The US Food and Drug Administration has placed clinical holds on six trials of the HIV medicine islatravir after some trial participants showed a decrease in total lymphocyte and CD4+ T cell counts – a sign of weakened immune systems. Developed by Merck & Co Inc, islatravir is being studied for both the treatment and prevention of HIV-1 infection. “With the FDA’s clinical hold, no new studies may be initiated,” the company announced on 13 December.
