Biotech stocks jumped Monday after pharmaceutical companies presented some positive drug trial results on experimental medicines that give hope for breakthrough treatments for a number of the world's toughest cancers.
The SPDR S&P Biotech XBI, an ETF that tracks the industry's biggest companies, was 1.3% higher in intraday trading, on pace for its first positive day in five. The sector was led by cancer drug company Mirati Therapeutics, which was more than 34% higher, on pace for its best day in nearly two years. Nektar Therapeutics was up 12%, on pace for its best day in a year.
Mirati's stock rose after Amgen presented positive data Monday in Chicago at the 2019 American Society of Clinical Oncology meeting.
Amgen 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. KRAS mutations are believed by scientists to cause cancer and is found in some patients with lung, pancreatic and colorectal cancers. That data was seen as a positive for Mirati, a smaller biotech company that is also developing drugs that target KRAS mutations.
"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. Amgen's result "reflect a higher likelihood of a positive readout" for Mirati's KRAS mutation-blocking drug.
Nektar Therapeutics also rallied after researchers presented data at ASCO on Saturday. The San Francisco-based biotech company said its experimental melanoma therapy, bempegaldesleukin, combined with Bristol-Myers Squibb's Opdivo helped a small number of patients with advanced skin cancer after a year.
Biotech stocks have fallen over the last three months with the broader health-care sector on concerns Washington lawmakers could make significant changes to the health-care landscape. Despite concerns, the biotech sector is up about 12% year to date compared to the 's 9% rally.
—CNBC's Gina Francolla contributed to this report.