Enlivex Announces New Preclinical Data in Ovarian Cancer Showing a Substantial Survival Benefit when Allocetra is Combined with PD-1 Checkpoint Inhibition at the American Society of Clinical Oncology (ASCO) Annual Meetin

Enlivex Announces New Preclinical Data in Ovarian

Cancer Showing a Substantial Survival Benefit when Allocetra is Combined with PD-1 Checkpoint Inhibition at the American Society of Clinical

Oncology (ASCO) Annual Meeting

Nes-Ziona, Israel, May 31, 2022 (GLOBE NEWSWIRE) - Enlivex

Therapeutics Ltd. (Nasdaq: ENLV, the "Company"), a clinical-stage macrophage reprogramming immunotherapy company, today announced

new preclinical data from an ovarian cancer study conducted in collaboration with Yale Cancer Center. The study showed substantial and

statistically significant improvements in survival benefit, survival duration and tumor burden reduction when Allocetra was combined

with an anti-PD1 checkpoint inhibitor. The data will be featured in an upcoming poster presentation at the ASCO Annual Meeting, which

is taking place both virtually and in-person at the McCormick Place convention center in Chicago, Illinois (United States) from June 3

The upcoming ASCO poster will also highlight a prior

preclinical study in mesothelioma cancer that showed a substantial survival benefit when Allocetra was combined with a commercially approved

anti-CTLA4 checkpoint inhibitor. Previously reported preclinical data in peritoneal cancer that show a substantial survival benefit when

Allocetra is combined with chimeric antigen receptor (CAR) T-cell therapy will also be presented.

Marcus Bosenberg, MD, PhD, Professor of Dermatology, Pathology, and

Immunobiology and Director of the Center for Precision Cancer Modeling at Yale Cancer Center, commented: "I am highly encouraged

by these preclinical findings, which clearly demonstrate Allocetra's potential to address a long-standing unmet need. The immunosuppressive

microenvironments of ovarian tumors have limited the clinical benefits of checkpoint inhibition in this indication. Allocetra may

reverse immunosuppressive tumor microenvironments and may ultimately improve patient outcomes by synergistically enhancing checkpoint

inhibitor efficacy in clinical trials."

Prof. Dror Mevorach, MD, Chief Scientific Officer of Enlivex, added:

"In these latest murine studies, we once again saw Allocetra synergistically combine with a checkpoint inhibitor to deliver

a statistically significant survival benefit in a difficult-to-treat solid tumor model. We are now working to translate these promising

findings to the clinic and expect to initiate two solid tumor trials evaluating Allocetra-based combinations by year-end. Through these

studies, we aim to clinically demonstrate the broad applicability of Allocetra's proposed mechanism of action to enable the expansion

of its potential therapeutic impact."

Ovarian Cancer, Checkpoint Inhibitors, and Macrophage-Solid Tumor

Ovarian cancer is currently the fifth leading cause of cancer death

among women. Stand-alone therapy with PD1 checkpoint inhibitors, which are designed to treat cancer by activating immune cells that can

identify and destroy tumors, has thus far shown limited efficacy in this indication. Prior clinical trials in ovarian cancer evaluating

anti-PD1 monotherapy have shown response rates of only 7% - 15%.

The limited response rates of checkpoint inhibitors in ovarian and

other solid cancers is linked to tumor defense mechanisms that facilitate the recruitment of macrophages which become "pro-tumor"

tumor associated macrophages (TAMs) rather than "anti-tumor" macrophages. Pro-tumor TAMs typically form a physical layer on

top of solid tumors and induce an immunosuppressive tumor microenvironment (TME). This in-turn promotes tumor growth and metastasis and

makes it very difficult for immune cells or any anti-cancer drug to efficiently attack cancerous cells. Allocetra is a cell therapy

in development that is targeted towards TAMs. Its proposed mechanism of action is to change the balance of macrophage populations so that

they skew towards anti-tumor macrophages and away from pro-tumor macrophages. This is expected to enhance the efficacy of checkpoint inhibitors

and other immunotherapeutic agents.

The Ovarian Cancer Model

To expand upon its previous preclinical findings in mesothelioma and

test the potential effects of cell-therapy-induced macrophage reprogramming in a second difficult-to-treat solid tumor model, Enlivex

collaborated with the Yale Cancer Center to run preclinical studies in which groups of mice were implanted with ID8 ovarian cancer cells.

The difference between the groups was the treatment given, which started on day 7 after the cancer's initial growth period.

Results from the preclinical ovarian cancer study further support Allocetra's

potential to significantly improve survival outcomes by facilitating macrophage reprogramming in the solid tumor microenvironment. Twelve

weeks after the initial treatment, untreated mice (vehicle) showed a survival rate of 0%, and a median survival duration of 6 weeks. Survival

duration was increased with stand-alone treatment with either an anti-PD1 inhibitor or Allocetra . The magnitude of the increases

were similar between these two monotherapy groups (42% and 58% increase, respectively), with no significant effect on overall survival

probability observed between the monotherapy groups. Notably, combining Allocetra with anti-PD1 therapy led to a synergistic anti-cancer

effect, with survival rates of up to 50% (5/10) and an 83% increase in median survival duration observed in the combination therapy groups.

The attached figure shows the Kaplan-Meier survival probability curve for each group of the study, and the table below provides the treatment

As previously reported, Enlivex plans to initiate a Phase Ib trial

evaluating Allocetra in combination with chemotherapy in solid peritoneal tumors in Q3 2022, and a Phase I/II trial evaluating

Allocetra in combination with an immune checkpoint inhibitor in late 2022.

The title of the upcoming ASCO poster is "In-vivo reprogramming

macrophages and dendritic cells with Allocetra-OTS: Successful mono- and combination-antitumor therapy." The poster will be presented

during the ASCO Annual Meeting's "Developmental Therapeutics - Immunotherapy" poster session, which is taking

place on June 5, 2022, from 8:00 AM - 11:00 AM CDT (9:00 AM - 12:00 PM ET). A copy of the poster's corresponding abstract is currently

available on the ASCO Annual Meeting Website.

ABOUT THE AMERICAN SOCIETY OF CLINICAL ONCOLOGY

Founded in 1964, the American Society of Clinical Oncology is the world's

leading professional organization for physicians and oncology professionals caring for people with cancer.

Allocetra is being developed as a universal, off-the-shelf cell

therapy designed to reprogram macrophages into their homeostatic state. Diseases such as solid cancers, sepsis, and many others reprogram

macrophages out of their homeostatic state. These non-homeostatic macrophages contribute significantly to the severity of the respective

diseases. By restoring macrophage homeostasis, Allocetra has the potential to provide a novel immunotherapeutic mechanism

of action for life-threatening clinical indications that are defined as "unmet medical needs", as a stand-alone therapy or in

combination with leading therapeutic agents.

Enlivex is a clinical-stage macrophage reprogramming

immunotherapy company developing Allocetra , a universal, off-the-shelf cell therapy designed to reprogram macrophages into

their homeostatic state. Resetting non-homeostatic macrophages into their homeostatic state is critical for immune system rebalancing

and resolution of life-threatening conditions. For more information, visit http://www.enlivex.com.

Safe Harbor Statement: This press

release contains forward-looking statements, which may be identified by words such as "expects," "plans," "projects,"

"will," "may," "anticipates," "believes," "should," "would", "could,"

"intends," "estimates," "suggests," "has the potential to" and other words of similar

meaning, including statements regarding expected cash balances, market opportunities for the results of current clinical studies and preclinical

experiments, the effectiveness of, and market opportunities for, ALLOCETRATM programs. All such forward-looking statements

are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Investors are cautioned

that forward-looking statements involve risks and uncertainties that may affect Enlivex's business and prospects, including

the risks that Enlivex may not succeed in generating any revenues or developing any commercial products; that the products in

development may fail, may not achieve the expected results or effectiveness and/or may not generate data that would support the approval

or marketing of these products for the indications being studied or for other indications; that ongoing studies may not continue to show

substantial or any activity; and other risks and uncertainties that may cause results to differ materially from those set forth in the

forward-looking statements. The results of clinical trials in humans may produce results that differ significantly from the results of

clinical and other trials in animals. The results of early-stage trials may differ significantly from the results of more developed, later-stage

trials. The development of any products using the ALLOCETRATM product line could also be affected by a number of other

factors, including unexpected safety, efficacy or manufacturing issues, additional time requirements for data analyses and decision making,

the impact of pharmaceutical industry regulation, the impact of competitive products and pricing and the impact of patents and other proprietary

rights held by competitors and other third parties. In addition to the risk factors described above, investors should consider the

economic, competitive, governmental, technological and other factors discussed in Enlivex's filings with the

Securities and Exchange Commission, including in the Company's most recent Annual Report on Form 20-F filed with the Securities

and Exchange Commission. The forward-looking statements contained in this press release speak only as of the date the statements

were made, and we do not undertake any obligation to update forward-looking statements, except as required under applicable law.

Shachar Shlosberger,

Enlivex Therapeutics, Ltd.

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