NEW YORK (TheStreet) -- A new stock index is debuting Tuesday to track the performance of companies developing cancer immunotherapies.

The Loncar Cancer Immunotherapy Index (LCINDX) is an equal-weighted basket of 25 pharmaceutical and biotech companies developing (or already marketing) drugs which use the body's own immune system to target and kill cancer cells.

"The goal of the Cancer Immunotherapy index is to give investors a better understanding of the immunotherapy sector by highlighting major companies involved and providing a metric to track their progress," said Brad Loncar, CEO of Loncar Investments, the provider of the new index. Loncar's "day job" involves managing a family investment portfolio focused primarily on biotech stocks. He's also a well-known member of the biotech Twitter (TWTR - Get Report) tribe.

Loncar's index has a singular focus on cancer immunotherapy but its constituent stocks represent a diverse cross section of pharma and biotech stocks, including Novartis (NVS - Get Report), Merck (MRK - Get Report), Bristol-Myers Squibb (BMY - Get Report), Celgene (CELG - Get Report), Juno Therapeutics (JUNO), Celldex Therapeutics (CLDX - Get Report), Incyte (INCY - Get Report), Advaxis (ADXS - Get Report) and Lion Biotechnologies (LBIO).

The complete index roster can be found at the LocarIndex web site.

Back-testing the cancer immunotherapy index yielded a year-to-date return of just under 28%. Since October, the index almost doubled in value, Loncar says, cautiously, because back-testing, even when conducted professionally, can't be relied upon for future performance. 

If the cancer immunotherapy index takes hold with investors, Loncar says his next step will be to create an exchange-traded fund that tracks the index.

Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.