FRANKFURT, Aug 7 (Reuters) - Germany's BioNTech , Pfizer's partner on COVID-19 vaccines, cut its drug development budget for this year after quarterly revenues were hurt by a plunge in pandemic-related demand.

Second-quarter revenue dropped to 167.7 million euros ($184 million) from 3.2 billion euros a year earlier, as write-offs on Pfizer's assets ate into profit share payments that BioNTech is entitled to receive from its U.S. partner.

The quarterly net loss was 190 million euros, down from a COVID-19-fuelled profit of 1.67 billion euros a year earlier.

"With some uncertainty on the revenue line, we are also carefully watching our spending by revisiting our cost base," said finance chief Jens Holstein, adding that BioNTech's ambition to become a multi-product oncology and infectious disease company was unchanged.

The company said it cut its projected research and development (R&D) budget for this year to between 2 and 2.2 billion euros, down from between 2.4 and 2.6 billion euros previously forecast.

R&D expenditures were 1.54 billion euros last year.

($1 = 0.9115 euros) (Reporting by Ludwig Burger Editing by Miranda Murray)