AcelRx Pharmaceuticals Inc. (NASDAQ:ACRX) fell $4.44 (41%) to $6.39 on Monday after receiving a complete response letter from FDA for an NDA for Zalviso sufentanil sublingual tablet system to treat moderate-to-severe acute pain. AcelRx said it hopes to resubmit the NDA by year end. At least one analyst downgraded the stock (see "Analyst Picks," page 20).

AcelRx recovered some of its losses to finish the week down $3.94 (36%) to $6.89.