- Pregnant or lactating - Studies to evaluate the potential for embryo toxicity and teratogenicity have not been performed for INCB7839. Until additional information is available, women of childbearing potential should use appropriate precautions to avoid becoming pregnant. Rituximab is Pregnancy Category C: There are no adequate and well-controlled studies of rituximab in pregnant women. Females of childbearing potential must have a negative urine or serum pregnancy test within 14 days of study treatment start