Kripke also acknowledged the challenge of restocking the peer-review panels after the agency's credibility was so publicly smeared by some of the country's top scientists. She said she took the job because she felt the agency's mission and potential was too important to lose.
Only the National Institutes of Health doles out more cancer research dollars than CPRIT, which has awarded more than $700 million so far.
Gov. Rick Perry told reporters in Houston on Tuesday that he wasn't previously aware of the resignation but said Gimson's decision to step down was his own.
Joining the mounting criticism of CPRIT is the woman credited with brainstorming the idea for the agency in the first place. Cathy Bonner, who served under former Texas Gov. Ann Richards, teamed with cancer survivor Lance Armstrong in selling Texas voters in 2007 on a constitutional amendment to create an unprecedented state-run effort to finance a war on disease.
Now Bonner says politics have sullied an agency that she said was built to fund research, not subsidize private companies.
"There appears to be a cover-up going on," Bonner said.
Peloton has declined comment about its award and has referred questions to CPRIT. The agency has said the company wasn't aware that its application was never scrutinized by an outside panel, as required under agency rules.
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