Actinium Pharmaceuticals, Inc. Announces Proposed Public Offering

Actinium Pharmaceuticals, Inc. Announces

Proposed Public Offering

NEW YORK, NY - June 16, 2020 -

Actinium Pharmaceuticals, Inc. (NYSE AMERICAN: ATNM) ("Actinium" or "the Company") today announced

that it intends to offer and sell shares of its common stock (or common stock equivalents in lieu thereof) in a public offering.

The offering is subject to market and other conditions, and there can be no assurance as to whether or when the offering may be

completed, or as to the actual size or terms of the offering.

H.C. Wainwright & Co. is acting

as exclusive placement agent for the offering.

Actinium intends to use the net proceeds

from the offering to complete its ongoing pivotal, Phase 3 SIERRA trial for its lead product candidate, Iomab-B, prepare and submit

a Biologics License Application ("BLA") to the U.S. Food and Drug Administration ("FDA") and Marketing

Authorization Application ("MAA") to the European Medicines Agency ("EMA") as well as commercialization

activities for Iomab-B in the United States. Net proceeds from this offering will also be used to progress Phase 1 trials for its

refocused CD33 program to the proof of concept stage, to support its AWE Technology Platform, Iomab-ACT program, research and development

and for general working capital needs.

A shelf registration statement on Form

S-3 relating to the public offering of the shares of common stock described above was filed with the Securities and Exchange Commission

("SEC") and was declared effective on October 12, 2017. The offering will be made only by means of a written prospectus

and prospectus supplement that form a part of the registration statement. A preliminary prospectus supplement describing the terms

of the offering will be filed with the SEC. Electronic copies of the preliminary prospectus supplement and the accompanying base

prospectus relating to the offering may be obtained, when available, from H.C. Wainwright & Co., LLC, 430 Park Avenue 3rd Floor,

New York, NY 10022, or by calling (646) 975-6996 or by emailing placements@hcwco.com or at the SEC's website at http://www.sec.gov.

This press release shall not constitute

an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state or jurisdiction

in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of

any such state or jurisdiction.

About Actinium Pharmaceuticals, Inc.

Actinium Pharmaceuticals, Inc. is a clinical-stage

biopharmaceutical company developing ARCs or Antibody Radiation-Conjugates, which combine the targeting ability of antibodies with

the cell killing ability of radiation. Actinium's lead application for our ARCs is targeted conditioning, which is intended to

selectively kill patient's cancer cells and certain immune cells prior to a BMT or Bone Marrow Transplant, CAR-T and other cell

therapies or gene therapy to enable engraftment of these transplanted cells with minimal toxicities. With our ARC approach, we

seek to improve patient outcomes and access to these potentially curative treatments by eliminating or reducing the non-targeted

chemotherapy that is used for conditioning in standard practice currently. Our lead product candidate, Iomab-B is being studied

in the ongoing pivotal Phase 3 Study of Iomab-B in Elderly Relapsed or Refractory Acute

Myeloid Leukemia (SIERRA) trial for BMT conditioning. The SIERRA trial is over fifty percent enrolled and promising single-agent,

feasibility and safety data has been highlighted at ASH, TCT, ASCO and SOHO annual meetings. Beyond Iomab-B, we are developing

a multi-disease, multi-target pipeline of clinical-stage ARCs targeting the antigens CD45 and CD33 for targeted conditioning and

as a therapeutic either in combination with other therapeutic modalities or as a single agent for patients with a broad range of

hematologic malignancies including acute myeloid leukemia, myelodysplastic syndrome and multiple myeloma. Underpinning our clinical

programs is our proprietary AWE (Antibody Warhead Enabling) technology platform. This is where our intellectual property portfolio

of over 120 patents, know-how, collective research and expertise in the field are being leveraged to construct and study novel

ARCs and ARC combinations to bolster our pipeline for strategic purposes. Our AWE technology platform is currently being utilized

in a collaborative research partnership with Astellas Pharma, Inc.

Statements for Actinium Pharmaceuticals, Inc.

may contain projections or other "forward-looking statements" within the meaning of the "safe-harbor" provisions

of the private securities litigation reform act of 1995 regarding future events or the future financial performance of the Company

which the Company undertakes no obligation to update, including but not limited to, statements relating to the Company's

expectations regarding the completion, timing and size of the proposed public offering and the intended use of proceeds of the

offering. These statements are based on management's current expectations and are subject to risks and uncertainties that may cause

actual results to differ materially from the anticipated or estimated future results, including the risks and uncertainties associated

with preliminary study results varying from final results, estimates of potential markets for drugs under development, clinical

trials, actions by the FDA and other governmental agencies, regulatory clearances, responses to regulatory matters, the market

demand for and acceptance of Actinium's products and services, performance of clinical research organizations and other risks detailed

from time to time in Actinium's filings with the Securities and Exchange Commission (the "SEC"), including without limitation

its most recent annual report on form 10-K, subsequent quarterly reports on Forms 10-Q and Forms 8-K, each as amended and supplemented

LifeSci Advisors, LLC