Mateon Provides Update on its R&D Effort Against COVID-19 April 30, 2020 Los Angeles Biotechnology Network News Los Angeles Biotech News Comments Off on Mateon Provides Update on its R&D Effort Against COVID-19 AGOURA HILLS, Calif., April 30, 2020 (GLOBE NEWSWIRE) — Mateon Therapeutics Inc. (OTCQB:MATN) report several peer-reviewed publications derived from its R&D effort against COVID-19.