Trial to Evaluate the Safety of Talimogene Laherparepvec Injected Into Tumors Alone and in Combination With Systemic Pembrolizumab MK-3475-611/Keynote-611

A Phase 1b/2, Multicenter, Open-label, Basket Trial to Evaluate the Safety of Talimogene Laherparepvec Injected Into Liver Tumors Alone and in Combination With Systemic Pembrolizumab in Phase 1b and to Evaluate the Efficacy and Safety of Intratumoral Talimogene Laherparepvec in Combination With Systemic Pembrolizumab to Treat Subjects With Advanced Solid Tumors in Phase 2 (MASTERKEY-318)

This is a phase 1b/2, multicenter, open-label, basket trial to evaluate the safety of talimogene laherparepvec injected intrahepatically into liver tumors alone and in combination with systemic intravenous (IV) administration of pembrolizumab, in subjects with non-hepatocellular carcinoma (HCC) liver metastases from breast adenocarcinoma (BC), colorectal adenocarcinoma (CRC), gastroesophageal cancer (GEC), melanoma, non-small cell lung cancer (NSCLC), clear cell renal cell carcinoma (RCC) in Part 1 Group A, and subjects with HCC with and without viral hepatitis in Part 1 Group B (viral hepatitis is only applicable in combination setting), and to evaluate the efficacy and safety of intratumoral talimogene laherparepvec in combination with systemic pembrolizumab in subjects with advanced triple negative breast cancer (TNBC), hormone receptor positive breast cancer, CRC, cutaneous squamous cell carcinoma (CSCC), and basal cell carcinoma (BCC) in Part 2 Group A and subjects with HCC with and without viral hepatitis in Part 2 Group B. The objective of Part 1 is to evaluate the safety of intrahepatic injection of talimogene laherparepvec into liver tumors alone and in combination with systemically administered pembrolizumab for the non-HCC (Group A) and HCC (Group B) cohorts separately. Part 2 consists of 2-stage design to evaluate the efficacy and safety of talimogene laherparepvec in combination with systemic pembrolizumab. Efficacy and safety will be evaluated in each of the five non-HCC tumor types from Group A separately. Similarly, the efficacy and safety of the combination treatment will be determined for Group B HCC subjects. As of Protocol Amendment 6 (dated 26 October 2021), intrahepatic injections of talimogene laherparepvec and liver biopsies are no longer performed in this study. Enrollment for this study has stopped.

Summary of Subject Eligibility Criteria:

Key Inclusion Criteria:

Subjects must be age ≥ 18 years at the time of informed consent. Subjects must have histologically or cytologically confirmed disease.

Part 1 is restricted to BC, CRC, GEC, melanoma, NSCLC, or RCC with liver metastases or HCC.

Part 2 Group A is restricted to advanced hormone receptor positive BC, CRC, TNBC, CSCC, and BCC with or without liver metastases.

• Part 2 Hormone receptor positive Breast Cancer Arm only: Histologically and/or cytologically confirmed diagnosis of estrogen receptor (ER) positive and/or progesterone receptor (PrR) positive breast cancer.
• Triple negative breast cancer: Histologically and/or cytologically confirmed diagnosis of ER negative, PrR negative, human epidermal growth factor receptor 2 (HER2)-Neu negative.

Part 2 Group B is restricted to HCC (fibrolamellar and mixed hepatocellular/cholangiocarcinoma subtypes are not eligible).

For HCC subjects with a diagnosis of hepatitis B, they must be on antiviral therapy for at least 4 weeks prior to enrollment and hepatitis B virus (HBV) viral load by real-time polymerase chain reaction (qPCR) must be < 100 IU/mL. HCC subjects with past or ongoing hepatitis C infection must have completed treatment for hepatitis C at least 1 month prior to study enrollment and hepatitis C viral load must be undetectable; subjects with hepatitis B and C must fulfill the eligibility criteria for hepatitis B and hepatitis C. Subjects with unresectable locally recurrent TNBC are eligible.

Non-HCC subjects must have received at least 1 prior standard of care systemic anti-cancer therapy for their locally advanced or metastatic disease. For the combination cohorts (Cohorts 5 and 6 in Part 1) and Part 2, subjects with melanoma CSCC or NSCLC do not need to have received prior therapy. In Part 1, subjects must have measurable liver tumors and liver tumors that are suitable for injection. In Part 2, subjects must have measurable disease and cutaneous, subcutaneous, lymph node, or liver tumors suitable for injection. NOTE: as of Protocol Amendment 6 [dated 26 October 2021], intrahepatic injections of talimogene laherparepvec and liver biopsies are no longer performed in this study, enrollment for this study has stopped. Eastern Cooperative Oncology Group (ECOG) performance status must be 0 or 1, and life expectancy should be approximately 5 months or more. Adequate hematological, renal, hepatic, and coagulation function is required. Liver function tests may be mildly abnormal but within the parameters. Child-Pugh score must be A.

Key Exclusion Criteria:

Subjects must not be candidates for surgery or locoregional therapy with curative intent or planned systemic anti-cancer therapy, with the exception of immunotherapy in the combination cohorts (Cohorts 5 and 6 in Part 1 and all subjects in Part 2). Liver tumors must not be estimated to invade approximately more than one-third of the liver. Liver tumor-directed therapy, hepatic surgery or major surgery, antibody-based therapy, or immunotherapy must not have been performed < 28 days, chemotherapy < 21 days, and targeted small molecule therapy or hormonal therapy < 14 days prior to enrollment. Subjects must either (1) have no central nervous system (CNS) metastasis, or carcinomatous meningitis, or (2) if CNS metastasis is present, must have stable treated cerebral metastases. Subjects must not have symptomatic auto-immune disease or be symptomatically immunosuppressed. They must not have a history of solid organ transplantation. For non-HCC, there must not be acute or chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infection. For HCC with prior hepatitis B and/or C infection, HBV and/or HCV viral load by qPCR must be undetectable, and they must not have had recent treatment within 12 weeks for HBV or HCV with certain antiviral medications in Part 1 Group B cohorts 1-5 and 6a, and Part 2 Group B HCC without viral hepatitis. For all patients in Part 1 and for patients in Part 2 where intrahepatic liver injection is planned (NOTE: as of Protocol Amendment 6 [dated 26 October 2021], intrahepatic injections of talimogene laherparepvec and liver biopsies are no longer performed in this study, enrollment for this study has stopped), there should be no macroscopic intravascular invasion of tumors into the main portal vein, hepatic vein, or vena cava. Subjects must not: have active herpetic skin lesions or prior complications of herpetic infection (eg, herpetic keratitis or encephalitis); require treatment with an antiherpetic drug; have received live-virus vaccination within 30 days of planned treatment start; have previous therapy with talimogene laherparepvec, oncolytic viruses, or tumor vaccine. Subjects in the combination treatment cohort must not have: a history or evidence of psychiatric, substance abuse, or any other clinically significant disorder; toxic effects of the most recent prior chemotherapy not resolved to grade 1 or less (except alopecia); or expected other cancer therapy while on study with the exception of local radiation to the site of bone or other metastasis for palliative treatment. Male subjects of reproductive potential in the combination treatment must be willing to use acceptable methods of effective contraception during treatment and through 4 months after the last dose of pembrolizumab.