A biotechnology sector-specific exchange traded fund specialized in tracking immunotherapy drugmakers bucked the broader market trends and surged Wednesday after MacroGenics (NasdaqGS: MGNX) announced upbeat breast cancer trial results.

The Loncar Cancer Immunotheraphy ETF (NasdaqGM: CNCR), which tracks companies that are developing new classes of therapies, increased 4.3% on Wednesday.

Fueling the gains in CNCR, MacroGenics shares jumped 126.5% on over 41 times its average daily volume. MGNX makes up 3.0% of CNCR’s underlying portfolio.

The cancer specalist MacroGenics popped off early Wednesday morning in response to a positive late-stage result for its HER2-positive breast cancer treatment candidate, margetuximab, The Motley Fool reported.

According to the press release, patients treated with a combination of margetuximab and chemotherapy demonstrated a statistically significant improvement in progression-free survival (PFS) compared to those receiving Roche’s Herceptin plus chemotherapy.

The results may have caught investors off guard as Citi issued a downgrade on MGNX to sell on Monday.

SVB Leerink analyst Jonathan Chang wrote in a note that “little value for the drug in the indication was represented in the stock going into the results,” according to Bloomberg.

The Loncar Cancer Immunotheraphy ETF tries to reflect the performance of the Loncar Cancer Immunotherapy Index, which was developed by biotechnology investor Brad Loncar. The underlying index tracks large pharmaceutical and growth-oriented biotechnology companies in the cancer treatment space. Specifically, the index tracks companies that are developing new classes of therapies, like checkpoint inhibitors, next generation vaccines and chimeric antigen receptor (CAR) technologies.

The underlying index tries adhere to a high strategic focus on the development of drugs that harness the body’s own immune system to fight cancer, or so-called immunotherapy, according to the fund’s prospectus. Companies with a high strategic focus on cancer immunotherapy found within the underlying index include one or more of the following: The company has a cancer immunotherapy drug approved by either the U.S. Food and Drug Administration or the European Medicines Agency; The company has a cancer immunotherapy drug in the human stage of testing; The company has announced intentions to begin human stage testing of a cancer immunotherapy drug; or The company has announced an immunotherapy collaboration or partnership with a major pharmaceutical company.

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