mRNA-4157/V940, in combination with KEYTRUDA, demonstrated a statistically significant and clinically meaningful reduction in the risk of disease recurrence or death compared to KEYTRUDA monotherapy in stage III/IV melanoma patients with high risk of recurrence following complete resection

Results are the first demonstration of efficacy for an investigational mRNA cancer treatment in a randomized clinical trial

Companies plan to discuss results with regulatory authorities and initiate a Phase 3 study in melanoma in 2023 and rapidly expand to additional tumor types

CAMBRIDGE, MA and RAHWAY, NJ / ACCESSWIRE / December 13, 2022 /Moderna, Inc. (NASDAQ:MRNA), a biotechnology company pioneering messenger RNA (mRNA) therapeutics and vaccines, and Merck (NYSE:MRK), known as MSD outside of the United States and Canada, today announced that the Phase 2b KEYNOTE-942/mRNA-4157-P201 trial of mRNA-4157/V940, an investigational personalized mRNA cancer vaccine, in combination with KEYTRUDA®, Merck's anti-PD-1 therapy, demonstrated a statistically significant and clinically meaningful improvement in the primary endpoint of recurrence-free survival (RFS) versus KEYTRUDA alone for the adjuvant treatment of patients with stage III/IV melanoma following complete resection. Adjuvant treatment with mRNA-4157/V940 in combination with KEYTRUDA reduced the risk of recurrence or death by 44% (HR=0.56 [95% CI, 0.31-1.08]; one-sided p-value=0.0266) compared with KEYTRUDA alone.

"Today's results are highly encouraging for the field of cancer treatment. mRNA has been transformative for COVID-19, and now, for the first time ever, we have demonstrated the potential for mRNA to have an impact on outcomes in a randomized clinical trial in melanoma," said Stéphane Bancel, Moderna's Chief Executive Officer. "We will begin additional studies in melanoma and other forms of cancer with the goal of bringing truly individualized cancer treatments to patients. We look forward to publishing the full data set and sharing the results at an upcoming oncology medical conference, as well as with health authorities."

"These positive findings represent an important milestone in our collaboration with Moderna," said Dr. Dean Y. Li, president, Merck Research Laboratories. "Over the last six years, our teams have worked closely together combining our respective expertise in mRNA and immuno-oncology with a focus on improving outcomes for patients with cancer. We look forward to advancing this program into the next phase of development."

"The results of this randomized Phase 2b trial are exciting for the field. These data provide the first evidence that we can improve on the rates of recurrence-free survival achieved by PD-1 blockade in resected high-risk melanoma. These findings also provide the first randomized evidence that a personalized neoantigen approach may be beneficial in melanoma," said Jeffrey S. Weber, MD, PhD, principal investigator of the study and Deputy Director of the Perlmutter Cancer Center at NYU Langone. Dr. Weber is a paid consultant for Merck and Moderna.

Adverse events observed with mRNA-4157/V940 in KEYNOTE-942 were consistent with those previously reported in a Phase 1 clinical trial. The safety profile of KEYTRUDA was consistent with that observed in previously reported studies. Serious treatment-related adverse events occurred in 14.4% of patients who received the combination arm of mRNA-4157/V940 and KEYTRUDA versus 10% with KEYTRUDA alone.

The companies plan to discuss the results with regulatory authorities and initiate a Phase 3 study in melanoma patients in 2023.

In October of this year, the companies announced that Merck had exercised its option to jointly develop and commercialize mRNA-4157/V940. Merck and Moderna will share costs and any profits equally under this worldwide collaboration.

Personalized cancer vaccines are designed to prime the immune system so that a patient can generate a tailored antitumor response specific to their tumor mutation signature. mRNA-4157/V940 is designed to stimulate an immune response by generating specific T cell responses based on the unique mutational signature of a patient's tumor. KEYTRUDA is an immunotherapy that works by increasing the ability of the body's immune system to help detect and fight tumor cells. Based on early clinical studies, combining mRNA-4157/V940 with KEYTRUDA may potentially provide an additive benefit and enhance T cell-mediated destruction of tumor cells.

About mRNA-4157/V940

mRNA-4157/V940 is a novel investigational messenger ribonucleic acid (mRNA)-based personalized cancer vaccine consisting of a single synthetic mRNA coding for up to 34 neoantigens that is designed and produced based on the unique mutational signature of the DNA sequence of the patient's tumor. Upon administration into the body, the algorithmically derived and RNA-encoded neoantigen sequences are endogenously translated and undergo natural cellular antigen processing and presentation, a key step in adaptive immunity.

About KEYNOTE-942/mRNA-4157-P201 (NCT03897881)

KEYNOTE-942 is an ongoing randomized, open-label Phase 2b trial that enrolled 157 patients with stage III/IV melanoma. Following complete surgical resection, patients were randomized to receive mRNA-4157/V940 (nine total doses of mRNA-4157) and KEYTRUDA (200 mg every three weeks up to 18 cycles [for approximately one year]) versus KEYTRUDA alone for approximately one year until disease recurrence or unacceptable toxicity. The primary endpoint is recurrence-free survival, and secondary endpoints include distant metastasis-free survival and safety.

Key eligibility criteria for the trial included: patients with resectable cutaneous melanoma metastatic to a lymph node and at high risk of recurrence, patients with complete resection within 13 weeks prior to the first dose of KEYTRUDA, patients were disease free at study entry (after surgery) with no loco-regional relapse or distant metastasis and no clinical evidence of brain metastases, patients had a formalin fixed paraffin embedded (FFPE) tumor sample available suitable for sequencing, Eastern Cooperative Oncology Group (ECOG) Performance Status 0 or 1 and patients with normal organ and marrow function reported at screening.

About Melanoma

Melanoma, the most serious form of skin cancer, is characterized by the uncontrolled growth of pigment-producing cells. The rates of melanoma have been rising over the past few decades, with nearly 325,000 new cases diagnosed worldwide in 2020. In the U.S., skin cancer is one of the most common types of cancer diagnosed, and melanoma accounts for a large majority of skin cancer deaths. It is estimated there will be nearly 100,000 new cases of melanoma diagnosed and almost 8,000 deaths resulting from the disease in the U.S. in 2022. The five-year survival rates are estimated to be 60.3% for stage III and 16.2% for stage IV.

About KEYTRUDA® (pembrolizumab) injection, 100 mg

KEYTRUDA is an anti-programmed death receptor-1 (PD-1) therapy that works by increasing the ability of the body's immune system to help detect and fight tumor cells. KEYTRUDA is a humanized monoclonal antibody that blocks the interaction between PD-1 and its ligands, PD-L1 and PD-L2, thereby activating T lymphocytes which may affect both tumor cells and healthy cells.

Merck has the industry's largest immuno-oncology clinical research program. There are currently more than 1,600 trials studying KEYTRUDA across a wide variety of cancers and treatment settings. The KEYTRUDA clinical program seeks to understand the role of KEYTRUDA across cancers and the factors that may predict a patient's likelihood of benefitting from treatment with KEYTRUDA, including exploring several different biomarkers.

Selected KEYTRUDA®(pembrolizumab) Indications in the U.S.

Melanoma

KEYTRUDA is indicated for the treatment of patients with unresectable or metastatic melanoma.

KEYTRUDA is indicated for the adjuvant treatment of adult and pediatric (12 years and older) patients with stage IIB, IIC, or III melanoma following complete resection.

See additional selected indications for KEYTRUDA in the U.S. after the Selected Important Safety Information

Selected Important Safety Information for KEYTRUDA

Severe and Fatal Immune-Mediated Adverse Reactions

KEYTRUDA is a monoclonal antibody that belongs to a class of drugs that bind to either the PD-1 or the PD-L1, blocking the PD-1/PD-L1 pathway, thereby removing inhibition of the immune response, potentially breaking peripheral tolerance and inducing immune-mediated adverse reactions. Immune-mediated adverse reactions, which may be severe or fatal, can occur in any organ system or tissue, can affect more than one body system simultaneously, and can occur at any time after starting treatment or after discontinuation of treatment. Important immune-mediated adverse reactions listed here may not include all possible severe and fatal immune-mediated adverse reactions.

Monitor patients closely for symptoms and signs that may be clinical manifestations of underlying immune-mediated adverse reactions. Early identification and management are essential to ensure safe use of anti-PD-1/PD-L1 treatments. Evaluate liver enzymes, creatinine, and thyroid function at baseline and periodically during treatment. For patients with TNBC treated with KEYTRUDA in the neoadjuvant setting, monitor blood cortisol at baseline, prior to surgery, and as clinically indicated. In cases of suspected immune-mediated adverse reactions, initiate appropriate workup to exclude alternative etiologies, including infection. Institute medical management promptly, including specialty consultation as appropriate.

Withhold or permanently discontinue KEYTRUDA depending on severity of the immune-mediated adverse reaction. In general, if KEYTRUDA requires interruption or discontinuation, administer systemic corticosteroid therapy (1 to 2 mg/kg/day prednisone or equivalent) until improvement to Grade 1 or less. Upon improvement to Grade 1 or less, initiate corticosteroid taper and continue to taper over at least 1 month. Consider administration of other systemic immunosuppressants in patients whose adverse reactions are not controlled with corticosteroid therapy.

Immune-Mediated Pneumonitis

KEYTRUDA can cause immune-mediated pneumonitis. The incidence is higher in patients who have received prior thoracic radiation. Immune-mediated pneumonitis occurred in 3.4% (94/2799) of patients receiving KEYTRUDA, including fatal (0.1%), Grade 4 (0.3%), Grade 3 (0.9%), and Grade 2 (1.3%) reactions. Systemic corticosteroids were required in 67% (63/94) of patients. Pneumonitis led to permanent discontinuation of KEYTRUDA in 1.3% (36) and withholding in 0.9% (26) of patients. All patients who were withheld reinitiated KEYTRUDA after symptom improvement; of these, 23% had recurrence. Pneumonitis resolved in 59% of the 94 patients.

Pneumonitis occurred in 8% (31/389) of adult patients with cHL receiving KEYTRUDA as a single agent, including Grades 3-4 in 2.3% of patients. Patients received high-dose corticosteroids for a median duration of 10 days (range: 2 days to 53 months). Pneumonitis rates were similar in patients with and without prior thoracic radiation. Pneumonitis led to discontinuation of KEYTRUDA in 5.4% (21) of patients. Of the patients who developed pneumonitis, 42% interrupted KEYTRUDA, 68% discontinued KEYTRUDA, and 77% had resolution.

Immune-Mediated Colitis

KEYTRUDA can cause immune-mediated colitis, which may present with diarrhea. Cytomegalovirus infection/reactivation has been reported in patients with corticosteroid-refractory immune-mediated colitis. In cases of corticosteroid-refractory colitis, consider repeating infectious workup to exclude alternative etiologies. Immune-mediated colitis occurred in 1.7% (48/2799) of patients receiving KEYTRUDA, including Grade 4 (