Merck and Pfizer Provide Update on JAVELIN Ovarian 100 Trial of Avelumab in Previously Untreated Advanced Ovarian Cancer

DARMSTADT,Germany and NEW YORK,Dec. 22,2018 --

Not intended for US,Canada and UK-based media

Merck and Pfizer Inc. (NYSE: PFE) today announced that data from a planned interim analysis of the Phase III JAVELIN Ovarian 100 study of avelumab* did not support the study's initial hypothesis,and therefore the alliance made the decision to terminate the trial in alignment with the independent Data Monitoring Committee.

The Merck-Pfizer alliance was the first to test an immunotherapy in this indication,given the significant unmet need in the treatment of ovarian cancer. Four out of five women with ovarian cancer are diagnosed at advanced stages.[1] Most women with advanced ovarian cancer ultimately die within five years due to refractory,resistant or recurrent disease.[2],[3]

Topline results showed that the study,which is evaluating avelumab in combination with and/or following platinum-based chemotherapy in previously untreated patients with ovarian cancer,would not achieve superiority in the pre-specified primary endpoint of progression-free survival. While detailed analyses of the data are ongoing,no new safety signals were observed,and the safety profile for avelumab in this trial appears consistent with that observed in the overall JAVELIN clinical development program. The alliance has notified health authorities and trial investigators of the interim findings and the decision to discontinue the trial. Detailed results will be shared with the scientific community. The JAVELINOvarian PARP 100 studyand earlier phase studies investigating avelumab in various combinations are ongoing.

*Avelumab is under clinical investigation for treatment of ovarian cancer. There is no guarantee that avelumab will be approved for ovarian cancer by any health authority worldwide.

About JAVELIN Ovarian 100

JAVELIN Ovarian 100 is a Phase III,multicenter,randomized,three-arm study investigating avelumab in combination with and/or as a maintenance treatment following carboplatin/paclitaxel chemotherapy in 998 previously untreated patients with locally advanced or metastatic (Stage III or Stage IV) epithelial ovarian cancer,fallopian tube cancer (FTC),or primary peritoneal cancer. The three arms are carboplatin/paclitaxel followed by observation; carboplatin/paclitaxel followed by avelumab maintenance; and avelumab plus carboplatin/paclitaxel followed by avelumab maintenance. The primary objectives are to demonstrate superior PFS for one or both avelumab-based treatment regimens compared with carboplatin/paclitaxel followed by observation.

About the JAVELIN Clinical Development Program

The clinical development program for avelumab,known as JAVELIN,involves at least 30 clinical programs and more than 9,000 patients evaluated across more than 15 different tumor types. In addition to ovarian cancer,these tumor types include breast,gastric/gastro-esophageal junction and head and neck cancers,Merkel cell carcinoma,non-small cell lung cancer,renal cell carcinoma and urothelial carcinoma.

About Ovarian Cancer

Every year,more than 295,000 women are diagnosed with ovarian cancer worldwide.[4] The disease is generally advanced when it is diagnosed,as it often has few to no symptoms at the early stages,making it difficult to detect. Symptoms also can be vague or non-specific,making it easy to confuse with less serious non-cancerous conditions. The five-year survival rate ranges from approximately 30% to 50%,but for those with metastatic disease,it drops to less than 20%.[5],[6]

About Avelumab (BAVENCIO®)

Avelumab (BAVENCIO®) is a human anti-programmed death ligand-1 (PD-L1) antibody. Avelumab has been shown in preclinical models to engage both the adaptive and innate immune functions. By blocking the interaction of PD-L1 with PD-1 receptors,avelumab has been shown to release the suppression of the T cell-mediated antitumor immune response in preclinical models.[7]-[9] Avelumab has also been shown to induce NK cell-mediated direct tumor cell lysis via antibody-dependent cell-mediated cytotoxicity (ADCC) in vitro.[9]-[11] In November 2014,Merck and Pfizer announced a strategic alliance to co-develop and co-commercialize avelumab.

Approved Indications in the US

In the US,the FDA granted accelerated approval for avelumab (BAVENCIO®) for the treatment of (i) adults and pediatric patients 12 years and older with metastatic Merkel cell carcinoma (mMCC) and (ii) patients with locally advanced or metastatic urothelial carcinoma (mUC) who have disease progression during or following platinum-containing chemotherapy,or have disease progression within 12months of neoadjuvant or adjuvant treatment with platinum-containing chemotherapy. These indications are approved under accelerated approval based on tumor response rate and duration of response. Continued approval for these indications may be contingent upon verification and description of clinical benefit in confirmatory trials.

Avelumab is currently approved for patients with MCC in more than 45 countries globally,with the majority of these approvals in a broad indication that is not limited to a specific line of treatment.

Important Safety Information from the US FDA-Approved Label

The warnings and precautions for BAVENCIO® include immune-mediated adverse reactions (such as pneumonitis,hepatitis,colitis,endocrinopathies,nephritis and renal dysfunction,and other adverse reactions),infusion-related reactions and embryo-fetal toxicity.

Common adverse reactions (reported in at least 20% of patients) in patients treated with avelumab for mMCC and patients with locally advanced or mUC include fatigue,musculoskeletal pain,diarrhea,nausea,infusion-related reaction,peripheral edema,decreased appetite/hypophagia,urinary tract infection and rash.

About Merck-Pfizer Alliance

Immuno-oncology is a top priority for Merck and Pfizer. The global strategic alliance between Merck and Pfizer enables the companies to benefit from each other's strengths and capabilities and further explore the therapeutic potential of avelumab,an anti-PD-L1 antibody initially discovered and developed by Merck. The immuno-oncology alliance is jointly developing and commercializing avelumab and advancing Pfizer's PD-1 antibody. The alliance is focused on developing high-priority international clinical programs to investigate avelumab as a monotherapy as well as combination regimens,and is striving to find new ways to treat cancer.

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About Merck

Merck,a vibrant science and technology company,operates across healthcare,life science and performance materials. Around 51,000 employees work to make a positive difference to millions of people's lives every day by creating more joyful and sustainable ways to live. From advancing gene editing technologies and discovering unique ways to treat the most challenging diseases to enabling the intelligence of devices - Merck is everywhere. In 2017,Merck generated sales of € 15.3 billion in 66 countries.

Scientific exploration and responsible entrepreneurship have been key to Merck's technological and scientific advances. This is how Merck has thrived since its founding in 1668. The founding family remains the majority owner of the publicly listed company. Merck holds the global rights to the Merck name and brand. The only exceptions are the United States and Canada,where the business sectors of Merck operate as EMD Serono in healthcare,MilliporeSigma in life science,and EMD Performance Materials. For more information about Merck visit http://www.merckgroup.com.

Pfizer Inc.: Working together for a healthier world®

At Pfizer,we apply science and our global resources to bring therapies to people that extend and significantly improve their lives. We strive to set the standard for quality,safety and value in the discovery,development and manufacture of health care products. Our global portfolio includes medicines and vaccines as well as many of the world's best-known consumer health care products. Every day,Pfizer colleagues work across developed and emerging markets to advance wellness,prevention,treatments and cures that challenge the most feared diseases of our time. Consistent with our responsibility as one of the world's premier innovative biopharmaceutical companies,we collaborate with health care providers,governments and local communities to support and expand access to reliable,affordable health care around the world. For more than 150 years,we have worked to make a difference for all who rely on us. We routinely post information that may be important to investors on our website athttp://www.pfizer.com. In addition,to learn more,please visit us onhttp://www.pfizer.comand follow us on Twitter at @Pfizer and @Pfizer_News,LinkedIn,YouTube and like us on Facebook at Facebook.com/Pfizer.

Pfizer Disclosure Notice

The information contained in this release is as of December 21,2018. Pfizer assumes no obligation to update forward-looking statements contained in this release as the result of new information or future events or developments.

This release contains forward-looking information about avelumab,including clinical trials evaluating avelumab for the treatment of ovarian cancer,the Merck-Pfizer Alliance involving anti-PD-L1 and anti-PD-1 therapies,and clinical development plans,including their potential benefits,that involves substantial risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. Risks and uncertainties include,among other things,uncertainties regarding the commercial success of avelumab; the uncertainties inherent in research and development,including the ability to meet anticipated clinical study commencement and completion dates and regulatory submission dates,as well as the possibility of unfavorable study results,including unfavorable new clinical data and additional analyses of existing clinical data; risks associated with interim data; the risk that clinical trial data are subject to differing interpretations,and,even when we view data as sufficient to support the safety and/or effectiveness of a product candidate,regulatory authorities may not share our views and may require additional data or may deny approval altogether; whether regulatory authorities will be satisfied with the design of and results from our clinical studies; whether and when any drug applications may be filed in any jurisdictions for any potential indications for avelumab,combination therapies or other product candidates; whether and when regulatory authorities in any jurisdictions where applications are pending or may be submitted for avelumab,combination therapies or other product candidates may approve any such applications,which will depend on the assessment by such regulatory authorities of the benefit-risk profile suggested by the totality of the efficacy and safety information submitted; decisions by regulatory authorities regarding labeling and other matters that could affect the availability or commercial potential of avelumab,combination therapies or other product candidates; and competitive developments.

A further description of risks and uncertainties can be found in Pfizer's Annual Report on Form 10-K for the fiscal year ended December 31,2017,and in its subsequent reports on Form 10-Q,including in the sections thereof captioned "Risk Factors" and "Forward-Looking Information and Factors That May Affect Future Results",as well as in its subsequent reports on Form 8-K,all of which are filed with the U.S. Securities and Exchange Commission and available at http://www.sec.gov and http://www.pfizer.com.

References

American Cancer Society. Survival Rates for Ovarian Cancer,by Stage. Available at: https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/annual-cancer-facts-and-figures/2018/cancer-facts-and-figures-special-section-ovarian-cancer-2018.pdf. Accessed December 2018.

Ledermann,JA,Raja FA,Fotopoulou C,et al. Newly diagnosed and relapsed epithelial ovarian carcinoma: ESMO Clinical Practice Guidelines for diagnosis,treatment and follow-up. Ann Oncol. 2013; 24 (Supplement 6): vi24-vi32,doi:10.1093/annonc/mdt333.

Ozol,RJ. Challenges for chemotherapy in ovarian cancer. Annals of Oncology 2006;17(5):v181-187.

World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project. Available at: https://www.wcrf.org/dietandcancer/cancer-trends/worldwide-cancer-data. Accessed December 2018.

World Cancer Research Fund / American Institute for Cancer Research. Continuous Update Project. Available at: https://www.wcrf.org/dietandcancer/ovarian-cancer. Accessed December 2018.

American Cancer Society. Survival Rates for Ovarian Cancer,by Stage. Available at: https://www.cancer.org/cancer/ovarian-cancer/detection-diagnosis-staging/survival-rates.html. Accessed December 2018.

Dolan DE,Gupta S. PD-1 pathway inhibitors: changing the landscape of cancer immunotherapy. Cancer Control. 2014;21(3):231-237.

Dahan R,Sega E,Engelhardt J,et al. FcγRs modulate the anti-tumor activity of antibodies targeting the PD-1/PD-L1 axis. Cancer Cell. 2015;28(3):285-295.

Boyerinas B,Jochems C,Fantini M,et al. Antibody-dependent cellular cytotoxicity activity of a novel anti-PD-L1 antibody avelumab (MSB0010718C) on human tumor cells.Cancer Immunol Res. 2015;3(10):1148-1157.

Kohrt HE,Houot R,Marabelle A,et al. Combination strategies to enhance antitumor ADCC.Immunotherapy. 2012;4(5):511-527.

Hamilton G,Rath B. Avelumab: combining immune checkpoint inhibition and antibody-dependent cytotoxicity.Expert Opin Biol Ther. 2017;17(4):515-523.

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