Merck: Terns Acquisition Fuels Bullish Thesis but DeepValue Report Still Cautions on Keytruda Cliff

What happened

On May 3, 2026, Seeking Alpha published a 'Strong Buy' thesis on Merck, citing the $6.7B Terns acquisition (TERN-701) and FDA Breakthrough Therapy Designation as key moves to offset Keytruda's 2028 patent expiration. The article also highlights subcutaneous Keytruda approvals and combination therapy PDUFA targets in bladder and renal cancers through 2026. However, the DeepValue Master Report from early 2026 maintains a 'WAIT' rating with a $119 price, emphasizing that Keytruda still represents 49% of sales and faces a two-step decline from biosimilars (2028) and IRA pricing (2029). The report flags a $2.5B FY2026 headwind from generics and IRA, an unresolved Gardasil China shipment pause, and limited margin of safety at 16.2x P/E. While the Terns deal strengthens the pipeline, the report argues that revenue impact is not material until 2028–2030, leaving near-term risk elevated.

Implication

Short term, the stock may rally on positive sentiment from Terns and pipeline news, but the DeepValue report's downside boundaries (trim above $135, attractive entry $105) suggest limited upside at current prices. The $2.5B headwind and Gardasil-China stalemate keep 2026 earnings under pressure; any delay in Terns close (Q2 2026) or unfavorable Keytruda PDUFA (April 28) could reverse gains. Medium-term, the Terns deal (TERN-701 for CML) and subcutaneous Keytruda provide optionality, but the report notes that Keytruda's LOE is a two-step event: biosimilar entry in Dec 2028 and IRA price setting in 2029. Until Merck shows concrete revenue from Winrevair, Capvaxive, and Terns, the earnings base remains fragile. Long term (2028+), successful execution of the pipeline could justify a higher valuation, but the report assigns only 25% probability to the bull case ($145). Investors should use any strength to trim positions, targeting re-entry near $105 when China restart or headwind containment is visible.

Thesis delta

The bullish news does not change the fundamental thesis; the DeepValue report already acknowledged the Terns deal as part of the 'Current Big Bets'. However, the article's strong buy stance contrasts with the report's 'WAIT' rating, as the report emphasizes that the Terns acquisition is not yet reflected in 2026 guidance and that the post-Keytruda gap remains unproven. The key shift is that the market may now assign more value to the pipeline, but the report still requires observable proof (e.g., Terns timeline, Gardasil restart, headwind containment) before rerating.