Independent Proxy Advisory Firms ISS and Glass Lewis Recommend Spectrum Pharmaceuticals Stockholders Vote “FOR” Proposed Transaction with Assertio Holdings, Inc. - Seite 2

About Spectrum Pharmaceuticals, Inc.

Spectrum is a commercial stage biopharmaceutical company, with a strategy of acquiring, developing, and commercializing novel and targeted oncology therapies. We have an in-house clinical development organization with regulatory and data management capabilities, in addition to commercial infrastructure and a field based sales force for our marketed product, ROLVEDON (eflapegrastim-xnst) Injection. For additional information on Spectrum please visit www.sppirx.com.

About ROLVEDON

ROLVEDON (eflapegrastim-xnst) injection is a long-acting granulocyte colony-stimulating factor (G-CSF) with a novel formulation. Spectrum has received an indication to decrease the incidence of infection, as manifested by febrile neutropenia, in adult patients with non-myeloid malignancies receiving myelosuppressive anti-cancer drugs associated with clinically significant incidence of febrile neutropenia. ROLVEDON is not indicated for the mobilization of peripheral blood progenitor cells for hematopoietic stem cell transplantation. The BLA for ROLVEDON was supported by data from two identically designed Phase 3, randomized, open-label, noninferiority clinical trials, ADVANCE and RECOVER, which evaluated the safety and efficacy of ROLVEDON in 643 early-stage breast cancer patients for the management of neutropenia due to myelosuppressive chemotherapy. In both studies, ROLVEDON demonstrated the pre-specified hypothesis of non-inferiority (NI) in mean duration of severe neutropenia (DSN) and a similar safety profile to pegfilgrastim. ROLVEDON also demonstrated non-inferiority to pegfilgrastim in the mean DSN across all four cycles (all NI p<0.0001) in both trials.

Please see the Important Safety Information below and the full prescribing information for ROLVEDON at www.rolvedon.com.

Notice Regarding Forward-looking Statements

This communication contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Generally, the words “anticipate,” “estimate,” “expect,” “project,” “intend,” “plan,” “contemplate,” “predict,” “forecast,” “likely,” “believe,” “target,” “will,” “could,” “would,” “should,” “potential,” “may” and similar expressions or their negative, may, but are not necessary to, identify forward-looking statements. Such forward-looking statements, including those regarding the timing, and consummation and anticipated benefits of the transaction described herein, involve risks and uncertainties. Assertio’s and Spectrum’s experience and results may differ materially from the experience and results anticipated in such statements. The accuracy of such statements is subject to a number of risks, uncertainties and assumptions including, but are not limited to, the following factors: the risk that the conditions to the closing of the transaction are not satisfied, including the risk that required approvals of the transaction from the stockholders of Assertio or stockholders of Spectrum or from regulators are not obtained; litigation relating to the transaction; uncertainties as to the timing of the consummation of the transaction and the ability of each party to consummate the transaction; risks that the proposed transaction disrupts the current plans or operations of Assertio or Spectrum; the ability of Assertio and Spectrum to retain and hire key personnel; competitive responses to the proposed transaction; unexpected costs, charges or expenses resulting from the transaction; potential adverse reactions or changes to relationships with customers, suppliers, distributors and other business partners resulting from the announcement or completion of the transaction; the combined company’s ability to achieve the synergies expected from the transaction, as well as delays, challenges and expenses associated with integrating the combined company’s existing businesses; Spectrum’s existing and new drug candidates may not prove safe or effective, the possibility that our existing and new applications to the FDA and other regulatory agencies may not receive approval in a timely manner or at all, the possibility that our existing and new drug candidates, if approved, may not be more effective, safer or more cost efficient than competing drugs, the possibility that our efforts to acquire or in-license and develop additional drug candidates may fail, our dependence on third parties for clinical trials, manufacturing, distribution and quality control; the impact of overall industry and general economic conditions, including inflation, interest rates and related monetary policy by governments in response to inflation; geopolitical events, including the war between Russia and Ukraine, and regulatory, economic and other risks associated therewith; and continued uncertainty around the ongoing impacts of the COVID-19 pandemic, as well as broader macroeconomic conditions. Other factors that might cause such a difference include those discussed in Assertio’s and Spectrum’s filings with the SEC, which include their Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, and in the definitive joint proxy statement/prospectus on Form S-4 filed, and declared effective, on June 15, 2023 in connection with the proposed transaction. For more information, see the section entitled “Risk Factors” and the forward looking statements disclosure contained in Assertio’s and Spectrum’s Annual Reports on Form 10-K and in other filings. All forward-looking statements made herein are based on information currently available to Spectrum as of the date of this communication. Spectrum undertakes no obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.