapy. The disease control rates were 20 percent and 48 percent for the monotherapy and combination arms, respectively.
Treatment-related adverse events (TRAEs) occurred in 82.6 percent (n=19/23) and 82.1 percent (n=23/28) of patients in monotherapy and combination arms, respectively. TRAEs resulting in trial discontinuation occurred in 7.1 percent of patients (n=2/28) in the combination arm. No TRAE discontinuations were recorded in patients in the monotherapy arm. The most common TRAEs (occurring in ≥10% of patients) in both study arms included: pyrexia, injection site pain, chills, and fatigue. In the monotherapy arm, additional TRAEs occurring in ≥10% of patients included: nausea, myalgia, headache, and tumor pain. In the combination arm, additional TRAEs occurring in ≥10% of patients included: pruritus, diarrhea, rash, and tachycardia.
About STING and MK-1454
STING is a signaling molecule that plays an important role in the body’s first line of defense against pathogens, such as bacteria and viruses (innate immune system). When activated, STING triggers the production of inflammatory proteins that can stimulate the immune system leading to the deployment of T cells, which are important in generating an effective immune mediated response to cancer cells.
Merck is exploring the role of the STING pathway across a variety of tumors as monotherapy and in combination with the company’s anti-PD-1 therapy, KEYTRUDA. MK-1454 is an investigational small molecule STING agonist administered as an intratumoral injection that is currently being evaluated in a Phase 1 clinical trial for the treatment of solid tumors and lymphomas (ClinicalTrials.gov, NCT03010176).
About Merck’s Oncology Pipeline
As an immuno-oncology research leader, Merck is committed to advancing a broad oncology pipeline targeting multiple aspects of cancer cell biology and immune-based pathways. Specifically, Merck is discovering and developing novel targets in four distinct research areas: immune agonists, negative immune regulators, cancer vaccines and immune modulators of the tumor microenvironment including oncolytic viruses. Today, Merck’s pipeline includes more than 20 investigational immuno-therapeutic candidates – including novel combinations with the company’s approved medicines – in both clinical and pre-clinical development.
Merck’s Focus on Cancer
Our goal is to translate breakthrough science into innovative oncology medicines to help people with cancer worldwide. At Merck, the potential to bring new hope to people with cancer drives our purpose and supporting accessibility to our cancer medicines is our commitment. As part of our focus on cancer, Merck is committed to exploring the potential of immuno-oncology with one of the largest development programs in the industry across more than 30 tumor types. We also continue to strengthen our portfolio through strategic acquisitions and are prioritizing the development of several promising oncology candidates with the potential to improve the treatment of advanced cancers. For more information about our oncology clinical trials, visit www.merck.com/clinicaltrials.
For more than a century, Merck, a leading global biopharmaceutical company known as MSD outside of the United States and Canada, has been inventing for life, bringing forward medicines and vaccines for many of the world’s most challenging diseases. Through our prescription medicines, vaccines, biologic therapies and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to health care through far-reaching policies, programs and partnerships. Today, Merck continues to be at the forefront of research to advance the prevention and treatment of diseases that threaten people and communities around the world - including cancer, cardio-metabolic diseases, emerging animal diseases, Alzheimer’s disease and infectious diseases including HIV and Ebola. For more information, visit www.merck.com and connect with us on Twitter, Facebook, Instagram, YouTube and LinkedIn.