Etigilimab (MPH-313)
On October 21, 2023, an update on the Companys Phase 1b/2 study investigating the safety and efficacy of etigilimab (anti-TIGIT) in combination with
nivolumab (anti-PD1) in recurrent/advanced solid tumors (ACTIVATE) was presented in a mini-oral session at the ESMO 2023 Congress in Madrid, Spain by Dr. Meredith McKean, Sarah Cannon Research Institute,
USA. Of 40 evaluable patients presented in select cohorts, three complete responses (CRs), seven partial responses (PRs) and eleven stable disease (SDs) beyond 112 days (3.7 months) were noted. Seven patients showed clinical benefit for ≥ 335
days (11 months). The data show promising efficacy in PDL1 low patients with six of seven on study ≥ 335 days (11 months) being PDL1 negative or low and all having high PVR tumoral expression. Etigilimab in combination with nivolumab continues
to be safe and well tolerated with no new safety signals noted. The last patient last dose was completed at the end of June 2023. The cervical cancer and uveal melanoma cohorts cleared the protocol Simon 2 Stage design interim futility monitoring
bar for expansion to Stage 2 and were endorsed by an independent data monitoring committee for expansion.
Etigilimab, in combination with nivolumab, is
in an ongoing investigator-led single-arm, two-stage, open-label Phase 1b/2 trial in a subtype of platinum-resistant recurrent
ovarian cancer (clear cell ovarian cancer) at The University of Texas MD Anderson Cancer Center, financed by the Cancer Focus Fund. This trial is being led by Dr. Shannon Westin. Enrollment is currently being expanded from the initial 10
patients to 20 patients.
The Company continues to seek a partner for further development of etigilimab.
Third Quarter 2023 Financial Information
As of
September 30, 2023, the Company had cash and short-term deposits of £51.2 million ($62.4 million). Cash and short-term deposits, net of expenditures, increased by £9.1 million ($11.1 million) during the third quarter of
2023.
In July 2023, the Company received a $9.0 million (£7.1 million) milestone payment from its partner, Ultragenyx, and gross proceeds of
$12.0 million (£9.3 million) from the issuance of 9,673,419 ADSs representing 48,367,095 ordinary shares through an at-the-market offering
pursuant to its Open Market Sale Agreement with Jefferies LLC. The Company expects its existing cash and short-term deposits, excluding income from existing or potential partnerships, will enable it to fund its currently committed clinical trials,
operating expenses and capital expenditure requirements into 2026.
About Mereo BioPharma
Mereo BioPharma is a biopharmaceutical company focused on the development of innovative therapeutics for rare diseases. The Company has two rare disease
product candidates, setrusumab for the treatment of Osteogenesis Imperfecta (OI) and alvelestat primarily for the treatment of severe alpha-1-antitrypsin
deficiency-associated lung disease (AATD-LD). The Companys partner, Ultragenyx Pharmaceutical, Inc., has initiated a pivotal Phase 2/3 pediatric study in young adults (5 to <26 years old) for
setrusumab in OI and a Phase 3 study in pediatric patients (2 to <7 years old) in the first half of 2023. The partnership with Ultragenyx includes potential milestone payments of up to $245 million (following the recent $9 million
milestone) and royalties to Mereo on commercial sales in Ultragenyx territories. Mereo has retained EU and UK commercial rights and will pay Ultragenyx royalties on commercial sales in those territories. Setrusumab has received orphan designation
for OI from the EMA and FDA, PRIME designation from the EMA and has pediatric disease designation from the FDA. Alvelestat has received U.S. Orphan Drug Designation for the treatment of AATD, Fast Track designation from the FDA, and positive data
were reported from a Phase 2 proof-of-concept study in North America, Europe and the UK. In addition to the rare disease programs, Mereo has two oncology product
candidates in clinical development. Etigilimab (anti-TIGIT) has completed enrollment in a Phase 1b/2 basket study evaluating its safety and efficacy in combination with an
anti-PD-1 in a range of tumor types including three rare tumors and three gynecological carcinomascervical, ovarian, and endometrial and is in an ongoing Phase
1b/2 investigator led study at the MD Anderson Cancer Center in clear cell ovarian cancer; navicixizumab, for the treatment of late line ovarian cancer, has completed a Phase 1 study and has been partnered with OncXerna Therapeutics, Inc. in a
global licensing agreement that includes payments of up to $300 million in milestones and royalties.
For more information on Mereo BioPharma, please
visit www.mereobiopharma.com.