

Nektar Therapeutics also rallied after researchers presented data at ASCO on Saturday. Amgen's result 'reflect a higher likelihood of a positive readout' for Mirati's KRAS mutation-blocking drug. 'We think that Amgen's phase 1 results should read positive Mirati's to stock,' said Varun Kumar, an analyst at Wall Street firm Cantor Fitzgerald.

That data was seen as a positive for Mirati, a smaller biotech company that is also developing drugs that target KRAS mutations. KRAS mutations are believed by scientists to cause cancer and is found in some patients with lung, pancreatic and colorectal cancers. Hard for doctors to access unapproved drugs: FDA's PazdurĪmgen researchers said an experimental drug targeting a mutated form of a gene known as KRAS shrank tumor growth in a small clinical trial of lung cancer patients.
