The phrase "are not as efficacious" is correct and usable in written English.
It can be used when comparing the effectiveness of two or more things, indicating that one is less effective than the other.
Example: "While some treatments are highly effective, others are not as efficacious in achieving the desired results."
Alternatives: "are not as effective" or "are less effective."
The results indicated that the sprout powders were not as efficacious as concentrated sprout extracts.
In those studies, the VP arm was not as efficacious as in other studies.
Thus, in the treatment of autoimmune arthritis, inhibiting RANKL is not as efficacious as inhibiting c-Fms.
Although dronedarone was not as efficacious as amiodarone in maintaining sinus rhythm, considering its lower risk of side effects, it may be reasonable to consider the use of dronedarone before initiating amiodarone.
In responders following treatment, the R2* value has been shown to increase, likely as a result of decreased blood flow; however, in this one published study this parameter was not as efficacious as changes in other DCE-MRI parameters, such as Ktrans, rBV, and rBF, or even morphological parameters such as tumour size, in indicating response [ 36].
31 However, a one year randomized trial comparing α blockade with terazosin to finasteride and placebo showed that although finasteride reduced prostate volume by 20%, it was not as efficacious as terazosin and no more efficacious than placebo in improving urinary symptoms and flow rates.
All respondents agreed that any additional prevention option that was not as efficacious as condoms would have to be introduced in combination with comprehensive educational programmes as an addition to the existing HIV prevention messages and, if done so correctly, could have a positive impact on condom use.
Even though we did begin treating the mice immediately after disease induction, the fact that anti-TNF treatment was not as efficacious as treatment with CP-690550 in murine CIA could be due to the role of IL-1 or other inflammatory mediators in this animal model.
These trials, organised by Merck (the vaccine's manufacturer) and the Programme for Appropriate Technology in Health (a medical charity based in Seattle), showed that although the new vaccine is not as efficacious in the poor world as it is in the rich, it is good enough to make a difference.
rFVIIa is usually given with tranexamic acid and is not as efficacious if the patient has a low fibrinogen.
