Olema Pharmaceuticals Shares Fall 15.1% Following AstraZeneca SERENA-4 Trial Results

Olema Pharmaceuticals (NASDAQ:OLMA) shares fell 15.1% in pre-market trading to $8.68 after AstraZeneca reported that its Phase 3 SERENA-4 trial of camizestrant did not meet its primary endpoint.

AstraZeneca said on Friday that camizestrant, in combination with palbociclib, did not demonstrate a statistically significant improvement in progression-free survival as a first-line treatment for patients with ER-positive, HER2-negative advanced breast cancer.

Investors were assessing the result in relation to Olema's lead candidate, palazestrant (OP-1250), which is being evaluated in the pivotal Phase 3 OPERA-01 trial.

Investors Assess Implications for Oral SERDs

Palazestrant is an oral selective estrogen receptor degrader and complete estrogen receptor antagonist, or SERD/CERAN.

Its mechanism therefore has similarities to camizestrant, although the outcome of AstraZeneca's trial does not determine the results of Olema's separate clinical programme.

According to the supplied information, the SERENA-4 result follows Roche's persevERA trial earlier in 2026, which also did not meet its objective in the first-line advanced breast cancer setting.

Following the AstraZeneca results, Stifel reduced its price target for Olema to $30 from $48 while maintaining a Buy rating.

Investors continue to await top-line results from Olema's OPERA-01 Phase 3 trial, which will provide clinical data specific to palazestrant.

Olema shares were trading above their 52-week low of $6.65 following Monday's decline, compared with a 52-week high of $36.26.

Olema's pre-market decline came during a weaker session for US equities. The Nasdaq fell 1.7%, while the S&P 500 declined 0.7%.

The share-price move followed the SERENA-4 results and Stifel's subsequent price-target reduction as investors assessed the potential implications for Olema's palazestrant development programme.