Repligen Corporation RGEN announced second-quarter 2021 adjusted earnings per share of 79 cents, beating the Zacks Consensus Estimate of 53 cents. Earnings also rose 88.1% year over year.Total revenues of $163 million also surpassed the Zacks Consensus Estimate of $145.17 million. Sales rose 86% year over year (81% in constant currency) on robust demand across all franchises, especially the filtration franchise, and higher COVID-related sales.Excluding the impact of currency and acquisitions/divestures, Repligen’s organic revenues grew 69% year over year for second-quarter 2021.Quarter in DetailProduct sales were up 86.3% year over year to $162.9 million for the second quarter.Sales of Repligen’s base business (excluding COVID-related business) were up 35% year over year. Acquisitions made by the company during 2020 added 15% to revenue growth while its COVID-19 vaccine-related programs contributed 49%. Revenues from filtration franchises more than doubled in first-half 2021.Adjusted gross margin was 62% for the second quarter, up 380 basis points (bps) year over year.For the reported quarter, adjusted research and development expenses were $8.03 million, up 93.6% from the year-ago figure.Adjusted selling, general and administrative expenses were $36.4 million, surging 71.6% year over year.Adjusted operating income was $56.6 million, increasing 122% year over year. Adjusted operating margin was 34.7%, up 550 bps year over year.As of Jun 30, 2021, Repligen had cash and cash equivalents worth $734.3 million compared with $711.3 million on Mar 31, 2021.Raised 2021 GuidanceRepligen raised its guidance for 2021 revenues, adjusted earnings and certain other items on first-quarter earnings call.Shares of Repligen were up 9.9% on Jul 27, attributable to strong second-quarter results and increased guidance. The company’s shares have gained 18.2% so far this year against the industry’s decrease of 1.9%.Image Source: Zacks Investment ResearchIt now expects revenues in the range of $625-$645 million, up from the previous guidance of $565-$590 million due to expectations for higher COVID-related revenues. The Zacks Consensus Estimates for revenues stands at $585.3 million.Anticipated revenues for 2021 indicates growth of 71-76% and 68-73% year over year on a reported and constant-currency basis, respectively. Organic growth is estimated in the range of 57-62%, up from the previous expectation of 42-49%.The company now expects COVID-related programs to generate revenues in the range of $170-$180 million, up from the previous guided range of $140-$160 million.Adjusted EPS is anticipated within $2.71-$2.78 per share, up from the previous guided range of $2.21-$2.28. The Zacks Consensus Estimates for earnings stands at $2.26 per share.Adjusted operating income is anticipated within $192-$197 million, which marks an increase from the previous guided range of $156-$162 million. Adjusted net income is projected in the $154-$158 million band, up from the previous expectation of $126-$130 million.Repligen Corporation Price Repligen Corporation price | Repligen Corporation QuoteZacks Rank & Other Stocks to ConsiderCurrently, Repligen holds a Zacks Rank #2 (Buy).Other top-ranked stocks from the biotech sector include Arvinas ARVN, Biomarin BMRN and Bicycle Therapeutics AG BCYC. While Biomarin sports a Zacks Rank #1 (Strong Buy), both Arvinas and Bicycle Therapeutics carry a Zacks Rank #2. You can see the complete list of today’s Zacks #1 Rank stocks here.Arvinas’ bottom-line estimates have significantly improved from a loss of $3.45 to earnings of $0.42 for 2021 and narrowed from a loss of $4.06 to $2.98 for 2022 in the past 30 days. The stock has risen 10.7% in the year so far.Biomarin’s earnings per share estimates have moved up from $2.33 to $2.35 for 2022 in the past 30 days.Bicycle Therapeutics’ loss per share estimates have narrowed from $3.18 to $2.79 for 2021 and from $3.63 to $3.29 in the past 30 days. The stock has risen 90.4% in the year so far. Zacks Names "Single Best Pick to Double" From thousands of stocks, 5 Zacks experts each have chosen their favorite to skyrocket +100% or more in months to come. From those 5, Director of Research Sheraz Mian hand-picks one to have the most explosive upside of all. You know this company from its past glory days, but few would expect that it's poised for a monster turnaround. Fresh from a successful repositioning and flush with A-list celeb endorsements, it could rival or surpass other recent Zacks' Stocks Set to Double like Boston Beer Company which shot up +143.0% in a little more than 9 months and Nvidia which boomed +175.9% in one year.Free: See Our Top Stock and 4 Runners Up >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report BioMarin Pharmaceutical Inc. (BMRN): Free Stock Analysis Report Repligen Corporation (RGEN): Free Stock Analysis Report Arvinas, Inc. (ARVN): Free Stock Analysis Report Bicycle Therapeutics PLC Sponsored ADR (BCYC): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research