Spectrum Announces Poziotinib ZENITH20 Trial HER2 Cohort (Cohort 2) Has Reached Enrollment Target

• Enrollment of cohort 2 was completed six months ahead of schedule
• Cohort 2 had a target enrollment of 87 NSCLC patients with HER2 exon
  20 insertion mutations
• Topline results from cohort 2 are expected in mid 2020
• Topline results from cohort 1, which enrolled NSCLC patients with EGFR
  exon 20 insertion mutations, are expected in Q4 2019

HENDERSON, Nev.–(BUSINESS WIRE)–Spectrum Pharmaceuticals, Inc. (NASDAQ-GS: SPPI), a biopharmaceutical
company focused on novel and targeted oncology therapies, announced
today the full enrollment of cohort 2 (N = 87) for previously treated
non-small cell lung cancer (NSCLC) patients with HER2 exon 20 insertion
mutations. Topline results from this cohort are expected by mid 2020.
This is the second cohort that has met enrollment target in Spectrum’s
ZENITH20 trial – an open-label, multi-center, global phase 2 trial
evaluating NSCLC patients with EGFR or HER2 exon 20 insertion mutations.

“Our global poziotinib development program is multifaceted and
progressing rapidly, which speaks to the high unmet need for patients
with this type of lung cancer,” said Joe Turgeon, President and CEO
of Spectrum Pharmaceuticals. “Topline results from cohort 1 in EGFR
patients are expected to be available later this year, and are intended
to provide the data for regulatory submission. Our goal at Spectrum is
to develop novel therapies to serve patients with high unmet medical
need, and we are diligently pursuing this goal with our poziotinib
program.”

The ZENITH20 trial consists of four cohorts of NSCLC patients with EGFR
or HER2 exon 20 insertion mutations, with each cohort independently
powered for a pre-specified statistical hypothesis. There are two
cohorts in the previously-treated NSCLC setting, cohorts 1 (EGFR) and 2
(HER2), and two in the first-line setting, cohorts 3 (EGFR) and 4
(HER2). The primary endpoint is objective response rate (ORR).
Additional endpoints include duration of response (DOR), disease control
rate (DCR), progression-free survival (PFS), and safety.

“The ZENITH20 trial is a critically important investigation for NSCLC
patients harboring exon 20 insertion mutations as these patients have a
poor prognosis and very limited treatment options,” said Francois Lebel,
M.D., F.R.C.P.C., Chief Medical Officer of Spectrum Pharmaceuticals. “A
new and targeted treatment is urgently needed. Our brisk enrollment
rates are very encouraging for such rare mutations and a strong
testimony to the strength of our team.”

About Poziotinib

Poziotinib is a novel, oral epidermal growth factor receptor tyrosine
kinase inhibitor (EGFR TKI) that inhibits the tyrosine kinase activity
of EGFR (HER1) as well as HER2 and HER4. Importantly this leads to the
inhibition of the proliferation of tumor cells that overexpress these
receptors. Mutations or overexpression/amplification of EGFR family
receptors have been associated with a number of different cancers,
including non-small cell lung cancer (NSCLC), breast cancer, and gastric
cancer. The full poziotinib targeted therapy clinical program is focused
on four development areas for EGFR and HER2 mutations, including
previously treated NSCLC, first-line NSCLC, treatment of other solid
tumors and combination therapy.

Spectrum received exclusive license from Hanmi Pharmaceuticals to
develop, manufacture, and commercialize poziotinib worldwide, excluding
Korea and China. Poziotinib is currently being investigated by Spectrum
and Hanmi in several trials in multiple solid tumors.

About Spectrum Pharmaceuticals, Inc.

Spectrum Pharmaceuticals is a biopharmaceutical company focused on
acquiring, developing, and commercializing novel and targeted drug
products, with a primary focus in hematology and oncology. Spectrum has
a strong track record of successfully executing across the
biopharmaceutical business model, from in-licensing and acquiring
differentiated drugs, clinically developing novel assets, successfully
gaining regulatory approvals and commercializing in a competitive
healthcare marketplace. Spectrum has a late-stage pipeline with novel
assets that serve areas of unmet need. This pipeline has the potential
to transform the company in the near future.

Notice Regarding Forward-Looking Statements

Certain statements in this press release may constitute
“forward-looking statements” within the meaning of the United States
Private Securities Litigation Reform Act of 1995, as amended to date.
These forward-looking statements relate to a variety of matters,
including, without limitation, statements that relate to Spectrum’s
business and its future, including the Company’s ability to advance
development of its late-stage pipeline assets, the ability of poziotinib
to meet currently unaddressed medical needs and the size of the
potential markets, the timing of the results of cohort 1 and cohort 2 in
Spectrum’s ZENITH20 clinical trial, the future potential of Spectrum’s
existing drug pipeline, the progression of the poziotinib development
program and other statements that are not purely statements of
historical fact. These forward-looking statements are made on the basis
of the current beliefs, expectations, and assumptions of the management
of Spectrum and are subject to significant risks and uncertainties that
could cause actual results to differ materially from what may be
expressed or implied in these forward-looking statements. Risks that
could cause actual results to differ include, but are not limited to,
the uncertainties inherent in new product development, including
clinical trial results and additional analysis of existing pre-clinical
and clinical data, the possibility that Spectrum’s new and existing drug
candidates, including poziotinib, may not ultimately prove to be safe or
effective, the possibility that Spectrum’s new and existing drug
candidates, if approved, may not be more effective, safer, or more cost
efficient than competing drugs, and other risks that are described in
further detail in the Company’s reports filed with the Securities and
Exchange Commission. The Company does not plan to update any such
forward-looking statements and expressly disclaims any duty to update
the information contained in this press release except as required by
law. For a further discussion of risks and uncertainties that could
cause actual results to differ from those expressed in these
forward-looking statements, as well as risks relating to the business of
Spectrum in general, see the risk disclosures in the Annual Report on
Form 10-K of Spectrum for the year ended December 31, 2018, and in
subsequent reports on Forms 10-Q and 8-K and other filings made with the
SEC by Spectrum.

SPECTRUM PHARMACEUTICALS, INC.® is a registered trademark of Spectrum
Pharmaceuticals, Inc and its affiliate. REDEFINING CANCER CARE™ and
the Spectrum Pharmaceuticals logos are trademarks owned by Spectrum
Pharmaceuticals, Inc. Any other trademarks are the property of their
respective owners.

© 2019 Spectrum Pharmaceuticals, Inc. All Rights Reserved

Contacts

Shiv Kapoor
Vice President, Strategic Planning & Investor Relations
702-835-6300
[email protected]