Mersana therapeutics layoffs 2023 – reason behind this

Due to financial constraints, Mersana Therapeutics had to lay off half its workforce. It is due to its flagship ovarian cancer medicine failing in a phase 1/2 trial, sending the biotech into a tailspin.

Mersana Therapeutics is a clinical-stage biopharmaceutical firm. It is driven by the fact that patients are eagerly awaiting new therapeutic alternatives. They are focusing on the development of innovative antibody-drug conjugates (ADCs). The business has created its own ADC platforms for cytotoxic and immunostimulatory ADCs. They are developing a pipeline of wholly owned and co-developed product candidates. They have the potential to treat different types of cancer.

At Mersana, they are passionate about developing therapies that will significantly enhance the lives of cancer patients. In this article, let us look into detail about the company and its layoffs.

Overview of Mersana Therapeutics

To develop new and improved medications, Mersana Therapeutics uses its biodegradable polymer platform (Fleximer). In 2001, it was founded. They are developing a pipeline of new medicines that can potentially treat various cancer diseases. They also make use of Fleximer’s adaptability through partnerships. This is to solve problems with nucleic acids, biologics, and small compounds in various therapeutic fields. These are related to safety, efficacy, and delivery.

Mersana Therapeutics is a modest healthcare organization with 169 staff members. It generates $26.6 million in annual revenue and is headquartered in Cambridge, Massachusetts.

Mersana Therapeutics, Inc., a publicly traded firm, aims to find and create a pipeline of antibody-drug conjugates (ADCs). It will target cancer in conditions with enormous unmet medical needs.

ADCs are a class of biopharmaceutical medications created as a targeted therapy for cancer treatment. In contrast to chemotherapy, ADCs are designed to target and destroy tumor cells while protecting healthy cells. About 56 pharmaceutical companies were working on ADCs as of 2019.

The company’s pipeline contains the following drugs:

  • XMT-1660,
  • a dolasynthene ADC that targets B7-H4 and XMT-2056,
  • an immunosynthene ADC that targets a brand-new HER2 epitope.

The company aims to “discover and develop antibody-drug conjugates for patients fighting cancer that will change their lives.”

An FDA hold was placed on one more of Mersana’s ADCs

An FDA hold relating to a patient’s death has been placed on Mersana Therapeutics. This time, the regulator has tightened its grip on the biotech’s primary antibody-drug conjugate (ADC). It was due to patient bleeding incidents that resulted in five fatalities.

Compared to the general population, treated patients with platinum-resistant ovarian cancer saw a greater rate of major bleeding events. It happened throughout the trials of the company’s principal asset, UpRi. This led regulators to halt two current investigations of the ADC partially. According to a Jun. 15, 2023 declaration, Mersana has dosed roughly 560 people thus far.

The partial holds affect the company’s phase 3 UP-NEXT trial and phase 1 dose expansion trial, UPGRADE-A. This halts recruitment in both. After finishing enrollment in October, Mersana’s UPLIFT registrational single-arm trial is unaffected. Patients already signed up for one of the three trials may continue receiving care.

The medication maker, focusing on ADC, informed authorities of the holds after submitting a new batch of safety information. This included information on the five fatal bleeding occurrences. The business claims that an investigation is being conducted to determine the cause.

The firm is waiting for an official written notice from regulators about the holds. Also, Mersana expects the FDA to request more thorough safety information.

The UPLIFT trial’s topline results are expected to be public in August. The biotech also intends to publish safety and efficacy data from that study.

What happened to the firm?

Naturally, the company’s stock price fell through the floor shortly after the market opened. It dropped nearly 60% to $4.06 from a closing price of $9.55 on Jun. 14, 2023. This erases any gains earned in the previous seven weeks (as of mid-July). The likelihood that the business will file an UpRi approval application by the end of the year pushed Mersana to do so. Investors are reducing their bets now that the safety profile is in doubt.

Mersana’s potential has increased during the past 15 months, in part. It’s because of three collaborations with GSK, Janssen, and Merck KGaA. The three transactions have a combined value of more than $3 billion.

The partnership with GSK was called into question in March. It happens after a patient in the first study of the two companies jointly developed drug, XMT-2056, experiences a fatality. It is a major adverse event thought to be related to the therapy.

It is unclear how UpRi’s two affected studies’ recruiting delays will influence Mersana’s clinical development plan and the funds needed to pay for it. At the end of March, the company stated it had approximately $280 million. It claimed it was enough to run through the second half of 2024.

In the first quarter of 2023, compared to the first quarter of 2022, Mersana reported a 32% rise in R&D spending. It was partly attributed to increasing staff size, manufacturing, and clinical costs.

Mersana reduces employment by half

The company specializing in antibody-drug conjugates was researching upifitamab silodosin in the UPLIFT trial. It included 268 patients with platinum-resistant ovarian cancer. One hundred forty-one of whom were NaPi2b-positive. However, according to Biotech, the drug’s overall response rate was only 13%. It is a tiny improvement above the 12% rate of chemotherapy alone.

Arvin Yang, M.D., chief medical officer of Mersana, stated in the statement,

“We are very disappointed that UPLIFT’s efficacy failed to replicate prior data from roughly 100 patients in the dose expansion stage of our phase 1b clinical trial. The response lasted longer than during the phase 1b clinical study for UpRi’s dose escalation. Yet, the primary endpoint lower bound of the confidence interval fell short of our aim. It excludes the 12% rate found with standard-of-care single-agent chemotherapy.”

(Note: Upifitamab Rilsodotin (UpRi) is a first-in-class Dolaflexin ADC that targets NaPi2b. It is a sodium-dependent phosphate transporter with minimal expression in healthy tissues. They have widespread expression in high-grade serous epithelial ovarian, fallopian tube, and primary peritoneal cancers.)

Upifitamab rilsodotin already had a cloud over it. AFTER RECEIVING THE COMPANY’S EVALUATION, the FDA partially halted two of its trials in July. As mentioned, it involves “serious incidents of bleeding that seem to occur at higher rates than background.”

The UPLIFT results were expected to provide greater insight into the safety profile of the ADC. But instead, the data effectively put a halt to the program.

Mersana is discontinuing the medication and refocusing on its platforms for dolasynthene and immunosynthene. The previous platform created the ADC XMT-1660, intended to target B7-H4. A phase 1 trial for solid tumors is currently in the dose-escalation phase of the study. CEO Anna Protopapas said it will begin with a dose expansion portion next year.

The same platform’s production of the HER2 epitope XMT-2056 has experienced its problems. The FDA imposed a partial clinical hold on the ADC in March after a patient experienced a fatal major adverse event that was thought to be related to the drug. For that, GSK paid $100 million for the license option in 2022.

Following the most recent setback for the business’ pipeline prospects, Protopapas stated that Mersana is now “taking aggressive steps. This is to broaden our cash runway. Also, we need to ensure that we have the resources to assess the clinical potential of our next-generation ADC product candidates.

The CEO remarked, “Unfortunately, this requires cutting our employees by almost 50%. Due to this strategic reprioritization, a very vibrant group of individuals who contributed to the development of Mersana will be leaving the company.”


According to Worker Adjustment and Retraining Notification (WARN) Notices, the number of employees affected at Mersana Therapeutics, Inc. was 124. The notice date was Jul. 27, 2023, and the layoff date was Aug. 15, 2023.

Unsurprisingly, investors seemed eager to separate themselves from the company. It was evidenced by the stock’s 75% decline to just 92 cents per share in the first hour of trade from its Jul. 26 close of $3.92.

The corporation does have some cash on hand. It has $286.6 million in cash and equivalents expected to last until 2026.