Support for Medicare for All is showing signs of slippage as top-tier Democratic presidential candidates Sens. Elizabeth Warren and Bernie Sanders struggle to sell the proposal without providing specifics on the financial costs for voters, says the Wall Street Journal.

Meanwhile, an abundance of other Health proposals aired by the Democratic primary field is complicating messaging efforts as polls show many voters still don’t understand what specific plans would do. Fifty-one percent of Americans back the Medicare-for-All proposals, which is down 5 percentage points since April, according to a poll released last week by the Kaiser Family Foundation.

“The details matter,” said David Blumenthal, president of The Commonwealth Fund, an independent research firm. “Those details will be central to the national debate on health care and health insurance coverage as the 2020 campaign season progresses.”

Medicare for All has dominated the Democratic presidential campaign. Some candidates support Sen. Bernie Sanders’s plan, but others have different ideas for how to get to universal coverage.

WSJ explains that Medicare for All would replace the current health system with a federal plan that would cover everyone. The proposal backed by Sens. Warren and Sanders would largely end private insurance. But with public support waning for a single-payer system, private insurers got a boost last week. Cigna Corp. and UnitedHealth Group Inc. both rocketed 10%, and Humana Inc. jumped 9%.

Here are last week’s other major winners and a lone loser among a small list of such:

Irving, TX-based Reata Pharmaceuticals Inc. (Nasdaq:RETA) led advancing issues, skyrocketing 73% for the week to $184.91 after the company released positive data for the midstage Moxie study of its drug candidate, omaveloxolone, in patients with a neuromuscular disease called Friedreich’s ataxia. As biotech investors have seen time and time again, positive clinical trial data can lead to monstrous one-day gains, especially if that data comes in a disease like Friedreich’s ataxia where multiple failures over the years have led to low expectations.

Using the modified Friedreich’s Ataxia Rating Scale (mFARS), patients treated with omaveloxolone had an average improvement of 1.55 points–improvement indicates a lower score on the scale–compared to an average worsening of 0.85 points for patients who received placebo. The 2.4-point difference was statistically significant. The clinical trial was set up to exclude patients with pes cavus, a musculoskeletal foot deformity that can keep patients from performing some of the tests in the mFARS exam. But even when patients with pes cavus were included, the difference in scores was 1.93 points, which was also statistically significant.

Elsewhere,  Assembly Biosciences Inc. (Nasdaq:ASMB) rocketed 73% to $15.05 after the company announced an update on its hepatitis B virus (HBV) programs. The first update, from a Phase 2a study evaluating the lead drug candidate ABI-H0731, suggests that the pipeline asset is effective in reducing DNA and RNA signatures of the virus. The second update, from a Phase 1b study of a next-generation drug candidate named ABI-H2158, suggests that the asset can reduce the activity of the virus after just 14 days.

The two lead candidates of Carmel, IN-based Assembly Biosciences belong to a class of drugs called core inhibitors. The compounds are intended to disrupt HBV replication and the pool of cccDNA–a type of DNA required for certain viruses to replicate–that is often permanently lodged in an individual’s cells. The biopharma announced that individuals treated with ABI-H0731 and nucleos(t)ide analogs (Nrtl) achieved a deeper decline in HBV DNA and RNA than those treated with Nrtl alone. The combination also led to steeper declines in the biomarkers thought to indicate the amount of cccDNA present in an individual’s cells.

And Endo International PLC (Nasdaq:ENDP) surged 32% to $4.88. The big gain came on speculation that a settlement could be at hand related to multiple opioid lawsuits involving Endo. Drugmakers Johnson & Johnson and Teva Pharmaceutical are reportedly offering multibillion-dollar settlements in opioid cases. Drug wholesale distributors AmerisourceBergen, Cardinal Health, and McKesson are also negotiating potential settlements. A reasonable settlement to end its opioid-related headaches would be fantastic news for Endo. The drugmaker has already announced settlements of opioid lawsuits with two Ohio counties.

Despite all of the buzz over other pharmaceutical companies and drug distributors proposing deals to settle opioid litigation, though, Dublin, IRL-based Endo hasn’t announced any new developments. And the company’s name hasn’t been mentioned as a party to any potential deals in recent reports.

But Syros Pharmaceuticals Inc. plunged 23% to $6.74. The gene-expression specialist announced that it would discontinue the development of its CDK7 inhibitor SY-1365 in favor of its alternative SY-5609 treatment, which is taken orally instead of by injection. Cambridge, MA-based Syros said that SY-5609 is stronger and more selective in inhibiting the CDK7 enzyme, and the oral treatment provides more flexibility in setting and maintaining dosages. CEO Dr. Nancy Simonian emphasized that Syros has learned a lot from SY-1365, but giving priority to SY-5609 reflects its “best-in-class potential.” Investors didn’t seem to agree, and the stock’s move reflects the disappointment that shareholders will have to wait until early 2020 for a planned Phase 1 trial of SY-5609 to begin.