Updated Phase 2 Results in Metastatic Triple-Negative Breast Cancer to be Presented at The 2018 San Antonio Breast Cancer Symposium (SABCS) Continue to Show Meaningful Clinical Benefit Consistent with Prior Results

Pivotal Randomized Study in Hormone Receptor-Positive (HR+)/Human Epidermal Growth Factor Receptor 2-Negative (HER2–) Metastatic Breast Cancer (mBC)

MORRIS PLAINS, N.J., Dec. 06, 2018 (GLOBE NEWSWIRE) — Immunomedics, Inc., (NASDAQ: IMMU) (“Immunomedics” or the “Company”), a leading biopharmaceutical company in the area of antibody-drug conjugates (ADC), today presents updated Phase 2 results at the 2018 SABCS, confirming that monotherapy with sacituzumab govitecan achieved an objective response rate (ORR) of over 30 percent among heavily pre-treated patients with metastatic triple-negative breast cancer (mTNBC), with a manageable safety profile.

“Response rates to chemotherapy are low in patients with pre-treated mTNBC, and clinically there is a high unmet need for mTNBC patients,” commented Aditya Bardia, MD, MPH, Director of Precision Medicine and attending physician at Center for Breast Cancer, Massachusetts General Hospital, Harvard Medical School, Boston, MA.

With an additional 5 months of follow-up for the previously reported mTNBC patient cohort, sacituzumab govitecan monotherapy continued to demonstrate robust clinical activity with an ORR of 33 percent and 34 percent based on local assessment and blinded independent central review (BICR), respectively. The key efficacy data are summarized in the table below.

“We believe these results show that sacituzumab govitecan can be a viable treatment option and help alleviate the unmet need in mTNBC,” stated Dr. Robert Iannone, Head of R&D and Chief Medical Officer of Immunomedics. “We have shared these updates with the FDA during its ongoing priority review of our Biologics License Application for accelerated approval of sacituzumab govitecan in metastatic TNBC.”

Treatment with sacituzumab govitecan was well tolerated, with a predictable and manageable safety profile, and low discontinuation rates due to adverse events. The most relevant adverse events were gastrointestinal and neutropenia, which were manageable with routine supportive care per general practice guidelines.

Below are details of the poster presentation at 2018 SABCS:

• Presenter: Dr. Kalinsky
• Program Number: P2-11-01
• Session: Poster Session 2: Treatment: Antibody based regimens (7:30 AM-9:00 AM Central Time)
• Date/Time: Thursday, December 6, 2018 – 7:30 am Central Time
• Room: Hall 1

Randomized Phase 3 Study in HR+/HER2– mBC
Following a dialogue with the FDA, the company has reached alignment on the design of a registration-enabling trial for HR+/HER2– mBC.

The global Phase 3 trial will enroll approximately 400 patients with HR+/HER2– mBC who have failed prior hormonal and CDK 4/6 inhibitor therapies, as well as at least 2 prior chemotherapies. The primary endpoint of this open-label study is progression free survival (PFS), with additional secondary endpoints including overall survival, CBR, health-related quality of life, and safety and tolerability.

Eligible patients will be randomized 1:1 to receive either sacituzumab govitecan or physicians’ choice of chemotherapy at clinical sites across North America and Europe. Patients will be treated until tumor progression, unacceptable toxicity, study withdrawal, or death.

Additionally, with guidance from the FDA, the protocol includes an interim analysis based on ORR that could serve as the basis for an accelerated approval submission.

As previously reported from a Phase 2 study at ASCO 2018, in 54 heavily pretreated HR+/HER2– mBC patients who had received a median of five prior treatment lines for metastatic disease, the ORR was 31 percent and the CBR was 48 percent. The median DoR was 7.4 months and the median PFS was 6.8 months, indicating that responses were durable.

About Sacituzumab Govitecan
Sacituzumab govitecan, our most advanced product candidate, is a novel, first-in-class antibody-drug conjugate (ADC). It is currently under priority review by the U.S. Food and Drug Administration for accelerated approval as a treatment of patients with metastatic triple-negative breast cancer who have received two prior therapies for metastatic disease. If approved, sacituzumab govitecan would be the first and only ADC approved for the treatment of metastatic triple negative breast cancer.

About Immunomedics
Immunomedics is a clinical-stage biopharmaceutical company developing monoclonal antibody-based products for the targeted treatment of cancer. Immunomedics’ corporate objective is to become a fully-integrated biopharmaceutical company and a leader in the field of antibody-drug conjugates. For additional information on the Company, please visit its website at https://immunomedics.com/. The information on its website does not, however, form a part of this press release.

Cautionary note regarding forward-looking statements
This release, in addition to historical information, may contain forward-looking statements made pursuant to the Private Securities Litigation Reform Act of 1995. Such statements, including statements regarding clinical trials (including the funding therefor, anticipated patient enrollment, trial outcomes, timing or associated costs), regulatory applications and related timelines, including the filing and approval timelines for BLAs and BLA supplements, out-licensing arrangements, forecasts of future operating results, potential collaborations, capital raising activities, and the timing for bringing any product candidate to market, involve significant risks and uncertainties and actual results could differ materially from those expressed or implied herein. Factors that could cause such differences include, but are not limited to, the Company’s dependence on business collaborations or availability of required financing from capital markets, or other sources on acceptable terms, if at all, in order to further develop our products and finance our operations, new product development (including clinical trials outcome and regulatory requirements/actions), the risk that we or any of our collaborators may be unable to secure regulatory approval of and market our drug candidates, risks associated with the outcome of pending litigation and competitive risks to marketed products, and the Company’s ability to repay its outstanding indebtedness, if and when required, as well as the risks discussed in the Company’s filings with the Securities and Exchange Commission. The Company is not under any obligation, and the Company expressly disclaims any obligation, to update or alter any forward-looking statements, whether as a result of new information, future events or otherwise.