Mersana Therapeutics, Inc.

Good morning, and welcome to the Mursana Therapeutics 3rd Quarter 2022 Conference Call and Webcast. Currently, all participants are in a listen-only mode. There will be a question and answer session at the end of this call. I would now like to turn the call over to Jason Frequette, Senior Vice President, Investor Relations and Corporate Communications. Please proceed.

Good morning, everyone. Before we begin, please note that this call will contain forward-looking statements within the meaning of federal securities laws. These statements include, but are not limited to, those related to the therapeutic potential of our product candidates and the potential of our platforms, business strategy, clinical trial design, initiation, execution, and data releases, regulatory plans and objectives, commercial opportunities, collaborations, and potential associated payments, operating expenses, and cash runway. Each of these forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected in such statements. These risks and uncertainties are discussed in the company's quarterly report on Form 10Q, filed with the Securities and Exchange Commission on August 8, 2022, and in subsequent SEC filings. Our filings are available at sec.gov or on our website, mersana.com. Except as required by law, we assume no obligation to update forward-looking statements publicly, even if new information becomes available. With that, let me turn the call over to Anna Protopappas, our President and Chief Executive Officer.

Thank you, Jason, and hello, everyone. Welcome to our conference call. Joining me today with prepared remarks are our Chief Medical Officer, Arvind Yank, and our Chief Financial Officer, Brian Descheidner. I'm also joined by certain other members of management who will be available to answer your questions. We have continued our forward momentum here at MERSANA with a number of significant accomplishments in recent months. Let's recap, beginning with the progress we have made in executing a comprehensive development plan to address areas of unmet need across the ovarian cancer landscape with UPRI. We achieved a major milestone last month with the completion of enrollment in UPLIFT, a single arm registration trial in platinum resistant ovarian cancer. We think it's noteworthy to point out that we were able to fully enroll this trial within just one year. We attribute this to three primary factors. First and foremost is the significant unmet need faced by patients with platinum resistant disease. Second is the high level of enthusiasm and engagement about UPRI among the investigators globally. And third is our team's strong execution. With UPLIFT fully enrolled, we are positioned for what we expect to be a robust top line data readout in mid 2023. and assuming that data are positive, a potential BLA submission by the end of next year. In addition to Uplift, we have commenced patient enrollment and dosing in UpNext, our phase three clinical trial of upper immunotherapy maintenance in NAPI to be positive recurrent platinum sensitive ovarian cancer, which we believe could support approvals outside of the United States. And then there is an upgrade A, our Phase 1-2 clinical trial enrolling platinum-sensitive patients for treatment with a combination of Opri and carboplatin. We are pleased to report that we are now nearing completion of the dose escalation portion of the trial. To date, 12 patients have been enrolled, a few of whom are still early in their treatment. Given the limited data set, We have opted against sharing data at this time. We expect to enter the dose expansion portion of upgrade A in the first quarter of 2023, and to present data that are more robust and mature in the second half of 2023. Beyond UPRI, we're excited to have began our phase one trial of 1660, our new dollar symptom product candidate, and we received fast track designation by the FDA for that candidate for the treatment of adult patients with advanced or metastatic triple negative breast cancer. Additionally, we recently opened our clinical sites and began screening activities for our phase one trial of XMT2056, our first immunosynthetic product candidate. Patient dosing is expected to get underway later this quarter. In parallel with our clinical pipeline progress, we also have continued to focus on innovation in research, leveraging our three highly differentiated platforms as product engines to generate new molecules that have the potential to address important unmet medical needs. Our platforms provide substantial opportunities for expanding our pipeline, either with wholly owned assets or through partnerships. The agreements we entered into with Janssen in the first quarter and GSK in the third quarter demonstrate our position as an ADC innovator and a partner of choice. And given the breadth of our assets and the interest in the ADC space, we see collaborations remaining a core part of our go-forward strategy. In summary, the Mursana team has made great strides across a number of key areas of focus with an uplift top-line data readout and potential PLA submission on the near-term horizon. Up next, an upgrade in motion to exciting and highly differentiated new NTCs entering the clinic and a balance sheet that's been strengthened through significant collaborations. I am very proud of what we've achieved thus far in 2022, and we have a strong foundation in place as we head towards what we expect to be a transformative 2023. With that, I will ask our Chief Medical Officer, Arvind Yang, to delve more deeply into our clinical progress and plans.