Stifel analyst Derek Archila reiterates a Hold rating on Aimmune Therapeutics (AIMT) after the FDA on Friday approved Palforzia for patients four to 17 years old with a peanut allergy. The stock rallied 16.5%, or $5.14, to $36.19 in after-hours trading late Friday. The shares already reflect "significant optimism" around the launch and look fairly valued at current levels, Archila tells investors in a research note. The analyst adds that Palforzia's approval is in-line with his thesis and that the Risk Evaluation and Mitigation Strategy, or REMS, requirements "seem pretty manageable." He believes Palforzia will face several logistical launch challenges and that payers could balk at reimbursement given the potential for increased healthcare resource utilization due to the treatment's safety profile. Ultimately, out year Palforzia sales estimates are too high, says Archila, who boosted his price target for the shares to $34 from $30. On January 8, the analyst upgraded DBV Technologies (DBVT), another company developing a treatment for peanut allergy, to Buy from Hold.